582 lines
21 KiB
ReStructuredText
582 lines
21 KiB
ReStructuredText
.. program:: nghttpx
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nghttpx - HTTP/2 proxy - HOW-TO
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===============================
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:doc:`nghttpx.1` is a proxy translating protocols between HTTP/2 and
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other protocols (e.g., HTTP/1). It operates in several modes and each
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mode may require additional programs to work with. This article
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describes each operation mode and explains the intended use-cases. It
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also covers some useful options later.
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Default mode
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------------
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If nghttpx is invoked without :option:`--http2-proxy`, it operates in
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default mode. In this mode, it works as reverse proxy (gateway) for
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both HTTP/2 and HTTP/1 clients to backend servers. This is also known
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as "HTTP/2 router".
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By default, frontend connection is encrypted using SSL/TLS. So
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server's private key and certificate must be supplied to the command
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line (or through configuration file). In this case, the frontend
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protocol selection will be done via ALPN or NPN.
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To turn off encryption on frontend connection, use ``no-tls`` keyword
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in :option:`--frontend` option. HTTP/2 and HTTP/1 are available on
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the frontend, and an HTTP/1 connection can be upgraded to HTTP/2 using
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HTTP Upgrade. Starting HTTP/2 connection by sending HTTP/2 connection
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preface is also supported.
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nghttpx can listen on multiple frontend addresses. This is achieved
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by using multiple :option:`--frontend` options. For each frontend
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address, TLS can be enabled or disabled.
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By default, backend connections are not encrypted. To enable TLS
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encryption on backend connections, use ``tls`` keyword in
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:option:`--backend` option. Using patterns and ``proto`` keyword in
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:option:`--backend` option, backend application protocol can be
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specified per host/request path pattern. It means that you can use
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both HTTP/2 and HTTP/1 in backend connections at the same time. Note
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that default backend protocol is HTTP/1.1. To use HTTP/2 in backend,
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you have to specify ``h2`` in ``proto`` keyword in :option:`--backend`
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explicitly.
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The backend is supposed to be a Web server. For example, to make
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nghttpx listen to encrypted HTTP/2 requests at port 8443, and a
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backend Web server is configured to listen to HTTP requests at port
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8080 on the same host, run nghttpx command-line like this:
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.. code-block:: text
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$ nghttpx -f0.0.0.0,8443 -b127.0.0.1,8080 /path/to/server.key /path/to/server.crt
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Then an HTTP/2 enabled client can access the nghttpx server using HTTP/2. For
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example, you can send a GET request using nghttp:
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.. code-block:: text
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$ nghttp -nv https://localhost:8443/
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HTTP/2 proxy mode
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-----------------
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If nghttpx is invoked with :option:`--http2-proxy` (or its shorthand
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:option:`-s`) option, it operates in HTTP/2 proxy mode. The supported
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protocols in frontend and backend connections are the same as in `default
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mode`_. The difference is that this mode acts like a forward proxy and
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assumes the backend is an HTTP proxy server (e.g., Squid, Apache Traffic
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Server). HTTP/1 requests must include an absolute URI in request line.
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By default, the frontend connection is encrypted. So this mode is
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also called secure proxy.
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To turn off encryption on the frontend connection, use ``no-tls`` keyword
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in :option:`--frontend` option.
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The backend must be an HTTP proxy server. nghttpx supports multiple
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backend server addresses. It translates incoming requests to HTTP
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request to backend server. The backend server performs real proxy
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work for each request, for example, dispatching requests to the origin
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server and caching contents.
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The backend connection is not encrypted by default. To enable
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encryption, use ``tls`` keyword in :option:`--backend` option. The
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default backend protocol is HTTP/1.1. To use HTTP/2 in backend
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connection, use :option:`--backend` option, and specify ``h2`` in
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``proto`` keyword explicitly.
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For example, to make nghttpx listen to encrypted HTTP/2 requests at
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port 8443, and a backend HTTP proxy server is configured to listen to
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HTTP/1 requests at port 8080 on the same host, run nghttpx command-line
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like this:
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.. code-block:: text
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$ nghttpx -s -f'*,8443' -b127.0.0.1,8080 /path/to/server.key /path/to/server.crt
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At the time of this writing, Firefox 41 and Chromium v46 can use
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nghttpx as HTTP/2 proxy.
