304 lines
12 KiB
ReStructuredText
304 lines
12 KiB
ReStructuredText
nghttpx - HTTP/2 proxy - HOW-TO
|
|
===============================
|
|
|
|
nghttpx is a proxy translating protocols between HTTP/2 and other
|
|
protocols (e.g., HTTP/1, SPDY). It operates in several modes and each
|
|
mode may require additional programs to work with. This article
|
|
describes each operation mode and explains the intended use-cases. It
|
|
also covers some useful options later.
|
|
|
|
Default mode
|
|
------------
|
|
|
|
If nghttpx is invoked without any ``-s``, ``-p`` and ``--client``, it
|
|
operates in default mode. In this mode, nghttpx frontend listens for
|
|
HTTP/2 requests and translates them to HTTP/1 requests. Thus it works
|
|
as reverse proxy (gateway) for HTTP/2 clients to HTTP/1 web server.
|
|
HTTP/1 requests are also supported in frontend as a fallback. If
|
|
nghttpx is linked with spdylay library and frontend connection is
|
|
SSL/TLS, the frontend also supports SPDY protocol.
|
|
|
|
By default, this mode's frontend connection is encrypted using
|
|
SSL/TLS. So server's private key and certificate must be supplied to
|
|
the command line (or through configuration file). In this case, the
|
|
frontend protocol selection will is done via ALPN or NPN.
|
|
|
|
With ``--frontend-no-tls`` option, user can turn off SSL/TLS in
|
|
frontend connection. In this case, SPDY protocol is not available
|
|
even if spdylay library is liked to nghttpx. HTTP/2 and HTTP/1 are
|
|
available on the frontend and a HTTP/1 connection can be upgraded to
|
|
HTTP/2 using HTTP Upgrade. Starting HTTP/2 connection by sending
|
|
HTTP/2 connection preface is also supported.
|
|
|
|
The backend is supposed to be HTTP/1 Web server. For example, to make
|
|
nghttpx listen to encrypted HTTP/2 requests at port 8443, and a
|
|
backend HTTP/1 web server is configured to listen to HTTP/1 request at
|
|
port 8080 in the same host, run nghttpx command-line like this::
|
|
|
|
$ nghttpx -f0.0.0.0,8443 -b127.0.0.1,8080 /path/to/server.key /path/to/server.crt
|
|
|
|
Then HTTP/2 enabled client can access to the nghttpx in HTTP/2. For
|
|
example, you can send GET request to the server using nghttp::
|
|
|
|
$ nghttp -nv https://localhost:8443/
|
|
|
|
HTTP/2 proxy mode
|
|
-----------------
|
|
|
|
If nghttpx is invoked with ``-s`` option, it operates in HTTP/2 proxy
|
|
mode. The supported protocols in frontend and backend connections are
|
|
the same in `default mode`_. The difference is that this mode acts
|
|
like forward proxy and assumes the backend is HTTP/1 proxy server
|
|
(e.g., squid, traffic server). So HTTP/1 request must include
|
|
absolute URI in request line.
|
|
|
|
By default, frontend connection is encrypted. So this mode is also
|
|
called secure proxy. If nghttpx is linked with spdylay, it supports
|
|
SPDY protocols and it works as so called SPDY proxy.
|
|
|
|
With ``--frontend-no-tls`` option, SSL/TLS is turned off in frontend
|
|
connection, so the connection gets insecure.
|
|
|
|
The backend must be HTTP/1 proxy server. nghttpx supports multiple
|
|
backend server addresses. It translates incoming requests to HTTP/1
|
|
request to backend server. The backend server performs real proxy
|
|
work for each request, for example, dispatching requests to the origin
|
|
server and caching contents.
|
|
|
|
For example, to make nghttpx listen to encrypted HTTP/2 requests at
|
|
port 8443, and a backend HTTP/1 proxy server is configured to listen
|
|
to HTTP/1 request at port 8080 in the same host, run nghttpx
|
|
command-line like this::
|
|
|
|
$ nghttpx -s -f'*,8443' -b127.0.0.1,8080 /path/to/server.key /path/to/server.crt
|
|
|
|
At the time of this writing, Firefox nightly supports HTTP/2 proxy.
|
|
Chromium can use nghttpx as secure (SPDY) proxy and will support
|
|
HTTP/2 proxy in the near future.
|
|
|
|
To make Firefox nightly or Chromium use nghttpx as HTTP/2 or SPDY
|
|
proxy, user has to create proxy.pac script file like this:
|
|
|
|
.. code-block:: javascript
|
|
|
|
function FindProxyForURL(url, host) {
|
|
return "HTTPS SERVERADDR:PORT";
|
|
}
|
|
|
|
``SERVERADDR`` and ``PORT`` is the hostname/address and port of the
|
|
machine nghttpx is running. Please note that both Firefox nightly and
|
|
Chromium require valid certificate for secure proxy.
