The DESY Repository Management Tool allows creating nightly snapshots from RedHat/AlmaLinux and/or Ubuntu/Debian repositories.
Many sites (such as DESY) typically "mirror" a whole set of linux repositories to avoid unnecessary network traffic to the original repositories located somewhere on the internet.
The goal of this tool is to allow a way of controlling how the package updates within this mirrors get "released" to different classes of machines managed in a computing center.
The following scenario should give you an idea:
Hosts managed at DESY are split into 3 different classes (Class A, Class B and Class C).
- Class A hosts should get the latest updates directly from the upstream repositories.
- Class B hosts should be a bit "safer", i.e. their repositories are kept a whole week behind the repositories of Class A hosts. In case of a repository being broken, Class A hosts will get broken before Class B hosts. This way you have time to react.
- Class C hosts are even "safer" than Class B, i.e. they stay 2 weeks behind the upstream repositories.
This translates into the following use-case:
- IT Desktops from the Linux-Systems group: configured to the upstream repositories, i.e. always get the latest package updates! (Class A)
- Remaining IT Desktops: 7 days behind the upstream repositories (Class B)
- IT Non-Critical Servers: 7 days behind the upstream repositories (Class B)
- IT Critical Servers: 2 weeks behind the upstream repositories (Class C)
- External Desktops: 2 weeks behind the upstream repositories (Class C)
- External Servers: 2 weeks behind the upstream repositories (Class C)
This tool does not take care of synchronizing the repositories from their original location into a local storage (mirroring). It only takes care of managing the local mirror directories in your repository server.
The management of the repositories is done by creating a "timeline" for each repository. Each timeline contains a defined amount of snapshots from the directory tree of the given repository. The snapshots within the timeline are taken on a nightly basis by simply calling 'cp -al' from the source directory of the repository into the timeline directory. This creates a complete copy of the source directory by hard-linking files into the destination directory. For more infos type 'man cp'. When the maximum amount of snapshots is reached, the oldest snapshot gets deleted. The Class A, Class B and Class C references are simply a bunch of symbolic links which point to the appropriate snapshots.
The whole timeline machinery was written in python and can also be used for other purposes than repository management. The code sections for repository management are isolated and could easily be replaced or discarded without affecting the internal working of the timeline class.
In order to use the repository management tool you just need to clone the git repository and configure the logging options by editing timeline-logging.cfg. This file is a standard python logging configuration file. For more details check out the Logging facility for Python.
The entrypoint is mrepo or python3 -m timeline, every subcommand can be called with --help to show a help dialog:
$ mrepo -h
usage: mrepo [-h] {config,create-default-links,create-link,create-named-snapshot,create-repo,create-snapshot,delete-link,delete-snapshot,rename-link,update-link} ...
positional arguments:
{config,create-default-links,create-link,create-named-snapshot,create-repo,create-snapshot,delete-link,delete-snapshot,rename-link,update-link}
Available subcommands
config Display timeline information or change advanced settings
create-default-links
Create default links
create-link Create a new link
create-named-snapshot
Create a new snapshot which is not kept, stored or managed within the timeline metadata
create-repo Create new repository timeline
create-snapshot Create new snapshot in a repository
delete-snapshot Delete snapshot from a repository
rename-link Rename link in a repository
update-link Update link with new snapshot target
options:
-h, --help show this help message and exit
$ mrepo config --help
usage: mrepo config [-h] [--max-snapshots MAX_SNAPSHOTS] [--excludes EXCLUDES] [--freeze] [--unfreeze] [--consistency-check] repository
positional arguments:
repository Reposity Location
options:
-h, --help show this help message and exit
--max-snapshots MAX_SNAPSHOTS
change the max. amount of snapshots
--excludes EXCLUDES change the list of excludes
--freeze freeze the timeline
--unfreeze unfreeze the timeline
--consistency-check check repository for consistency
examples:
mrepo config /srv/repo/linux/ubuntu.timeline --freeze
mrepo config /srv/repo/linux/ubuntu.timeline --unfreeze
mrepo config /srv/repo/linux/ubuntu.timeline --consistency-check
mrepo config /srv/repo/linux/ubuntu.timeline --max-snapshots=42
Let's try to create a new timeline for a dummy repository...
mrepo create-repo -i dummyrepo /etc/skel /tmp/skel.timeline
In this case our dummy repository is the /etc/skel folder and our destination directory for creating our timeline is /tmp/skel.timeline.
