Proxy

Allows passing requests to another (proxied) server.

When building from the source code, the module is built by default; it can be disabled with the build option --without-http_proxy_module.

In packages and images from our repositories, the module is included in the build.

Related guides

• First Steps: proxies requests to a local app.

• Runtime Control: a cache zone with file= survives restarts.

• Connection Handling: proxying and the WebSocket timeout.

• Load Balancing: proxy_next_upstream sets the retry conditions.

• Console Light Web Panel: cache zones fill the Caches tab.

Configuration Example

location / {
    proxy_pass       http://localhost:8000;
    proxy_set_header Host      $host;
    proxy_set_header X-Real-IP $remote_addr;

    proxy_cache       cache_zone;
    proxy_cache_valid 200 302 10m;
    proxy_cache_valid 404      1m;
}

Directives

proxy_bind

Syntax	proxy_bind address [transparent] | off;
Default	—
Context	http, server, location

Makes outgoing connections to a proxied server originate from the specified local IP address with an optional port. Parameter value can contain variables. The special value off cancels the effect of the proxy_bind directive inherited from the previous configuration level, which allows the system to auto-assign the local IP address and port.

By default, this value is evaluated once when the request is initialized, before a proxied server is selected. In Angie PRO, evaluation happens after each proxied server selection (including retries), so the bind address can depend on the selected server; for example, via the $upstream_current_addr variable. If the evaluated value is empty, no binding is made.

The transparent parameter allows outgoing connections to a proxied server originate from a non-local IP address, for example, from a real IP address of a client:

proxy_bind $remote_addr transparent;

In order for this parameter to work, it is usually necessary to run Angie worker processes with the superuser privileges. On Linux it is not required as if the transparent parameter is specified, worker processes inherit the CAP_NET_RAW capability from the master process.

Note

It is necessary to configure kernel routing table to intercept network traffic from the proxied server.

proxy_buffer_size

Syntax	proxy_buffer_size size;
Default	proxy_buffer_size 4k|8k;
Context	http, server, location

Sets the size of the buffer used for reading the first part of the response received from the proxied server. This part usually contains a small response header. By default, the buffer size is equal to one memory page. This is either 4K or 8K, depending on a platform. It can be made smaller, however.

proxy_buffering

Syntax	proxy_buffering on | off;
Default	proxy_buffering on;
Context	http, server, location

Enables or disables buffering of responses from the proxied server.

on

Angie sends the response to the client in parallel with reading it from the proxied server; the client does not wait for the whole response. The response is read into the buffers set by the proxy_buffer_size and proxy_buffers directives. A buffer is passed for sending once it is completely filled, and the total size of the buffers busy sending is limited by proxy_busy_buffers_size. A partially filled buffer waits until it fills up or the response ends, so data normally reaches the client in whole buffers. Responses that must reach the client as they are produced therefore need off. Part of the response is written to a temporary file on disk when all buffers are full and the client reads slower than the proxied server sends. Responses that are cached or stored on disk always pass through a temporary file. Writing to temporary files is controlled by the proxy_max_temp_file_size and proxy_temp_file_write_size directives. Buffering frees the proxied server as soon as that server has sent its whole response, instead of holding the connection to it for as long as a slow client takes to read.

off

Every portion of data read from the proxied server is passed to the client immediately, with no minimum size: 10 bytes read from a 4K buffer are sent right away. Angie uses a single buffer, set by the proxy_buffer_size directive, so it reads no more than that size at a time. No temporary file is used, so responses are neither cached nor stored on disk, and neither proxy_limit_rate nor limit_rate has any effect. off suits responses that must reach the client as they are produced: Server-Sent Events, long polling, and streaming.

Buffering can also be enabled or disabled by passing "yes" or "no" in the X-Accel-Buffering response header field. This capability can be disabled using the proxy_ignore_headers directive.

proxy_buffers

Syntax	proxy_buffers number size;
Default	proxy_buffers 8 4k | 8k;
Context	http, server, location

Sets the number and size of the buffers used for reading a response from the proxied server, for a single connection.

By default, the buffer size is equal to one memory page. This is either 4K or 8K, depending on a platform.

proxy_busy_buffers_size

Syntax	proxy_busy_buffers_size size;
Default	proxy_busy_buffers_size 8k | 16k;
Context	http, server, location

When buffering of responses from the proxied server is enabled, limits the total size of buffers that can be busy sending a response to the client while the response is not yet fully read. In the meantime, the rest of the buffers can be used for reading the response and, if needed, buffering part of the response to a temporary file.

By default, size is limited by the size of two buffers set by the proxy_buffer_size and proxy_buffers directives.

proxy_cache

Syntax	proxy_cache zone | off [path=path];
Default	proxy_cache off;
Context	http, server, location

Defines a shared memory zone used for caching. The same zone can be used in several places. Parameter value can contain variables.

off	disables caching inherited from the previous configuration level.

In Angie PRO, you can specify multiple proxy_cache_path directives that use the same keys_zone value to enable cache sharding. When doing so, you should set the path parameter of the proxy_cache directive that uses this keys_zone value:

path=path

The value is evaluated at the time of caching the response from the backend and is expected to use variables, including those containing information from the response. If the response is taken from the cache, the path is not reevaluated; thus, a cached response retains its original path until it is removed from the cache.

This allows selecting the needed cache path by applying map directives or scripts to responses from the backend. Example for Content-Type:

proxy_cache_path /cache/one keys_zone=zone:10m;
proxy_cache_path /cache/two keys_zone=zone;

map $upstream_http_content_type $cache {
   ~^text/  one;
   default  two;
}

server {
   ...
   location / {
       proxy_pass http://backend;
       proxy_cache zone path=/cache/$cache;
       proxy_cache_valid 200 10m;
   }
}

Here there are two cache paths and a variable mapping to distinguish between them. If Content-Type starts with text/, the first path will be chosen, otherwise the second.

Note

When using proxy_cache, you typically need to also set the proxy_cache_valid directive to explicitly specify the caching time for responses. If it's not set, Angie doesn't use default values but determines the response caching time based on HTTP response headers from the server in the following priority order:

1. The X-Accel-Expires header (highest priority).

2. The Cache-Control header with max-age or s-maxage parameters.

3. The Expires header.

If none of these headers contain valid values or are not present at all, the response will not be cached because its expiration time cannot be determined.

proxy_cache_background_update

Syntax	proxy_cache_background_update on | off;
Default	proxy_cache_background_update off;
Context	http, server, location

Allows starting a background subrequest to update an expired cache item, while a stale cached response is returned to the client.

