fix: docker cp of dangling symlink (#943)

[jsoref]

Fixes #943

[codecov]

Codecov Report

Merging #948 (653ba97) into master (0f04942) will increase coverage by 8.23%.
The diff coverage is 66.89%.

@@            Coverage Diff             @@
##           master     #948      +/-   ##
==========================================
+ Coverage   49.27%   57.50%   +8.23%     
==========================================
  Files          23       32       +9     
  Lines        2401     4594    +2193     
==========================================
+ Hits         1183     2642    +1459     
- Misses       1090     1729     +639     
- Partials      128      223      +95     

Impacted Files	Coverage Δ
pkg/common/job_error.go	0.00% <0.00%> (ø)
pkg/common/outbound_ip.go	0.00% <0.00%> (ø)
pkg/common/testflag.go	0.00% <0.00%> (ø)
pkg/container/docker_volume.go	0.00% <0.00%> (ø)
pkg/model/action.go	0.00% <0.00%> (ø)
pkg/model/step_result.go	0.00% <0.00%> (ø)
pkg/container/docker_run.go	5.54% <13.79%> (+3.61%)	⬆️
pkg/common/git.go	49.82% <31.81%> (-9.97%)	⬇️
pkg/runner/logger.go	65.43% <37.50%> (+1.28%)	⬆️
pkg/container/docker_auth.go	45.00% <45.00%> (ø)
... and 38 more

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[ChristopherHX]

Thanks, ( dangling ) symlinks are now also working on windows.

[ZauberNerd]

There's symlink error handling in the io.Copy block:

act/pkg/container/docker_run.go

Line 592 in 9f9eacf

if fi.Mode()&os.ModeSymlink == os.ModeSymlink {

shoudn't that be removed as we will never reach it?

Also: How is this change macOS only? I don't have a mac handy so I tested on Linux and could reproduce it just as well.
Edit: Ok, there are differences between macOS and Linux. I don't get the Error: open /.../act/dangling/baz: no such file or directory but act still exits with a non-zero status when running on act@master. With this change the reproducer workflow succeeds.

[jsoref]

I use act on macOS, and thus describe things based on this. It seemed unlikely to me that such a thing wouldn't have been tripped on already by Linux users, so I described things based on how I encountered them. That there is some difference between how it behaves on Linux may have contributed to how I described it.

If the problem happens for everyone, then I can change the description to not specify.

I'll remove the code you've identified.

[ZauberNerd]

Thanks, yeah looks like it happens on all platforms. With the fix #971 from Christopher applied the error is now also printed for me (DEBU[0000] open /.../act-dangling/baz: no such file or directory).