Configuration options
=====================
B4 doesn't have a separate configuration file but uses ``git-config`` to
retrieve a set of b4-specific settings. This means that you can have three
levels of b4 configuration:

- system-wide, in ``/etc/gitconfig``
- per-user, in ``$HOME/.gitconfig``
- per-repo, in ``somerepo/.git/config``

Since the purpose of b4 is to work with git repositories, this allows
the usual fall-through configuration, with local settings specified in
``.git/config`` overriding the global defaults.

You can also use the command-line switch ``-c/--config`` to override
specific options, for example::

    b4 --config b4.midmask=https://some.host/%s

Per-project defaults
~~~~~~~~~~~~~~~~~~~~
A project may ship their own b4 configuration file with some defaults,
located at the top-level of the git tree. If you're not sure where a
configuration option is coming from, see if there is a ``.b4-config``
file in the repository you're currently using.

Configuration options
---------------------
All settings are under the ``b4`` section. For example, to set the
``b4.midmask`` option, add the following section to the relevant git
config file::

    [b4]
      midmask = https://some.host/%s

Core options
~~~~~~~~~~~~
These options control many of the core features of b4.

``b4.midmask``
  Specifies the server from where to retrieve the messages specified by
  their message-id.

  Default: ``https://lore.kernel.org/%s``

``b4.linkmask``
  B4 uses this setting to construct the URL in the ``Link:`` trailers.
  If you want a shorter option, you can also use
  ``https://msgid.link/%s``, which is an alias for lore.kernel.org.

  Default: ``https://lore.kernel.org/%s``

``b4.searchmask``
  B4 uses this setting to query and retrieve threads matching specific
  search terms. For example, it can retrieve trailer updates using the
  series ``change-id`` identifier.

  Default: ``https://lore.kernel.org/all/?x=m&t=1&q=%s``

``b4.linktrailermask`` (v0.13+)
  Overrides the format of the ``Link:`` trailer, in case you want to
  call it something other than "Link." For example, some projects
  use "Message-Id" trailers instead::

      linktrailermask = Message-ID: <%s>

  The ``%s`` is the placeholder for the message-id.

  Note: starting with version 0.14, you can pass the ``-i`` command-line
  switch instead of ``-l`` to automatically insert the ``Message-ID``
  trailer.

  Default: ``Link: https://lore.kernel.org/%s``

``b4.listid-preference``
  Sometimes messages with the same message-id can have different
  contents, because some servers modify message bodies to inject list
  subscription information. B4 attempts to de-duplicate the results
  using the ``List-Id`` header. You may use this parameter to specify
  the order of preference, using comma-separated strings with shell-style
  wildcard globbing.

  Default: ``*.feeds.kernel.org, *.linux.dev,*.kernel.org,*``

``b4.save-maildirs``
  The "mbox" file format is actually several incompatible standards,
  such as "mboxo" vs. "mboxrd." Setting this option can avoid potential
  problems by saving retrieved threads as Maildirs.

  Default: ``no``

``b4.trailer-order``
  This lets you control the order of trailers that get added to your own
  custody section of the commit message. By default, b4 applies these
  trailers in the order received. However, if you want to list trailers
  in a specific order, you can try something like::

      trailer-order = link*,fixes*,acked*,reviewed*,tested*,*

  The "chain of custody" is an important concept in patch-based code
  review process. Each "Signed-off-by" trailer indicates where the
  custody section of previous reviewer ends and the new one starts. Your
  own custody section is always between the previous-to-last
  "Signed-off-by" trailer, if any, and the bottom of the trailer
  section. For example::

      Fixes: abcde (Commit info)
      Suggested-by: Alex Reporter <alex.reporter@example.com>
      Signed-off-by: Betty Developer <betty.developer@example.com>
      Acked-by: Chandra Acker <chandra.acker@example.com>
      Reviewed-by: Debby Reviewer <debby.reviewer@example.com>
      Signed-off-by: Ezri Submaintainer <ezri.submaintainer@example.com>
      Link: https://msgid.link/some@thing.foo
      Tested-by: Finn Tester <finn.tester@example.com>
      Signed-off-by: Your Name <your.name@example.com>

  Your custody section is beneath "Ezri Submaintainer," so the only
  trailers considered for reordering are "Link" and "Tested-by." Your
  own Signed-off-by trailer is always at the bottom of your own custody
  section.

  Default: ``*``

``b4.trailers-ignore-from``
  A comma-separated list of addresses that b4 should always ignore
  when applying follow-up trailers. This is useful when dealing with
  reports generated by some automated bots. For example::

      trailers-ignore-from = lkp@intel.com, someotherbot@example.org

  Default: ``None``

``b4.cache-expire``
  B4 caches retrieved threads for 10 minutes. This option allows
  tweaking the time that the cache remains valid. Many commands also
  allow a ``--no-cache`` flag to force b4 to perform remote lookups.

