Adding upstream version 5.3.1.upstream/5.3.1upstream

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

1 files changed, 293 insertions, 0 deletions

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+.. SPDX-License-Identifier: GPL-3.0-or-later
+
+.. _upgrading:
+
+*********
+Upgrading
+*********
+
+This section summarizes steps required when upgrading to newer Knot Resolver versions.
+We advise users to also read :ref:`release_notes` for respective versions.
+Section *Module changes* is relevant only for users who develop or use third-party modules.
+
+
+Upcoming changes
+================
+
+Following section provides information about selected changes in not-yet-released versions.
+We advise users to prepare for these changes sooner rather than later to make it easier to upgrade to
+newer versions when they are released.
+
+* Going forward DNS-over-HTTP (DoH) will be supported only over HTTP/2 with TLS.
+  This limitation allows us to provide a new :ref:`more reliable and scalable implementation
+  of DoH <dns-over-https>` (``kind='doh2'``).
+* Command line option ``--forks`` (``-f``) `is deprecated and will be eventually removed
+  <https://gitlab.nic.cz/knot/knot-resolver/-/issues/631>`_.
+  Preferred way to manage :ref:`systemd-multiple-instances` is to use a process manager,
+  e.g. systemd_ or supervisord_.
+
+.. _`systemd`: https://systemd.io/
+.. _`supervisord`: http://supervisord.org/
+
+
+5.2 to 5.3
+==========
+
+Configuration file
+------------------
+
+* Module ``dnstap``: option ``log_responses`` has been moved inside a new ``client`` section. Refer to the configuration example in :ref:`mod-dnstap`.
+
+Packagers & Developers
+----------------------
+
+* Knot DNS >= 2.9 is required.
+
+5.1 to 5.2
+==========
+
+Users
+-----
+
+* DoH over HTTP/1 and unencrypted transports is still available in
+  :ref:`legacy http module <mod-http-doh>` (``kind='doh'``).
+  This module will not receive receive any more bugfixes and will be eventually removed.
+* Users of :ref:`control-sockets` API need to terminate each command sent to resolver with newline
+  character (ASCII ``\n``). Correct usage: ``cache.stats()\n``.
+  Newline terminated commands are accepted by all resolver versions >= 1.0.0.
+* `DNS Flag Day 2020 <https://dnsflagday.net/2020/>`_ is now effective and Knot Resolver uses
+  maximum size of UDP answer to 1232 bytes. Please double-check your firewall,
+  it has to allow DNS traffic on UDP and **also TCP** port 53.
+* Human readable output in interactive mode and from :ref:`control-sockets` was improved and
+  as consequence slightly changed its format. Users who need machine readable output for scripts
+  should use Lua function ``tojson()`` to convert Lua values into standard JSON format instead
+  of attempting to parse the human readable output.
+  For example API call ``tojson(cache.stats())\n`` will return JSON string with ``cache.stats()``
+  results represented as dictionary.
+  Function ``tojson()`` is available in all resolver versions >= 1.0.0.
+
+Configuration file
+------------------
+
+* Statistics exporter :ref:`mod-graphite` now uses default prefix which combines
+  :func:`hostname()` and :envvar:`worker.id` instead of bare :func:`hostname()`.
+  This prevents :ref:`systemd-multiple-instances` from sending
+  conflicting statistics to server. In case you want to continue in previous time series you
+  can manually set the old values using option ``prefix``
+  in :ref:`Graphite configuration <mod-graphite>`.
+  Beware that non-default values require careful
+  :ref:`instance-specific-configuration` to avoid conflicting names.
+* Lua variable :envvar:`worker.id` is now a string with either Systemd instance name or PID
+  (instead of number). If your custom configuration uses :envvar:`worker.id` value please
+  check your scripts.
+
+Module changes
+--------------
+* Reply packet :c:type:`kr_request.answer`
+  `is not allocated <https://gitlab.nic.cz/knot/knot-resolver/-/merge_requests/985>`_
+  immediately when the request comes.
+  See the new :c:func:`kr_request_ensure_answer` function,
+  wrapped for lua as ``req:ensure_answer()``.
+
+
+5.0 to 5.1
+==========
+
+Module changes
+--------------
+
+* Modules which use :c:type:`kr_request.trace_log` handler need update to modified handler API. Example migration is `modules/watchdog/watchdog.lua <https://gitlab.nic.cz/knot/knot-resolver/-/merge_requests/957/diffs#6831501329bbf9e494048fe269c6b02944fc227c>`_.
