目录
changegroup
—增加远程修改集之后commit
—创建新修改集之后incoming
—增加远程修改集之后outgoing
—传播修改集之后prechangegroup
—增加远程修改集之前precommit
—提交修改集之前preoutgoing
—传播修改集之前pretag
—创建标签之前pretxnchangegroup
—完成增加远程修改集之前pretxncommit
—完成提交之前preupdate
—更新或合并工作目录之前tag
—创建标签之后update
—更新或合并工作目录之后Mercurial offers a powerful mechanism to let you perform automated actions in response to events that occur in a repository. In some cases, you can even control Mercurial's response to those events.
The name Mercurial uses for one of these actions is a hook. Hooks are called “triggers” in some revision control systems, but the two names refer to the same idea.
Here is a brief list of the hooks that Mercurial supports. We will revisit each of these hooks in more detail later, in 第 10.7 节 “编写钩子的信息”.
Each of the hooks whose description begins with the word “Controlling” has the ability to determine whether an activity can proceed. If the hook succeeds, the activity may proceed; if it fails, the activity is either not permitted or undone, depending on the hook.
changegroup
: This is run after a group of
changesets has been brought into the repository from elsewhere.
commit
: This is run after a new changeset has
been created in the local repository.
incoming
: This is run once for each new
changeset that is brought into the repository from elsewhere. Notice the
difference from changegroup
, which is run
once per group of changesets brought in.
outgoing
: This is run after a group of
changesets has been transmitted from this repository.
prechangegroup
: This is run before starting
to bring a group of changesets into the repository.
precommit
: Controlling. This is run before
starting a commit.
preoutgoing
: Controlling. This is run before
starting to transmit a group of changesets from this repository.
pretxnchangegroup
: Controlling. This is run
after a group of changesets has been brought into the local repository from
another, but before the transaction completes that will make the changes
permanent in the repository.
pretxncommit
: Controlling. This is run after
a new changeset has been created in the local repository, but before the
transaction completes that will make it permanent.
preupdate
: Controlling. This is run before
starting an update or merge of the working directory.
update
: This is run after an update or merge
of the working directory has finished.
When you run a Mercurial command in a repository, and the command causes a hook to run, that hook runs on your system, under your user account, with your privilege level. Since hooks are arbitrary pieces of executable code, you should treat them with an appropriate level of suspicion. Do not install a hook unless you are confident that you know who created it and what it does.
In some cases, you may be exposed to hooks that you did not install
yourself. If you work with Mercurial on an unfamiliar system, Mercurial
will run hooks defined in that system's global ~/.hgrc
file.
If you are working with a repository owned by another user, Mercurial can
run hooks defined in that user's repository, but it will still run them as
“you”. For example, if you hg
pull from that repository, and its .hg/hgrc
defines a local outgoing
hook, that hook will run under your user
account, even though you don't own that repository.
To see what hooks are defined in a repository, use the hg showconfig hooks command. If you are working in one repository, but talking to another that you do not own (e.g. using hg pull or hg incoming), remember that it is the other repository's hooks you should be checking, not your own.
In Mercurial, hooks are not revision controlled, and do not propagate when you clone, or pull from, a repository. The reason for this is simple: a hook is a completely arbitrary piece of executable code. It runs under your user identity, with your privilege level, on your machine.
It would be extremely reckless for any distributed revision control system to implement revision-controlled hooks, as this would offer an easily exploitable way to subvert the accounts of users of the revision control system.
Since Mercurial does not propagate hooks, if you are collaborating with other people on a common project, you should not assume that they are using the same Mercurial hooks as you are, or that theirs are correctly configured. You should document the hooks you expect people to use.
In a corporate intranet, this is somewhat easier to control, as you can for
example provide a “standard” installation of Mercurial on an
NFS filesystem, and use a site-wide ~/.hgrc
file to define hooks that all users will
see. However, this too has its limits; see below.
Mercurial allows you to override a hook definition by redefining the hook. You can disable it by setting its value to the empty string, or change its behavior as you wish.
If you deploy a system- or site-wide ~/.hgrc
file that defines some hooks, you should
thus understand that your users can disable or override those hooks.
Sometimes you may want to enforce a policy that you do not want others to be
able to work around. For example, you may have a requirement that every
changeset must pass a rigorous set of tests. Defining this requirement via
a hook in a site-wide ~/.hgrc
won't work
for remote users on laptops, and of course local users can subvert it at
will by overriding the hook.
Instead, you can set up your policies for use of Mercurial so that people are expected to propagate changes through a well-known “canonical” server that you have locked down and configured appropriately.
One way to do this is via a combination of social engineering and technology. Set up a restricted-access account; users can push changes over the network to repositories managed by this account, but they cannot log into the account and run normal shell commands. In this scenario, a user can commit a changeset that contains any old garbage they want.
When someone pushes a changeset to the server that everyone pulls from, the server will test the changeset before it accepts it as permanent, and reject it if it fails to pass the test suite. If people only pull changes from this filtering server, it will serve to ensure that all changes that people pull have been automatically vetted.
It is easy to write a Mercurial hook. Let's start with a hook that runs
when you finish a hg commit, and simply
prints the hash of the changeset you just created. The hook is called
commit
.
All hooks follow the pattern in this example.