Warning

The use of a stale cached response while it's being updated must be allowed.

proxy_cache_bypass

Syntax	proxy_cache_bypass string ...;
Default	—
Context	http, server, location

Defines conditions under which the response will not be taken from cache. If at least one value of the string parameters is not empty and is not equal to "0", then the response will not be taken from cache:

proxy_cache_bypass $cookie_nocache $arg_nocache$arg_comment;
proxy_cache_bypass $http_pragma    $http_authorization;

Parameter values can contain variables.

Can be used together with the proxy_no_cache directive.

proxy_cache_convert_head

Syntax	proxy_cache_convert_head on | off;
Default	proxy_cache_convert_head on;
Context	http, server, location

Enables or disables the conversion of the "HEAD" method to "GET" for caching. If conversion is disabled, the cache key must include the $request_method.

proxy_cache_key

Syntax	proxy_cache_key string;
Default	proxy_cache_key $scheme$proxy_host$request_uri;
Context	http, server, location

Defines a key for caching. The key can contain variables. For example,

proxy_cache_key "$host$request_uri $cookie_user";

By default, the directive's value is close to the string

proxy_cache_key $scheme$proxy_host$uri$is_args$args;

proxy_cache_lock

Syntax	proxy_cache_lock on | off;
Default	proxy_cache_lock off;
Context	http, server, location

When enabled, only one request at a time will be allowed to populate a new cache element identified according to the proxy_cache_key directive by passing a request to the proxied server. Other requests for the same cache element will either wait for a response to appear in cache or for the cache lock for this element to be released, up to the time set by the proxy_cache_lock_timeout directive.

proxy_cache_lock_age

Syntax	proxy_cache_lock_age time;
Default	proxy_cache_lock_age 5s;
Context	http, server, location

If the last request passed to the proxied server for populating a new cache element has not completed for the specified time, one more request may be passed to the proxied server.

proxy_cache_lock_timeout

Syntax	proxy_cache_lock_timeout time;
Default	proxy_cache_lock_timeout 5s;
Context	http, server, location

Sets a timeout for proxy_cache_lock. When the time expires, the request will be passed to the proxied server, however, the response will not be cached.

proxy_cache_max_range_offset

Syntax	proxy_cache_max_range_offset number;
Default	—
Context	http, server, location

Sets an offset in bytes for byte-range requests. If the range is beyond the specified offset, the range request will be passed to the proxied server and the response will not be cached.

proxy_cache_methods

Syntax	proxy_cache_methods GET | HEAD | POST ...;
Default	proxy_cache_methods GET HEAD;
Context	http, server, location

If the client request method is listed in this directive, then the response will be cached. "GET" and "HEAD" methods are always added to the list, but it is recommended to specify them explicitly. See also the proxy_no_cache directive.

proxy_cache_min_uses

Syntax	proxy_cache_min_uses number;
Default	proxy_cache_min_uses 1;
Context	http, server, location

Sets the number of requests after which the response will be cached.

Warning

Cache metadata is stored in shared memory. Manually deleting cache files does not reset the counters and may lead to unpredictable behavior. For a complete reset, stop the server, delete the cache directory, and start again.

Note

Third-party cache purge modules (for example, Cache Purge) only delete files but do not reset the proxy_cache_min_uses counter. The directive is intended to protect the cache from pollution by infrequent requests, and resetting the counter on purge may negatively affect performance.

proxy_cache_path

Syntax	proxy_cache_path path [levels=levels] [use_temp_path=on | off] keys_zone=name:size[:file=file] [inactive=time] [max_size=size] [min_free=size] [manager_files=number] [manager_sleep=time] [manager_threshold=time] [loader_files=number] [loader_sleep=time] [loader_threshold=time];
Default	—
Context	http

Sets the path and other parameters of a cache. Cache data are stored in files. The file name in a cache is a result of applying the MD5 function to the cache key.

levels

defines hierarchy levels of a cache: from 1 to 3, each level accepts values 1 or 2.

For example, in the following configuration:

proxy_cache_path /data/angie/cache levels=1:2 keys_zone=one:10m;

file names in a cache will look like this:

/data/angie/cache/c/29/b7f54b2df7773722d382f4809d65029c

A cached response is first written to a temporary file, and then the file is renamed. Temporary files and the cache can be put on different file systems. However, be aware that in this case a file is copied across two file systems instead of the cheap renaming operation. It is thus recommended that for any given location both cache and a directory holding temporary files are put on the same file system.

use_temp_path=on | off	determines the directory to be used for temporary files
on	If the parameter is not specified or set to on, the directory specified by the proxy_temp_path directive for the given location will be used
off	temporary files will be placed directly in the cache directory
keys_zone	Sets the name and size of the shared memory zone for storing all active keys and information about data. Cache metadata is stored in shared memory. The zone size is specified in bytes and must be at least two system memory pages. The k and m suffixes are also accepted; unlike max_size, this parameter does not accept g. A zone of 1 megabyte is sufficient to store about 8000 keys. When an optional file is specified with keys_zone, Angie dumps the contents of this zone to disk when the main process terminates and attempts to restore it at the same memory address on the next startup or after binary upgrade, to ensure more reliable data persistence and reduce cache loading time. If the file has incompatible content, for example because an incompatible build wrote it, Angie renames it with the .old suffix, logs discarded due to incompatible content, and creates the zone anew. The cache loader then fills the zone from the cache directory, as on a start without the file, so cached responses are not lost. You can either delete the renamed file, or restore its name and revert Angie to the configuration and version in which this file was originally created. If the zone size in the configuration no longer matches the size saved in the file, the configuration fails to load until the file is removed or the original size is restored. The configuration also fails to load if the zone cannot be mapped at the memory address saved in the file: Angie logs mmap(MAP_ANON|MAP_SHARED, ...) failed if that address is already in use, or failed to restore zone at address if the operating system maps the zone at a different address. Warning Make sure the path to the file is specified correctly and has the necessary access permissions for Angie to use, and is protected from unauthorized access; relative paths are based on the prefix.
inactive	If cached data is not accessed within the time set by this parameter, it is removed, regardless of its freshness; each access resets this timer. This differs from the size-based eviction performed by the cache manager described below: inactivity-based removal applies even when the cache is below max_size, and it ignores the validity periods configured with proxy_cache_valid. By default, inactive is 10 minutes.

Note

In Angie PRO, multiple proxy_cache_path directives can be specified with the same keys_zone value. The shared memory zone size can only be specified in the first one. Selection between directives will be made based on the path parameter of the corresponding proxy_cache directive.

