1GIT-RECEIVE-PACK(1) Git Manual GIT-RECEIVE-PACK(1)
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6 git-receive-pack - Receive what is pushed into the repository
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9 git-receive-pack <directory>
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12 Invoked by git send-pack and updates the repository with the
13 information fed from the remote end.
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15 This command is usually not invoked directly by the end user. The UI
16 for the protocol is on the git send-pack side, and the program pair is
17 meant to be used to push updates to remote repository. For pull
18 operations, see git-fetch-pack(1).
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20 The command allows for creation and fast-forwarding of sha1 refs
21 (heads/tags) on the remote end (strictly speaking, it is the local end
22 git-receive-pack runs, but to the user who is sitting at the send-pack
23 end, it is updating the remote. Confused?)
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25 There are other real-world examples of using update and post-update
26 hooks found in the Documentation/howto directory.
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28 git-receive-pack honours the receive.denyNonFastForwards config option,
29 which tells it if updates to a ref should be denied if they are not
30 fast-forwards.
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32 A number of other receive.* config options are available to tweak its
33 behavior, see git-config(1).
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36 <directory>
37 The repository to sync into.
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40 Before any ref is updated, if $GIT_DIR/hooks/pre-receive file exists
41 and is executable, it will be invoked once with no parameters. The
42 standard input of the hook will be one line per ref to be updated:
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44 sha1-old SP sha1-new SP refname LF
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46 The refname value is relative to $GIT_DIR; e.g. for the master head
47 this is "refs/heads/master". The two sha1 values before each refname
48 are the object names for the refname before and after the update. Refs
49 to be created will have sha1-old equal to 0{40}, while refs to be
50 deleted will have sha1-new equal to 0{40}, otherwise sha1-old and
51 sha1-new should be valid objects in the repository.
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53 When accepting a signed push (see git-push(1)), the signed push
54 certificate is stored in a blob and an environment variable
55 GIT_PUSH_CERT can be consulted for its object name. See the description
56 of post-receive hook for an example. In addition, the certificate is
57 verified using GPG and the result is exported with the following
58 environment variables:
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60 GIT_PUSH_CERT_SIGNER
61 The name and the e-mail address of the owner of the key that signed
62 the push certificate.
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64 GIT_PUSH_CERT_KEY
65 The GPG key ID of the key that signed the push certificate.
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67 GIT_PUSH_CERT_STATUS
68 The status of GPG verification of the push certificate, using the
69 same mnemonic as used in %G? format of git log family of commands
70 (see git-log(1)).
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72 GIT_PUSH_CERT_NONCE
73 The nonce string the process asked the signer to include in the
74 push certificate. If this does not match the value recorded on the
75 "nonce" header in the push certificate, it may indicate that the
76 certificate is a valid one that is being replayed from a separate
77 "git push" session.
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79 GIT_PUSH_CERT_NONCE_STATUS
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81 UNSOLICITED
82 "git push --signed" sent a nonce when we did not ask it to send
83 one.
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85 MISSING
86 "git push --signed" did not send any nonce header.
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88 BAD
89 "git push --signed" sent a bogus nonce.
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91 OK
92 "git push --signed" sent the nonce we asked it to send.
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94 SLOP
95 "git push --signed" sent a nonce different from what we asked
96 it to send now, but in a previous session. See
97 GIT_PUSH_CERT_NONCE_SLOP environment variable.
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99 GIT_PUSH_CERT_NONCE_SLOP
100 "git push --signed" sent a nonce different from what we asked it to
101 send now, but in a different session whose starting time is
102 different by this many seconds from the current session. Only
103 meaningful when GIT_PUSH_CERT_NONCE_STATUS says SLOP. Also read
104 about receive.certNonceSlop variable in git-config(1).
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106 This hook is called before any refname is updated and before any
107 fast-forward checks are performed.
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109 If the pre-receive hook exits with a non-zero exit status no updates
110 will be performed, and the update, post-receive and post-update hooks
111 will not be invoked either. This can be useful to quickly bail out if
112 the update is not to be supported.
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114 See the notes on the quarantine environment below.
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117 Before each ref is updated, if $GIT_DIR/hooks/update file exists and is
118 executable, it is invoked once per ref, with three parameters:
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120 $GIT_DIR/hooks/update refname sha1-old sha1-new
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122 The refname parameter is relative to $GIT_DIR; e.g. for the master head
123 this is "refs/heads/master". The two sha1 arguments are the object
124 names for the refname before and after the update. Note that the hook
125 is called before the refname is updated, so either sha1-old is 0{40}
126 (meaning there is no such ref yet), or it should match what is recorded
127 in refname.