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To make Firefox or Chromium use nghttpx as HTTP/2 proxy, user has to
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create proxy.pac script file like this:
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.. code-block:: javascript
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function FindProxyForURL(url, host) {
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return "HTTPS SERVERADDR:PORT";
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}
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``SERVERADDR`` and ``PORT`` is the hostname/address and port of the
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machine nghttpx is running. Please note that both Firefox and
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Chromium require valid certificate for secure proxy.
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For Firefox, open Preference window and select Advanced then click
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Network tab. Clicking Connection Settings button will show the
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dialog. Select "Automatic proxy configuration URL" and enter the path
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to proxy.pac file, something like this:
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.. code-block:: text
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file:///path/to/proxy.pac
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For Chromium, use following command-line:
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.. code-block:: text
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$ google-chrome --proxy-pac-url=file:///path/to/proxy.pac --use-npn
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As HTTP/1 proxy server, Squid may work as out-of-box. Traffic server
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requires to be configured as forward proxy. Here is the minimum
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configuration items to edit:
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.. code-block:: text
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CONFIG proxy.config.reverse_proxy.enabled INT 0
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CONFIG proxy.config.url_remap.remap_required INT 0
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Consult Traffic server `documentation
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<http://trafficserver.readthedocs.org/en/latest/admin-guide/configuration/transparent-forward-proxying.en.html>`_
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to know how to configure traffic server as forward proxy and its
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security implications.
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ALPN support
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------------
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ALPN support requires OpenSSL >= 1.0.2.
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Disable frontend SSL/TLS
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------------------------
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The frontend connections are encrypted with SSL/TLS by default. To
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turn off SSL/TLS, use ``no-tls`` keyword in :option:`--frontend`
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option. If this option is used, the private key and certificate are
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not required to run nghttpx.
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Enable backend SSL/TLS
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----------------------
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The backend connections are not encrypted by default. To enable
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SSL/TLS encryption, use ``tls`` keyword in :option:`--backend` option.
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Enable SSL/TLS on memcached connection
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--------------------------------------
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By default, memcached connection is not encrypted. To enable
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encryption, use ``tls`` keyword in
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:option:`--tls-ticket-key-memcached` for TLS ticket key, and
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:option:`--tls-session-cache-memcached` for TLS session cache.
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Specifying additional server certificates
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-----------------------------------------
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nghttpx accepts additional server private key and certificate pairs
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using :option:`--subcert` option. It can be used multiple times.
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Specifying additional CA certificate
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------------------------------------
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By default, nghttpx tries to read CA certificate from system. But
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depending on the system you use, this may fail or is not supported.
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To specify CA certificate manually, use :option:`--cacert` option.
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The specified file must be PEM format and can contain multiple
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certificates.
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By default, nghttpx validates server's certificate. If you want to
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turn off this validation, knowing this is really insecure and what you
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are doing, you can use :option:`--insecure` option to disable
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certificate validation.
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Read/write rate limit
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---------------------
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nghttpx supports transfer rate limiting on frontend connections. You
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can do rate limit per frontend connection for reading and writing
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individually.
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To perform rate limit for reading, use :option:`--read-rate` and
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:option:`--read-burst` options. For writing, use
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:option:`--write-rate` and :option:`--write-burst`.
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Please note that rate limit is performed on top of TCP and nothing to
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do with HTTP/2 flow control.
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Rewriting location header field
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-------------------------------
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nghttpx automatically rewrites location response header field if the
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following all conditions satisfy:
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* In the default mode (:option:`--http2-proxy` is not used)
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* :option:`--no-location-rewrite` is not used
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* URI in location header field is an absolute URI
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* URI in location header field includes non empty host component.
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* host (without port) in URI in location header field must match the
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host appearing in ``:authority`` or ``host`` header field.
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When rewrite happens, URI scheme is replaced with the ones used in
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frontend, and authority is replaced with which appears in
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``:authority``, or ``host`` request header field. ``:authority``
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header field has precedence over ``host``.
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Hot swapping
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------------
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nghttpx supports hot swapping using signals. The hot swapping in
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nghttpx is multi step process. First send USR2 signal to nghttpx
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process. It will do fork and execute new executable, using same
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command-line arguments and environment variables.
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As of nghttpx version 1.20.0, that is all you have to do. The new
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main process sends QUIT signal to the original process, when it is
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ready to serve requests, to shut it down gracefully.
