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nghttp2/doc/nghttpx.h2r

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FILES
-----
*/etc/nghttpx/nghttpx.conf*
The default configuration file path nghttpx searches at startup.
The configuration file path can be changed using :option:`--conf`
option.
Those lines which are staring ``#`` are treated as comment.
The option name in the configuration file is the long command-line
option name with leading ``--`` stripped (e.g., ``frontend``). Put
``=`` between option name and value. Don't put extra leading or
trailing spaces.
When specifying arguments including characters which have special
meaning to a shell, we usually use quotes so that shell does not
interpret them. When writing this configuration file, quotes for
this purpose must not be used. For example, specify additional
request header field, do this:
.. code-block:: text
add-request-header=foo: bar
instead of:
.. code-block:: text
add-request-header="foo: bar"
The options which do not take argument in the command-line *take*
argument in the configuration file. Specify ``yes`` as an argument
(e.g., ``http2-proxy=yes``). If other string is given, it is
ignored.
To specify private key and certificate file which are given as
positional arguments in command-line, use ``private-key-file`` and
``certificate-file``.
:option:`--conf` option cannot be used in the configuration file and
will be ignored if specified.
Error log
Error log is written to stderr by default. It can be configured
using :option:`--errorlog-file`. The format of log message is as
follows:
<datetime> <master-pid> <current-pid> <thread-id> <level> (<filename>:<line>) <msg>
<datetime>
It is a combination of date and time when the log is written. It
is in ISO 8601 format.
<master-pid>
It is a master process ID.
<current-pid>
It is a process ID which writes this log.
<thread-id>
It is a thread ID which writes this log. It would be unique
within <current-pid>.
<filename> and <line>
They are source file name, and line number which produce this log.
<msg>
It is a log message body.
SIGNALS
-------
SIGQUIT
Shutdown gracefully. First accept pending connections and stop
accepting connection. After all connections are handled, nghttpx
exits.
SIGHUP
Reload configuration file given in :option:`--conf`.
SIGUSR1
Reopen log files.
SIGUSR2
Fork and execute nghttpx. It will execute the binary in the same
path with same command-line arguments and environment variables. As
of nghttpx version 1.20.0, the new master process sends SIGQUIT to
the original master process when it is ready to serve requests. For
the earlier versions of nghttpx, user has to send SIGQUIT to the
original master process.
The difference between SIGUSR2 (+ SIGQUIT) and SIGHUP is that former
is usually used to execute new binary, and the master process is
newly spawned. On the other hand, the latter just reloads
configuration file, and the same master process continues to exist.
.. note::
nghttpx consists of multiple processes: one process for processing
these signals, and another one for processing requests. The former
spawns the latter. The former is called master process, and the
latter is called worker process. If neverbleed is enabled, the
worker process spawns neverbleed daemon process which does RSA key
processing. The above signal must be sent to the master process.
If the other processes received one of them, it is ignored. This
behaviour of these processes may change in the future release. In
other words, in the future release, the processes other than master
process may terminate upon the reception of these signals.
Therefore these signals should not be sent to the processes other
than master process.
SERVER PUSH
-----------
nghttpx supports HTTP/2 server push in default mode with Link header
field. nghttpx looks for Link header field (`RFC 5988
<http://tools.ietf.org/html/rfc5988>`_) in response headers from
backend server and extracts URI-reference with parameter
``rel=preload`` (see `preload
<http://w3c.github.io/preload/#interoperability-with-http-link-header>`_)
and pushes those URIs to the frontend client. Here is a sample Link
header field to initiate server push:
.. code-block:: text
Link: </fonts/font.woff>; rel=preload
Link: </css/theme.css>; rel=preload
Currently, the following restriction is applied for server push:
1. The associated stream must have method "GET" or "POST". The
associated stream's status code must be 200.
This limitation may be loosened in the future release.
nghttpx also supports server push if both frontend and backend are
HTTP/2 in default mode. In this case, in addition to server push via
Link header field, server push from backend is forwarded to frontend
HTTP/2 session.