A special cache manager process monitors the maximum cache size and the minimum amount of free space on the filesystem with the cache, and removes the least recently used data when the maximum cache size is exceeded or there is insufficient free space. Data removal occurs in iterations.

max_size	maximum threshold value for cache size The value is specified in bytes; the k, m, and g suffixes are also accepted. By default, the cache size is not limited.
min_free	minimum threshold value for free space on the file system with the cache The value is specified in the same units as max_size. The default value 0 disables free space monitoring. On platforms that do not support querying file system statistics, the parameter is ignored, and Angie logs the warning min_free is not supported on this platform, ignored.
manager_files	maximum number of cache items to be removed in one iteration By default: 100.
manager_threshold	limits the duration of one iteration By default: 200 milliseconds.
manager_sleep	configures a pause between iterations By default: 50 milliseconds.

One minute after Angie starts, a special cache loader process is activated. It scans the filesystem for previously cached data and loads this information into the cache zone. This process works iteratively; each iteration processes a limited number of items specified by the loader_files parameter, ensures it doesn't exceed loader_threshold, then takes a short pause defined by loader_sleep before moving to the next batch. Iterations continue until the loader has processed all existing cache entries on disk:

loader_files	maximum number of cache items to load in one iteration By default: 100
loader_threshold	limits the duration of one iteration By default: 200 milliseconds
loader_sleep	configures a pause between iterations By default: 50 milliseconds

Note

A zone restored from the file of the keys_zone parameter keeps the cache keys it held when Angie saved it. If the cache loader had finished by then, it does not scan the cache directory again, and the zone is complete as soon as Angie starts. If Angie stopped before the loader started, that is, within the first minute after a start, the loader fills the restored zone as described above.

If Angie stops while the loader is still running, a graceful shutdown (angie -s quit) waits for the loader to finish. A fast shutdown that signals only the master process, such as angie -s stop or docker stop, interrupts the loader instead. The loader then does not resume after the restart, and the restored zone stays incomplete; its cold field in the /status/http/caches/ API section stays true. To have the loader rebuild such a zone, delete the file before starting Angie. If the loader process receives the signal itself, for example when the signal is sent to every Angie process, it stops cleanly and scans the cache directory again after the restart.

proxy_cache_revalidate

Syntax	proxy_cache_revalidate on | off;
Default	proxy_cache_revalidate off;
Context	http, server, location

Enables revalidation of expired cache items using conditional requests with the If-Modified-Since and If-None-Match header fields.

proxy_cache_use_stale

Syntax	proxy_cache_use_stale error | timeout | invalid_header | updating | http_500 | http_502 | http_503 | http_504 | http_403 | http_404 | http_429 | non_idempotent | off ...;
Default	proxy_cache_use_stale off;
Context	http, server, location

Determines in which cases a stale cached response can be used. The directive parameters match those of the proxy_next_upstream directive.

error	permits using a stale cached response if a proxied server to process a request cannot be selected.
updating	additional parameter, permits using a stale cached response if it is currently being updated. This allows minimizing the number of accesses to proxied servers when updating cached data.
non_idempotent	permits using a stale cached response if a request with a non-idempotent method has already been sent to a proxied server and communication with that server then fails for any reason; of the non-idempotent methods only POST can be cached, and proxy_cache_methods must enable it.

Using a stale cached response can also be enabled directly in the response header for a specified number of seconds after the response became stale:

• The stale-while-revalidate extension of the Cache-Control header field permits using a stale cached response if it is currently being updated.

• The stale-if-error extension of the Cache-Control header field permits using a stale cached response in case of an error.

Note

This has lower priority than using the directive parameters.

To minimize the number of accesses to proxied servers when populating a new cache element, the proxy_cache_lock directive can be used.

proxy_cache_valid

Syntax	proxy_cache_valid [code ... | any] time;
Default	—
Context	http, server, location

Sets caching time for different response codes. For example, the directives

proxy_cache_valid 200 302 10m;
proxy_cache_valid 404      1m;

set 10 minutes of caching for responses with codes 200 and 302 and 1 minute for responses with code 404.

If only caching time is specified,

proxy_cache_valid 5m;

then only 200, 301, and 302 responses are cached.

In addition, the any parameter can be specified to cache any responses:

proxy_cache_valid 200 302 10m;
proxy_cache_valid 301      1h;
proxy_cache_valid any      1m;

Note

Parameters of caching can also be set directly in the response header. This has higher priority than setting of caching time using the directive.

• The X-Accel-Expires header field sets caching time of a response in seconds. The zero value disables caching for a response. If the value starts with the @ prefix, it sets an absolute time in seconds since Epoch, up to which the response may be cached.

• If the header does not include the X-Accel-Expires field, parameters of caching may be set in the header fields Expires or Cache-Control.

• If the header includes the Set-Cookie field, such a response will not be cached.

• If the header includes the Vary field with the special value "*", such a response will not be cached. If the header includes the Vary field with another value, such a response will be cached taking into account the corresponding request header fields.

Processing of one or more of these response header fields can be disabled using the proxy_ignore_headers directive.

proxy_connect_timeout

Syntax	proxy_connect_timeout time;
Default	proxy_connect_timeout 60s;
Context	http, server, location

Defines a timeout for establishing a connection with a proxied server. It should be noted that this timeout cannot usually exceed 75 seconds.

Note

This timeout does not govern idle connections: how long an already-open one is kept for reuse is set by keepalive_timeout in an upstream block whose connections are cached with keepalive.

proxy_connection_drop

Syntax	proxy_connection_drop time | on | off;
Default	proxy_connection_drop off;
Context	http, server, location

Enables termination of all active connections to the proxied server after it has been removed from the group or marked as permanently unavailable by a reresolve process or the API command DELETE. Idle connections in the cache are not affected.

A connection is terminated when the next read or write event is processed for either the client or the proxied server.

Setting time enables a connection termination timeout; with on set, connections are dropped immediately.

proxy_cookie_domain

Syntax	proxy_cookie_domain off; proxy_cookie_domain domain replacement;
Default	proxy_cookie_domain off;
Context	http, server, location

Sets a text that should be changed in the domain attribute of the Set-Cookie header fields of a proxied server response. Suppose a proxied server returned the Set-Cookie header field with the attribute "domain=localhost". The directive

proxy_cookie_domain localhost example.org;

will rewrite this attribute to "domain=example.org".

The leading dot in the domain and replacement strings, as well as in the domain attribute, is ignored. The value is case-insensitive.

The domain and replacement strings can contain variables:

proxy_cookie_domain www.$host $host;

The directive can also be specified using regular expressions. In this case, domain should start with the "~" symbol. The regular expression can contain named and positional captures, and replacement can reference them:

proxy_cookie_domain ~\.(?P<sl_domain>[-0-9a-z]+\.[a-z]+)$ $sl_domain;

Multiple proxy_cookie_domain directives may be specified at the same level:

proxy_cookie_domain localhost example.org;
proxy_cookie_domain ~\.([a-z]+\.[a-z]+)$ $1;

If several directives can be applied to the cookie, the first one will be chosen.