Most probably you will get the following error calling the previous command:
mrepo create-repos -i dummyrepo /etc/skel/ /tmp/skel.timeline
2016-01-06 16:49:30 - Timeline - INFO - configuring timeline [dummyrepo] from source [/etc/skel/] into destination [/tmp/skel.timeline]
2016-01-06 16:49:30 - Timeline.dummyrepo - INFO - creating new snapshot [2016.01.06-164930]
2016-01-06 16:49:30 - Timeline.dummyrepo - INFO - saving current timeline state...
cp: cannot create hard link ‘/tmp/skel.timeline/2016.01.06-164930/.mkshrc’ to ‘/etc/skel/.mkshrc’: Invalid cross-device link
Traceback (most recent call last):
File "mrepo", line 26, in <module>
t.create_snapshot()
File "/afs/desy.de/user/e/engels/work/systems/desyops-git-repos/mrepo/timeline/timeline.py", line 450, in create_snapshot
self._snapshot_copy_by_hardlink( self._source, snapshot_path )
File "/afs/desy.de/user/e/engels/work/systems/desyops-git-repos/mrepo/timeline/timeline.py", line 329, in _snapshot_copy_by_hardlink
subprocess.check_call(['cp', '-al', source_obj, snapshot_path ])
File "/usr/lib/python2.7/subprocess.py", line 540, in check_call
raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['cp', '-al', '/etc/skel/.mkshrc', '/tmp/skel.timeline/2016.01.06-164930']' returned non-zero exit status 1
This means that we are trying to create a repository timeline in a device other than the one where the source directory of your repository is located (/tmp and /etc are mounted as different devices). In other words, you can only create snapshots from a repository within the same device. This is due to the natural constraints of using hard-links in the linux operating system (https://en.wikipedia.org/wiki/Hard_link#Limitations_of_hard_links).
Let's make our dummy example work by creating everything within /tmp.
rm -rf /tmp/skel.timeline
cp -a /etc/skel /tmp/
mrepo create-repository -i dummyrepo /tmp/skel /tmp/skel.timeline
2016-01-07 12:17:21 - Timeline - INFO - configuring timeline [dummyrepo] from source [/tmp/skel] into destination [/tmp/skel.timeline]
2016-01-07 12:17:21 - Timeline.dummyrepo - INFO - creating new snapshot [2016.01.07-121721]
2016-01-07 12:17:21 - Timeline.dummyrepo - INFO - saving current timeline state...
2016-01-07 12:17:21 - Timeline.dummyrepo - INFO - creating new link [upstream] to snapshot [2016.01.07-121721]
2016-01-07 12:17:21 - Timeline.dummyrepo - INFO - saving current timeline state...
2016-01-07 12:17:21 - Timeline.dummyrepo - INFO - creating new link [downstream] to snapshot [2016.01.07-121721]
2016-01-07 12:17:21 - Timeline.dummyrepo - INFO - saving current timeline state...
2016-01-07 12:17:21 - Timeline.dummyrepo - INFO - creating new link [offset003] to snapshot [2016.01.07-121721]
2016-01-07 12:17:21 - Timeline.dummyrepo - INFO - saving current timeline state...
...
That's basically it. We have now created a new repository timeline. Let's have a look:
ls -l /tmp/skel.timeline/
total 8
drwxr-xr-x 2 engels it 4096 Jan 7 12:17 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 downstream -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset003 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset007 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset014 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset021 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset030 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset060 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset090 -> 2016.01.07-121721
-rw-r--r-- 1 engels it 1658 Jan 7 12:17 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 upstream -> 2016.01.07-121721
Since the script was called using the option '-i', it created already an initial snapshot (2016.01.07-121721) and a few symbolic links.
We can of course check if the copy was really done by hard-linking:
stat /tmp/skel/examples.desktop
File: ‘/tmp/skel/examples.desktop’
Size: 8980 Blocks: 24 IO Block: 4096 regular file
Device: 803h/2051d Inode: 109 Links: 2
...
stat /tmp/skel.timeline/2016.01.07-121721/examples.desktop
File: ‘/tmp/skel.timeline/2016.01.07-121721/examples.desktop’
Size: 8980 Blocks: 24 IO Block: 4096 regular file
Device: 803h/2051d Inode: 109 Links: 2
...