$
hg init hook-test
$
cd hook-test
$
echo '[hooks]' >> .hg/hgrc
$
echo 'commit = echo committed $HG_NODE' >> .hg/hgrc
$
cat .hg/hgrc
[hooks] commit = echo committed $HG_NODE$
echo a > a
$
hg add a
$
hg commit -m 'testing commit hook'
committed c79dd86aa70ed92447baffeceda6acd3ce878982
You add an entry to the hooks
section of
your ~/.hgrc
. On the left is the name
of the event to trigger on; on the right is the action to take. As you can
see, you can run an arbitrary shell command in a hook. Mercurial passes
extra information to the hook using environment variables (look for
HG_NODE
in the example).
Quite often, you will want to define more than one hook for a particular kind of event, as shown below.
$
echo 'commit.when = echo -n "date of commit: "; date' >> .hg/hgrc
$
echo a >> a
$
hg commit -m 'i have two hooks'
committed 54f1f1437586a510d8df6076c89ec9976098c392 date of commit: Fri Oct 23 01:37:52 GMT 2009
Mercurial lets you do this by adding an extension to
the end of a hook's name. You extend a hook's name by giving the name of
the hook, followed by a full stop (the “.
”
character), followed by some more text of your choosing. For example,
Mercurial will run both commit.foo
and
commit.bar
when the commit
event
occurs.
To give a well-defined order of execution when there are multiple hooks
defined for an event, Mercurial sorts hooks by extension, and executes the
hook commands in this sorted order. In the above example, it will execute
commit.bar
before commit.foo
, and
commit
before both.
It is a good idea to use a somewhat descriptive extension when you define a new hook. This will help you to remember what the hook was for. If the hook fails, you'll get an error message that contains the hook name and extension, so using a descriptive extension could give you an immediate hint as to why the hook failed (see 第 10.3.2 节 “控制处理的活动” for an example).
In our earlier examples, we used the commit
hook, which is run after a commit has completed. This is one of several
Mercurial hooks that run after an activity finishes. Such hooks have no way
of influencing the activity itself.
Mercurial defines a number of events that occur before an activity starts; or after it starts, but before it finishes. Hooks that trigger on these events have the added ability to choose whether the activity can continue, or will abort.
The pretxncommit
hook runs after a commit has
all but completed. In other words, the metadata representing the changeset
has been written out to disk, but the transaction has not yet been allowed
to complete. The pretxncommit
hook has the
ability to decide whether the transaction can complete, or must be rolled
back.
If the pretxncommit
hook exits with a status
code of zero, the transaction is allowed to complete; the commit finishes;
and the commit
hook is run. If the pretxncommit
hook exits with a non-zero status code,
the transaction is rolled back; the metadata representing the changeset is
erased; and the commit
hook is not run.
$
cat check_bug_id
#!/bin/sh # check that a commit comment mentions a numeric bug id hg log -r $1 --template {desc} | grep -q "\<bug *[0-9]"$
echo 'pretxncommit.bug_id_required = ./check_bug_id $HG_NODE' >> .hg/hgrc
$
echo a >> a
$
hg commit -m 'i am not mentioning a bug id'
transaction abort! rollback completed abort: pretxncommit.bug_id_required hook exited with status 1$
hg commit -m 'i refer you to bug 666'
committed 4d5d46af37128acd6bb745048a3fd9a028ca9946 date of commit: Fri Oct 23 01:37:52 GMT 2009
The hook in the example above checks that a commit comment contains a bug ID. If it does, the commit can complete. If not, the commit is rolled back.
When you are writing a hook, you might find it useful to run Mercurial
either with the -v
option, or the
verbose
config item set to
“true”. When you do so, Mercurial will print a message before
it calls each hook.
You can write a hook either as a normal program—typically a shell script—or as a Python function that is executed within the Mercurial process.
Writing a hook as an external program has the advantage that it requires no knowledge of Mercurial's internals. You can call normal Mercurial commands to get any added information you need. The trade-off is that external hooks are slower than in-process hooks.
An in-process Python hook has complete access to the Mercurial API, and does not “shell out” to another process, so it is inherently faster than an external hook. It is also easier to obtain much of the information that a hook requires by using the Mercurial API than by running Mercurial commands.
If you are comfortable with Python, or require high performance, writing your hooks in Python may be a good choice. However, when you have a straightforward hook to write and you don't need to care about performance (probably the majority of hooks), a shell script is perfectly fine.
Mercurial calls each hook with a set of well-defined parameters. In Python, a parameter is passed as a keyword argument to your hook function. For an external program, a parameter is passed as an environment variable.
Whether your hook is written in Python or as a shell script, the
hook-specific parameter names and values will be the same. A boolean
parameter will be represented as a boolean value in Python, but as the
number 1 (for “true”) or 0 (for “false”) as an
environment variable for an external hook. If a hook parameter is named
foo
, the keyword argument for a Python hook will also be
named foo
, while the environment variable for an external
hook will be named HG_FOO
.
A hook that executes successfully must exit with a status of zero if external, or return boolean “false” if in-process. Failure is indicated with a non-zero exit status from an external hook, or an in-process hook returning boolean “true”. If an in-process hook raises an exception, the hook is considered to have failed.
For a hook that controls whether an activity can proceed, zero/false means “allow”, while non-zero/true/exception means “deny”.
When you define an external hook in your ~/.hgrc
and the hook is run, its value is passed
to your shell, which interprets it. This means that you can use normal
shell constructs in the body of the hook.
