git-receive-pack(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | PRE-RECEIVE HOOK | UPDATE HOOK | POST-RECEIVE HOOK | POST-UPDATE HOOK | QUARANTINE ENVIRONMENT | SEE ALSO | GIT | COLOPHON

GIT-RECEIVE-PACK(1)            Git Manual            GIT-RECEIVE-PACK(1)

NAME         top

       git-receive-pack - Receive what is pushed into the repository

SYNOPSIS         top

       git-receive-pack <directory>

DESCRIPTION         top

       Invoked by git send-pack and updates the repository with the
       information fed from the remote end.

       This command is usually not invoked directly by the end user. The
       UI for the protocol is on the git send-pack side, and the program
       pair is meant to be used to push updates to remote repository.
       For pull operations, see git-fetch-pack(1).

       The command allows for creation and fast-forwarding of sha1 refs
       (heads/tags) on the remote end (strictly speaking, it is the
       local end git-receive-pack runs, but to the user who is sitting
       at the send-pack end, it is updating the remote. Confused?)

       There are other real-world examples of using update and
       post-update hooks found in the Documentation/howto directory.

       git-receive-pack honours the receive.denyNonFastForwards config
       option, which tells it if updates to a ref should be denied if
       they are not fast-forwards.

       A number of other receive.* config options are available to tweak
       its behavior, see git-config(1).

OPTIONS         top

       <directory>
           The repository to sync into.

PRE-RECEIVE HOOK         top

       Before any ref is updated, if $GIT_DIR/hooks/pre-receive file
       exists and is executable, it will be invoked once with no
       parameters. The standard input of the hook will be one line per
       ref to be updated:

           sha1-old SP sha1-new SP refname LF

       The refname value is relative to $GIT_DIR; e.g. for the master
       head this is "refs/heads/master". The two sha1 values before each
       refname are the object names for the refname before and after the
       update. Refs to be created will have sha1-old equal to 0{40},
       while refs to be deleted will have sha1-new equal to 0{40},
       otherwise sha1-old and sha1-new should be valid objects in the
       repository.

       When accepting a signed push (see git-push(1)), the signed push
       certificate is stored in a blob and an environment variable
       GIT_PUSH_CERT can be consulted for its object name. See the
       description of post-receive hook for an example. In addition, the
       certificate is verified using GPG and the result is exported with
       the following environment variables:

       GIT_PUSH_CERT_SIGNER
           The name and the e-mail address of the owner of the key that
           signed the push certificate.

       GIT_PUSH_CERT_KEY
           The GPG key ID of the key that signed the push certificate.

       GIT_PUSH_CERT_STATUS
           The status of GPG verification of the push certificate, using
           the same mnemonic as used in %G?  format of git log family of
           commands (see git-log(1)).

       GIT_PUSH_CERT_NONCE
           The nonce string the process asked the signer to include in
           the push certificate. If this does not match the value
           recorded on the "nonce" header in the push certificate, it
           may indicate that the certificate is a valid one that is
           being replayed from a separate "git push" session.

       GIT_PUSH_CERT_NONCE_STATUS

           UNSOLICITED
               "git push --signed" sent a nonce when we did not ask it
               to send one.

           MISSING
               "git push --signed" did not send any nonce header.

           BAD
               "git push --signed" sent a bogus nonce.

           OK
               "git push --signed" sent the nonce we asked it to send.

           SLOP
               "git push --signed" sent a nonce different from what we
               asked it to send now, but in a previous session. See
               GIT_PUSH_CERT_NONCE_SLOP environment variable.

       GIT_PUSH_CERT_NONCE_SLOP
           "git push --signed" sent a nonce different from what we asked
           it to send now, but in a different session whose starting
           time is different by this many seconds from the current
           session. Only meaningful when GIT_PUSH_CERT_NONCE_STATUS says
           SLOP. Also read about receive.certNonceSlop variable in
           git-config(1).

       This hook is called before any refname is updated and before any
       fast-forward checks are performed.

       If the pre-receive hook exits with a non-zero exit status no
       updates will be performed, and the update, post-receive and
       post-update hooks will not be invoked either. This can be useful
       to quickly bail out if the update is not to be supported.

       See the notes on the quarantine environment below.

UPDATE HOOK         top

       Before each ref is updated, if $GIT_DIR/hooks/update file exists
       and is executable, it is invoked once per ref, with three
       parameters:

           $GIT_DIR/hooks/update refname sha1-old sha1-new

       The refname parameter is relative to $GIT_DIR; e.g. for the
       master head this is "refs/heads/master". The two sha1 arguments
       are the object names for the refname before and after the update.
       Note that the hook is called before the refname is updated, so
       either sha1-old is 0{40} (meaning there is no such ref yet), or
       it should match what is recorded in refname.

       The hook should exit with non-zero status if it wants to disallow
       updating the named ref. Otherwise it should exit with zero.