|
|
|
|
For Firefox nightly, open Preference window and select Advanced then
|
|
click Network tab. Clicking Connection Settings button will show the
|
|
dialog. Select "Automatic proxy configuration URL" and enter the path
|
|
to proxy.pac file, something like this::
|
|
|
|
file:///path/to/proxy.pac
|
|
|
|
For Chromium, use following command-line::
|
|
|
|
$ google-chrome --proxy-pac-url=file:///path/to/proxy.pac --use-npn
|
|
|
|
As HTTP/1 proxy server, Squid may work as out-of-box. Traffic server
|
|
requires to be configured as forward proxy. Here is the minimum
|
|
configuration items to edit::
|
|
|
|
CONFIG proxy.config.reverse_proxy.enabled INT 0
|
|
CONFIG proxy.config.url_remap.remap_required INT 0
|
|
|
|
Consult Traffic server `documentation
|
|
<https://docs.trafficserver.apache.org/en/latest/admin/forward-proxy.en.html>`_
|
|
to know how to configure traffic server as forward proxy and its
|
|
security implications.
|
|
|
|
Client mode
|
|
-----------
|
|
|
|
If nghttpx is invoked with ``--client`` option, it operates in client
|
|
mode. In this mode, nghttpx listens for plain, unencrypted HTTP/2 and
|
|
HTTP/1 requests and translates them to encrypted HTTP/2 requests to
|
|
the backend. User cannot enable SSL/TLS in frontend connection.
|
|
|
|
HTTP/1 frontend connection can be upgraded to HTTP/2 using HTTP
|
|
Upgrade. To disable SSL/TLS in backend connection, use
|
|
``--backend-no-tls`` option.
|
|
|
|
By default, the number of backend HTTP/2 connections per worker
|
|
(thread) is determined by number of ``-b`` option. To adjust this
|
|
value, use ``--backend-http2-connections-per-worker`` option.
|
|
|
|
The backend server is supporsed to be a HTTP/2 web server (e.g.,
|
|
nghttpd). The one use-case of this mode is utilize existing HTTP/1
|
|
clients to test HTTP/2 deployment. Suppose that HTTP/2 web server
|
|
listens to port 80 without encryption. Then run nghttpx as client
|
|
mode to access to that web server::
|
|
|
|
$ nghttpx --client -f127.0.0.1,8080 -b127.0.0.1,80 --backend-no-tls
|
|
|
|
.. note::
|
|
|
|
You may need ``-k`` option if HTTP/2 server enables SSL/TLS and
|
|
its certificate is self-signed. But please note that it is
|
|
insecure.
|
|
|
|
Then you can use curl to access HTTP/2 server via nghttpx::
|
|
|
|
$ curl http://localhost:8080/
|
|
|
|
Client proxy mode
|
|
-----------------
|
|
|
|
If nghttpx is invoked with ``-p`` option, it operates in client proxy
|
|
mode. This mode behaves like `client mode`_, but it works like
|
|
forward proxy. So HTTP/1 request must include absolute URI in request
|
|
line.
|
|
|
|
HTTP/1 frontend connection can be upgraded to HTTP/2 using HTTP
|
|
Upgrade. To disable SSL/TLS in backend connection, use
|
|
``--backend-no-tls`` option.
|
|
|
|
By default, the number of backend HTTP/2 connections per worker
|
|
(thread) is determined by number of ``-b`` option. To adjust this
|
|
value, use ``--backend-http2-connections-per-worker`` option.
|
|
|
|
The backend server must be a HTTP/2 proxy. You can use nghttpx in
|
|
`HTTP/2 proxy mode`_ as backend server. The one use-case of this mode
|
|
is utilize existing HTTP/1 clients to test HTTP/2 connections between
|
|
2 proxies. The another use-case is use this mode to aggregate local
|
|
HTTP/1 connections to one HTTP/2 backend encrypted connection. This
|
|
makes HTTP/1 clients which does not support secure proxy can use
|
|
secure HTTP/2 proxy via nghttpx client mode.
|
|
|
|
Suppose that HTTP/2 proxy listens to port 8443, just like we saw in
|
|
`HTTP/2 proxy mode`_. To run nghttpx in client proxy mode to access
|
|
that server, invoke nghttpx like this::
|
|
|
|
$ nghttpx -p -f127.0.0.1,8080 -b127.0.0.1,8443
|
|
|
|
.. note::
|
|
|
|
You may need ``-k`` option if HTTP/2 server's certificate is
|
|
self-signed. But please note that it is insecure.
|
|
|
|
Then you can use curl to issue HTTP request via HTTP/2 proxy::
|
|
|
|
$ curl --http-proxy=http://localhost:8080 http://www.google.com/
|
|
|
|
You can configure web browser to use localhost:8080 as forward
|
|
proxy.
|
|
|
|
HTTP/2 bridge mode
|
|
------------------
|
|
|
|
If nghttpx is invoked with ``--http2-bridge`` option, it operates in
|
|
HTTP/2 bridge mode. The supported protocols in frontend connections
|
|
are the same in `default mode`_. The protocol in backend is HTTP/2
|
|
only.