  Default: ``10``

.. _shazam_settings:

``am`` and ``shazam`` settings
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
These settings control ``b4 am`` and ``b4 shazam`` behavior.

``b4.shazam-am-flags``
  Additional flags to pass to ``git am`` when applying patches.

  Default: ``None``

``b4.shazam-merge-flags``
  Additional flags to pass to ``git merge`` when performing a merge with
  ``b4 shazam -M``

  Default: ``--signoff``

``b4.shazam-merge-template``
  Path to a template to use when creating a merge commit. See
  ``shazam-merge-template.example`` for an example.

  Default: ``None``

``b4.am-perpatch-check-cmd`` (v0.14+)
  The command to use when running with ``--check``. If b4 finds
  ``scripts/checkpatch.pl`` at the top of your git tree, it uses the
  command shown below by default.

  Default: ``./scripts/checkpatch.pl -q --terse --no-summary --mailback``

.. _attestation_settings:

Attestation settings
~~~~~~~~~~~~~~~~~~~~
``b4.attestation-policy``

  B4 supports domain-level and end-to-end attestation of patches using
  the `patatt`_ library. There are four different operation modes:

  * ``off``: don't bother checking attestation at all
  * ``softfail``: print green marks when attestation is passing and
    red marks when it's failing
  * ``hardfail``: exit with an error when any attestation checks fail

  Default: ``softfail``

``b4.attestation-check-dkim``
  Controls whether to perform DKIM attestation checks.

  Default: ``yes``

``b4.attestation-dns-resolvers`` (v0.14+)
  You can specify your own DNS servers if you are on a company network
  and your OS-provided resolvers aren't able to perform domain key
  lookups. For example, to use Google DNS servers::

      attestation-dns-resolvers = 8.8.8.8, 8.8.4.4

  Default: ``None``

``b4.attestation-staleness-days``
  Ignore attestation signatures that are more than this many days
  old. This helps avoid a class of attacks when someone re-sends old
  patches that contain known security bugs.

  Default: ``30``

``b4.attestation-gnupghome``
  Sets ``GNUPGHOME`` before running PGP attestation checks that rely on
  GnuPG.

  Default: ``None``

``b4.gpgbin``
  Full path to a different binary to use for ``gpg``. B4 also checks the
  ``gpg.program`` setting, and uses that value, if found.

  Default: ``None``

``b4.keyringsrc``
  See ``patatt`` for details on how to configure keyrings. For example,
  you can clone the kernel.org pgp keys repository and use it for
  attestation::

      git clone https://git.kernel.org/pub/scm/docs/kernel/pgpkeys.git

  Then set the following in your ``~/.gitconfig``::

      [b4]
        keyringsrc = ~/path/to/pgpkeys/.keyring

  Default: ``None``

.. _ty_settings:

``ty`` settings
~~~~~~~~~~~~~~~
``b4.thanks-pr-template``, ``b4.thanks-am-template``
  Full paths to the templates to use when generating thank-you messages
  for contributors. See example templates provided with the project.

  Default: ``None``

``b4.thanks-commit-url-mask``
  Used when creating summaries for ``b4 ty``, and can be a value like::

      thanks-commit-url-mask = https://git.kernel.org/username/c/%.12s

  If not set, b4 falls back to using commit hashes.

  .. note::

     See this page for more info on convenient git.kernel.org short URLs:
     https://korg.docs.kernel.org/git-url-shorteners.html

  Default: ``None``

``b4.thanks-from-name`` (v0.13+)
  The name to use in the ``From:`` header when sending thank-you notes.
  By default, b4 uses ``user.name``. For example::

      thanks-from-name = Project Foo Thanks Bot

  Default: ``None``

``b4.thanks-from-email`` (v0.13+)
  The email to use in the ``From:`` header when sending thank-you notes.
  By default, b4 uses ``user.email``. For example::

      thanks-from-email = thanks-bot@example.com

  Default: ``None``

``b4.thanks-treename``
  Name of the tree to use in the thank-you templates.

  Default: ``None``

``b4.email-exclude``
  A list of addresses to always exclude from the message recipients.
  Expects a comma-separated list with shell-style globbing. E.g.::

      email-exclude = *@codeaurora.org, *@obsolete.example.com

  Default: ``None``

``b4.sendemail-identity``
  The ``sendemail`` identity to use when sending mail directly with b4.
  This setting applies to ``b4 send`` and ``b4 ty``. See ``man
  git-send-email`` for info about sendemail identities.

  Default: ``None``

``b4.ty-send-email`` (v0.11+)
  When set, tells ``b4 ty`` to send email directly instead of writing
  out ``.thanks`` files.