HTTP/2 server push will be disabled if :option:`--http2-proxy` is
used.
UNIX DOMAIN SOCKET
------------------
nghttpx supports UNIX domain socket with a filename for both frontend
and backend connections.
Please note that current nghttpx implementation does not delete a
socket with a filename. And on start up, if nghttpx detects that the
specified socket already exists in the file system, nghttpx first
deletes it. However, if SIGUSR2 is used to execute new binary and
both old and new configurations use same filename, new binary does not
delete the socket and continues to use it.
OCSP STAPLING
-------------
OCSP query is done using external Python script
``fetch-ocsp-response``, which has been originally developed in Perl
as part of h2o project (https://github.com/h2o/h2o), and was
translated into Python.
The script file is usually installed under
``$(prefix)/share/nghttp2/`` directory. The actual path to script can
be customized using :option:`--fetch-ocsp-response-file` option.
If OCSP query is failed, previous OCSP response, if any, is continued
to be used.
:option:`--fetch-ocsp-response-file` option provides wide range of
possibility to manage OCSP response. It can take an arbitrary script
or executable. The requirement is that it supports the command-line
interface of ``fetch-ocsp-response`` script, and it must return a
valid DER encoded OCSP response on success. It must return exit code
0 on success, and 75 for temporary error, and the other error code for
generic failure. For large cluster of servers, it is not efficient
for each server to perform OCSP query using ``fetch-ocsp-response``.
Instead, you can retrieve OCSP response in some way, and store it in a
disk or a shared database. Then specify a program in
:option:`--fetch-ocsp-response-file` to fetch it from those stores.
This could provide a way to share the OCSP response between fleet of
servers, and also any OCSP query strategy can be applied which may be
beyond the ability of nghttpx itself or ``fetch-ocsp-response``
script.
TLS SESSION RESUMPTION
----------------------
nghttpx supports TLS session resumption through both session ID and
session ticket.
SESSION ID RESUMPTION
~~~~~~~~~~~~~~~~~~~~~
By default, session ID is shared by all worker threads.
If :option:`--tls-session-cache-memcached` is given, nghttpx will
insert serialized session data to memcached with
``nghttpx:tls-session-cache:`` + lowercase hex string of session ID
as a memcached entry key, with expiry time 12 hours. Session timeout
is set to 12 hours.
By default, connections to memcached server are not encrypted. To
enable encryption, use ``tls`` keyword in
:option:`--tls-session-cache-memcached` option.
TLS SESSION TICKET RESUMPTION
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
By default, session ticket is shared by all worker threads. The
automatic key rotation is also enabled by default. Every an hour, new
encryption key is generated, and previous encryption key becomes
decryption only key. We set session timeout to 12 hours, and thus we
keep at most 12 keys.
If :option:`--tls-ticket-key-memcached` is given, encryption keys are
retrieved from memcached. nghttpx just reads keys from memcached; one
has to deploy key generator program to update keys frequently (e.g.,
every 1 hour). The example key generator tlsticketupdate.go is
available under contrib directory in nghttp2 archive. The memcached
entry key is ``nghttpx:tls-ticket-key``. The data format stored in
memcached is the binary format described below:
.. code-block:: text
+--------------+-------+----------------+
| VERSION (4) |LEN (2)|KEY(48 or 80) ...
+--------------+-------+----------------+
^ |
| |
+------------------------+
(LEN, KEY) pair can be repeated
All numbers in the above figure is bytes. All integer fields are
network byte order.
First 4 bytes integer VERSION field, which must be 1. The 2 bytes
integer LEN field gives the length of following KEY field, which
contains key. If :option:`--tls-ticket-key-cipher`\=aes-128-cbc is
used, LEN must be 48. If
:option:`--tls-ticket-key-cipher`\=aes-256-cbc is used, LEN must be
80. LEN and KEY pair can be repeated multiple times to store multiple
keys. The key appeared first is used as encryption key. All the
remaining keys are used as decryption only.