An executable hook is always run with its current directory set to a repository's root directory.
Each hook parameter is passed in as an environment variable; the name is
upper-cased, and prefixed with the string
“HG_
”.
With the exception of hook parameters, Mercurial does not set or modify any environment variables when running a hook. This is useful to remember if you are writing a site-wide hook that may be run by a number of different users with differing environment variables set. In multi-user situations, you should not rely on environment variables being set to the values you have in your environment when testing the hook.
The ~/.hgrc
syntax for defining an
in-process hook is slightly different than for an executable hook. The
value of the hook must start with the text
“python:
”, and continue with the
fully-qualified name of a callable object to use as the hook's value.
The module in which a hook lives is automatically imported when a hook is
run. So long as you have the module name and PYTHONPATH
right, it should “just work”.
The following ~/.hgrc
example snippet
illustrates the syntax and meaning of the notions we just described.
[hooks] commit.example = python:mymodule.submodule.myhook
When Mercurial runs the commit.example
hook, it imports
mymodule.submodule
, looks for the callable object named
myhook
, and calls it.
The simplest in-process hook does nothing, but illustrates the basic shape of the hook API:
def myhook(ui, repo, **kwargs): pass
The first argument to a Python hook is always a ui
object. The second is a repository
object; at the moment, it is always an instance of localrepository
. Following
these two arguments are other keyword arguments. Which ones are passed in
depends on the hook being called, but a hook can ignore arguments it doesn't
care about by dropping them into a keyword argument dict, as with
**kwargs
above.
It's hard to imagine a useful commit message being very short. The simple
pretxncommit
hook of the example below will
prevent you from committing a changeset with a message that is less than ten
bytes long.
$
cat .hg/hgrc
[hooks] pretxncommit.msglen = test `hg tip --template {desc} | wc -c` -ge 10$
echo a > a
$
hg add a
$
hg commit -A -m 'too short'
transaction abort! rollback completed abort: pretxncommit.msglen hook exited with status 1$
hg commit -A -m 'long enough'
An interesting use of a commit-related hook is to help you to write cleaner code. A simple example of “cleaner code” is the dictum that a change should not add any new lines of text that contain “trailing whitespace”. Trailing whitespace is a series of space and tab characters at the end of a line of text. In most cases, trailing whitespace is unnecessary, invisible noise, but it is occasionally problematic, and people often prefer to get rid of it.
You can use either the precommit
or pretxncommit
hook to tell whether you have a trailing
whitespace problem. If you use the precommit
hook, the hook will not know which files you are committing, so it will have
to check every modified file in the repository for trailing white space. If
you want to commit a change to just the file foo
, but
the file bar
contains trailing whitespace, doing a
check in the precommit
hook will prevent you
from committing foo
due to the problem with
bar
. This doesn't seem right.
Should you choose the pretxncommit
hook, the
check won't occur until just before the transaction for the commit
completes. This will allow you to check for problems only the exact files
that are being committed. However, if you entered the commit message
interactively and the hook fails, the transaction will roll back; you'll
have to re-enter the commit message after you fix the trailing whitespace
and run hg commit again.
$
cat .hg/hgrc
[hooks] pretxncommit.whitespace = hg export tip | (! egrep -q '^\+.*[ \t]$')$
echo 'a ' > a
$
hg commit -A -m 'test with trailing whitespace'
adding a transaction abort! rollback completed abort: pretxncommit.whitespace hook exited with status 1$
echo 'a' > a
$
hg commit -A -m 'drop trailing whitespace and try again'
In this example, we introduce a simple pretxncommit
hook that checks for trailing
whitespace. This hook is short, but not very helpful. It exits with an
error status if a change adds a line with trailing whitespace to any file,
but does not print any information that might help us to identify the
offending file or line. It also has the nice property of not paying
attention to unmodified lines; only lines that introduce new trailing
whitespace cause problems.
#!/usr/bin/env python # # save as .hg/check_whitespace.py and make executable import re def trailing_whitespace(difflines): # linenum, header = 0, False for line in difflines: if header: # remember the name of the file that this diff affects m = re.match(r'(?:---|\+\+\+) ([^\t]+)', line) if m and m.group(1) != '/dev/null': filename = m.group(1).split('/', 1)[-1] if line.startswith('+++ '): header = False continue if line.startswith('diff '): header = True continue # hunk header - save the line number m = re.match(r'@@ -\d+,\d+ \+(\d+),', line) if m: linenum = int(m.group(1)) continue # hunk body - check for an added line with trailing whitespace m = re.match(r'\+.*\s$', line) if m: yield filename, linenum if line and line[0] in ' +': linenum += 1 if __name__ == '__main__': import os, sys added = 0 for filename, linenum in trailing_whitespace(os.popen('hg export tip')): print >> sys.stderr, ('%s, line %d: trailing whitespace added' % (filename, linenum)) added += 1 if added: # save the commit message so we don't need to retype it os.system('hg tip --template "{desc}" > .hg/commit.save') print >> sys.stderr, 'commit message saved to .hg/commit.save' sys.exit(1)
The above version is much more complex, but also more useful. It parses a
unified diff to see if any lines add trailing whitespace, and prints the
name of the file and the line number of each such occurrence. Even better,
if the change adds trailing whitespace, this hook saves the commit comment
and prints the name of the save file before exiting and telling Mercurial to
roll the transaction back, so you can use the -l filename
option to hg commit to reuse the saved commit message once
you've corrected the problem.