  Default: ``no``

.. _patchwork_settings:

Patchwork integration settings
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If your project uses a patchwork server, setting these allows you to
integrate your b4 workflow with patchwork.

``b4.pw-url``
  The URL of your patchwork server. Note, that this should point at the
  top-level of your patchwork installation and **not** at the project patch
  listing. For example::

      pw-url = https://patchwork.kernel.org/

  Default: ``None``

``b4.pw-key``
  The API key from your user profile to use when authenticating with the
  patchwork server.

  Default: ``None``

``b4.pw-project``
  The name of the patchwork project, exactly as seen in the URL
  sub-path. For example::

      pw-project = linux-usb

  Default: ``None``

``b4.pw-review-state``
  Enabling this option makes ``b4 am`` or ``b4 shazam`` automatically set
  the review status of the retrieved patches. For example::

      pw-review-state = under-review

  Default: ``None``

``b4.pw-accept-state``
  Enabling this option makes ``b4 ty`` set the status of any applied patches
  to the specified state. For example::

      pw-accept-state = accepted

  Default: ``None``

``b4.pw-discard-state``
  Enabling this option makes ``b4 ty -d`` set the status of any matching
  patches to the specified state. For example::

      pw-discard-state = rejected

  Default: ``None``

.. _contributor_settings:

Contributor-oriented settings
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

``b4.send-endpoint-web``
  The web submission endpoint to use. See :ref:`web_endpoint`.

  Default: ``None``

``b4.send-series-to``
  A comma-separated list of addresses to always add to the "To:" header.
  See :ref:`prep_recipients`.

  Default: ``None``

``b4.send-series-cc``
  A comma-separated list of addresses to always add to the "Cc:" header.
  See :ref:`prep_recipients`.

  Default: ``None``

``b4.send-no-patatt-sign``
  Instructs b4 not to sign patches with patatt before sending them. Note, that
  using the web submission endpoint requires using signed patches.

  Default: ``no``

``b4.send-auto-to-cmd``
  The command to use for obtaining the list of "To:" recipients. Has no effect
  if the specified script isn't present in the repository.

  Default: ``scripts/get_maintainer.pl --nogit --nogit-fallback --nogit-chief-penguins --norolestats --nol``

``b4.send-auto-cc-cmd``
  The command to use for obtaining the list of Cc: recipients. Has no effect
  if the specified script isn't present in the repository.

  Default:: ``scripts/get_maintainer.pl --nogit --nogit-fallback --nogit-chief-penguins --norolestats --nom``

``b4.send-same-thread`` (v0.13+)
  When sending a new version of a series, send it in the same thread as
  the previous version. B4 sends the first message of the new series as
  a reply to the previous version's cover letter.

  Default: ``no``

``b4.prep-cover-strategy``
  Alternative cover letter storage strategy to use, in case you don't
  want to use the default ``commit`` strategy. See
  :ref:`prep_cover_strategies`.

  Default: ``commit``

``b4.prep-cover-template``
  Path to the template to use for the cover letter. The template supports the
  following tokens:

  * ``${cover}``: the content of the cover letter itself
  * ``${shortlog}``: the ``git shortlog`` output for the series
  * ``${diffstat}``: the ``git diff --stat`` output for the series
  * ``${range_diff}``: the ``git range-diff`` output against the previous revision of the series
  * ``${base_commit}``: the base commit of the series
  * ``${change_id}``: the change-id of the series
  * ``${signature}``: your signature, either from ``~/.signature`` if found, or from your Git config

  Default: ``None``

``b4.send-prefixes`` (v0.11+)
  Extra prefixes to add to ``[PATCH]`` (e.g. ``RFC mydrv``).

  This setting can be replaced for a series with ``b4 prep --set-prefixes``.

  Default: ``None``

``b4.prep-perpatch-check-cmd`` (v0.14+)
  The command to use when running ``--check``. If b4 finds
  ``scripts/checkpatch.pl`` at the top of your git tree, it uses the
  command shown below by default.

  Default: ``./scripts/checkpatch.pl -q --terse --no-summary --mailback --showfile```

``b4.prep-pre-flight-checks`` (v0.14+)
  You can use this to turn off some or all pre-flight checks that b4 runs
  prior to sending out patches. To cancel all checks::

      [b4]
      prep-pre-flight-checks = disable-all

  To turn off specific checks, list each one of them, separated by
  comma::

      [b4]
      prep-pre-flight-checks = disable-needs-auto-to-cc, needs-checking


To document
-----------
``b4.gh-api-key``
  Deliberately undocumented because the feature is incomplete and poorly
  tested.

.. _`patatt`: https://pypi.org/project/patatt/