Display network information of checkpoints created with Podman

[nishantxscooby]

Summary

• Parse the network.status file from Podman checkpoint archives to extract IP and MAC address information
• Display network info in show, inspect (tree and JSON formats), and diff output, matching existing CRI-O behavior
• Gracefully handle missing network.status files for backward compatibility with older checkpoints

Closes #132

Changes

File	Description
lib/metadata.go	Add PodmanNetworkStatus types and ReadContainerCheckpointNetworkStatus() reader
internal/container.go	Update getPodmanInfo() to read network.status and extract IP/MAC
internal/config_extractor.go, internal/oci_image_build.go	Pass checkpoint directory to getContainerInfo()
cmd/show.go, cmd/inspect.go, cmd/diff.go	Add network.status to required files for extraction
lib/metadata_test.go	Unit tests for network status parsing (single/multiple subnets, file-not-found)
test/data/network.status	Test fixture matching the format from the issue
test/checkpointctl.bats	BATS tests for show, inspect tree, and inspect JSON with network info

Test plan

• Go unit tests pass (go test -v ./... — 30/30 pass)
• Podman checkpoint with network.status shows IP and MAC in show output
• Podman checkpoint with network.status shows IP and MAC in inspect tree output
• Podman checkpoint with network.status shows IP and MAC in inspect JSON output
• Podman checkpoint without network.status still works (no IP/MAC columns)
• CRI-O checkpoint still works as before
• Multiple checkpoints display correctly

[nishantxscooby]

Hello maintainers, this PR is ready to be reviewed, Thankyou :D

[github-actions]

Test Results

86 tests  +5   86 ✅ +5   3s ⏱️ -1s
 1 suites ±0    0 💤 ±0 
 1 files   ±0    0 ❌ ±0 

Results for commit 3fc6820. ± Comparison against base commit 44489aa.

♻️ This comment has been updated with latest results.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 98.73418% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 79.98%. Comparing base (44489aa) to head (3fc6820).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/oci_image_build.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #206      +/-   ##
==========================================
+ Coverage   78.71%   79.98%   +1.27%     
==========================================
  Files          16       16              
  Lines        1701     1759      +58     
==========================================
+ Hits         1339     1407      +68     
+ Misses        269      263       -6     
+ Partials       93       89       -4     

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[adrianreber]

I am not sure what the changes to the diff command are doing. Is this necessary? Does this change anything?

I am also not sure if we want it in the show command. The problem with the table is that is gets harder to read the more content it has.

For the inspect command it makes sense.

Can you also add a test with a broken network status file to see if the parser handles it gracefully.

Also tell us which AI tool you have been using as described in https://github.com/checkpoint-restore/checkpointctl?tab=contributing-ov-file

I guess there is no collision but I would like to see #201 merged first before additional features.

@rst0git as you opened #132 is this how envisioned this? Or is this the wrong approach?

[nishantxscooby]

Thanks for the review :D

diff command: ig you're right, the CheckpointMetadata struct in diff.go doesn't include IP/MAC fields, so the extracted network.status data is never used in the diff output. I'll revert that change.

show command: The show command already conditionally displays IP and MAC columns for CRI-O checkpoints (as shown in the README example). The columns only appear when the values are non-empty, so Podman checkpoints without network.status won't get extra columns. This change just enables the same behavior for Podman to keep it consistent. But happy to drop it if you'd prefer to keep network info only in inspect.

Broken network status test: Will add a test with a broken/malformed network.status file to verify graceful handling.

PR #201: No problem, I'll rebase once #201 is merged.

For the AI, I have been using cursor, sorry forgot to mention :(

[rst0git]

I guess there is no collision but I would like to see #201 merged first before additional features.

Sure, it makes sense. Let me review it.

@rst0git as you opened #132 is this how envisioned this? Or is this the wrong approach?

The main idea is to show network information about checkpoints created with Podman, similar to the way we do this for checkpoints created with CRI-O. It should be straightforward.

[adrianreber]

show command: The show command already conditionally displays IP and MAC columns for CRI-O checkpoints (as shown in the README example). The columns only appear when the values are non-empty, so Podman checkpoints without network.status won't get extra columns. This change just enables the same behavior for Podman to keep it consistent. But happy to drop it if you'd prefer to keep network info only in inspect.

Right, adding it to show makes sense.

[nishantxscooby]

Rebased on latest main (now that #201 is merged), addressed all review feedback

Changes since last review:

• Reverted the unnecessary diff command change
• Added tests with a broken/malformed network.status file (both BATS and Go unit tests) to verify graceful handling
• Rebased on top of Refactor inspect to use single data collection phase #201

All tests passing. Ready for another look when you get a chance.