By default, connections to memcached server are not encrypted. To
enable encryption, use ``tls`` keyword in
:option:`--tls-ticket-key-memcached` option.
If :option:`--tls-ticket-key-file` is given, encryption key is read
from the given file. In this case, nghttpx does not rotate key
automatically. To rotate key, one has to restart nghttpx (see
SIGNALS).
CERTIFICATE TRANSPARENCY
------------------------
nghttpx supports TLS ``signed_certificate_timestamp`` extension (`RFC
6962 <https://tools.ietf.org/html/rfc6962>`_). The relevant options
are :option:`--tls-sct-dir` and ``sct-dir`` parameter in
:option:`--subcert`. They takes a directory, and nghttpx reads all
files whose extension is ``.sct`` under the directory. The ``*.sct``
files are encoded as ``SignedCertificateTimestamp`` struct described
in `section 3.2 of RFC 69662
<https://tools.ietf.org/html/rfc6962#section-3.2>`_. This format is
the same one used by `nginx-ct
<https://github.com/grahamedgecombe/nginx-ct>`_ and `mod_ssl_ct
<https://httpd.apache.org/docs/trunk/mod/mod_ssl_ct.html>`_.
`ct-submit <https://github.com/grahamedgecombe/ct-submit>`_ can be
used to submit certificates to log servers, and obtain the
``SignedCertificateTimestamp`` struct which can be used with nghttpx.
MRUBY SCRIPTING
---------------
.. warning::
The current mruby extension API is experimental and not frozen. The
API is subject to change in the future release.
.. warning::
Almost all string value returned from method, or attribute is a
fresh new mruby string, which involves memory allocation, and
copies. Therefore, it is strongly recommended to store a return
value in a local variable, and use it, instead of calling method or
accessing attribute repeatedly.
nghttpx allows users to extend its capability using mruby scripts.
nghttpx has 2 hook points to execute mruby script: request phase and
response phase. The request phase hook is invoked after all request
header fields are received from client. The response phase hook is
invoked after all response header fields are received from backend
server. These hooks allows users to modify header fields, or common
HTTP variables, like authority or request path, and even return custom
response without forwarding request to backend servers.
To specify mruby script file, use :option:`--mruby-file` option. The
script will be evaluated once per thread on startup, and it must
instantiate object and evaluate it as the return value (e.g.,
``App.new``). This object is called app object. If app object
defines ``on_req`` method, it is called with :rb:class:`Nghttpx::Env`
object on request hook. Similarly, if app object defines ``on_resp``
method, it is called with :rb:class:`Nghttpx::Env` object on response
hook. For each method invocation, user can can access
:rb:class:`Nghttpx::Request` and :rb:class:`Nghttpx::Response` objects
via :rb:attr:`Nghttpx::Env#req` and :rb:attr:`Nghttpx::Env#resp`
respectively.
.. rb:module:: Nghttpx
.. rb:const:: REQUEST_PHASE
Constant to represent request phase.
.. rb:const:: RESPONSE_PHASE
Constant to represent response phase.
.. rb:class:: Env
Object to represent current request specific context.
.. rb:attr_reader:: req
Return :rb:class:`Request` object.
.. rb:attr_reader:: resp
Return :rb:class:`Response` object.
.. rb:attr_reader:: ctx
Return Ruby hash object. It persists until request finishes.
So values set in request phase hook can be retrieved in
response phase hook.
.. rb:attr_reader:: phase
Return the current phase.
.. rb:attr_reader:: remote_addr
Return IP address of a remote client. If connection is made
via UNIX domain socket, this returns the string "localhost".
.. rb:attr_reader:: server_addr
Return address of server that accepted the connection. This
is a string which specified in :option:`--frontend` option,
excluding port number, and not a resolved IP address. For
UNIX domain socket, this is a path to UNIX domain socket.
