feat: display file descriptors

[snprajwal]

The file descriptors opened by the processes in the checkpoint can now be viewed with the --fds flag. This currently displays the file type, FD, and the path.

An example output for a checkpoint of httpd container (provided by @rst0git):

test
├── Image: docker.io/library/httpd:2.4
├── ID: 41ddbcab288ab3d2d119896aa96187b474bbe3084640b6559b0edc0a41f12277
├── Runtime: crun
├── Created: 2023-07-06T09:08:34+01:00
├── Engine: Podman
├── Checkpoint Size: 5.2 MiB
├── Root Fs Diff Size: 2.0 KiB
└── Process tree
    └── [1]  httpd
        ├── [3]  httpd
        │   ├── [REG 0]  /dev/null
        │   ├── [PIPE 1]  pipe[793149]
        │   ├── [PIPE 2]  pipe[793150]
        │   ├── [INETSK 3]  INETSK.36
        │   ├── [INETSK 4]  INETSK.37
        │   ├── [PIPE 5]  pipe[794937]
        │   ├── [PIPE 6]  pipe[794937]
        │   ├── [PIPE 7]  pipe[793149]
        │   ├── [EVENTPOLL 8]  EVENTPOLL.44
        │   ├── [PIPE 9]  pipe[796833]
        │   ├── [PIPE 10]  pipe[796833]
        │   ├── [cwd]  /usr/local/apache2
        │   └── [root]  /
        ├── [4]  httpd
        │   ├── [REG 0]  /dev/null
        │   ├── [PIPE 1]  pipe[793149]
        │   ├── [PIPE 2]  pipe[793150]
        │   ├── [INETSK 3]  INETSK.36
        │   ├── [INETSK 4]  INETSK.37
        │   ├── [PIPE 5]  pipe[794937]
        │   ├── [PIPE 6]  pipe[794937]
        │   ├── [PIPE 7]  pipe[793149]
        │   ├── [EVENTPOLL 8]  EVENTPOLL.49
        │   ├── [PIPE 9]  pipe[789308]
        │   ├── [PIPE 10]  pipe[789308]
        │   ├── [cwd]  /usr/local/apache2
        │   └── [root]  /
        ├── [5]  httpd
        │   ├── [REG 0]  /dev/null
        │   ├── [PIPE 1]  pipe[793149]
        │   ├── [PIPE 2]  pipe[793150]
        │   ├── [INETSK 3]  INETSK.36
        │   ├── [INETSK 4]  INETSK.37
        │   ├── [PIPE 5]  pipe[794937]
        │   ├── [PIPE 6]  pipe[794937]
        │   ├── [PIPE 7]  pipe[793149]
        │   ├── [EVENTPOLL 8]  EVENTPOLL.54
        │   ├── [PIPE 9]  pipe[792449]
        │   ├── [PIPE 10]  pipe[792449]
        │   ├── [cwd]  /usr/local/apache2
        │   └── [root]  /
        ├── [REG 0]  /dev/null
        ├── [PIPE 1]  pipe[793149]
        ├── [PIPE 2]  pipe[793150]
        ├── [INETSK 3]  INETSK.36
        ├── [INETSK 4]  INETSK.37
        ├── [PIPE 5]  pipe[794937]
        ├── [PIPE 6]  pipe[794937]
        ├── [PIPE 7]  pipe[793149]
        ├── [cwd]  /usr/local/apache2
        └── [root]  /

[codecov-commenter]

Codecov Report

Patch coverage: 85.61% and project coverage change: +2.17 🎉

Comparison is base (69a4966) 80.00% compared to head (6a534c5) 82.17%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #74      +/-   ##
==========================================
+ Coverage   80.00%   82.17%   +2.17%     
==========================================
  Files           3        4       +1     
  Lines         435      533      +98     
==========================================
+ Hits          348      438      +90     
- Misses         64       70       +6     
- Partials       23       25       +2     

Impacted Files	Coverage Δ
container.go	76.19% <76.54%> (-4.04%)	⬇️
checkpointctl.go	90.44% <88.28%> (+3.49%)	⬆️
tree.go	90.32% <90.32%> (ø)

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[github-actions]

Test Results

36 tests  +3   36 ✔️ +3   0s ⏱️ ±0s
  1 suites ±0     0 💤 ±0 
  1 files   ±0     0 ❌ ±0 

Results for commit 064f017. ± Comparison against base commit 5a00d39.

♻️ This comment has been updated with latest results.

[rst0git]

LGTM

[adrianreber]

The binary size check does not seem to work any more. I just see one run of it. No comparison.

Can you add an example of what this looks like in the PR description?

[snprajwal]

The binary size workflow should be working now, I rebased this branch against main.

[snprajwal]

I forgot to do a nil pointer check while searching for the process node in the tree. Updated the commit with those changes now.