The off parameter cancels the effect of the proxy_cookie_domain directives inherited from the previous configuration level.

proxy_cookie_flags

Syntax	proxy_cookie_flags off | cookie [flag] [flag] [flag];
Default	proxy_cookie_flags off;
Context	http, server, location

Sets one or more flags for the cookie. The cookie can contain variables. The flag can contain variables.

The secure, httponly, samesite=strict, samesite=lax, samesite=none parameters add the corresponding flags.

The nosecure, nohttponly, nosamesite parameters remove the corresponding flags.

The cookie can also be specified using regular expressions. In this case, cookie should start with a "~" symbol.

Several proxy_cookie_flags directives can be specified on the same configuration level:

proxy_cookie_flags one httponly;
proxy_cookie_flags ~ nosecure samesite=strict;

If several directives can be applied to the cookie, the first matching directive will be chosen. In the example, the httponly flag is added to the cookie one, for all other cookies the samesite=strict flag is added and the secure flag is deleted.

The off parameter cancels the effect of the proxy_cookie_flags directives inherited from the previous configuration level.

proxy_cookie_path

Syntax	proxy_cookie_path off; proxy_cookie_path path replacement;
Default	proxy_cookie_path off;
Context	http, server, location

Sets a text that should be changed in the path attribute of the Set-Cookie header fields of a proxied server response. Suppose a proxied server returned the Set-Cookie header field with the attribute "path=/two/some/uri/". The directive

proxy_cookie_path /two/ /;

will rewrite this attribute to "path=/some/uri/".

The path and replacement strings can contain variables:

proxy_cookie_path $uri /some$uri;

The directive can also be specified using regular expressions. In this case, path should either start with a "~" symbol for a case-sensitive matching, or with the "~*" symbols for case-insensitive matching. The regular expression can contain named and positional captures, and replacement can reference them:

proxy_cookie_path ~*^/user/([^/]+) /u/$1;

Several proxy_cookie_path directives can be specified on the same level:

proxy_cookie_path /one/ /;
proxy_cookie_path / /two/;

If several directives can be applied to the cookie, the first matching directive will be chosen.

The off parameter cancels the effect of the proxy_cookie_path directives inherited from the previous configuration level.

proxy_force_ranges

Syntax	proxy_force_ranges on | off;
Default	proxy_force_ranges off;
Context	http, server, location

Enables byte-range support for both cached and uncached responses from the proxied server regardless of the Accept-Ranges field in these responses.

proxy_headers_hash_bucket_size

Syntax	proxy_headers_hash_bucket_size size;
Default	proxy_headers_hash_bucket_size 64;
Context	http, server, location

Sets the bucket size for hash tables used by the proxy_hide_header and proxy_set_header directives. The details of setting up hash tables are provided separately.

proxy_headers_hash_max_size

Syntax	proxy_headers_hash_max_size size;
Default	proxy_headers_hash_max_size 512;
Context	http, server, location

Sets the maximum size of hash tables used by the proxy_hide_header and proxy_set_header directives. The details of setting up hash tables are provided separately.

proxy_hide_header

Syntax	proxy_hide_header field;
Default	—
Context	http, server, location

By default, Angie does not pass the header fields Date, Server, X-Pad, and X-Accel-... from the response of a proxied server to a client. The proxy_hide_header directive sets additional fields that will not be passed. If, on the contrary, the passing of fields needs to be permitted, the proxy_pass_header directive can be used.

proxy_http3_hq

Syntax	proxy_http3_hq on | off;
Default	proxy_http3_hq off;
Context	http, server, location

Toggles the special hq-interop negotiation mode, which is used for QUIC interop tests that Angie relies on.

Warning

Enable this mode only to run specialized tests that explicitly require it.

proxy_http3_max_concurrent_streams

Syntax	proxy_http3_max_concurrent_streams number;
Default	proxy_http3_max_concurrent_streams 128;
Context	http, server, location

Initializes HTTP/3 and QUIC settings and sets the maximum number of concurrent HTTP/3 request streams in a connection. Requires enabling keepalive connections.

proxy_http3_max_table_capacity

Syntax	proxy_http3_max_table_capacity number;
Default	proxy_http3_max_table_capacity 4096;
Context	http, server, location

Sets the dynamic table capacity for proxy connections.

Note

A similar directive http3_max_table_capacity sets this value for server connections. To avoid errors, dynamic table usage is disabled when caching is enabled in proxy mode.

proxy_http3_stream_buffer_size

Syntax	proxy_http3_stream_buffer_size size;
Default	proxy_http3_stream_buffer_size 64k;
Context	http, server, location

Sets the size of the buffer used for reading and writing QUIC streams.

proxy_http_version

Syntax	proxy_http_version 1.0 | 1.1 | 2 | 3;
Default	proxy_http_version 1.1;
Context	http, server, location, if in location, limit_except

Sets the HTTP protocol version for proxying. Version 1.1 or higher is recommended for use with keepalive connections.

proxy_ignore_client_abort

Syntax	proxy_ignore_client_abort on | off;
Default	proxy_ignore_client_abort off;
Context	http, server, location

Determines whether the connection with a proxied server should be closed when a client closes the connection without waiting for a response.

proxy_ignore_headers

Syntax	proxy_ignore_headers field ...;
Default	—
Context	http, server, location

Disables processing of certain response header fields from the proxied server. The following fields can be ignored: X-Accel-Redirect, X-Accel-Expires, X-Accel-Limit-Rate, X-Accel-Buffering, X-Accel-Charset, Expires, Cache-Control, Set-Cookie, and Vary.

If not disabled, processing of these header fields has the following effect:

• X-Accel-Expires, Expires, Cache-Control, Set-Cookie, and Vary set the parameters of response caching;

• X-Accel-Redirect performs an internal redirect to the specified URI or named location;

• X-Accel-Limit-Rate sets the rate limit for transmission of a response to a client;

• X-Accel-Buffering enables or disables buffering of a response;

• X-Accel-Charset sets the desired charset of a response.

proxy_intercept_errors

Syntax	proxy_intercept_errors on | off;
Default	proxy_intercept_errors off;
Context	http, server, location

Determines whether proxied responses with codes greater than or equal to 300 should be passed to a client or be intercepted and redirected to Angie for processing with the error_page directive.

proxy_limit_rate

Syntax	proxy_limit_rate rate;
Default	proxy_limit_rate 0;
Context	http, server, location

Limits the speed of reading the response from the proxied server. The rate is specified in bytes per second and can contain variables.