.. rb:attr_reader:: server_port
Return port number of the server frontend which accepted the
connection from client.
.. rb:attr_reader:: tls_used
Return true if TLS is used on the connection.
.. rb:attr_reader:: tls_sni
Return the TLS SNI value which client sent in this connection.
.. rb:class:: Request
Object to represent request from client. The modification to
Request object is allowed only in request phase hook.
.. rb:attr_reader:: http_version_major
Return HTTP major version.
.. rb:attr_reader:: http_version_minor
Return HTTP minor version.
.. rb:attr_accessor:: method
HTTP method. On assignment, copy of given value is assigned.
We don't accept arbitrary method name. We will document them
later, but well known methods, like GET, PUT and POST, are all
supported.
.. rb:attr_accessor:: authority
Authority (i.e., example.org), including optional port
component . On assignment, copy of given value is assigned.
.. rb:attr_accessor:: scheme
Scheme (i.e., http, https). On assignment, copy of given
value is assigned.
.. rb:attr_accessor:: path
Request path, including query component (i.e., /index.html).
On assignment, copy of given value is assigned. The path does
not include authority component of URI. This may include
query component. nghttpx makes certain normalization for
path. It decodes percent-encoding for unreserved characters
(see https://tools.ietf.org/html/rfc3986#section-2.3), and
resolves ".." and ".". But it may leave characters which
should be percent-encoded as is. So be careful when comparing
path against desired string.
.. rb:attr_reader:: headers
Return Ruby hash containing copy of request header fields.
Changing values in returned hash does not change request
header fields actually used in request processing. Use
:rb:meth:`Nghttpx::Request#add_header` or
:rb:meth:`Nghttpx::Request#set_header` to change request
header fields.
.. rb:method:: add_header(key, value)
Add header entry associated with key. The value can be single
string or array of string. It does not replace any existing
values associated with key.
.. rb:method:: set_header(key, value)
Set header entry associated with key. The value can be single
string or array of string. It replaces any existing values
associated with key.
.. rb:method:: clear_headers
Clear all existing request header fields.
.. rb:method:: push(uri)
Initiate to push resource identified by *uri*. Only HTTP/2
protocol supports this feature. For the other protocols, this
method is noop. *uri* can be absolute URI, absolute path or
relative path to the current request. For absolute or
relative path, scheme and authority are inherited from the
current request. Currently, method is always GET. nghttpx
will issue request to backend servers to fulfill this request.
The request and response phase hooks will be called for pushed
resource as well.
.. rb:class:: Response
Object to represent response from backend server.
.. rb:attr_reader:: http_version_major
Return HTTP major version.
.. rb:attr_reader:: http_version_minor
Return HTTP minor version.
.. rb:attr_accessor:: status
HTTP status code. It must be in the range [200, 999],
inclusive. The non-final status code is not supported in
mruby scripting at the moment.
.. rb:attr_reader:: headers
Return Ruby hash containing copy of response header fields.
Changing values in returned hash does not change response
header fields actually used in response processing. Use
:rb:meth:`Nghttpx::Response#add_header` or
:rb:meth:`Nghttpx::Response#set_header` to change response
header fields.
.. rb:method:: add_header(key, value)
Add header entry associated with key. The value can be single
string or array of string. It does not replace any existing
values associated with key.
.. rb:method:: set_header(key, value)
Set header entry associated with key. The value can be single
string or array of string. It replaces any existing values
associated with key.
.. rb:method:: clear_headers
Clear all existing response header fields.
.. rb:method:: return(body)
Return custom response *body* to a client. When this method
is called in request phase hook, the request is not forwarded
to the backend, and response phase hook for this request will
not be invoked. When this method is called in response phase
hook, response from backend server is canceled and discarded.