Example how to create a new snapshot for the newly created repository:
mrepo create-snapshot /tmp/skel.timeline
2016-01-07 13:54:56 - Timeline - INFO - loading timeline instance from [/tmp/skel.timeline/.timeline]
2016-01-07 13:54:56 - Timeline - INFO - configuring timeline [dummyrepo] from source [/tmp/skel] into destination [/tmp/skel.timeline]
2016-01-07 13:54:56 - Timeline.dummyrepo - INFO - loading timeline state...
2016-01-07 13:54:56 - Timeline.dummyrepo - INFO - timeline state loaded from [/tmp/skel.timeline/.timeline]
2016-01-07 13:54:56 - Timeline.dummyrepo - INFO - creating new snapshot [2016.01.07-135456]
2016-01-07 13:54:56 - Timeline.dummyrepo - INFO - saving current timeline state...
2016-01-07 13:54:56 - Timeline.dummyrepo - INFO - updating link [upstream] to snapshot [2016.01.07-135456]
2016-01-07 13:54:56 - Timeline.dummyrepo - INFO - saving current timeline state...
2016-01-07 13:54:56 - Timeline.dummyrepo - INFO - updated link [upstream] to snapshot [2016.01.07-135456]
Now we should see the new snapshot:
ls -l /tmp/skel.timeline/
total 12
drwxr-xr-x 2 engels it 4096 Jan 7 12:17 2016.01.07-121721
drwxr-xr-x 2 engels it 4096 Jan 7 13:54 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 downstream -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset003 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset007 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset014 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset021 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset030 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset060 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset090 -> 2016.01.07-121721
-rw-r--r-- 1 engels it 1658 Jan 7 13:54 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 7 13:54 upstream -> 2016.01.07-135456
We also see that the 'upstream' link has been updated to the newly created snapshot (2016.01.07-135456).
If we create 2 new snapshots:
mrepo create-snapshot /tmp/skel.timeline
mrepo create-snapshot /tmp/skel.timeline
We can see that the offset003 link will stay pinned to the 3rd snapshot (2016.01.07-135456):
ls -l /tmp/skel.timeline/
total 20
drwxr-xr-x 2 engels it 4096 Jan 7 12:17 2016.01.07-121721
drwxr-xr-x 2 engels it 4096 Jan 7 13:54 2016.01.07-135456
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135727
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 downstream -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 13:57 offset003 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset007 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset014 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset021 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset030 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset060 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset090 -> 2016.01.07-121721
-rw-r--r-- 1 engels it 1658 Jan 7 13:57 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 7 13:57 upstream -> 2016.01.07-135729
Besides creating "regular" snapshots one can create a new "named" snapshot which will be a completely independent copy of the repository:
mrepo create-named-snapshot /tmp/skel.timeline/skel.mycopy
2016-01-07 14:01:25 - Timeline - INFO - loading timeline instance from [/tmp/skel.timeline/.timeline]
2016-01-07 14:01:25 - Timeline - INFO - configuring timeline [dummyrepo] from source [/tmp/skel] into destination [/tmp/skel.timeline]
2016-01-07 14:01:25 - Timeline.dummyrepo - INFO - loading timeline state...
2016-01-07 14:01:25 - Timeline.dummyrepo - INFO - timeline state loaded from [/tmp/skel.timeline/.timeline]
2016-01-07 14:01:25 - Timeline.dummyrepo - INFO - creating new snapshot [skel.mycopy]
ls -l /tmp/skel.timeline/
total 24
drwxr-xr-x 2 engels it 4096 Jan 7 12:17 2016.01.07-121721
drwxr-xr-x 2 engels it 4096 Jan 7 13:54 2016.01.07-135456
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135727
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 downstream -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 13:57 offset003 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset007 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset014 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset021 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset030 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset060 -> 2016.01.07-121721
lrwxrwxrwx 1 engels it 17 Jan 7 12:17 offset090 -> 2016.01.07-121721
drwxr-xr-x 2 engels it 4096 Jan 7 14:01 skel.mycopy
-rw-r--r-- 1 engels it 1658 Jan 7 13:57 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 7 13:57 upstream -> 2016.01.07-135729
Note that this copy is completely independent. This means that it is not tracked in any way within the timeline metadata and will therefore not be affected by any of the timeline methods including snapshot rotation.
