|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
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)
git-receive-pack - Receive what is pushed into the repository
git receive-pack <git-dir>
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 a remote repository.
For pull operations, see git-fetch-pack(1).
The command allows for the 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).
<git-dir>
The repository to sync into.
--http-backend-info-refs
Used by git-http-backend(1) to serve up
$GIT_URL/info/refs?service=git-receive-pack requests. See
--http-backend-info-refs in git-upload-pack(1).
--skip-connectivity-check
Bypasses the connectivity checks that validate the existence
of all objects in the transitive closure of reachable objects.
This option is intended for server operators that want to
implement their own object connectivity validation outside of
Git. This is useful in such cases where the server-side knows
additional information about how Git is being used and thus
can rely on certain guarantees to more efficiently compute
object connectivity that Git itself cannot make. Usage of this
option without a reliable external mechanism to ensure full
reachable object connectivity risks corrupting the repository
and should not be used in the general case.
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.
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.
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.
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
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.
git-send-pack(1), gitnamespaces(7)
Part of the git(1) suite
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 2025-08-11. (At that time,
the date of the most recent commit that was found in the
repository was 2025-08-07.) 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
[email protected]
Git 2.51.0.rc1 2025-08-07 GIT-RECEIVE-PACK(1)
Pages that refer to this page: git(1), git-config(1), git-push(1), git-send-pack(1), git-upload-pack(1), githooks(5), gitnamespaces(7)
|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|