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For earlier versions of nghttpx, you have to do one more thing. At
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this point, both current and new processes can accept requests. To
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gracefully shutdown current process, send QUIT signal to current
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nghttpx process. When all existing frontend connections are done, the
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current process will exit. At this point, only new nghttpx process
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exists and serves incoming requests.
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If you want to just reload configuration file without executing new
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binary, send SIGHUP to nghttpx main process.
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Re-opening log files
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--------------------
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When rotating log files, it is desirable to re-open log files after
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log rotation daemon renamed existing log files. To tell nghttpx to
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re-open log files, send USR1 signal to nghttpx process. It will
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re-open files specified by :option:`--accesslog-file` and
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:option:`--errorlog-file` options.
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Multiple frontend addresses
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---------------------------
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nghttpx can listen on multiple frontend addresses. To specify them,
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just use :option:`--frontend` (or its shorthand :option:`-f`) option
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repeatedly. TLS can be enabled or disabled per frontend address
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basis. For example, to listen on port 443 with TLS enabled, and on
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port 80 without TLS:
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.. code-block:: text
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frontend=*,443
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frontend=*,80;no-tls
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Multiple backend addresses
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--------------------------
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nghttpx supports multiple backend addresses. To specify them, just
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use :option:`--backend` (or its shorthand :option:`-b`) option
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repeatedly. For example, to use ``192.168.0.10:8080`` and
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``192.168.0.11:8080``, use command-line like this:
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``-b192.168.0.10,8080 -b192.168.0.11,8080``. In configuration file,
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this looks like:
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.. code-block:: text
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backend=192.168.0.10,8080
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backend=192.168.0.11,8008
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nghttpx can route request to different backend according to request
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host and path. For example, to route request destined to host
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``doc.example.com`` to backend server ``docserv:3000``, you can write
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like so:
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.. code-block:: text
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backend=docserv,3000;doc.example.com/
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When you write this option in command-line, you should enclose
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argument with single or double quotes, since the character ``;`` has a
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special meaning in shell.
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To route, request to request path ``/foo`` to backend server
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``[::1]:8080``, you can write like so:
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.. code-block:: text
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backend=::1,8080;/foo
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If the last character of path pattern is ``/``, all request paths
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which start with that pattern match:
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.. code-block:: text
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backend=::1,8080;/bar/
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The request path ``/bar/buzz`` matches the ``/bar/``.
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You can use ``*`` at the end of the path pattern to make it wildcard
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pattern. ``*`` must match at least one character:
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.. code-block:: text
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backend=::1,8080;/sample*
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The request path ``/sample1/foo`` matches the ``/sample*`` pattern.
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Of course, you can specify both host and request path at the same
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time:
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.. code-block:: text
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backend=192.168.0.10,8080;example.com/foo
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We can use ``*`` in the left most position of host to achieve wildcard
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suffix match. If ``*`` is the left most character, then the remaining
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string should match the request host suffix. ``*`` must match at
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least one character. For example, ``*.example.com`` matches
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``www.example.com`` and ``dev.example.com``, and does not match
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``example.com`` and ``nghttp2.org``. The exact match (without ``*``)
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always takes precedence over wildcard match.
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One important thing you have to remember is that we have to specify
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default routing pattern for so called "catch all" pattern. To write
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"catch all" pattern, just specify backend server address, without
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pattern.
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Usually, host is the value of ``Host`` header field. In HTTP/2, the
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value of ``:authority`` pseudo header field is used.
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When you write multiple backend addresses sharing the same routing
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pattern, they are used as load balancing. For example, to use 2
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servers ``serv1:3000`` and ``serv2:3000`` for request host
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``example.com`` and path ``/myservice``, you can write like so:
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.. code-block:: text
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backend=serv1,3000;example.com/myservice
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backend=serv2,3000;example.com/myservice
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You can also specify backend application protocol in
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:option:`--backend` option using ``proto`` keyword after pattern.
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Utilizing this allows ngttpx to route certain request to HTTP/2, other
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requests to HTTP/1. For example, to route requests to ``/ws/`` in
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backend HTTP/1.1 connection, and use backend HTTP/2 for other
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requests, do this:
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.. code-block:: text
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backend=serv1,3000;/;proto=h2
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backend=serv1,3000;/ws/;proto=http/1.1
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The default backend protocol is HTTP/1.1.
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TLS can be enabled per pattern basis:
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.. code-block:: text
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backend=serv1,8443;/;proto=h2;tls
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backend=serv2,8080;/ws/;proto=http/1.1
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In the above case, connection to serv1 will be encrypted by TLS. On
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the other hand, connection to serv2 will not be encrypted by TLS.