0	disables rate limiting

Note

The limit is set per a request, so if Angie simultaneously opens two connections to the proxied server, the overall rate will be twice as much as the specified limit. The limitation works only if buffering of responses from the proxied server is enabled.

proxy_max_temp_file_size

Syntax	proxy_max_temp_file_size size;
Default	proxy_max_temp_file_size 1024m;
Context	http, server, location

When buffering of responses from the proxied server is enabled, and the whole response does not fit into the buffers set by the proxy_buffer_size and proxy_buffers directives, a part of the response can be saved to a temporary file. This directive sets the maximum size of the temporary file. The size of data written to the temporary file at a time is set by the proxy_temp_file_write_size directive.

0	disables buffering of responses to temporary files

Note

This restriction does not apply to responses that will be cached or stored on disk.

proxy_method

Syntax	proxy_method method;
Default	—
Context	http, server, location

Specifies the HTTP method to use in requests forwarded to the proxied server instead of the method from the client request. Parameter value can contain variables.

proxy_next_upstream

Syntax	proxy_next_upstream error | timeout | invalid_header | http_500 | http_502 | http_503 | http_504 | http_403 | http_404 | http_429 | non_idempotent | off ...;
Default	proxy_next_upstream error timeout;
Context	http, server, location

Specifies in which cases a request should be passed to the next server in the upstream group:

error	an error occurred while establishing a connection with the server, passing a request to it, or reading the response header;
timeout	a timeout has occurred while establishing a connection with the server, passing a request to it, or reading the response header;
invalid_header	a server returned an empty or invalid response;
http_500	a server returned a response with the code 500;
http_502	a server returned a response with the code 502;
http_503	a server returned a response with the code 503;
http_504	a server returned a response with the code 504;
http_403	a server returned a response with the code 403;
http_404	a server returned a response with the code 404;
http_429	a server returned a response with the code 429;
non_idempotent	normally, requests with a non-idempotent method (POST, LOCK, PATCH) are not passed to the next server if a request has been sent to an upstream server; enabling this option explicitly allows retrying such requests;
off	disables passing a request to the next server.

If all upstream servers are unavailable or return a response with a status considered an error by proxy_next_upstream, Angie returns its own standard error page instead of the response body from the last upstream server.

Note

It should be understood that passing a request to the next server is only possible if nothing has been sent to a client yet. That is, if an error or timeout occurs in the middle of the transferring of a response, fixing this is impossible.

The directive also defines what is considered an unsuccessful attempt of communication with a server.

error timeout invalid_header	are always considered unsuccessful attempts, even if they are not specified in the directive
http_500 http_502 http_503 http_504 http_429	are considered unsuccessful attempts only if they are specified in the directive
http_403 http_404	are never considered unsuccessful attempts

Passing a request to the next server can be limited by the number of tries and by time.

proxy_next_upstream_timeout

Syntax	proxy_next_upstream_timeout time;
Default	proxy_next_upstream_timeout 0;
Context	http, server, location

Limits the time during which a request can be passed to the next server.

0	disables this limitation

proxy_next_upstream_tries

Syntax	proxy_next_upstream_tries number;
Default	proxy_next_upstream_tries 0;
Context	http, server, location

Limits the number of possible tries for passing a request to the next server.

0	disables this limitation

proxy_no_cache

Syntax	proxy_no_cache string ...;
Default	—
Context	http, server, location

Defines conditions under which the response will not be saved to a cache. If at least one value of the string parameters is not empty and is not equal to "0" then the response will not be saved:

proxy_no_cache $cookie_nocache $arg_nocache$arg_comment;
proxy_no_cache $http_pragma    $http_authorization;

Parameter values can contain variables.

Can be used along with the proxy_cache_bypass directive.

proxy_pass

Syntax	proxy_pass uri;
Default	—
Context	location, if in location, limit_except

Sets the protocol and address of a proxied server and an optional URI to which a location should be mapped. As a protocol, http or https can be specified. The address can be specified as a domain name or IP address, and an optional port:

proxy_pass http://localhost:8000/uri/;

or as a UNIX-domain socket path specified after the word unix and enclosed in colons:

proxy_pass http://unix:/tmp/backend.socket:/uri/;

If a domain name resolves to several addresses, all of them will be used in a round-robin fashion. In addition, an address can be specified as a server group.

Parameter value can contain variables. In this case, if an address is specified as a domain name, the name is searched among the described server groups, and, if not found, is determined using a resolver.

Note

A domain name in proxy_pass that contains no variables and does not match a defined server group implicitly creates a server group of a single server, equivalent to:

upstream example.com {
    server example.com;
}

These server group names are shared across the entire http configuration, regardless of the server block where proxy_pass appears. Because the implicitly created server has no resolve parameter, the name is resolved once, at configuration load time, and the obtained addresses are used until the next reload, even when a resolver is configured.

As a result, a proxy_pass whose variable evaluates to that same name reuses this existing server group with its load-time addresses instead of resolving the name per request through the resolver. To re-resolve the name at runtime and follow DNS changes, define the server group explicitly and add the resolve parameter to its server.

A request URI is passed to the server as follows:

• If the proxy_pass directive is specified with a URI, then when a request is passed to the server, the part of a normalized request URI matching the location is replaced by a URI specified in the directive:

  location /name/ {
      proxy_pass http://127.0.0.1/remote/;
  }
  

  The server receives a request for /name/page as /remote/page.

• If proxy_pass is specified without a URI, the server receives the request URI with its arguments exactly as the client sent it (the value of $request_uri), provided that Angie has not changed the URI or the arguments before proxying the request. Otherwise, the server receives the current value of $uri, which is the normalized URI, followed by the current arguments. Characters that cannot appear literally in a URI path, such as spaces, are percent-encoded again in this case; the arguments are passed as they are.

  The URI or the arguments count as changed when:

  • the regular expression of a rewrite directive matches;

  • the $args variable is assigned a value, even its current one;

  • the request is internally redirected to a URI, for example, by the index or error_page directive, by the last parameter of try_files, or by the X-Accel-Redirect response header field.

  A redirect to a named location does not change the URI, whether it is made by goto, error_page, try_files, or X-Accel-Redirect.

  For example, a client requests /some/path/%7Euser//a%20b?x=1. In this configuration, the server receives the request URI unchanged:

  location /some/path/ {
      proxy_pass http://127.0.0.1;
  }
  

  In this configuration, the rewrite directive changes the URI:

  location /some/path/ {
      rewrite    ^/some/path/(.*)$ /other/$1 break;
      proxy_pass http://127.0.0.1;
  }
  

  The server receives /other/~user/a%20b?x=1: %7E is decoded, the double slash is merged, and the space is encoded again.

In some cases, the part of a request URI to be replaced cannot be determined:

• When location is specified using a regular expression, inside a named or combined location, and inside an if or limit_except block.

  In these cases, proxy_pass without variables must be specified without a URI; otherwise, Angie refuses to load the configuration.