$
cat .hg/hgrc
[hooks] pretxncommit.whitespace = .hg/check_whitespace.py$
echo 'a ' >> a
$
hg commit -A -m 'add new line with trailing whitespace'
a, line 2: trailing whitespace added commit message saved to .hg/commit.save transaction abort! rollback completed abort: pretxncommit.whitespace hook exited with status 1$
sed -i 's, *$,,' a
$
hg commit -A -m 'trimmed trailing whitespace'
a, line 2: trailing whitespace added commit message saved to .hg/commit.save transaction abort! rollback completed abort: pretxncommit.whitespace hook exited with status 1
As a final aside, note in the example above the use of sed's in-place editing feature to get rid of trailing whitespace from a file. This is concise and useful enough that I will reproduce it here (using perl for good measure).
perl -pi -e 's,\s+$,,' filename
Mercurial ships with several bundled hooks. You can find them in the
hgext
directory of a Mercurial source
tree. If you are using a Mercurial binary package, the hooks will be
located in the hgext
directory of
wherever your package installer put Mercurial.
The acl
extension lets you control which
remote users are allowed to push changesets to a networked server. You can
protect any portion of a repository (including the entire repo), so that a
specific remote user can push changes that do not affect the protected
portion.
This extension implements access control based on the identity of the user performing a push, not on who committed the changesets they're pushing. It makes sense to use this hook only if you have a locked-down server environment that authenticates remote users, and you want to be sure that only specific users are allowed to push changes to that server.
In order to manage incoming changesets, the acl
hook must be used as a pretxnchangegroup
hook. This lets it see which files
are modified by each incoming changeset, and roll back a group of changesets
if they modify “forbidden” files. Example:
[hooks] pretxnchangegroup.acl = python:hgext.acl.hook
The acl
extension is configured using three
sections.
The acl
section has only one entry, sources
, which lists the sources of incoming
changesets that the hook should pay attention to. You don't normally need
to configure this section.
serve
: Control incoming changesets that
are arriving from a remote repository over http or ssh. This is the default
value of sources
, and usually the only
setting you'll need for this configuration item.
pull
: Control incoming changesets that are
arriving via a pull from a local repository.
push
: Control incoming changesets that are
arriving via a push from a local repository.
bundle
: Control incoming changesets that
are arriving from another repository via a bundle.
The acl.allow
section controls the
users that are allowed to add changesets to the repository. If this section
is not present, all users that are not explicitly denied are allowed. If
this section is present, all users that are not explicitly allowed are
denied (so an empty section means that all users are denied).
The acl.deny
section determines which
users are denied from adding changesets to the repository. If this section
is not present or is empty, no users are denied.
The syntaxes for the acl.allow
and
acl.deny
sections are identical. On
the left of each entry is a glob pattern that matches files or directories,
relative to the root of the repository; on the right, a user name.
In the following example, the user docwriter
can only
push changes to the docs
subtree of
the repository, while intern
can push changes to any file
or directory except source/sensitive
.
[acl.allow] docs/** = docwriter [acl.deny] source/sensitive/** = intern
If you want to test the acl
hook, run it
with Mercurial's debugging output enabled. Since you'll probably be running
it on a server where it's not convenient (or sometimes possible) to pass in
the --debug
option, don't forget that
you can enable debugging output in your ~/.hgrc
:
[ui] debug = true
With this enabled, the acl
hook will print
enough information to let you figure out why it is allowing or forbidding
pushes from specific users.
The bugzilla
extension adds a comment to a
Bugzilla bug whenever it finds a reference to that bug ID in a commit
comment. You can install this hook on a shared server, so that any time a
remote user pushes changes to this server, the hook gets run.
It adds a comment to the bug that looks like this (you can configure the contents of the comment—see below):
Changeset aad8b264143a, made by Joe User <joe.user@domain.com> in the frobnitz repository, refers to this bug. For complete details, see http://hg.domain.com/frobnitz?cmd=changeset;node=aad8b264143a Changeset description: Fix bug 10483 by guarding against some NULL pointers
The value of this hook is that it automates the process of updating a bug any time a changeset refers to it. If you configure the hook properly, it makes it easy for people to browse straight from a Bugzilla bug to a changeset that refers to that bug.
You can use the code in this hook as a starting point for some more exotic Bugzilla integration recipes. Here are a few possibilities:
Require that every changeset pushed to the server have a valid bug ID in its
commit comment. In this case, you'd want to configure the hook as a
pretxncommit
hook. This would allow the hook
to reject changes that didn't contain bug IDs.
Allow incoming changesets to automatically modify the state of a bug, as well as simply adding a comment. For example, the hook could recognise the string “fixed bug 31337” as indicating that it should update the state of bug 31337 to “requires testing”.
You should configure this hook in your server's ~/.hgrc
as an incoming
hook, for example as follows:
[hooks] incoming.bugzilla = python:hgext.bugzilla.hook
Because of the specialised nature of this hook, and because Bugzilla was not written with this kind of integration in mind, configuring this hook is a somewhat involved process.
Before you begin, you must install the MySQL bindings for Python on the host(s) where you'll be running the hook. If this is not available as a binary package for your system, you can download it from [web:mysql-python].