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Dynamic hostname lookup
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-----------------------
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By default, nghttpx performs backend hostname lookup at start up, or
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configuration reload, and keeps using them in its entire session. To
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make nghttpx perform hostname lookup dynamically, use ``dns``
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parameter in :option:`--backend` option, like so:
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.. code-block:: text
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backend=foo.example.com,80;;dns
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nghttpx will cache resolved addresses for certain period of time. To
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change this cache period, use :option:`--dns-cache-timeout`.
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Enable PROXY protocol
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---------------------
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PROXY protocol can be enabled per frontend. In order to enable PROXY
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protocol, use ``proxyproto`` parameter in :option:`--frontend` option,
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like so:
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.. code-block:: text
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frontend=*,443;proxyproto
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nghttpx supports both PROXY protocol v1 and v2. AF_UNIX in PROXY
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protocol version 2 is ignored.
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Session affinity
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----------------
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Two kinds of session affinity are available: client IP, and HTTP
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Cookie.
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To enable client IP based affinity, specify ``affinity=ip`` parameter
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in :option:`--backend` option. If PROXY protocol is enabled, then an
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address obtained from PROXY protocol is taken into consideration.
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To enable HTTP Cookie based affinity, specify ``affinity=cookie``
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parameter, and specify a name of cookie in ``affinity-cookie-name``
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parameter. Optionally, a Path attribute can be specified in
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``affinity-cookie-path`` parameter:
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.. code-block:: text
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backend=127.0.0.1,3000;;affinity=cookie;affinity-cookie-name=nghttpxlb;affinity-cookie-path=/
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Secure attribute of cookie is set if client connection is protected by
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TLS.
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PSK cipher suites
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-----------------
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nghttpx supports pre-shared key (PSK) cipher suites for both frontend
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and backend TLS connections. For frontend connection, use
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:option:`--psk-secrets` option to specify a file which contains PSK
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identity and secrets. The format of the file is
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``<identity>:<hex-secret>``, where ``<identity>`` is PSK identity, and
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``<hex-secret>`` is PSK secret in hex, like so:
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.. code-block:: text
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client1:9567800e065e078085c241d54a01c6c3f24b3bab71a606600f4c6ad2c134f3b9
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client2:b1376c3f8f6dcf7c886c5bdcceecd1e6f1d708622b6ddd21bda26ebd0c0bca99
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nghttpx server accepts any of the identity and secret pairs in the
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file. The default cipher suite list does not contain PSK cipher
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suites. In order to use PSK, PSK cipher suite must be enabled by
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using :option:`--ciphers` option. The desired PSK cipher suite may be
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listed in `HTTP/2 cipher black list
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<https://tools.ietf.org/html/rfc7540#appendix-A>`_. In order to use
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such PSK cipher suite with HTTP/2, disable HTTP/2 cipher black list by
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using :option:`--no-http2-cipher-black-list` option. But you should
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understand its implications.
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At the time of writing, even if only PSK cipher suites are specified
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in :option:`--ciphers` option, certificate and private key are still
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required.
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For backend connection, use :option:`--client-psk-secrets` option to
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specify a file which contains single PSK identity and secret. The
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format is the same as the file used by :option:`--psk-secrets`
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described above, but only first identity and secret pair is solely
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used, like so:
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.. code-block:: text
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client2:b1376c3f8f6dcf7c886c5bdcceecd1e6f1d708622b6ddd21bda26ebd0c0bca99
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The default cipher suite list does not contain PSK cipher suites. In
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order to use PSK, PSK cipher suite must be enabled by using
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:option:`--client-ciphers` option. The desired PSK cipher suite may
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be listed in `HTTP/2 cipher black list
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<https://tools.ietf.org/html/rfc7540#appendix-A>`_. In order to use
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such PSK cipher suite with HTTP/2, disable HTTP/2 cipher black list by
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using :option:`--client-no-http2-cipher-black-list` option. But you
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should understand its implications.