Let's remove 2 snapshots:
mrepo delete-snapshot /tmp/skel.timeline/2016.01.07-135727
mrepo delete-snapshot /tmp/skel.timeline/2016.01.07-121721
ls -l /tmp/skel.timeline
total 16
drwxr-xr-x 2 engels it 4096 Jan 7 13:54 2016.01.07-135456
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 downstream -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 13:57 offset003 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset007 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset014 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset021 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset030 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset060 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset090 -> 2016.01.07-135456
drwxr-xr-x 2 engels it 4096 Jan 7 14:01 skel.mycopy
-rw-r--r-- 1 engels it 1658 Jan 7 14:05 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 7 13:57 upstream -> 2016.01.07-135729
That's it. More details can be found in the log files:
tail /tmp/timeline-debug.log
2016-01-07 14:05:27 - timeline - Timeline.dummyrepo - INFO - 576 - updating link [offset090] to snapshot [2016.01.07-135456]
2016-01-07 14:05:27 - timeline - Timeline.dummyrepo - INFO - 227 - saving current timeline state...
2016-01-07 14:05:27 - timeline - Timeline.dummyrepo - INFO - 227 - saving current timeline state...
2016-01-07 14:05:27 - timeline - Timeline.dummyrepo - DEBUG - 233 - current state saved into [/tmp/skel.timeline/.timeline]
2016-01-07 14:05:27 - timeline - Timeline.dummyrepo - INFO - 604 - updated link [offset090] to snapshot [2016.01.07-135456]
2016-01-07 14:05:27 - timeline - Timeline.dummyrepo - INFO - 604 - updated link [offset090] to snapshot [2016.01.07-135456]
2016-01-07 14:05:27 - timeline - Timeline.dummyrepo - INFO - 227 - saving current timeline state...
2016-01-07 14:05:27 - timeline - Timeline.dummyrepo - INFO - 227 - saving current timeline state...
2016-01-07 14:05:27 - timeline - Timeline.dummyrepo - DEBUG - 233 - current state saved into [/tmp/skel.timeline/.timeline]
2016-01-07 14:05:27 - timeline - Timeline.dummyrepo - DEBUG - 490 - deleted snapshot [2016.01.07-121721] [{'path': '/tmp/skel.timeline/2016.01.07-121721', 'links': [], 'created': datetime.datetime(2016, 1, 7, 12, 17, 21, 551751)}]
The log files show that some symbolic links had to be relinked to a nearest neighbour due to the fact that the original snapshot they were pointing to has been removed.
As previously stated, named snapshots are not tracked by the timeline and can therefore be removed using regular linux tools such as 'rm'. However it's safer to remove them with the mrepo delete-snapshot tool, since you might otherwise by accident remove a regular snapshot which is referenced in the timeline metadata.
mrepo delete-snapshot /tmp/skel.timeline/skel.mycopy
Example on how to create a new link:
mrepo create-link /tmp/skel.timeline/myskel.link
ls -l /tmp/skel.timeline
total 15
drwxr-xr-x 2 engels it 4096 Jan 7 13:54 2016.01.07-135456
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 downstream -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:17 myskel.link -> 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 13:57 offset003 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset007 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset014 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset021 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset030 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset060 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset090 -> 2016.01.07-135456
-rw-r--r-- 1 engels it 1658 Jan 7 14:17 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 7 13:57 upstream -> 2016.01.07-135729
Per default, new links point to the newest (upstream) snapshot and do not have a max-offset value set. Links without max-offset stay pinned to their snapshot until max snapshots are reached. When this limit is reached, links are updated to stay pinned to the "oldest" (downstream) snapshot until they are updated to point to a "newer" snapshot.