|
|
|
|
With ``--frontend-no-tls`` option, SSL/TLS is turned off in frontend
|
|
connection, so the connection gets insecure. To disable SSL/TLS in
|
|
backend connection, use ``--backend-no-tls`` option.
|
|
|
|
By default, the number of backend HTTP/2 connections per worker
|
|
(thread) is determined by number of ``-b`` option. To adjust this
|
|
value, use ``--backend-http2-connections-per-worker`` option.
|
|
|
|
The backend server is supporsed to be a HTTP/2 web server or HTTP/2
|
|
proxy. If backend server is HTTP/2 proxy, use
|
|
``--no-location-rewrite`` and ``--no-host-rewrite`` options to disable
|
|
rewriting location, host and :authority header field.
|
|
|
|
The use-case of this mode is aggregate the incoming connections to one
|
|
HTTP/2 connection. One backend HTTP/2 connection is created per
|
|
worker (thread).
|
|
|
|
Disable SSL/TLS
|
|
---------------
|
|
|
|
In `default mode`_, `HTTP/2 proxy mode`_ and `HTTP/2 bridge mode`_,
|
|
frontend connections are encrypted with SSL/TLS by default. To turn
|
|
off SSL/TLS, use ``--frontend-no-tls`` option. If this option is
|
|
used, the private key and certificate are not required to run nghttpx.
|
|
|
|
In `client mode`_, `client proxy mode`_ and `HTTP/2 bridge mode`_,
|
|
backend connections are encrypted with SSL/TLS by default. To turn
|
|
off SSL/TLS, use ``--backend-no-tls`` option.
|
|
|
|
Specifying additional CA certificate
|
|
------------------------------------
|
|
|
|
By default, nghttpx tries to read CA certificate from system. But
|
|
depending on the system you use, this may fail or is not supported.
|
|
To specify CA certificate manually, use ``--cacert`` option. The
|
|
specified file must be PEM format and can contain multiple
|
|
certificates.
|
|
|
|
By default, nghttpx validates server's certificate. If you want to
|
|
turn off this validation, knowing this is really insecure and what you
|
|
are doing, you can use ``-k`` option to disable certificate
|
|
validation.
|
|
|
|
Read/write rate limit
|
|
---------------------
|
|
|
|
nghttpx supports transfer rate limiting on frontend connections. You
|
|
can do rate limit per frontend connection for reading and writing
|
|
individually.
|
|
|
|
To perform rate limit for reading, use ``--read-rate`` and
|
|
``--read-burst`` options. For writing, use ``--write-rate`` and
|
|
``--write-burst``.
|
|
|
|
Please note that rate limit is performed on top of TCP and nothing to
|
|
do with HTTP/2 flow control.
|
|
|
|
Rewriting location header field
|
|
-------------------------------
|
|
|
|
nghttpx automatically rewrites location response header field if the
|
|
following all conditions satisfy:
|
|
|
|
* URI in location header field is not absolute URI or is not https URI.
|
|
* URI in location header field includes non empty host component.
|
|
* host (without port) in URI in location header field must match the
|
|
host appearing in :authority or host header field.
|
|
|
|
When rewrite happens, URI scheme and port are replaced with the ones
|
|
used in frontend, and host is replaced with which appears in
|
|
:authority or host request header field. :authority header field has
|
|
precedence. If the above conditions are not met with the host value
|
|
in :authority header field, rewrite is retried with the value in host
|
|
header field.
|
|
|
|
Hot swapping
|
|
------------
|
|
|
|
nghttpx supports hot swapping using signals. The hot swapping in
|
|
nghttpx is multi step process. First send USR2 signal to nghttpx
|
|
process. It will do fork and execute new executable, using same
|
|
command-line arguments and environment variables. At this point, both
|
|
current and new processes can accept requests. To gracefully shutdown
|
|
current process, send QUIT signal to current nghttpx process. When
|
|
all existing frontend connections are done, the current process will
|
|
exit. At this point, only new nghttpx process exists and serves
|
|
incoming requests.
|
|
|
|
Re-opening log files
|
|
--------------------
|
|
|
|
When rotating log files, it is desirable to re-open log files after
|
|
log rotation daemon renamed existing log files. To tell nghttpx to
|
|
re-open log files, send USR1 signal to nghttpx process. It will
|
|
re-open files specified by ``--accesslog-file`` and
|
|
``--errorlog-file`` options.
|
|
|
|
Multiple backend addresses
|
|
--------------------------
|
|
|
|
nghttpx supports multiple backend addresses. To specify them, just
|
|
use ``-b`` option repeatedly. For example, to use backend1:8080 and
|
|
backend2:8080, use command-line like this: ``-bbackend1,8080
|
|
-bbackend2,8080``. For HTTP/2 backend, see also
|
|
``--backend-http2-connections-per-worker`` option.
|