Log stdout when exec errors

[hellt]

When docker exec fails to find a command to run it seems it puts it in the stdout, rather than stderr.

This new log print prints stderr and stdout when exec errors or contains non 0 rc.

DEBU[0009] error during mgmt_server status check: %!s(<nil>), exit code: 126, stderr: , stdout: OCI runtime exec failed: exec failed: unable to  tart container process: exec: "sr_cli": executable file not found in $PATH: unknown

[hellt]

@steiler I think I am going mad lol
For some reason the logger eats up the first character when printing it the Stdout: here.
I am curious if you can crack this mystery:

DEBU[0002] mgmt_server status check failed, output: 
Cmd: sr_cli -d info from state system app-management application mgmt_server state | grep running
ReturnCode: 126
 tdout: OCI runtime exec failed: exec failed: unable to start container process: exec: "sr_cli": executable file not found in $PATH: unknown

Note, the tdout string.

[hellt]

for this log message to appear, change the command here from sr_cli to some garbage

containerlab/nodes/srl/srl.go

Line 109 in ada8a8d

mgmtServerRdyCmd = `sr_cli -d "info from state system app-management application mgmt_server state | grep running"`

[codecov]

Codecov Report

Merging #1495 (f77d8b6) into main (4348879) will decrease coverage by 0.03%.
Report is 5 commits behind head on main.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main    #1495      +/-   ##
==========================================
- Coverage   21.08%   21.05%   -0.03%     
==========================================
  Files          65       65              
  Lines        7063     7073      +10     
==========================================
  Hits         1489     1489              
- Misses       5443     5453      +10     
  Partials      131      131              

Files Changed	Coverage Δ
clab/exec/exec.go	6.29% <0.00%> (-0.54%)	⬇️