To ensure that links are kept at a maximum offset, we need to use the option --max-offset, e.g.
mrepo create-link --max-offset=2 /tmp/skel.timeline/mylink.offset2
ls -l /tmp/skel.timeline
total 12
drwxr-xr-x 2 engels it 4096 Jan 7 13:54 2016.01.07-135456
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 downstream -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 8 08:47 mylink.offset2 -> 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 14:17 myskel.link -> 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 13:57 offset003 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset007 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset014 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset021 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset030 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset060 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset090 -> 2016.01.07-135456
-rw-r--r-- 1 engels it 1658 Jan 8 08:47 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 7 13:57 upstream -> 2016.01.07-135729
Let's check:
mrepo create-snapshot /tmp/skel.timeline
mrepo create-snapshot /tmp/skel.timeline
ls -l /tmp/skel.timeline
total 20
drwxr-xr-x 2 engels it 4096 Jan 7 13:54 2016.01.07-135456
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135729
drwxr-xr-x 2 engels it 4096 Jan 8 08:48 2016.01.08-084852
drwxr-xr-x 2 engels it 4096 Jan 8 08:48 2016.01.08-084855
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 downstream -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 8 08:48 mylink.offset2 -> 2016.01.08-084852
lrwxrwxrwx 1 engels it 17 Jan 7 14:17 myskel.link -> 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 8 08:48 offset003 -> 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset007 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset014 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset021 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset030 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset060 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset090 -> 2016.01.07-135456
-rw-r--r-- 1 engels it 1658 Jan 8 08:48 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 8 08:48 upstream -> 2016.01.08-084855
Looks good :)
Note that specifying max-offset=2 doesn't mean that the link will be set initially to the 2nd snapshot. For this purpose you still need to use the --snapshot option. (This might change in the future...)
Deleting links is done using mrepo delete-link. E.g.
mrepo delete-link /tmp/skel.timeline/myskel.link
ls -l /tmp/skel.timeline
total 20
drwxr-xr-x 2 engels it 4096 Jan 7 13:54 2016.01.07-135456
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135729
drwxr-xr-x 2 engels it 4096 Jan 8 08:48 2016.01.08-084852
drwxr-xr-x 2 engels it 4096 Jan 8 08:48 2016.01.08-084855
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 downstream -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 8 08:48 mylink.offset2 -> 2016.01.08-084852
lrwxrwxrwx 1 engels it 17 Jan 8 08:48 offset003 -> 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset007 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset014 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset021 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset030 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset060 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset090 -> 2016.01.07-135456
-rw-r--r-- 1 engels it 1658 Jan 8 08:52 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 8 08:48 upstream -> 2016.01.08-084855
Since links are tracked by the timeline instance, they must be renamed using the appropriate tool (mrepo rename-link), e.g.:
mrepo rename-link /tmp/skel.timeline/mylink.offset2 /tmp/skel.timeline/mylink.offset002
ls -l /tmp/skel.timeline
total 20
drwxr-xr-x 2 engels it 4096 Jan 7 13:54 2016.01.07-135456
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135729
drwxr-xr-x 2 engels it 4096 Jan 8 08:48 2016.01.08-084852
drwxr-xr-x 2 engels it 4096 Jan 8 08:48 2016.01.08-084855
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 downstream -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 8 08:54 mylink.offset002 -> 2016.01.08-084852
lrwxrwxrwx 1 engels it 17 Jan 8 08:48 offset003 -> 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset007 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset014 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset021 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset030 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset060 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset090 -> 2016.01.07-135456
-rw-r--r-- 1 engels it 1658 Jan 8 08:54 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 8 08:48 upstream -> 2016.01.08-084855
Updating links to point to a different snapshot must also be done using the appropriate tool (mrepo update-link), e.g.:
mrepo update-link /tmp/skel.timeline/mylink.offset002
ls -l /tmp/skel.timeline
total 20
drwxr-xr-x 2 engels it 4096 Jan 7 13:54 2016.01.07-135456
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135729
drwxr-xr-x 2 engels it 4096 Jan 8 08:48 2016.01.08-084852
drwxr-xr-x 2 engels it 4096 Jan 8 08:48 2016.01.08-084855
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 downstream -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 8 08:55 mylink.offset002 -> 2016.01.08-084855
lrwxrwxrwx 1 engels it 17 Jan 8 08:48 offset003 -> 2016.01.07-135729
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset007 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset014 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset021 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset030 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset060 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset090 -> 2016.01.07-135456
-rw-r--r-- 1 engels it 1658 Jan 8 08:55 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 8 08:48 upstream -> 2016.01.08-084855
Per default links are updated to the upstream snapshot unless the option --snapshot is used to specify a specific snapshot.