       Successful execution (a zero exit status) of this hook does not
       ensure the ref will actually be updated, it is only a
       prerequisite. As such it is not a good idea to send notices (e.g.
       email) from this hook. Consider using the post-receive hook
       instead.

POST-RECEIVE HOOK         top

       After all refs were updated (or attempted to be updated), if any
       ref update was successful, and if $GIT_DIR/hooks/post-receive
       file exists and is executable, it will be invoked once with no
       parameters. The standard input of the hook will be one line for
       each successfully updated ref:

           sha1-old SP sha1-new SP refname LF

       The refname value is relative to $GIT_DIR; e.g. for the master
       head this is "refs/heads/master". The two sha1 values before each
       refname are the object names for the refname before and after the
       update. Refs that were created will have sha1-old equal to 0{40},
       while refs that were deleted will have sha1-new equal to 0{40},
       otherwise sha1-old and sha1-new should be valid objects in the
       repository.

       The GIT_PUSH_CERT* environment variables can be inspected, just
       as in pre-receive hook, after accepting a signed push.

       Using this hook, it is easy to generate mails describing the
       updates to the repository. This example script sends one mail
       message per ref listing the commits pushed to the repository, and
       logs the push certificates of signed pushes with good signatures
       to a logger service:

           #!/bin/sh
           # mail out commit update information.
           while read oval nval ref
           do
                   if expr "$oval" : '0*$' >/dev/null
                   then
                           echo "Created a new ref, with the following commits:"
                           git rev-list --pretty "$nval"
                   else
                           echo "New commits:"
                           git rev-list --pretty "$nval" "^$oval"
                   fi |
                   mail -s "Changes to ref $ref" commit-list@mydomain
           done
           # log signed push certificate, if any
           if test -n "${GIT_PUSH_CERT-}" && test ${GIT_PUSH_CERT_STATUS} = G
           then
                   (
                           echo expected nonce is ${GIT_PUSH_NONCE}
                           git cat-file blob ${GIT_PUSH_CERT}
                   ) | mail -s "push certificate from $GIT_PUSH_CERT_SIGNER" push-log@mydomain
           fi
           exit 0

       The exit code from this hook invocation is ignored, however a
       non-zero exit code will generate an error message.

       Note that it is possible for refname to not have sha1-new when
       this hook runs. This can easily occur if another user modifies
       the ref after it was updated by git-receive-pack, but before the
       hook was able to evaluate it. It is recommended that hooks rely
       on sha1-new rather than the current value of refname.

POST-UPDATE HOOK         top

       After all other processing, if at least one ref was updated, and
       if $GIT_DIR/hooks/post-update file exists and is executable, then
       post-update will be called with the list of refs that have been
       updated. This can be used to implement any repository wide
       cleanup tasks.

       The exit code from this hook invocation is ignored; the only
       thing left for git-receive-pack to do at that point is to exit
       itself anyway.

       This hook can be used, for example, to run git update-server-info
       if the repository is packed and is served via a dumb transport.

           #!/bin/sh
           exec git update-server-info

QUARANTINE ENVIRONMENT         top

       When receive-pack takes in objects, they are placed into a
       temporary "quarantine" directory within the $GIT_DIR/objects
       directory and migrated into the main object store only after the
       pre-receive hook has completed. If the push fails before then,
       the temporary directory is removed entirely.

       This has a few user-visible effects and caveats:

        1. Pushes which fail due to problems with the incoming pack,
           missing objects, or due to the pre-receive hook will not
           leave any on-disk data. This is usually helpful to prevent
           repeated failed pushes from filling up your disk, but can
           make debugging more challenging.

        2. Any objects created by the pre-receive hook will be created
           in the quarantine directory (and migrated only if it
           succeeds).

        3. The pre-receive hook MUST NOT update any refs to point to
           quarantined objects. Other programs accessing the repository
           will not be able to see the objects (and if the pre-receive
           hook fails, those refs would become corrupted). For safety,
           any ref updates from within pre-receive are automatically
           rejected.

SEE ALSO         top

       git-send-pack(1), gitnamespaces(7)

GIT         top

       Part of the git(1) suite

COLOPHON         top

       This page is part of the git (Git distributed version control
       system) project.  Information about the project can be found at
       ⟨http://git-scm.com/⟩.  If you have a bug report for this manual
       page, see ⟨http://git-scm.com/community⟩.  This page was obtained
       from the project's upstream Git repository
       ⟨https://github.com/git/git.git⟩ on 2021-08-27.  (At that time,
       the date of the most recent commit that was found in the
       repository was 2021-08-24.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

Git 2.33.0.69.gc420321         08/27/2021            GIT-RECEIVE-PACK(1)

Pages that refer to this page: git(1)git-config(1)git-push(1)git-send-pack(1)githooks(5)gitnamespaces(7)