Configuration information for this hook lives in the bugzilla
section of your ~/.hgrc
.
version
: The version of Bugzilla
installed on the server. The database schema that Bugzilla uses changes
occasionally, so this hook has to know exactly which schema to use.
host
: The hostname of the MySQL
server that stores your Bugzilla data. The database must be configured to
allow connections from whatever host you are running the bugzilla
hook on.
user
: The username with which to
connect to the MySQL server. The database must be configured to allow this
user to connect from whatever host you are running the bugzilla
hook on. This user must be able to access
and modify Bugzilla tables. The default value of this item is
bugs
, which is the standard name of the Bugzilla user in
a MySQL database.
password
: The MySQL password for the
user you configured above. This is stored as plain text, so you should make
sure that unauthorised users cannot read the ~/.hgrc
file where you store this information.
db
: The name of the Bugzilla database
on the MySQL server. The default value of this item is
bugs
, which is the standard name of the MySQL database
where Bugzilla stores its data.
notify
: If you want Bugzilla to send
out a notification email to subscribers after this hook has added a comment
to a bug, you will need this hook to run a command whenever it updates the
database. The command to run depends on where you have installed Bugzilla,
but it will typically look something like this, if you have Bugzilla
installed in /var/www/html/bugzilla
:
cd /var/www/html/bugzilla && ./processmail %s nobody@nowhere.com
The Bugzilla processmail
program expects to be given a
bug ID (the hook replaces “%s
” with the bug
ID) and an email address. It also expects to be able to write to some
files in the directory that it runs in. If Bugzilla and this hook are not
installed on the same machine, you will need to find a way to run
processmail
on the server where Bugzilla is installed.
By default, the bugzilla
hook tries to use
the email address of a changeset's committer as the Bugzilla user name with
which to update a bug. If this does not suit your needs, you can map
committer email addresses to Bugzilla user names using a usermap
section.
Each item in the usermap
section
contains an email address on the left, and a Bugzilla user name on the
right.
[usermap] jane.user@example.com = jane
You can either keep the usermap
data in
a normal ~/.hgrc
, or tell the bugzilla
hook to read the information from an
external usermap
file. In the latter case, you can
store usermap
data by itself in (for example) a
user-modifiable repository. This makes it possible to let your users
maintain their own usermap
entries.
The main ~/.hgrc
file might look like
this:
# regular hgrc file refers to external usermap file [bugzilla] usermap = /home/hg/repos/userdata/bugzilla-usermap.conf
While the usermap
file that it refers to might look
like this:
# bugzilla-usermap.conf - inside a hg repository [usermap] stephanie@example.com = steph
You can configure the text that this hook adds as a comment; you specify it
in the form of a Mercurial template. Several ~/.hgrc
entries (still in the bugzilla
section) control this behavior.
strip
: The number of leading path elements to strip from
a repository's path name to construct a partial path for a URL. For example,
if the repositories on your server live under /home/hg/repos
, and you have a repository whose
path is /home/hg/repos/app/tests
,
then setting strip
to 4
will give a
partial path of app/tests
. The hook
will make this partial path available when expanding a template, as
webroot
.
template
: The text of the template to use. In addition
to the usual changeset-related variables, this template can use
hgweb
(the value of the hgweb
configuration item above) and webroot
(the path
constructed using strip
above).
In addition, you can add a baseurl
item to
the web
section of your ~/.hgrc
. The bugzilla
hook will make this available when
expanding a template, as the base string to use when constructing a URL that
will let users browse from a Bugzilla comment to view a changeset. Example:
[web] baseurl = http://hg.domain.com/
Here is an example set of bugzilla
hook
config information.
[bugzilla] host = bugzilla.example.com password = mypassword version = 2.16 # server-side repos live in /home/hg/repos, so strip 4 leading # separators strip = 4 hgweb = http://hg.example.com/ usermap = /home/hg/repos/notify/bugzilla.conf template = Changeset {node|short}, made by {author} in the {webroot} repo, refers to this bug.\n For complete details, see {hgweb}{webroot}?cmd=changeset;node={node|short}\n Changeset description:\n \t{desc|tabindent}
The most common problems with configuring the bugzilla
hook relate to running Bugzilla's
processmail
script and mapping committer names to user
names.
Recall from 第 10.6.2.1 节 “配置 bugzilla
钩子” above that the user
that runs the Mercurial process on the server is also the one that will run
the processmail
script. The
processmail
script sometimes causes Bugzilla to write
to files in its configuration directory, and Bugzilla's configuration files
are usually owned by the user that your web server runs under.
You can cause processmail
to be run with the suitable
user's identity using the sudo command. Here is an
example entry for a sudoers
file.
hg_user = (httpd_user) NOPASSWD: /var/www/html/bugzilla/processmail-wrapper %s
This allows the hg_user
user to run a
processmail-wrapper
program under the identity of
httpd_user
.
This indirection through a wrapper script is necessary, because
processmail
expects to be run with its current
directory set to wherever you installed Bugzilla; you can't specify that
kind of constraint in a sudoers
file. The contents of
the wrapper script are simple:
#!/bin/sh cd `dirname $0` && ./processmail "$1" nobody@example.com
It doesn't seem to matter what email address you pass to
processmail
.
If your usermap
is not set up
correctly, users will see an error message from the bugzilla
hook when they push changes to the server.