Updating links doesn't affect the max-offset value. This means that when the max-offset value is reached the link is kept pinned to the max-offset snapshot. Let's check:
mrepo create-snapshot /tmp/skel.timeline
mrepo create-snapshot /tmp/skel.timeline
ls -l /tmp/skel.timeline
total 28
drwxr-xr-x 2 engels it 4096 Jan 7 13:54 2016.01.07-135456
drwxr-xr-x 2 engels it 4096 Jan 7 13:57 2016.01.07-135729
drwxr-xr-x 2 engels it 4096 Jan 8 08:48 2016.01.08-084852
drwxr-xr-x 2 engels it 4096 Jan 8 08:48 2016.01.08-084855
drwxr-xr-x 2 engels it 4096 Jan 8 08:57 2016.01.08-085724
drwxr-xr-x 2 engels it 4096 Jan 8 08:57 2016.01.08-085727
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 downstream -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 8 08:57 mylink.offset002 -> 2016.01.08-085724
lrwxrwxrwx 1 engels it 17 Jan 8 08:57 offset003 -> 2016.01.08-084855
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset007 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset014 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset021 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset030 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset060 -> 2016.01.07-135456
lrwxrwxrwx 1 engels it 17 Jan 7 14:05 offset090 -> 2016.01.07-135456
-rw-r--r-- 1 engels it 1658 Jan 8 08:57 timeline.cfg
lrwxrwxrwx 1 engels it 17 Jan 8 08:57 upstream -> 2016.01.08-085727
Looks good :) mylink.offset002 keeps pointing at the second snapshot.
For changing advanced settings or displaying timeline informations one needs to use the mrepo config tool.
mrepo config -v /tmp/skel.timeline
Freezing the repository prevents most operations including creating new snapshots. This should only be used in emergency situations where the upstream repository is broken and you do not want to propagate the error to your production repositories. Let's check:
mrepo config --freeze /tmp/skel.timeline
2016-01-08 09:06:41 - Timeline - INFO - loading timeline instance from [/tmp/skel.timeline/.timeline]
2016-01-08 09:06:41 - Timeline - INFO - configuring timeline [dummyrepo] from source [/tmp/skel] into destination [/tmp/skel.timeline]
2016-01-08 09:06:41 - Timeline.dummyrepo - INFO - loading timeline state...
2016-01-08 09:06:41 - Timeline.dummyrepo - INFO - timeline state loaded from [/tmp/skel.timeline/.timeline]
2016-01-08 09:06:41 - Timeline.dummyrepo - INFO - timeline has been frozen by user [root]
2016-01-08 09:06:41 - Timeline.dummyrepo - INFO - saving current timeline state...
mrepo create-snapshot /tmp/skel.timeline
2016-01-08 09:07:08 - Timeline - INFO - loading timeline instance from [/tmp/skel.timeline/.timeline]
2016-01-08 09:07:08 - Timeline - INFO - configuring timeline [dummyrepo] from source [/tmp/skel] into destination [/tmp/skel.timeline]
2016-01-08 09:07:08 - Timeline.dummyrepo - INFO - loading timeline state...
2016-01-08 09:07:08 - Timeline.dummyrepo - INFO - timeline state loaded from [/tmp/skel.timeline/.timeline]
2016-01-08 09:07:08 - Timeline.dummyrepo - INFO - creating new snapshot [2016.01.08-090708]
Traceback (most recent call last):
File "mrepo", line 42, in <module>
t.create_snapshot( random_sleep_before_snapshot=options['random_sleep'], sleep_after_snapshot=options['sleep_after'])
File "/afs/desy.de/user/e/engels/work/systems/desyops-git-repos/mrepo/timeline/timeline.py", line 438, in create_snapshot
self._check_frozen()
File "/afs/desy.de/user/e/engels/work/systems/desyops-git-repos/mrepo/timeline/timeline.py", line 687, in _check_frozen
raise Exception('timeline is frozen!')
Exception: timeline is frozen!
Let's unfreeze it:
mrepo config --unfreeze /tmp/skel.timeline
2016-01-08 09:08:28 - Timeline - INFO - loading timeline instance from [/tmp/skel.timeline/.timeline]
2016-01-08 09:08:28 - Timeline - INFO - configuring timeline [dummyrepo] from source [/tmp/skel] into destination [/tmp/skel.timeline]
2016-01-08 09:08:28 - Timeline.dummyrepo - INFO - loading timeline state...
