Add remap command for TCP listen port remapping (Closes #169)#190
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UtkarshSingh-06 wants to merge 1 commit intocheckpoint-restore:mainfrom
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Add remap command for TCP listen port remapping (Closes #169)#190UtkarshSingh-06 wants to merge 1 commit intocheckpoint-restore:mainfrom
UtkarshSingh-06 wants to merge 1 commit intocheckpoint-restore:mainfrom
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This commit adds a new 'remap' command to checkpointctl that allows remapping TCP listen ports in checkpoint archives. This addresses issue checkpoint-restore#169 by providing functionality similar to --tcp-listen-remap option of criu-image-streamer or edit_files_img.py script. The implementation: - Adds a new 'remap' command that accepts --tcp-listen-remap flag - Extracts files.img from checkpoint archives - Parses files.img to find TCP listen sockets (SOCK_STREAM, TCP_LISTEN state) - Remaps the source port according to the provided mappings - Repacks the modified files.img back into the checkpoint archive Port mappings are specified in the format old_port:new_port, with multiple mappings separated by commas. Closes checkpoint-restore#169 Signed-off-by: UtkarshSingh-06 <[email protected]>
rst0git
reviewed
Jan 18, 2026
| --tcp-listen-remap 8080:80,8443:443 | ||
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| Example: | ||
| checkpointctl remap checkpoint.tar --tcp-listen-remap 8080:80`, |
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It would be better to use more generic command name. For example, something like the following:
checkpointctl edit --tcp-listen-remap 8080:80 checkpoint.tarThis will allow us to extend the "edit" functionality with other features in the future.
rst0git
reviewed
Jan 18, 2026
| defer os.RemoveAll(tempDir) | ||
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| // Extract entire archive | ||
| if err := extractArchive(archiveFile.Name(), tempDir); err != nil { |
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In some cases, container checkpoints can be very large (>100 GB). Extracting the entire archive then recreating it again is not the best way of implementing this edit operation. Perhaps we can avoid both temporary storage requirements and unnecessary I/O by using a streaming tar reader/writer and replace the modified CRIU image on the fly.
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Description
This PR implements the remapping of TCP listen ports in container checkpoint archives, addressing issue #169. This provides functionality similar to the --tcp-listen-remap\ option of \criu-image-streamer\ or the \edit_files_img.py\ script.
Changes
emap\ command to checkpointctl
Usage
The command accepts port mappings in the format \old_port:new_port:
\\�ash
checkpointctl remap checkpoint.tar --tcp-listen-remap 8080:80
\\
Multiple port mappings can be specified by separating them with commas:
\\�ash
checkpointctl remap checkpoint.tar --tcp-listen-remap 8080:80,8443:443
\\
Technical Details
Related Issue
Closes #169
Testing
The implementation:
All code changes are well-documented with comments explaining the functionality.