The error message will look like this:
cannot find bugzilla user id for john.q.public@example.com
What this means is that the committer's address,
john.q.public@example.com
, is not a valid Bugzilla user
name, nor does it have an entry in your usermap
that maps it to a valid Bugzilla user
name.
Although Mercurial's built-in web server provides RSS feeds of changes in
every repository, many people prefer to receive change notifications via
email. The notify
hook lets you send out
notifications to a set of email addresses whenever changesets arrive that
those subscribers are interested in.
As with the bugzilla
hook, the notify
hook is template-driven, so you can customise
the contents of the notification messages that it sends.
By default, the notify
hook includes a diff
of every changeset that it sends out; you can limit the size of the diff, or
turn this feature off entirely. It is useful for letting subscribers review
changes immediately, rather than clicking to follow a URL.
You can set up the notify
hook to send one
email message per incoming changeset, or one per incoming group of
changesets (all those that arrived in a single pull or push).
[hooks] # send one email per group of changes changegroup.notify = python:hgext.notify.hook # send one email per change incoming.notify = python:hgext.notify.hook
Configuration information for this hook lives in the notify
section of a ~/.hgrc
file.
test
: By default, this hook does not
send out email at all; instead, it prints the message that it
would send. Set this item to false
to allow email to be sent. The reason that sending of email is turned off by
default is that it takes several tries to configure this extension exactly
as you would like, and it would be bad form to spam subscribers with a
number of “broken” notifications while you debug your
configuration.
config
: The path to a configuration
file that contains subscription information. This is kept separate from the
main ~/.hgrc
so that you can maintain it
in a repository of its own. People can then clone that repository, update
their subscriptions, and push the changes back to your server.
strip
: The number of leading path
separator characters to strip from a repository's path, when deciding
whether a repository has subscribers. For example, if the repositories on
your server live in /home/hg/repos
,
and notify
is considering a repository
named /home/hg/repos/shared/test
,
setting strip
to 4
will cause notify
to trim the path it
considers down to shared/test
, and it
will match subscribers against that.
template
: The template text to use when
sending messages. This specifies both the contents of the message header
and its body.
maxdiff
: The maximum number of lines of
diff data to append to the end of a message. If a diff is longer than this,
it is truncated. By default, this is set to 300. Set this to
0
to omit diffs from notification emails.
sources
: A list of sources of
changesets to consider. This lets you limit notify
to only sending out email about changes that
remote users pushed into this repository via a server, for example. See
第 10.7.3.1 节 “修改集的来源” for the sources you can specify here.
If you set the baseurl
item in the
web
section, you can use it in a template;
it will be available as webroot
.
Here is an example set of notify
configuration information.
[notify] # really send email test = false # subscriber data lives in the notify repo config = /home/hg/repos/notify/notify.conf # repos live in /home/hg/repos on server, so strip 4 "/" chars strip = 4 template = X-Hg-Repo: {webroot}\n Subject: {webroot}: {desc|firstline|strip}\n From: {author} \n\n changeset {node|short} in {root} \n\ndetails: {baseurl}{webroot}?cmd=changeset;node={node|short} description: {desc|tabindent|strip} [web] baseurl = http://hg.example.com/
This will produce a message that looks like the following:
X-Hg-Repo: tests/slave Subject: tests/slave: Handle error case when slave has no buffers Date: Wed, 2 Aug 2006 15:25:46 -0700 (PDT) changeset 3cba9bfe74b5 in /home/hg/repos/tests/slave details: http://hg.example.com/tests/slave?cmd=changeset;node=3cba9bfe74b5 description: Handle error case when slave has no buffers diffs (54 lines): diff -r 9d95df7cf2ad -r 3cba9bfe74b5 include/tests.h --- a/include/tests.h Wed Aug 02 15:19:52 2006 -0700 +++ b/include/tests.h Wed Aug 02 15:25:26 2006 -0700 @@ -212,6 +212,15 @@ static __inline__ void test_headers(void *h) [...snip...]
An in-process hook is called with arguments of the following form:
def myhook(ui, repo, **kwargs): pass
The ui
parameter is a ui
object. The repo
parameter is a localrepository
object. The
names and values of the **kwargs
parameters depend on the
hook being invoked, with the following common features:
If a parameter is named node
or
parentN
, it will contain a hexadecimal changeset ID. The
empty string is used to represent “null changeset ID” instead
of a string of zeroes.
If a parameter is named url
, it will contain the URL of a
remote repository, if that can be determined.
Boolean-valued parameters are represented as Python bool
objects.
An in-process hook is called without a change to the process's working directory (unlike external hooks, which are run in the root of the repository). It must not change the process's working directory, or it will cause any calls it makes into the Mercurial API to fail.
If a hook returns a boolean “false” value, it is considered to have succeeded. If it returns a boolean “true” value or raises an exception, it is considered to have failed. A useful way to think of the calling convention is “tell me if you fail”.
Note that changeset IDs are passed into Python hooks as hexadecimal strings,
not the binary hashes that Mercurial's APIs normally use. To convert a hash
from hex to binary, use the bin
function.
An external hook is passed to the shell of the user running Mercurial. Features of that shell, such as variable substitution and command redirection, are available. The hook is run in the root directory of the repository (unlike in-process hooks, which are run in the same directory that Mercurial was run in).
