Since the "pass" option supports both strings and variables, a generic
nxt_var_t structure can be used in the configuration phase, and the "name"
field in actions is redundant.
No functional changes.
This commit introduces the replacement of the client address based on the value
of a specified HTTP header. This is intended for use when Unit is placed
behind a reverse proxy like nginx or a CDN.
You must specify the source addresses of the trusted proxies. This can be
accomplished with any valid IP pattern supported by Unit's match block:
["10.0.0.1", "10.4.0.0/16", "!192.168.1.1"]
The feature is configured per listener.
The client address replacement functionality only operates when there is a
source IP match and the specified header is present. Typically this would be
an 'X-Forwarded-For' header.
{
"listeners": {
"127.0.0.1:8080": {
"client_ip": {
"header": "X-Forwarded-For",
"source": [
"10.0.0.0/8"
]
},
"pass": "applications/my_app"
},
}
}
If a request occurs and Unit receives a header like below:
"X-Forwarded-For: 84.123.23.23"
By default, Unit trusts the last rightmost IP in the header, so REMOTE_ADDR
will be set to 84.123.23.23 if the connection originated from 10.0.0.0/8.
If Unit runs behind consecutive reverse proxies and receives a header similar
to the following:
"X-Forwarded-For: 84.123.23.23, 10.0.0.254"
You will need to enable "recursive" checking, which walks the header from
last address to first and chooses the first non-trusted address it finds.
{
"listeners": {
"127.0.0.1:8080": {
"client_ip": {
"header": "X-Forwarded-For",
"source": [
"10.0.0.0/8"
]
"recursive": true,
},
"pass": "applications/my_app"
},
}
}
If a connection from 10.0.0.0/8 occurs, the chain is walked. Here, 10.0.0.254
is also a trusted address so the client address will be replaced with
84.123.23.23.
If all IP addresses in the header are trusted, the client address is set to
the first address in the header:
If 10.0.0.0/8 is trusted and "X-Forwarded-For: 10.0.0.3, 10.0.0.2, 10.0.0.1",
the client address will be replaced with 10.0.0.3.
This is useful to escape "/" in path fragments. For example, in order
to reference the application named "foo/bar":
{
"pass": "applications/foo%2Fbar"
}
This is required due to lack of a graceful shutdown: there is a small gap
between the runtime's memory pool release and router process's exit. Thus, a
worker thread may start processing a request between these two operations,
which may result in an http fields hash access and subsequent crash.
To simplify issue reproduction, it makes sense to add a 2 sec sleep before
exit() in nxt_runtime_exit().
The "return" action can be used to immediately generate a simple HTTP response
with an arbitrary status:
{
"action": {
"return": 404
}
}
This is especially useful for denying access to specific resources.
It allows proceeding to another action if a file isn't available.
An example:
{
"share": "/data/www/",
"fallback": {
"pass": "applications/php"
}
}
In the example above, an attempt is made first to serve a request with
a file from the "/data/www/" directory. If there's no such file, the
request is passed to the "php" application.
Fallback actions may be nested:
{
"share": "/data/www/",
"fallback": {
"share": "/data/cache/",
"fallback": {
"proxy": "http://127.0.0.1:9000"
}
}
}