2016-01-08 09:08:28 - Timeline.dummyrepo - INFO - timeline state loaded from [/tmp/skel.timeline/.timeline]
2016-01-08 09:08:28 - Timeline.dummyrepo - INFO - timeline previously frozen by user [root] has been unfrozen by [root]
2016-01-08 09:08:28 - Timeline.dummyrepo - INFO - saving current timeline state...
The maximum amount of snapshots can easily be changed as follows:
mrepo config --max-snapshots=10 /tmp/skel.timeline
The maximum amount of snapshots can also be changed in the timeline configuration file (see below).
Each timeline instance contains a configuration file where more advanced settings can be changed. For example which directories should be excluded when creating new snapshots or which directories/files should be "hard-copied" instead of "hard-linked".
cat /srv/repo/linux/scientific.timeline/timeline.cfg
[MAIN]
# ============================================================================================================================= =
# warning: this file is constantly auto-generated! do not be surprised if any comments get lost
# ============================================================================================================================= =
max_snapshots = 90
diff_log_path = /srv/repo/log/linux
[ADVANCED]
# ============================================================================================================================= =
# advanced options. do not touch this section unless you know what you are doing!
# options description:
# excludes: colon-separated list of files/directories to be excluded when creating snapshots
# no absolute paths allowed. only top-level paths or relative paths, e.g.
# excludes = testing:dev:tmp:i386/builds
# in this example the path i386/builds contains a subfolder. due to technical details these "relative paths" are not
# skipped during the copy process. instead, they get deleted _after_ the copy process has taken place.
# copy_files_recursive: colon-separated list of file names to be copied (i.e. not hard-linked) when creating snapshots
# copy_dirs_recursive: colon-separated list of directory names to be copied (i.e. not hard-linked) when creating snapshots
# warning: the previous copy options perform a _recursive_ find in the source directory and _copy_ any found objects!
# ============================================================================================================================= =
excludes = sl41:sl42:303:304:305:307:308:309:30rolling:40:40rolling:41:42:43:44:45:46:47:48:49:50:51:510:511:52:53:54:55:56:57:58:59:5rolling:6.0:6.1:6.2:6.3:6.4
copy_files_recursive =
copy_dirs_recursive = repodata
We can see in this example that quite a number of objects are excluded during the snapshot process.
We can also see that all directories named "repodata" will be hard-copied when creating new snapshots. This setting is typical for other Yum repositories as well. The reason why this directory needs to be copied instead of hard-linking is because it contains the repository metadata.
cat /srv/repo/linux/ubuntu.timeline/timeline.cfg
[MAIN]
# ============================================================================================================================= =
# warning: this file is constantly auto-generated! do not be surprised if any comments get lost
# ============================================================================================================================= =
max_snapshots = 90
diff_log_path = /srv/repo/log/linux
[ADVANCED]
# ============================================================================================================================= =
# advanced options. do not touch this section unless you know what you are doing!
# options description:
# excludes: colon-separated list of files/directories to be excluded when creating snapshots
# no absolute paths allowed. only top-level paths or relative paths, e.g.
# excludes = testing:dev:tmp:i386/builds
# in this example the path i386/builds contains a subfolder. due to technical details these "relative paths" are not
# skipped during the copy process. instead, they get deleted _after_ the copy process has taken place.
# copy_files_recursive: colon-separated list of file names to be copied (i.e. not hard-linked) when creating snapshots
# copy_dirs_recursive: colon-separated list of directory names to be copied (i.e. not hard-linked) when creating snapshots
# warning: the previous copy options perform a _recursive_ find in the source directory and _copy_ any found objects!
# ============================================================================================================================= =
excludes =
copy_files_recursive = Release:Release.gpg:InRelease:Contents-*.gz:Index
copy_dirs_recursive = binary-*:source
This example shows that we recursively copy all 'source' directories and all directories matching the regular expressions 'binary-'. We also recursively copy all files matching the regular expression 'Contents-.gz' and all files that are named 'Release', 'Release.gpg', 'InRelease' or 'Index'. This are typical settings for Debian-like repositories.
The diff_log_path setting can be used to generate "diff reports" whenever new snapshots are created. I.e. whenever a snapshot is created a new diff report will be generated in the given directory which contains the differences to the "previous snapshot".
This setting is per default not set.