Configuration File Version Control
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We are using Bazaar to track files in /etc on python.org machines. Bazaar, also known as BZR, is a version-control system written in Python.
The home page for Bazaar is at http://bazaar-vcs.org/.
Send questions about the use of Bazaar on python.org to <amk at python.org>.
/etc/ -- various directories tracked /data/ -- initialized but nothing tracked yet
/etc/ -- various directories tracked /data/ -- MoinMoin configuration
/etc/ -- various directories tracked
The command-line interface resembles that of CVS, but the executable is named bzr.
A more detailed introduction to Bazaar's basic features is part of the docs: http://doc.bazaar-vcs.org/bzr.dev/tutorial.htm
To get a list of available subcommands, run bzr help.
To get more details about one particular subcommand, run bzr help <command-name>.
Setting your ID
Bazaar remembers your ID and uses this ID when committing changes. If you're doing stuff as root, this means we won't know who made a particular change.
/usr/bin/bzr is a wrapper script that checks that the ID has been set, reporting an error and stopping when it hasn't been.
To set your ID, set the BZREMAIL environment variable:
To commit a change: bzr commit -m "Add new virtual host" /etc
If you omit the path name, committing will search the entire repository containing the current directory, so you don't need to supply the path if you're currently in /etc. It's OK to commit only a portion of the tree; if you're in /etc/apache2 and do a commit specifying the current directory (bzr commit .), you'll only commit changes in /etc/apache2 and its subdirectories.
To back out an uncommitted change: bzr revert /etc/database.conf restores the last committed version of the file.
The revert subcommand works recursively on directories, so bzr revert /etc will undo all the changes you've made to the configuration files.
What have I changed?
bzr status lists the names of files that are different from the last committed version:
root@matterhorn:/etc# bzr status removed: nanorc added: vnc.conf modified: syslog.conf root@matterhorn:/etc#
To get a diff-style display of changes, use bzr diff:
root@matterhorn:/etc# bzr diff |less === removed file 'nanorc' --- nanorc +++ /dev/null @@ -1,314 +0,0 @@ -## Sample initialization file for GNU nano ... === modified file 'syslog.conf' --- syslog.conf +++ syslog.conf @@ -56,16 +56,3 @@ # *.=debug;*.=info;\ # *.=notice;*.=warn /dev/tty8 -# The named pipe /dev/xconsole is for the `xconsole' utility. To use it, -# you must invoke `xconsole' with the `-file' option: -# -# $ xconsole -file /dev/xconsole [...] -# -# -daemon.*;mail.*;\ - news.crit;news.err;news.notice;\ - *.=debug;*.=info;\ - *.=notice;*.=warn |/dev/xconsole -
The --diff-options switch can be used to change the output of the underlying diff program.
To begin tracking a new configuration file, it must be added to the repository and then committed:
bzr add /etc/database.conf bzr commit -m "Add database config" /etc/
If you delete a tracked file using rm, Bazaar will notice it's gone and remove it from the repository when you commit:
root@matterhorn:/etc# rm database.conf root@matterhorn:/etc# bzr status removed: database.conf root@matterhorn:/etc# bzr commit -m "Remove file" missing database.conf deleted database.conf Committed revision 9. root@matterhorn:/etc#
The bzr rm subcommand stops tracking a file, but does **not** remove the working copy in /etc.
bzr log displays all changes that have been made to the tracked files:
root@bag:/etc# bzr log |less ------------------------------------------------------------ revno: 3 committer: XXX@python.org branch nick: etc timestamp: Sat 2007-03-03 04:14:44 +0100 message: Add Apache files ------------------------------------------------------------ revno: 2 committer: XXX@python.org branch nick: etc timestamp: Sat 2007-03-03 00:16:43 +0100 message: Add a bunch of postfix config files. ...
Initializing a new machine
Here's how to set up the version control on a new system.
1. Initialize the /etc directory as a Bazaar repository.
bzr init /etc
This will create a directory called /etc/.bzr/ that stores the history of changes.
2. Make the 'add' and 'status' subcommands ignore all files by default.
bzr ignore '*'
This prevents a stray bzr add lacking arguments from adding lots and lots of files.
3. Manually add the files you want to track:
bzr add /etc/network/interfaces bzr add /etc/apache2/httpd.conf ...
4. Commit for the first time:
cd /etc bzr commit -m "Record configuration files"