Hook parameters are passed to the hook as environment variables. Each
environment variable's name is converted in upper case and prefixed with the
string “HG_
”. For example, if the name of a
parameter is “node
”, the name of the
environment variable representing that parameter will be
“HG_NODE
”.
A boolean parameter is represented as the string
“1
” for “true”,
“0
” for “false”. If an
environment variable is named HG_NODE
,
HG_PARENT1
or HG_PARENT2
, it contains a
changeset ID represented as a hexadecimal string. The empty string is used
to represent “null changeset ID” instead of a string of
zeroes. If an environment variable is named HG_URL
, it will
contain the URL of a remote repository, if that can be determined.
If a hook exits with a status of zero, it is considered to have succeeded. If it exits with a non-zero status, it is considered to have failed.
A hook that involves the transfer of changesets between a local repository and another may be able to find out information about the “far side”. Mercurial knows how changes are being transferred, and in many cases where they are being transferred to or from.
Mercurial will tell a hook what means are, or were, used to transfer
changesets between repositories. This is provided by Mercurial in a Python
parameter named source
, or an environment variable named
HG_SOURCE
.
serve
: Changesets are transferred to or from a remote
repository over http or ssh.
pull
: Changesets are being transferred via a pull from
one repository into another.
push
: Changesets are being transferred via a push from
one repository into another.
bundle
: Changesets are being transferred to or from a
bundle.
When possible, Mercurial will tell a hook the location of the “far
side” of an activity that transfers changeset data between
repositories. This is provided by Mercurial in a Python parameter named
url
, or an environment variable named
HG_URL
.
This information is not always known. If a hook is invoked in a repository that is being served via http or ssh, Mercurial cannot tell where the remote repository is, but it may know where the client is connecting from. In such cases, the URL will take one of the following forms:
This hook is run after a group of pre-existing changesets has been added to
the repository, for example via a hg pull
or hg unbundle. This hook is run once per
operation that added one or more changesets. This is in contrast to the
incoming
hook, which is run once per
changeset, regardless of whether the changesets arrive in a group.
Some possible uses for this hook include kicking off an automated build or test of the added changesets, updating a bug database, or notifying subscribers that a repository contains new changes.
node
: A changeset ID. The changeset ID of the first
changeset in the group that was added. All changesets between this and
tip
, inclusive, were added by a single
hg pull, hg
push or hg unbundle.
source
: A string. The source of these changes. See
第 10.7.3.1 节 “修改集的来源” for details.
url
: A URL. The location of the remote repository, if
known. See 第 10.7.3.2 节 “修改集要到哪里—远程版本库的地址” for more information.
See also: incoming
(第 10.8.3 节 “incoming
—增加远程修改集之后”), prechangegroup
(第 10.8.5 节 “prechangegroup
—增加远程修改集之前”), pretxnchangegroup
(第 10.8.9 节 “pretxnchangegroup
—完成增加远程修改集之前”)
This hook is run after a new changeset has been created.
See also: precommit
(第 10.8.6 节 “precommit
—提交修改集之前”), pretxncommit
(第 10.8.10 节 “pretxncommit
—完成提交之前”)
This hook is run after a pre-existing changeset has been added to the repository, for example via a hg push. If a group of changesets was added in a single operation, this hook is called once for each added changeset.
You can use this hook for the same purposes as the changegroup
hook (第 10.8.1 节 “changegroup
—增加远程修改集之后”); it's simply more convenient sometimes to
run a hook once per group of changesets, while other times it's handier once
per changeset.
source
: A string. The source of these changes. See
第 10.7.3.1 节 “修改集的来源” for details.
url
: A URL. The location of the remote repository, if
known. See 第 10.7.3.2 节 “修改集要到哪里—远程版本库的地址” for more information.
See also: changegroup
(第 10.8.1 节 “changegroup
—增加远程修改集之后”) prechangegroup
(第 10.8.5 节 “prechangegroup
—增加远程修改集之前”), pretxnchangegroup
(第 10.8.9 节 “pretxnchangegroup
—完成增加远程修改集之前”)
This hook is run after a group of changesets has been propagated out of this repository, for example by a hg push or hg bundle command.
One possible use for this hook is to notify administrators that changes have been pulled.
node
: A changeset ID. The changeset ID of the first
changeset of the group that was sent.
source
: A string. The source of the of the operation
(see 第 10.7.3.1 节 “修改集的来源”). If a remote client pulled changes
from this repository, source
will be
serve
. If the client that obtained changes from this
repository was local, source
will be
bundle
, pull
, or
push
, depending on the operation the client performed.
url
: A URL. The location of the remote repository, if
known. See 第 10.7.3.2 节 “修改集要到哪里—远程版本库的地址” for more information.
See also: preoutgoing
(第 10.8.7 节 “preoutgoing
—传播修改集之前”)
This controlling hook is run before Mercurial begins to add a group of changesets from another repository.
This hook does not have any information about the changesets to be added, because it is run before transmission of those changesets is allowed to begin. If this hook fails, the changesets will not be transmitted.
One use for this hook is to prevent external changes from being added to a repository. For example, you could use this to “freeze” a server-hosted branch temporarily or permanently so that users cannot push to it, while still allowing a local administrator to modify the repository.
source
: A string. The source of these changes. See
第 10.7.3.1 节 “修改集的来源” for details.
url
: A URL. The location of the remote repository, if
known. See 第 10.7.3.2 节 “修改集要到哪里—远程版本库的地址” for more information.