• When the rewrite directive with the break flag changes the URI inside the proxied location, so the request stays in that location:

  location /name/ {
      rewrite    /name/([^/]+) /users?name=$1 break;
      proxy_pass http://127.0.0.1;
  }
  

  In this case, the URI specified in the directive is ignored and the full changed request URI is passed to the server.

• When variables are used in proxy_pass:

  location /name/ {
      proxy_pass http://127.0.0.1$request_uri;
  }
  

  In this case, if a URI is specified in the directive, it is passed to the server as is, replacing the original request URI.

WebSocket proxying requires special configuration.

Note

If proxy_pass is placed in a location with a trailing slash in the prefix (for example, location /name/), and the auto_redirect directive is set to default, requests without a trailing slash will be redirected (/name -> /name/).

proxy_pass_header

Syntax	proxy_pass_header field;
Default	—
Context	http, server, location

Permits passing otherwise disabled header fields from a proxied server to a client.

proxy_pass_request_body

Syntax	proxy_pass_request_body on | off;
Default	proxy_pass_request_body on;
Context	http, server, location

Indicates whether the original request body is passed to the proxied server.

location /x-accel-redirect-here/ {
    proxy_method GET;
    proxy_pass_request_body off;
    proxy_set_header Content-Length "";

    proxy_pass ...;
}

See also the proxy_set_header and proxy_pass_request_headers directives.

proxy_pass_request_headers

Syntax	proxy_pass_request_headers on | off;
Default	proxy_pass_request_headers on;
Context	http, server, location

Indicates whether the header fields of the original request are passed to the proxied server.

location /x-accel-redirect-here/ {
    proxy_method GET;
    proxy_pass_request_headers off;
    proxy_pass_request_body off;

    proxy_pass ...;
}

See also the proxy_set_header and proxy_pass_request_body directives.

proxy_pass_trailers

Syntax	proxy_pass_trailers on | off;
Default	proxy_pass_trailers off;
Context	http, server, location

Allows passing trailer fields from a proxied server to a client.

A trailer section in HTTP/1.1 is explicitly enabled.

location / {
    proxy_http_version 1.1;
    proxy_set_header Connection "te";
    proxy_set_header TE "trailers";
    proxy_pass_trailers on;

    proxy_pass ...;
}

proxy_quic_active_connection_id_limit

Syntax	proxy_quic_active_connection_id_limit number;
Default	proxy_quic_active_connection_id_limit 2;
Context	http, server, location

Sets the QUIC active_connection_id_limit transport parameter value. This is the maximum number of active connection IDs that can be maintained per server.

proxy_quic_gso

Syntax	proxy_quic_gso on | off;
Default	proxy_quic_gso off;
Context	http, server, location

Toggles sending data in QUIC-optimized batch mode using generic segmentation offload.

proxy_quic_host_key

Syntax	proxy_quic_host_key file;
Default	—
Context	http, server, location

Sets a file with the secret key used with QUIC to encrypt Stateless Reset and Address Validation tokens. By default, a random key is generated at each restart. Tokens generated with old keys are not accepted.

proxy_read_timeout

Syntax	proxy_read_timeout time;
Default	proxy_read_timeout 60s;
Context	http, server, location

Defines a timeout for reading a response from the proxied server. The timeout is set only between two successive read operations, not for the transmission of the whole response. If the proxied server does not transmit anything within this time, the connection is closed.

proxy_redirect

Syntax	proxy_redirect default; proxy_redirect off; proxy_redirect redirect replacement;
Default	proxy_redirect default;
Context	http, server, location

Sets the text that should be changed in the "Location" and "Refresh" header fields of a proxied server response.

Suppose a proxied server returned the header field:

Location: http://localhost:8000/two/some/uri/

The directive

proxy_redirect http://localhost:8000/two/ http://frontend/one/;

will rewrite this string to:

Location: http://frontend/one/some/uri/

A server name may be omitted in the replacement string:

proxy_redirect http://localhost:8000/two/ /;

then the primary server's name and port, if different from 80, will be inserted.

The default replacement specified by the default parameter uses the parameters of the location and proxy_pass directives. Hence, the two configurations below are equivalent:

location /one/ {
    proxy_pass     http://upstream:port/two/;
    proxy_redirect default;
}

location /one/ {
    proxy_pass     http://upstream:port/two/;
    proxy_redirect http://upstream:port/two/ /one/;
}

Warning

The default parameter is not permitted if proxy_pass is specified using variables.

A replacement string can contain variables:

proxy_redirect http://localhost:8000/ http://$host:$server_port/;

A redirect can also contain variables:

proxy_redirect http://$proxy_host:8000/ /;

The directive can be specified using regular expressions. In this case, redirect should either start with the "~" symbol for a case-sensitive matching, or with the "~*" symbols for case-insensitive matching. The regular expression can contain named and positional captures, and replacement can reference them:

proxy_redirect ~^(http://[^:]+):\d+(/.+)$ $1$2;
proxy_redirect ~*/user/([^/]+)/(.+)$      http://$1.example.com/$2;

Several proxy_redirect directives can be specified on the same level:

proxy_redirect default;
proxy_redirect http://localhost:8000/  /;
proxy_redirect http://www.example.com/ /;

If several directives can be applied to the header fields of a proxied server response, the first matching directive will be chosen.

The off parameter cancels the effect of the proxy_redirect directives inherited from the previous configuration level.

Using this directive, it is also possible to add host names to relative redirects issued by a proxied server:

proxy_redirect / /;

proxy_request_buffering

Syntax	proxy_request_buffering on | off;
Default	proxy_request_buffering on;
Context	http, server, location

Enables or disables buffering of a client request body.

on	the entire request body is read from the client before sending the request to a proxied server.
off	the request body is sent to the proxied server immediately as it is received. In this case, the request cannot be passed to the next server if Angie already started sending the request body.

When HTTP/1.1 chunked transfer encoding is used to send the original request body, the request body is buffered regardless of the directive value unless HTTP/1.1, HTTP/2, or HTTP/3 is enabled for proxying.

proxy_send_lowat

Syntax	proxy_send_lowat size;
Default	proxy_send_lowat 0;
Context	http, server, location

If the directive is set to a non-zero value, Angie will try to minimize the number of send operations on outgoing connections to a proxied server by using either NOTE_LOWAT flag of the kqueue method, or the SO_SNDLOWAT socket option, with the specified size.