[nishantxscooby]

Hello, let me know if this requires some changes from my side or is ready to be merged, thanks for your time :)

[nishantxscooby]

Hello, I think the above merged fix fixes it all? let me know if any changes are required so I can work on it, Thankyou :)

[rst0git]

Hello, I think the above merged fix fixes it all? let me know if any changes are required so I can work on it, Thankyou :)

@nishantxscooby AI agents work well but only for well defined problems or tasks. In my message above I didn't describe the problem or the potential solution very well and left too much ambiguity. Can you try reading my message yourself and see if this is the right approach :)

[adrianreber]

Please do not include the go-criu update in this PR.

Please also re-order and squash the commits. No merge commits in the PR please. Use one commit for the changes and split the test changes into separate commits. Maybe one commit for the unit tests the other for the integration/e2e tests.

[nishantxscooby]

@adrianreber Hello, is it fine now? :)

[rst0git]

@nishantxscooby I've updated your patches here: https://github.com/rst0git/checkpointctl/commits/podman-network-status

Podman checkpoints:

Displaying container checkpoint tree view from /tmp/test.tar

looper
├── Image: docker.io/library/busybox:latest
├── ID: c00a173fe7241cf6f4c052571a371bc18eb6ce89512c5545bfb636020814d81e
├── Runtime: crun
├── Created: 2026-03-13T21:11:20Z
├── Engine: Podman
├── Network Interfaces
│   ├── net1 (eth0)
│   │   ├── IP: 10.89.0.2/24
│   │   ├── MAC: 02:60:91:3e:6c:55
│   │   └── Gateway: 10.89.0.1
│   └── net2 (eth1)
│       ├── IP: 10.89.1.2/24
│       ├── MAC: 9a:52:c1:ef:92:e9
│       └── Gateway: 10.89.1.1
└── Checkpoint size: 336.1 KiB
    └── Memory pages size: 300.0 KiB

looper
├── Image: docker.io/library/busybox:latest
├── ID: 274be359d4947d98206280ff2acef87c7b3a50c434e079fc8b4604dba46e5e1e
├── Runtime: crun
├── Created: 2026-03-13T21:21:31Z
├── Engine: Podman
├── Network Interfaces
│   └── podman (eth0)
│       ├── IP: 10.88.0.21/16
│       ├── MAC: f6:92:a1:69:c2:49
│       └── Gateway: 10.88.0.1
└── Checkpoint size: 332.1 KiB
    └── Memory pages size: 296.0 KiB

CRI-O checkpoints (only IP address info is included):

Displaying container checkpoint tree view from /var/lib/kubelet/checkpoints/checkpoint-checkpoint-test_default-checkpoint-test-2026-03-13T21:43:06Z.tar

checkpoint-test
├── Image: docker.io/library/busybox:latest
├── ID: 68bb2fa6a1765e137dc0fecc4804385fdf1d1379e50f8d33cf8525f0b9e5e0a0
├── Runtime: crun
├── Created: 2026-03-13T21:42:59.05135916Z
├── Checkpointed: 2026-03-13T21:43:06Z
├── Engine: CRI-O
├── IP: 192.168.87.136
├── Checkpoint size: 314.6 KiB
│   └── Memory pages size: 296.0 KiB
└── Root FS diff size: 3.5 KiB

containerd checkpoints don't include network information.

[rst0git]

Signed-off-by: nishantxscooby officialnishant21@gmail.com

@nishantxscooby Would you be able to use a real name?

[nishantxscooby]

I hope that's fine now :) @rst0git

[adrianreber]

Please do not add fixup commits. Apply the fixes to the commit which introduces the change.

[nishantxscooby]

But the tests were failing, so eventually I had to :(

[rst0git]

Use one commit for the changes and split the test changes into separate commits. Maybe one commit for the unit tests the other for the integration/e2e tests.

@nishantxscooby It would be good also to follow Adrian's suggestion above. Here is an example:

1. inspect: Display network information for Podman checkpoints
2. test: Add unit tests for network status parsing and tree rendering
3. test: Add integration tests for network status display

You can use git rebase -i HEAD~4 to edit your commits, then do git push -f to update your branch.

[nishantxscooby]

Okay, I'll look into this, but for now I've removed the fixup commits, lmk if that's fine

[adrianreber]

But the tests were failing, so eventually I had to :(

Yes, fixing it is correct, but include the fix in your original commit instead of creating a new commit. As long as the changes are only in the PR you can rewrite the commits as long as necessary.

Also just use one Signed-off-by line in the commit messages.

[nishantxscooby]

Okay, I'll keep all of this in mind, sorry for the chaos. :(

[adrianreber]

The ordering and splitting of the commits looks good. Please attribute which AI tool you have used in each commit.

We will review the code in a next step.

[rst0git]

LGTM.

I've reviewed and tested these changes with Podman, CRI-O and containerd. A few minor changes: I've updated the patches to remove network info from the show table output and only display it in the inspect tree view, since there isn't enough space in the table. I've also updated the README examples and unit and integration tests.

I've also added Devesh Goyal as a co-author for the first patch as he created an initial version here: #162

[nishantxscooby]

Cool, thankyou so much :)