See also: changegroup
(第 10.8.1 节 “changegroup
—增加远程修改集之后”), incoming
(第 10.8.3 节 “incoming
—增加远程修改集之后”), pretxnchangegroup
(第 10.8.9 节 “pretxnchangegroup
—完成增加远程修改集之前”)
This hook is run before Mercurial begins to commit a new changeset. It is run before Mercurial has any of the metadata for the commit, such as the files to be committed, the commit message, or the commit date.
One use for this hook is to disable the ability to commit new changesets, while still allowing incoming changesets. Another is to run a build or test, and only allow the commit to begin if the build or test succeeds.
If the commit proceeds, the parents of the working directory will become the parents of the new changeset.
See also: commit
(第 10.8.2 节 “commit
—创建新修改集之后”), pretxncommit
(第 10.8.10 节 “pretxncommit
—完成提交之前”)
This hook is invoked before Mercurial knows the identities of the changesets to be transmitted.
One use for this hook is to prevent changes from being transmitted to another repository.
source
: A string. The source of the operation that is
attempting to obtain changes from this repository (see 第 10.7.3.1 节 “修改集的来源”). See the documentation for the
source
parameter to the outgoing
hook, in 第 10.8.4 节 “outgoing
—传播修改集之后”,
for possible values of this parameter.
url
: A URL. The location of the remote repository, if
known. See 第 10.7.3.2 节 “修改集要到哪里—远程版本库的地址” for more information.
See also: outgoing
(第 10.8.4 节 “outgoing
—传播修改集之后”)
This controlling hook is run before a tag is created. If the hook succeeds, creation of the tag proceeds. If the hook fails, the tag is not created.
If the tag to be created is revision-controlled, the precommit
and pretxncommit
hooks (第 10.8.2 节 “commit
—创建新修改集之后”
and 第 10.8.10 节 “pretxncommit
—完成提交之前”) will also be run.
See also: tag
(第 10.8.12 节 “tag
—创建标签之后”)
This controlling hook is run before a transaction—that manages the addition of a group of new changesets from outside the repository—completes. If the hook succeeds, the transaction completes, and all of the changesets become permanent within this repository. If the hook fails, the transaction is rolled back, and the data for the changesets is erased.
This hook can access the metadata associated with the almost-added changesets, but it should not do anything permanent with this data. It must also not modify the working directory.
While this hook is running, if other Mercurial processes access this repository, they will be able to see the almost-added changesets as if they are permanent. This may lead to race conditions if you do not take steps to avoid them.
This hook can be used to automatically vet a group of changesets. If the hook fails, all of the changesets are “rejected” when the transaction rolls back.
node
: A changeset ID. The changeset ID of the first
changeset in the group that was added. All changesets between this and
tip
, inclusive, were added by a single
hg pull, hg
push or hg unbundle.
source
: A string. The source of these changes. See
第 10.7.3.1 节 “修改集的来源” for details.
url
: A URL. The location of the remote repository, if
known. See 第 10.7.3.2 节 “修改集要到哪里—远程版本库的地址” for more information.
See also: changegroup
(第 10.8.1 节 “changegroup
—增加远程修改集之后”), incoming
(第 10.8.3 节 “incoming
—增加远程修改集之后”), prechangegroup
(第 10.8.5 节 “prechangegroup
—增加远程修改集之前”)
This controlling hook is run before a transaction—that manages a new commit—completes. If the hook succeeds, the transaction completes and the changeset becomes permanent within this repository. If the hook fails, the transaction is rolled back, and the commit data is erased.
This hook can access the metadata associated with the almost-new changeset, but it should not do anything permanent with this data. It must also not modify the working directory.
While this hook is running, if other Mercurial processes access this repository, they will be able to see the almost-new changeset as if it is permanent. This may lead to race conditions if you do not take steps to avoid them.
参见: precommit
(第 10.8.6 节 “precommit
—提交修改集之前”)
This controlling hook is run before an update or merge of the working directory begins. It is run only if Mercurial's normal pre-update checks determine that the update or merge can proceed. If the hook succeeds, the update or merge may proceed; if it fails, the update or merge does not start.
parent1
: A changeset ID. The ID of the parent that the
working directory is to be updated to. If the working directory is being
merged, it will not change this parent.
parent2
: A changeset ID. Only set if the working
directory is being merged. The ID of the revision that the working
directory is being merged with.
See also: update
(第 10.8.13 节 “update
—更新或合并工作目录之后”)
This hook is run after a tag has been created.
If the created tag is revision-controlled, the commit
hook (section 第 10.8.2 节 “commit
—创建新修改集之后”) is run before this hook.
参见: pretag
(第 10.8.8 节 “pretag
—创建标签之前”)
This hook is run after an update or merge of the working directory completes. Since a merge can fail (if the external hgmerge command fails to resolve conflicts in a file), this hook communicates whether the update or merge completed cleanly.
error
: A boolean. Indicates whether the update or merge
completed successfully.
parent1
: A changeset ID. The ID of the parent that the
working directory was updated to. If the working directory was merged, it
will not have changed this parent.
parent2
: A changeset ID. Only set if the working
directory was merged. The ID of the revision that the working directory was
merged with.
See also: preupdate
(第 10.8.11 节 “preupdate
—更新或合并工作目录之前”)