Adding upstream version 5.7.1.upstream/5.7.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 98 insertions, 0 deletions

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+.. SPDX-License-Identifier: GPL-3.0-or-later
+
+**********************
+Configuration Overview
+**********************
+
+Configuration file is named ``/etc/knot-resolver/kresd.conf`` and is read when
+you execute Knot Resolver using systemd commands described in section
+:ref:`quickstart-startup`. [#]_
+
+.. _config-syntax:
+
+Syntax
+======
+
+The configuration file syntax allows you to specify different kinds of data:
+
+  - ``group.option = 123456``
+  - ``group.option = "string value"``
+  - ``group.command(123456, "string value")``
+  - ``group.command({ key1 = "value1", key2 = 222, key3 = "third value" })``
+  - ``globalcommand(a_parameter_1, a_parameter_2, a_parameter_3, etc)``
+  - ``-- any text after -- sign is ignored till end of line``
+
+Following **configuration file snippet** starts listening for unencrypted and also encrypted DNS queries on IP address 192.0.2.1, and sets cache size.
+
+.. code-block:: lua
+
+        -- this is a comment: listen for unencrypted queries
+        net.listen('192.0.2.1')
+        -- another comment: listen for queries encrypted using TLS on port 853
+        net.listen('192.0.2.1', 853, { kind = 'tls' })
+        -- 10 MB cache is suitable for a very small deployment
+        cache.size = 10 * MB
+
+.. tip::
+   When copy&pasting examples from this manual please pay close
+   attention to brackets and also line ordering - order of lines matters.
+
+   The configuration language is in fact Lua script, so you can use full power
+   of this programming language. See article
+   `Learn Lua in 15 minutes`_ for a syntax overview.
+
+When you modify configuration file on disk restart resolver process to get
+changes into effect. See chapter :ref:`systemd-zero-downtime-restarts` if even short
+outages are not acceptable for your deployment.
+
+.. [#] If you decide to run binary ``/usr/sbin/kresd`` manually (instead of
+   using systemd) do not forget to specify ``-c`` option with path to
+   configuration file, otherwise ``kresd`` will read file named ``config`` from
+   its current working directory.
+
+Documentation Conventions
+=========================
+
+Besides text configuration file, Knot Resolver also supports interactive and dynamic configuration using scripts or external systems, which is described in chapter :ref:`runtime-cfg`. Through this manual we present examples for both usage types - static configuration in a text file (see above) and also the interactive mode.
+
+The **interactive prompt** is denoted by ``>``, so all examples starting with ``>`` character are transcripts of user (or script) interaction with Knot Resolver and resolver's responses. For example:
+
+.. code-block:: lua
+
+        > -- this is a comment entered into interactive prompt
+        > -- comments have no effect here
+        > -- the next line shows a command entered interactively and its output
+        > log_level()
+        'notice'
+        > -- the previous line without > character is output from log_level() command
+
+Following example demonstrates how to interactively list all currently loaded modules, and includes multi-line output:
+
+.. code-block:: lua
+
+        > modules.list()
+        {
+            'iterate',
+            'validate',
+            'cache',
+            'ta_update',
+            'ta_signal_query',
+            'policy',
+            'priming',
+            'detect_time_skew',
+            'detect_time_jump',
+            'ta_sentinel',
+            'edns_keepalive',
+            'refuse_nord',
+            'watchdog',
+        }
+
+
+Before we dive into configuring features, let us explain modularization basics.
+
+.. include:: ../daemon/bindings/modules.rst
+
+Now you know what configuration file to modify, how to read examples and what modules are so you are ready for a real configuration work!
+
+.. _`Learn Lua in 15 minutes`: http://tylerneylon.com/a/learn-lua/
+