Add operations for FreezeUnit and ThawUnit

[irishair]

We are trying to use bluechi for multi-node container ochestration in our automotive HPC.
In our system, we have additional requirements for suspend and resume of units.
From systemd 246, it supports "systemctl freeze/thaw" and D-Bus APIs for those based on cgroup v2.
So we added a new feature that supports freeze and thaw units on multi-node to bluechi, and we would like to submit this patch.

This PR contains following changes.

• Add FreezeUnit/ThawUnit operations to agent and manager
• Add freeze/thaw commands to client
• Add FreezeUnit/ThawUnit interfaces to DBus-API

Example test results

# bluechictl freeze ak7_master_sub v2x-client.service
Unit v2x-client.service freeze operation done


# systemctl status v2x-client.service
● v2x-client.service - systemd service for v2x client container
Loaded: loaded (/etc/containers/systemd/v2x-client.container; generated)
Active: active (running) (frozen) since Wed 2023-08-21 14:26:34 KST; 2min 37s ago
Main PID: 3451 (conmon)
  Tasks: 21 (limit: 7782)
Memory: 25.8M
    CPU: 6.107s
CGroup: /system.slice/v2x-client.service
         ├─libpod-payload-7ea31bcb6eb869693e09d7ca49b57cfbb3cbf51adfdaa0c54cc008c5068119a4
         │ ├─3454 /bin/bash /usr/local/akitos/communications/v2xservice/bin/v2x_client.sh start_sync
         │ └─3496 /usr/lib/v2x_agent/v2x_agent --config=/tmp/v2xservice/conf/v2x_config.json
         └─runtime
           └─3451 /usr/bin/conmon --api-version 1 -c 7ea31bcb6eb869693e09d7ca49b57cfbb3cbf51adfdaa0c54cc008c5068119a4 -u 7ea31bcb6eb869693e09d7ca49b57cfbb3cbf51adfdaa0c54cc008c5068119a4 -r /usr/bin/crun>


# bluechictl thaw ak7_master_sub v2x-client.service
Unit v2x-client.service thaw operation done

[pypingou]

hi @irishair

First of all, many thanks for this PR and your interest in the project!

I just wanted to flag that we're currently in the process of changing the license of the project from GPLv2+ to LGPLv2.1+: (cf #462) as well as contributing it to the Eclipse Foundation for it to become part of the Eclipse SDV umbrella.
So I wanted to double-check that you are fine with your contribution being under either of these licenses.

Thanks in advance! :)

[rhatdan]

Need fixed for bluechi-ctl as well.

[pypingou]

Need fixed for bluechi-ctl as well.

as in, could you also document these features in https://github.com/containers/bluechi/blob/main/doc/man/bluechictl.1.md ?

[irishair]

Need fixed for bluechi-ctl as well.

as in, could you also document these features in https://github.com/containers/bluechi/blob/main/doc/man/bluechictl.1.md ?

I updated bluechictl.1.md.
bluechictl commands for freeze and thaw are already applied.
Thanks for your comments :)

[irishair]

hi @irishair

First of all, many thanks for this PR and your interest in the project!

I just wanted to flag that we're currently in the process of changing the license of the project from GPLv2+ to LGPLv2.1+: (cf #462) as well as contributing it to the Eclipse Foundation for it to become part of the Eclipse SDV umbrella. So I wanted to double-check that you are fine with your contribution being under either of these licenses.

Thanks in advance! :)

Yes, we are fine with license change.
Thanks for letting me know.

[engelmi]

LGTM, great work!

@irishair Could you fetch the latest changes from main? Then the 2 failing integration tests should pass as well and we could merge.

It would be great to have integration tests for these new features, but that can be done in a separate PR - I'll create an issue for it.
Update: Created #495

[irishair]

LGTM, great work!

@irishair Could you fetch the latest changes from main? Then the 2 failing integration tests should pass as well and we could merge.

It would be great to have integration tests for these new features, but that can be done in a separate PR - I'll create an issue for it.

fetched latest changes, and I'll follow up on the issue for integration test.

[mwperina]

LGTM

[dougsland]

LGTM @irishair should we consider a RFE for bluechi status to show the service as running (frozen) ?

# ./bluechictl freeze control chronyd.service
Unit chronyd.service freeze operation done

[root@control client]# ./bluechictl status control chronyd.service
UNIT		| LOADED	| ACTIVE	| SUBSTATE	| ENABLED	|
--------------------------------------------------------------------------------
chronyd.service	| loaded	| active	| running	| enabled	|

● chronyd.service - NTP client/server
     Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; preset: enabled)
     Active: active (running) (frozen) since Wed 2023-08-23 23:38:10 UTC; 11min ago

[dougsland]

We got LGTM from @engelmi @mwperina and me, merging. The bluechictl status can be handle in different PR.

[irishair]

LGTM @irishair should we consider a RFE for bluechi status to show the service as running (frozen) ?

# ./bluechictl freeze control chronyd.service
Unit chronyd.service freeze operation done

[root@control client]# ./bluechictl status control chronyd.service
UNIT		| LOADED	| ACTIVE	| SUBSTATE	| ENABLED	|
--------------------------------------------------------------------------------
chronyd.service	| loaded	| active	| running	| enabled	|

● chronyd.service - NTP client/server
     Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; preset: enabled)
     Active: active (running) (frozen) since Wed 2023-08-23 23:38:10 UTC; 11min ago

I'll apply this to bluechictl status as a different PR.
Thanks for notifying.

[engelmi]

Good idea @dougsland!
I created issue #499 to keep track of this

I'll apply this to bluechictl status as a different PR.
Thanks for notifying.

@irishair If you submit a PR, you can reference #499.
nvm, just saw your PR #497