Note

This directive is ignored on Linux, Solaris, and Windows.

proxy_send_timeout

Syntax	proxy_send_timeout time;
Default	proxy_send_timeout 60s;
Context	http, server, location

Sets a timeout for transmitting a request to the proxied server. The timeout is set only between two successive write operations, not for the transmission of the whole request. If the proxied server does not receive anything within this time, the connection is closed.

proxy_set_body

Syntax	proxy_set_body value;
Default	—
Context	http, server, location

Allows redefining the request body passed to the proxied server. The value can contain variables.

proxy_set_header

Syntax	proxy_set_header field value;
Default	proxy_set_header Host $proxy_host;
Context	http, server, location

Allows redefining or appending fields to the request header passed to the proxied server. The value can contain variables. These directives are inherited from the previous configuration level if and only if there are no proxy_set_header directives defined on the current level. By default, only two fields are redefined:

proxy_set_header Host       $proxy_host;
proxy_set_header Connection close;

If caching is enabled, the header fields If-Modified-Since, If-Unmodified-Since, If-None-Match, If-Match, Range, and If-Range from the original request are not passed to the proxied server.

An unchanged "Host" request header field can be passed like this:

proxy_set_header Host       $http_host;

However, if this field is not present in a client request header then nothing will be passed. In such a case it is better to use the $host variable - its value equals the server name in the "Host" request header field or the primary server name if this field is not present:

proxy_set_header Host       $host;

In addition, the server name can be passed together with the port of the proxied server:

proxy_set_header Host       $host:$proxy_port;

If the value of a header field is an empty string then this field will not be passed to a proxied server:

proxy_set_header Accept-Encoding "";

proxy_socket_keepalive

Syntax	proxy_socket_keepalive on | off;
Default	proxy_socket_keepalive off;
Context	http, server, location

Configures the "TCP keepalive" behavior for outgoing connections to a proxied server.

off	By default, the operating system's settings are in effect for the socket.
on	The SO_KEEPALIVE socket option is turned on for the socket.

proxy_ssl_certificate

Syntax	proxy_ssl_certificate file [file] | data:certificate;
Default	—
Context	http, server, location

Specifies the certificate in the PEM format used for authentication to a proxied HTTPS server.

The value is interpreted as in ssl_certificate: a file path, or the PEM text of the certificate after the data: prefix. The value can contain variables; they are evaluated each time Angie establishes a connection to the proxied HTTPS server, so all variables of the request are available, including those assigned by set. If the evaluated certificate value is empty, no client certificate is sent. To avoid loading certificates for every connection, enable proxy_ssl_certificate_cache.

When proxy_ssl_ntls is enabled, the directive accepts two arguments instead of one:

location /proxy {
    proxy_ssl_ntls  on;

    proxy_ssl_certificate      sign.crt enc.crt;
    proxy_ssl_certificate_key  sign.key enc.key;

    proxy_ssl_ciphers "ECC-SM2-WITH-SM4-SM3:ECDHE-SM2-WITH-SM4-SM3:RSA";

    proxy_pass https://backend:443;
}

proxy_ssl_certificate_cache

Syntax	proxy_ssl_certificate_cache off; proxy_ssl_certificate_cache max=N [inactive=time] [valid=time];
Default	proxy_ssl_certificate_cache off;
Context	http, server, location

Defines a cache that stores SSL certificates and secret keys specified using variables.

The directive supports the following parameters:

• max — sets the maximum number of elements in the cache. When the cache overflows, the least recently used (LRU) elements are removed.

• inactive — defines the time after which an element is removed if it has not been accessed during this time, even if still within its valid period; each access resets this timer. The default is 10 seconds.

• valid — defines the time during which a cached element is reused without checks. The default is 60 seconds. After this period, an element loaded from a file is reloaded only if the file has changed, and a key loaded with the engine: or store: prefix is loaded again; an element specified with the data: prefix stays valid.

• off — disables the cache.

Keys protected by a passphrase (see proxy_ssl_password_file) are not cached.

Example:

proxy_ssl_certificate       /etc/angie/ssl/$host.crt;
proxy_ssl_certificate_key   /etc/angie/ssl/$host.key;
proxy_ssl_certificate_cache max=1000 inactive=20s valid=1m;

proxy_ssl_certificate_key

Syntax	proxy_ssl_certificate_key file [file] | data:key | engine:name:id | store:uri;
Default	—
Context	http, server, location

Specifies the secret key in the PEM format used for authentication to a proxied HTTPS server.

The value, including the engine: and store: prefixes, is interpreted as in ssl_certificate_key, and variables in it work as described in proxy_ssl_certificate. A key protected by a passphrase is decrypted with the passphrases from proxy_ssl_password_file.

When proxy_ssl_ntls is enabled, the directive accepts two arguments instead of one:

location /proxy {
    proxy_ssl_ntls  on;

    proxy_ssl_certificate      sign.crt enc.crt;
    proxy_ssl_certificate_key  sign.key enc.key;

    proxy_ssl_ciphers "ECC-SM2-WITH-SM4-SM3:ECDHE-SM2-WITH-SM4-SM3:RSA";

    proxy_pass https://backend:443;
}

proxy_ssl_ciphers

Syntax	proxy_ssl_ciphers ciphers;
Default	proxy_ssl_ciphers DEFAULT;
Context	http, server, location

Specifies the enabled ciphers for requests to a proxied HTTPS server. The ciphers are specified in the format understood by the OpenSSL library.

The list of ciphers depends on the version of OpenSSL installed. The full list can be viewed using the openssl ciphers command.

Warning

With OpenSSL, the proxy_ssl_ciphers directive does not configure TLS 1.3 ciphers; set them with the Ciphersuites command of the proxy_ssl_conf_command directive instead. The proxy_ssl_ciphers directive ignores TLS 1.3 cipher names in its value, so such names do not restrict TLS 1.3 connections. If the value consists only of such names, for example TLS_AES_128_GCM_SHA256, the configuration fails to load with the no cipher match error.

• With LibreSSL, TLS 1.3 ciphers can be configured using proxy_ssl_ciphers.

• With BoringSSL, TLS 1.3 ciphers cannot be configured at all.

proxy_ssl_conf_command

Syntax	proxy_ssl_conf_command name value;
Default	—
Context	http, server, location

Sets arbitrary OpenSSL configuration commands when establishing a connection with the proxied HTTPS server.

Note

The directive is supported when using OpenSSL 1.0.2 or higher. The Ciphersuites command, which sets TLS 1.3 ciphers, requires OpenSSL 1.1.1 or higher.

Several proxy_ssl_conf_command directives can be specified on the same level. These directives are inherited from the previous configuration level if and only if there are no proxy_ssl_conf_command directives defined on the current level.

Warning

Note that configuring OpenSSL directly might result in unexpected behavior.

proxy_ssl_crl

Syntax	proxy_ssl_crl file;
Default	—
Context	http, server, location

Specifies a file with revoked certificates (CRL) in the PEM format used to verify the certificate of the proxied HTTPS server.

proxy_ssl_keylog_file

Added in version 1.12.0.