+* Modules which were using logger :c:func:`kr_log_qverbose_impl` need migration to new logger :c:func:`kr_log_q`. Example migration is `modules/rebinding/rebinding.lua <https://gitlab.nic.cz/knot/knot-resolver/-/merge_requests/957/diffs#6c74dcae147221ca64286a3ed028057adb6813b9>`_.
+* Modules which were using :c:func:`kr_ranked_rrarray_add` should note that on success it no longer returns exclusively zero but index into the array (non-negative).  Error states are unchanged (negative).
+
+
+4.x to 5.x
+==========
+
+Users
+-----
+
+* Control socket location has changed
+
+  .. csv-table::
+     :header: "","4.x location","5.x location"
+
+     "with systemd","``/run/knot-resolver/control@$ID``","``/run/knot-resolver/control/$ID``"
+     "without systemd","``$PWD/tty/$PID``","``$PWD/control/$PID``"
+
+* ``-f`` / ``--forks`` command-line option is deprecated.
+  In case you just want to trigger non-interactive mode, there's new ``-n`` / ``--noninteractive``.
+  This forking style `was not ergonomic <https://gitlab.nic.cz/knot/knot-resolver/issues/529>`_;
+  with independent kresd processes you can better utilize a process manager (e.g. systemd).
+
+
+Configuration file
+------------------
+
+* Network interface are now configured in ``kresd.conf`` with
+  :func:`net.listen` instead of systemd sockets (`#485
+  <https://gitlab.nic.cz/knot/knot-resolver/issues/485>`_). See
+  the following examples.
+
+  .. tip:: You can find suggested network interface settings based on your
+     previous systemd socket configuration in
+     ``/var/lib/knot-resolver/.upgrade-4-to-5/kresd.conf.net`` which is created
+     during the package update to version 5.x.
+
+  .. csv-table::
+     :header: "4.x - systemd socket file", "5.x - kresd.conf"
+
+      "kresd.socket
+      | [Socket]
+      | ListenDatagram=127.0.0.1:53
+      | ListenStream=127.0.0.1:53","| ``net.listen('127.0.0.1', 53, { kind = 'dns' })``"
+      "kresd.socket
+      | [Socket]
+      | FreeBind=true
+      | BindIPv6Only=both
+      | ListenDatagram=[::1]:53
+      | ListenStream=[::1]:53
+      "," | ``net.listen('127.0.0.1', 53, { kind = 'dns', freebind = true })``
+      | ``net.listen('::1', 53, { kind = 'dns', freebind = true })``"
+      "kresd-tls.socket
+      | [Socket]
+      | ListenStream=127.0.0.1:853","| ``net.listen('127.0.0.1', 853, { kind = 'tls' })``"
+      "kresd-doh.socket
+      | [Socket]
+      | ListenStream=127.0.0.1:443","| ``net.listen('127.0.0.1', 443, { kind = 'doh' })``"
+      "kresd-webmgmt.socket
+      | [Socket]
+      | ListenStream=127.0.0.1:8453","| ``net.listen('127.0.0.1', 8453, { kind = 'webmgmt' })``"
+
+* :func:`net.listen` throws an error if it fails to bind. Use ``freebind=true`` option
+  to bind to nonlocal addresses.
+
+
+4.2.2 to 4.3+
+=============
+
+Module changes
+--------------
+
+* In case you wrote your own module which directly calls function
+  ``kr_ranked_rrarray_add()``, you need to additionally call function
+  ``kr_ranked_rrarray_finalize()`` after each batch (before changing
+  the added memory regions). For a specific example see `changes in dns64 module
+  <https://gitlab.nic.cz/knot/knot-resolver/commit/edb8ffef7fbe48befeb3f7164d38079dd0be3302#1fe36e8ac0729b279645f7237b7122b1c457a982>`_.
+
+.. _upgrade-from-3-to-4:
+
+4.x to 4.2.1+
+=============
+
+Users
+-----
+
+* If you have previously installed ``knot-resolver-dbgsym`` package on Debian,
+  please remove it and install ``knot-resolver-dbg`` instead.
+
+3.x to 4.x
+==========
+
+Users
+-----
+
+* DNSSEC validation is now turned on by default. If you need to disable it, see
+  :ref:`dnssec-config`.
+* ``-k/--keyfile`` and ``-K/--keyfile-ro`` daemon options were removed. If needed,
+  use ``trust_anchors.add_file()`` in configuration file instead.
+* Configuration for :ref:`HTTP module <mod-http>` changed significantly as result of
+  adding :ref:`mod-http-doh` support. Please see examples below.