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129 The hook should exit with non-zero status if it wants to disallow
130 updating the named ref. Otherwise it should exit with zero.
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132 Successful execution (a zero exit status) of this hook does not ensure
133 the ref will actually be updated, it is only a prerequisite. As such it
134 is not a good idea to send notices (e.g. email) from this hook.
135 Consider using the post-receive hook instead.
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138 After all refs were updated (or attempted to be updated), if any ref
139 update was successful, and if $GIT_DIR/hooks/post-receive file exists
140 and is executable, it will be invoked once with no parameters. The
141 standard input of the hook will be one line for each successfully
142 updated ref:
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144 sha1-old SP sha1-new SP refname LF
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146 The refname value is relative to $GIT_DIR; e.g. for the master head
147 this is "refs/heads/master". The two sha1 values before each refname
148 are the object names for the refname before and after the update. Refs
149 that were created will have sha1-old equal to 0{40}, while refs that
150 were deleted will have sha1-new equal to 0{40}, otherwise sha1-old and
151 sha1-new should be valid objects in the repository.
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153 The GIT_PUSH_CERT* environment variables can be inspected, just as in
154 pre-receive hook, after accepting a signed push.
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156 Using this hook, it is easy to generate mails describing the updates to
157 the repository. This example script sends one mail message per ref
158 listing the commits pushed to the repository, and logs the push
159 certificates of signed pushes with good signatures to a logger service:
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161 #!/bin/sh
162 # mail out commit update information.
163 while read oval nval ref
164 do
165 if expr "$oval" : '0*$' >/dev/null
166 then
167 echo "Created a new ref, with the following commits:"
168 git rev-list --pretty "$nval"
169 else
170 echo "New commits:"
171 git rev-list --pretty "$nval" "^$oval"
172 fi |
173 mail -s "Changes to ref $ref" commit-list@mydomain
174 done
175 # log signed push certificate, if any
176 if test -n "${GIT_PUSH_CERT-}" && test ${GIT_PUSH_CERT_STATUS} = G
177 then
178 (
179 echo expected nonce is ${GIT_PUSH_NONCE}
180 git cat-file blob ${GIT_PUSH_CERT}
181 ) | mail -s "push certificate from $GIT_PUSH_CERT_SIGNER" push-log@mydomain
182 fi
183 exit 0
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185 The exit code from this hook invocation is ignored, however a non-zero
186 exit code will generate an error message.
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188 Note that it is possible for refname to not have sha1-new when this
189 hook runs. This can easily occur if another user modifies the ref after
190 it was updated by git-receive-pack, but before the hook was able to
191 evaluate it. It is recommended that hooks rely on sha1-new rather than
192 the current value of refname.
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195 After all other processing, if at least one ref was updated, and if
196 $GIT_DIR/hooks/post-update file exists and is executable, then
197 post-update will be called with the list of refs that have been
198 updated. This can be used to implement any repository wide cleanup
199 tasks.
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201 The exit code from this hook invocation is ignored; the only thing left
202 for git-receive-pack to do at that point is to exit itself anyway.
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204 This hook can be used, for example, to run git update-server-info if
205 the repository is packed and is served via a dumb transport.
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207 #!/bin/sh
208 exec git update-server-info
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211 When receive-pack takes in objects, they are placed into a temporary
212 "quarantine" directory within the $GIT_DIR/objects directory and
213 migrated into the main object store only after the pre-receive hook has
214 completed. If the push fails before then, the temporary directory is
215 removed entirely.
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217 This has a few user-visible effects and caveats:
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219 1. Pushes which fail due to problems with the incoming pack, missing
220 objects, or due to the pre-receive hook will not leave any on-disk
221 data. This is usually helpful to prevent repeated failed pushes
222 from filling up your disk, but can make debugging more challenging.
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224 2. Any objects created by the pre-receive hook will be created in the
225 quarantine directory (and migrated only if it succeeds).
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227 3. The pre-receive hook MUST NOT update any refs to point to
228 quarantined objects. Other programs accessing the repository will
229 not be able to see the objects (and if the pre-receive hook fails,
230 those refs would become corrupted). For safety, any ref updates
231 from within pre-receive are automatically rejected.
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234 git-send-pack(1), gitnamespaces(7)
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237 Part of the git(1) suite
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241Git 2.31.1 2021-03-26 GIT-RECEIVE-PACK(1)