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TLSv1.3
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-------
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|
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As of nghttpx v1.34.0, if it is built with OpenSSL 1.1.1 or later, it
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supports TLSv1.3. 0-RTT data is supported, but by default its
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processing is postponed until TLS handshake completes to mitigate
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replay attack. This costs extra round trip and reduces effectiveness
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of 0-RTT data. :option:`--tls-no-postpone-early-data` makes nghttpx
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not wait for handshake to complete before forwarding request included
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in 0-RTT to get full potential of 0-RTT data. In this case, nghttpx
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adds ``Early-Data: 1`` header field when forwarding a request to a
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backend server. All backend servers should recognize this header
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field and understand that there is a risk for replay attack. See `RFC
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8470 <https://tools.ietf.org/html/rfc8470>`_ for ``Early-Data`` header
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field.
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nghttpx disables anti replay protection provided by OpenSSL. The anti
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replay protection of OpenSSL requires that a resumed request must hit
|
|
the same server which generates the session ticket. Therefore it
|
|
might not work nicely in a deployment where there are multiple nghttpx
|
|
instances sharing ticket encryption keys via memcached.
|
|
|
|
Because TLSv1.3 completely changes the semantics of cipher suite
|
|
naming scheme and structure, nghttpx provides the new option
|
|
:option:`--tls13-ciphers` and :option:`--tls13-client-ciphers` to
|
|
change preferred cipher list for TLSv1.3.
|
|
|
|
WebSockets over HTTP/2
|
|
----------------------
|
|
|
|
nghttpx supports `RFC 8441 <https://tools.ietf.org/html/rfc8441>`_
|
|
Bootstrapping WebSockets with HTTP/2 for both frontend and backend
|
|
connections. This feature is enabled by default and no configuration
|
|
is required.
|
|
|
|
Migration from nghttpx v1.18.x or earlier
|
|
-----------------------------------------
|
|
|
|
As of nghttpx v1.19.0, :option:`--ciphers` option only changes cipher
|
|
list for frontend TLS connection. In order to change cipher list for
|
|
backend connection, use :option:`--client-ciphers` option.
|
|
|
|
Similarly, :option:`--no-http2-cipher-black-list` option only disables
|
|
HTTP/2 cipher black list for frontend connection. In order to disable
|
|
HTTP/2 cipher black list for backend connection, use
|
|
:option:`--client-no-http2-cipher-black-list` option.
|
|
|
|
``--accept-proxy-protocol`` option was deprecated. Instead, use
|
|
``proxyproto`` parameter in :option:`--frontend` option to enable
|
|
PROXY protocol support per frontend.
|
|
|
|
Migration from nghttpx v1.8.0 or earlier
|
|
----------------------------------------
|
|
|
|
As of nghttpx 1.9.0, ``--frontend-no-tls`` and ``--backend-no-tls``
|
|
have been removed.
|
|
|
|
To disable encryption on frontend connection, use ``no-tls`` keyword
|
|
in :option:`--frontend` potion:
|
|
|
|
.. code-block:: text
|
|
|
|
frontend=*,3000;no-tls
|
|
|
|
The TLS encryption is now disabled on backend connection in all modes
|
|
by default. To enable encryption on backend connection, use ``tls``
|
|
keyword in :option:`--backend` option:
|
|
|
|
.. code-block:: text
|
|
|
|
backend=127.0.0.1,8080;tls
|
|
|
|
As of nghttpx 1.9.0, ``--http2-bridge``, ``--client`` and
|
|
``--client-proxy`` options have been removed. These functionality can
|
|
be used using combinations of options.
|
|
|
|
Use following option instead of ``--http2-bridge``:
|
|
|
|
.. code-block:: text
|
|
|
|
backend=<ADDR>,<PORT>;;proto=h2;tls
|
|
|
|
Use following options instead of ``--client``:
|
|
|
|
.. code-block:: text
|
|
|
|
frontend=<ADDR>,<PORT>;no-tls
|
|
backend=<ADDR>,<PORT>;;proto=h2;tls
|
|
|
|
Use following options instead of ``--client-proxy``:
|
|
|
|
.. code-block:: text
|
|
|
|
http2-proxy=yes
|
|
frontend=<ADDR>,<PORT>;no-tls
|
|
backend=<ADDR>,<PORT>;;proto=h2;tls
|
|
|
|
We also removed ``--backend-http2-connections-per-worker`` option. It
|
|
was present because previously the number of backend h2 connection was
|
|
statically configured, and defaulted to 1. Now the number of backend
|
|
h2 connection is increased on demand. We know the maximum number of
|
|
concurrent streams per connection. When we push as many request as
|
|
the maximum concurrency to the one connection, we create another new
|
|
connection so that we can distribute load and avoid delay the request
|
|
processing. This is done automatically without any configuration.
|