+* In case you are using your own custom modules, move them to the new module
+  location. The exact location depends on your distribution. Generally, modules previously
+  in ``/usr/lib/kdns_modules`` should be moved to ``/usr/lib/knot-resolver/kres_modules``.
+
+Configuration file
+~~~~~~~~~~~~~~~~~~
+
+* ``trust_anchors.file``, ``trust_anchors.config()`` and ``trust_anchors.negative``
+  aliases were removed to avoid duplicity and confusion. Migration table:
+
+  .. csv-table::
+     :header: "3.x configuration", "4.x configuration"
+
+     "``trust_anchors.file = path``", "``trust_anchors.add_file(path)``"
+     "``trust_anchors.config(path, readonly)``", "``trust_anchors.add_file(path, readonly)``"
+     "``trust_anchors.negative = nta_set``", "``trust_anchors.set_insecure(nta_set)``"
+
+* ``trust_anchors.keyfile_default`` is no longer accessible and is can be set
+  only at compile time. To turn off DNSSEC, use :func:`trust_anchors.remove()`.
+
+  .. csv-table::
+     :header: "3.x configuration", "4.x configuration"
+
+     "``trust_anchors.keyfile_default = nil``", "``trust_anchors.remove('.')``"
+
+* Network for HTTP endpoints is now configured using same mechanism as for normal DNS enpoints,
+  please refer to chapter :ref:`network-configuration`. Migration table:
+
+  .. csv-table::
+     :header: "3.x configuration", "4.x configuration"
+
+     "``modules = { http = { host = '192.0.2.1', port = 443 }}``","see chapter :ref:`network-configuration`"
+     "``http.config({ host = '192.0.2.1', port = 443 })``","see chapter :ref:`network-configuration`"
+     "``modules = { http = { endpoints = ... }}``","see chapter :ref:`mod-http-custom-endpoint`"
+     "``http.config({ endpoints = ... })``","see chapter :ref:`mod-http-custom-endpoint`"
+
+Packagers & Developers
+----------------------
+
+* Knot DNS >= 2.8 is required.
+* meson >= 0.46 and ninja is required.
+* meson build system is now used for compiling the project. For instructions, see
+  the :ref:`build`. Packagers should pay attention to section :ref:`packaging`
+  for information about systemd unit files and trust anchors.
+* Embedding LMDB is no longer supported, lmdb is now required as an external dependency.
+* Trust anchors file from upstream is installed and used as default unless you
+  override ``keyfile_default`` during build.
+
+Module changes
+~~~~~~~~~~~~~~
+
+* Default module location has changed from ``{libdir}/kdns_modules`` to
+  ``{libdir}/knot-resolver/kres_modules``. Modules are now in the lua namespace
+  ``kres_modules.*``.
+* ``kr_straddr_split()`` API has changed.
+
+* C modules defining ``*_layer`` or ``*_props`` symbols need to use a different style, but it's typically a trivial change.
+  Instead of exporting the corresponding symbols, the module should assign pointers to its static structures inside its ``*_init()`` function.  Example migration:
+  `bogus_log module <https://gitlab.nic.cz/knot/knot-resolver/commit/2875a3970#9fa69cdc6ee1903dc22e3262f58996395acab364>`_.
+
+.. _upgrade-from-2-to-3:
+
+2.x to 3.x
+==========
+
+Users
+-----
+
+* Module :ref:`mod-hints` has option :func:`hints.use_nodata` enabled by default,
+  which is what most users expect. Add ``hints.use_nodata(false)`` to your config
+  to revert to the old behavior.
+* Modules ``cookie`` and ``version`` were removed.
+  Please remove relevant configuration lines with ``modules.load()`` and ``modules =``
+  from configuration file.
+* Valid configuration must open cache using ``cache.open()`` or ``cache.size =``
+  before executing cache operations like ``cache.clear()``.
+  (Older versions were silently ignoring such cache operations.)
+
+Packagers & Developers
+----------------------
+
+* Knot DNS >= 2.7.2 is required.
+
+Module changes
+~~~~~~~~~~~~~~
+
+* API for Lua modules was refactored, please see :ref:`significant-lua-changes`.
+* New layer was added: ``answer_finalize``.
+* ``kr_request`` keeps ``::qsource.packet`` beyond the ``begin`` layer.
+* ``kr_request::qsource.tcp`` renamed to ``::qsource.flags.tcp``.
+* ``kr_request::has_tls`` renamed to ``::qsource.flags.tls``.
+* ``kr_zonecut_add()``, ``kr_zonecut_del()`` and ``kr_nsrep_sort()`` changed
+  parameters slightly.