The status code and response header fields should be set
before using this method. To set status code, use :rb:meth To
set response header fields, use
:rb:attr:`Nghttpx::Response#status`. If status code is not
set, 200 is used. :rb:meth:`Nghttpx::Response#add_header` and
:rb:meth:`Nghttpx::Response#set_header`. When this method is
invoked in response phase hook, the response headers are
filled with the ones received from backend server. To send
completely custom header fields, first call
:rb:meth:`Nghttpx::Response#clear_headers` to erase all
existing header fields, and then add required header fields.
It is an error to call this method twice for a given request.
.. rb:method:: send_info(status, headers)
Send non-final (informational) response to a client. *status*
must be in the range [100, 199], inclusive. *headers* is a
hash containing response header fields. Its key must be a
string, and the associated value must be either string or
array of strings. Since this is not a final response, even if
this method is invoked, request is still forwarded to a
backend unless :rb:meth:`Nghttpx::Response#return` is called.
This method can be called multiple times. It cannot be called
after :rb:meth:`Nghttpx::Response#return` is called.
MRUBY EXAMPLES
~~~~~~~~~~~~~~
Modify request path:
.. code-block:: ruby
class App
def on_req(env)
env.req.path = "/apps#{env.req.path}"
end
end
App.new
Don't forget to instantiate and evaluate object at the last line.
Restrict permission of viewing a content to a specific client
addresses:
.. code-block:: ruby
class App
def on_req(env)
allowed_clients = ["127.0.0.1", "::1"]
if env.req.path.start_with?("/log/") &&
!allowed_clients.include?(env.remote_addr) then
env.resp.status = 404
env.resp.return "permission denied"
end
end
end
App.new
API ENDPOINTS
-------------
nghttpx exposes API endpoints to manipulate it via HTTP based API. By
default, API endpoint is disabled. To enable it, add a dedicated
frontend for API using :option:`--frontend` option with "api"
parameter. All requests which come from this frontend address, will
be treated as API request.
The response is normally JSON dictionary, and at least includes the
following keys:
status
The status of the request processing. The following values are
defined:
Success
The request was successful.
Failure
The request was failed. No change has been made.
code
HTTP status code
Additionally, depending on the API endpoint, ``data`` key may be
present, and its value contains the API endpoint specific data.
We wrote "normally", since nghttpx may return ordinal HTML response in
some cases where the error has occurred before reaching API endpoint
(e.g., header field is too large).
The following section describes available API endpoints.
POST /api/v1beta1/backendconfig
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This API replaces the current backend server settings with the
requested ones. The request method should be POST, but PUT is also
acceptable. The request body must be nghttpx configuration file
format. For configuration file format, see `FILES`_ section. The
line separator inside the request body must be single LF (0x0A).
Currently, only :option:`backend <--backend>` option is parsed, the
others are simply ignored. The semantics of this API is replace the
current backend with the backend options in request body. Describe
the desired set of backend severs, and nghttpx makes it happen. If
there is no :option:`backend <--backend>` option is found in request
body, the current set of backend is replaced with the :option:`backend
<--backend>` option's default value, which is ``127.0.0.1,80``.
The replacement is done instantly without breaking existing
connections or requests. It also avoids any process creation as is
the case with hot swapping with signals.
The one limitation is that only numeric IP address is allowed in
:option:`backend <--backend>` in request body unless "dns" parameter
is used while non numeric hostname is allowed in command-line or
configuration file is read using :option:`--conf`.
GET /api/v1beta1/configrevision
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This API returns configuration revision of the current nghttpx. The
configuration revision is opaque string, and it changes after each
reloading by SIGHUP. With this API, an external application knows
that whether nghttpx has finished reloading its configuration by
comparing the configuration revisions between before and after
reloading. It is recommended to disable persistent (keep-alive)
connection for this purpose in order to avoid to send a request using
the reused connection which may bound to an old process.
This API returns response including ``data`` key. Its value is JSON
object, and it contains at least the following key:
configRevision
The configuration revision of the current nghttpx
SEE ALSO
--------
:manpage:`nghttp(1)`, :manpage:`nghttpd(1)`, :manpage:`h2load(1)`
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