dasscm
dass configuration managment (dasscm) is a simple solution for managing system configuration file with Subversion. It is favored because of its easy setup and low footsprint. It can be easily integrated into Nagios monitoring.
Features
- version file directly on the target system. Keeping track of the Subversion checkout is done automatically in the background
- work with your system id, but checkin files with your Subversion id
- easy status check (checks if all files are checked in). Easy integration into Nagios
Installation Repositories
| package downloads | http://software.opensuse.org/download/package?project=home:dassit&package=dasscm |
| repositories | http://download.opensuse.org/repositories/home:/dassit/ |
| source code | source:dasscm/trunk |
Wording
It is not always easy to get the context of eg. repository, because it can mean "server side svn repository", "package repository", like "RPM repository" or sometimes also your local svn ckeckout. To distinguish between the different terms, we try to use the following terms in a consistent way:
| target system | the system were dasscm is installed and used |
| Subverson server | the system were your SVN repository is hosted |
| system files | config and other files on your system, like /etc/ntp.conf |
| system files managed by dasscm | the part of your system files that has already been checked in to Subversion via dasscm |
| local svn checkout | your local svn checkout on the target system |
| svn repository | the Subversion repository were the "system files managed by dasscm" are versioned |
| package repository | the installation source repository for dasscm |
About
dasscm is a wrapper Perl script around the svn command.
If you're planing to check-in your system configuration files into a Subversion repository, dasscm eases your life.
Instead of copying files from the system to the corresponding local subversion checkout directory and commit them there, you just use:
dasscm login dasscm add /etc/ntp.conf
Missing directories are added automatically.
But the real advantage, compared to plain svn is, that there is the possibility to check, if your local system files have changed against the repository. Just call:
dasscm status
For Nagios NRPE integration use
dasscm check
Pre-Requirements
- an existing empty directory in a subversion repository. Normally you create a new directory of every dasscm installation (like http://mysubversionserver/config/HOSTNAME)
- a user with read permissions to this subversion repository. The username
dasscmis a good choice
Configuration
After installing it is required to configure dasscm.
All configuration changes have to be done in the file /etc/dasscm.conf
Include(source:dasscm/trunk/etc/dasscm.conf, text/plain)
Set the following variables according to your needs:
DASSCM_REPOSITORY_NAME=system-namenormally hostname -fDASSCM_CHECKOUT_USERNAME=dasscmsubversion user with read-only permissions DASSCM_CHECKOUT_PASSWORD=dasscm-passwordsubversion password for $DASSCM_CHECKOUT_USERNAMEDASSCM_SVN_REPOSITORY_BASE=http://your-svn-repository/path/subversion directory in which the $DASSCM_REPOSITORY_NAMEdirectory is located
If it not already exists, you can create your subversion subdirectory by
source /etc/dasscm.conf svn mkdir -m "initial" --no-auth-cache $DASSCM_SVN_REPOSITORY_BASE/$DASSCM_REPOSITORY_NAME
Subcommands
dasscm suppots following subcommands:
add PATH_PROD
add a file to the subversion repository
Unlike the native svn command,
dasscm adds and immediatly submits a file to the subversion repository
blame PATH_REPO
like "svn blame"
check
perform Nagios NRPE conform check
cleanup
internal, used to clean repository checkout
commit PATH_REPO
commit a changed file to the subversion repository
complete CMD
internal, used for bash completion
complete_path
internal, used for bash completion
complete_repopath
internal, used for bash completion
diff PATH_REPO
display the differences between files on the system and the repository
help CMD
print help and usage information
init
initialize local subversion checkout.
This is the first thing to do (after configuring /etc/dasscm.conf)
login USER
user login to Subversion repositoty
ls PATH_REPO
list file from repository
permissions
internal, used to update information about file permissions
revert PATH_REPO
revert local changes back to version from the repository (see diff)
status PATH_REPO
display status information about modified and deleted files.
If no path is given "/" is assumed
(in contract to "svn" with assumes ".")
update PATH_REPO
update local repository checkout
Normally, this is done automatically
login
For convinience use
dasscm login
This opens a shell, where the environment is set to the required values.
add files/directories
For example cups configuration
# it is recommended to check initially check a file before you first edit it. Use the comment "orig" dasscm add -m "orig" /etc/sysconfig/cups # make you changes to /etc/sysconfig/cups dasscm commit -m "my comment about my change" /etc/sysconfig/cups
checkin modified files
dasscm commit -m "my comment about my change" /etc/sysconfig/cups
Note: every "add" also calls "commit", so the command "commit" is not really required
status
dasscm status
store file permissions
on every call of dasscm add/commit als file permissions are evaluated and stored in the file
/etc/permissions.d/dasscm.permissions_backup
restore file permissions
On SUSE system:
cp -a /etc/permissions.d/dasscm.permissions_backup /etc/permissions.d/dasscm.permissions # change all file permissions to the values, that are defined in the file /etc/permissions.d/*.permissions /sbin/conf.d/SuSEconfig.permissions
diff
dasscm diff $filename
shows the differences of a local system file against the file in the local svn checkout.
revert
If a local system file is modified (see dasscm diff)
it can be reverted to the checked in version by
dasscm revert $filename
help
for online-help type
dasscm help
dasscm as non-root user
Using dasscm as non-root user requires sufficient permissions.
- create group
dasscm. Default GID is 4199 chgrp dasscm /etc/dasscm.conf- verify group
dasscmhas read permission on/etc/dasscm.conf
why sudo?
sudo is required to guarantee that the user has access to all files on the target system.
configure dasscm for non-root users
# check if group dasscm is defined (GID 4199 is default) # The group must contain all users that should use dasscm getent group dasscm # read permission on config file chgrp dasscm /etc/dasscm.conf # add sudo rule echo " Defaults env_keep+=DASSCM_USERNAME Defaults env_keep+=DASSCM_PASSWORD dasscm ALL=(ALL) NOPASSWD:/usr/bin/dasscm" >> /etc/sudoers
Also check, that requiretty is disabled.
On SUSE, this is the default, on RedHat it requires modifying the /etc/sudoers.
usage (non-root)
# login dasscm login sudo dasscm status sudo dasscm ls sudo dasscm add <DATEINAME>
Nagios/NRPE Check
Client-side configuration for NRPE.
dasscm comes with config files for nrpe and sudo.
Unfortunally, not all distributions have directories for
/etc/nagios/nrpe.d or /etc/sudoers.d/.
If the distributions does not provide these directories,
dasscm delivers the configs in /usr/share/doc/packages/dasscm/.
In this case, the dasscm configuration must be integrated into the system manually.
When not using the delivered config files at all, it is still possible, to configure the services purely manually:
# nrpe config file CFG=/etc/nagios/nrpe.cfg # get NRPE user NRPE_USER=`sed -n 's/nrpe_user=//p' $CFG` echo "NRPE_USER: $NRPE_USER" # add NRPE_USER sudo rule for dasscm grep -q "dasscm check" /etc/sudoers || echo "$NRPE_USER ALL=(ALL) NOPASSWD:/usr/bin/dasscm check" >> /etc/sudoers # add check_dasscm to NRPE config grep -q dasscm $CFG || echo "command[check_dasscm]=sudo dasscm check" >> $CFG # restart nrpe /etc/init.d/nrpe restart
It is possible to user the dasscm nrpe check without sudo, that file without read-permissions will not be checked