Syntax	proxy_ssl_keylog_file file;
Default	—
Context	http, server, location

Specifies a file to log SSL/TLS keys for connections to proxied HTTPS servers in the context, using the SSLKEYLOGFILE format used by tools such as Wireshark to decrypt captured TLS traffic.

The directive should not be used with LibreSSL.

Warning

The file contains sensitive TLS key material that can decrypt captured traffic for the corresponding connections. Use this directive only for debugging or protocol analysis, restrict access to the file, and remove it when no longer needed.

proxy_ssl_name

Syntax	proxy_ssl_name name;
Default	proxy_ssl_name $proxy_host;
Context	http, server, location

Allows overriding the server name used to verify the certificate of the proxied HTTPS server and to be passed through SNI when establishing a connection with the proxied HTTPS server.

The server name can also be specified with variables.

By default, the host part of the proxy_pass URL is used.

proxy_ssl_ntls

Syntax	proxy_ssl_ntls on | off;
Default	proxy_ssl_ntls off;
Context	http, server, location

Enables client-side support for NTLS using the Tongsuo TLS library.

location /proxy {
    proxy_ssl_ntls  on;

    proxy_ssl_certificate      sign.crt enc.crt;
    proxy_ssl_certificate_key  sign.key enc.key;

    proxy_ssl_ciphers "ECC-SM2-WITH-SM4-SM3:ECDHE-SM2-WITH-SM4-SM3:RSA";

    proxy_pass https://backend:443;
}

Note

Angie must be built with the --with-ntls configuration parameter and an SSL library with NTLS support:

$ ./configure --with-openssl=../Tongsuo-8.3.0 \
              --with-openssl-opt=enable-ntls  \
              --with-ntls

proxy_ssl_password_file

Syntax	proxy_ssl_password_file file;
Default	—
Context	http, server, location

Specifies a file with passphrases for secret keys where each passphrase is specified on a separate line. Passphrases are tried in turn when loading the key.

proxy_ssl_protocols

Syntax	proxy_ssl_protocols SSLv2 | SSLv3 | TLSv1 | TLSv1.1 | TLSv1.2 | TLSv1.3 ...;
Default	proxy_ssl_protocols TLSv1.2 TLSv1.3;
Context	http, server, location

Enables the specified protocols for requests to a proxied HTTPS server.

proxy_ssl_server_name

Syntax	proxy_ssl_server_name on | off;
Default	proxy_ssl_server_name off;
Context	http, server, location

Enables or disables passing the server name set by the proxy_ssl_name directive via the Server Name Indication TLS extension (SNI, RFC 6066) when establishing a connection with the proxied HTTPS server.

proxy_ssl_session_reuse

Syntax	proxy_ssl_session_reuse on | off;
Default	proxy_ssl_session_reuse on;
Context	http, server, location

Determines whether SSL sessions can be reused when working with the proxied server. If the SSL3_GET_FINISHED:digest check failed error appears in the logs, try disabling session reuse.

proxy_ssl_trusted_certificate

Syntax	proxy_ssl_trusted_certificate file;
Default	—
Context	http, server, location

Specifies a file with trusted CA certificates in the PEM format used to verify the certificate of the proxied HTTPS server.

proxy_ssl_verify

Syntax	proxy_ssl_verify on | off;
Default	proxy_ssl_verify off;
Context	http, server, location

Enables or disables verification of the proxied HTTPS server certificate.

proxy_ssl_verify_depth

Syntax	proxy_ssl_verify_depth number;
Default	proxy_ssl_verify_depth 1;
Context	http, server, location

Sets the verification depth in the proxied HTTPS server certificate chain.

proxy_store

Syntax	proxy_store on | off | string;
Default	proxy_store off;
Context	http, server, location

Enables saving of files to a disk.

on	saves files according to the paths specified in the alias or root directives
off	disables saving of files

The file name can be set explicitly using a string with variables:

proxy_store /data/www$original_uri;

The modification time of files is set according to the received Last-Modified header field in the response. The response is first written to a temporary file, and then the file is renamed. The temporary file and the persistent store for the response can be on different file systems. However, be aware that in this case instead of the cheap rename operation within one file system, the file is copied from one file system to another. It is thus recommended that for any given location both saved files and a directory holding temporary files, set by the proxy_temp_path directive, are put on the same file system.

This directive can be used to create local copies of static unchangeable files, e.g.:

location /images/ {
    root               /data/www;
    error_page         404 = /fetch$uri;
}

location /fetch/ {
    internal;

    proxy_pass         http://backend/;
    proxy_store        on;
    proxy_store_access user:rw group:rw all:r;
    proxy_temp_path    /data/temp;

    alias              /data/www/;
}

or like this:

location /images/ {
    root               /data/www;
    error_page         404 = @fetch;
}

location @fetch {
    internal;

    proxy_pass         http://backend;
    proxy_store        on;
    proxy_store_access user:rw group:rw all:r;
    proxy_temp_path    /data/temp;

    root               /data/www;
}

proxy_store_access

Syntax	proxy_store_access users:permissions [users:permissions] [users:permissions];
Default	proxy_store_access user:rw;
Context	http, server, location

Sets access permissions for newly created files and directories, e.g.:

proxy_store_access user:rw group:rw all:r;

If any group or all access permissions are specified, then user permissions may be omitted:

proxy_store_access group:rw all:r;

proxy_temp_file_write_size

Syntax	proxy_temp_file_write_size size;
Default	proxy_temp_file_write_size 8k|16k;
Context	http, server, location

Limits the size of data written to a temporary file at a time, when buffering of responses from the proxied server to temporary files is enabled. By default, size is limited by two buffers set by the proxy_buffer_size and proxy_buffers directives. The maximum size of a temporary file is set by the proxy_max_temp_file_size directive.

proxy_temp_path

Syntax	proxy_temp_path path [level1 [level2 [level3]]];
Default	proxy_temp_path proxy_temp; (the path depends on the build option --http-proxy-temp-path)
Context	http, server, location

Defines a directory for storing temporary files with data received from proxied servers. Up to three-level subdirectory hierarchy can be used underneath the specified directory. For example, in the following configuration

proxy_temp_path /spool/angie/proxy_temp 1 2;

a temporary file might look like this:

/spool/angie/proxy_temp/7/45/00000123457

See also the use_temp_path parameter of the proxy_cache_path directive.

Built-in Variables

The module supports built-in variables that can be used to compose headers using the proxy_set_header directive:

$proxy_add_x_forwarded_for

the X-Forwarded-For client request header field with the $remote_addr variable appended to it, separated by a comma. If the X-Forwarded-For field is not present in the client request header, the $proxy_add_x_forwarded_for variable is equal to the $remote_addr variable.

$proxy_host

name and port of a proxied server as specified in the proxy_pass directive;

$proxy_port

port of a proxied server as specified in the proxy_pass directive, or the protocol's default port;