The `cloudbuildResourcesFromBuildLog()` function from the internal GCP
package could cause panic while parsing Build job log which failed early
and didn't create any Compute Engine resources. The function relied on
the `Regexp.FindStringSubmatch()` method to always return a match
while being used on the build log. Accessing a member of a nil slice
would cause a panic in `osbuild-worker`, such as:
Stack trace of thread 185316:
#0 0x0000564e5393b5e1 runtime.raise (osbuild-worker)
#1 0x0000564e5391fa1e runtime.sigfwdgo (osbuild-worker)
#2 0x0000564e5391e354 runtime.sigtrampgo (osbuild-worker)
#3 0x0000564e5393b953 runtime.sigtramp (osbuild-worker)
#4 0x00007f37e98e3b20 __restore_rt (libpthread.so.0)
#5 0x0000564e5393b5e1 runtime.raise (osbuild-worker)
#6 0x0000564e5391f5ea runtime.crash (osbuild-worker)
#7 0x0000564e53909306 runtime.fatalpanic (osbuild-worker)
#8 0x0000564e53908ca1 runtime.gopanic (osbuild-worker)
#9 0x0000564e53906b65 runtime.goPanicIndex (osbuild-worker)
#10 0x0000564e5420b36e github.com/osbuild/osbuild-composer/internal/cloud/gcp.cloudbuildResourcesFromBuildLog (osbuild-worker)
#11 0x0000564e54209ebb github.com/osbuild/osbuild-composer/internal/cloud/gcp.(*GCP).CloudbuildBuildCleanup (osbuild-worker)
#12 0x0000564e54b05a9b main.(*OSBuildJobImpl).Run (osbuild-worker)
#13 0x0000564e54b08854 main.main (osbuild-worker)
#14 0x0000564e5390b722 runtime.main (osbuild-worker)
#15 0x0000564e53939a11 runtime.goexit (osbuild-worker)
Add a unit test testing this scenario.
Make the `cloudbuildResourcesFromBuildLog()` function more robust and
not blindly expect to find matches in the build log. As a result the
`cloudbuildBuildResources` struct instance returned from the function
may be empty. Subsequently make sure that the `CloudbuildBuildCleanup()`
method handles an empty `cloudbuildBuildResources` instance correctly.
Specifically the `storageCacheDir.bucket` may be an empty string and
thus won't exist. Ensure that this does not result in infinite loop by
checking for `storage.ErrBucketNotExist` while iterating the bucket
objects.
Signed-off-by: Tomas Hozza <thozza@redhat.com>
5e591ccc3d