imagebuildah: fix an attempt to write to a nil map #3533
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
If the build for a single stage fails, we break out of the loop that's iterating through all of the stages over in its own goroutine, and start cleaning up after the stages that were already completed. Because the function that launched that goroutine also calls its cleanup function in non-error cases, the cleanup function sets the map that's used to keep track of what needs to be cleaned up to `nil` after the function finishes iterating through the map, so that we won't try to clean up (a given thing that needs to be cleaned up) more than once. Because the loop that's iterating through all of the stages is running in its own goroutine, it doesn't stop when the function that started it returns in error cases, so it would still attempt to build subsequent stages. Have it check for cases where the map variable has already been cleared, or if one of the stages that it's already run returned an error. If the function that it calls to build the stage, using the map variable as a parameter, is already running at that point, it'll have a non-`nil` map, so it won't crash, but it might not be cleaned up correctly, either. If such a stage finishes, either successfully or with an error, the goroutine would try to pass the result back to its parent(?) goroutine over a channel that was no longer being read from, and it would stall, never releasing the jobs semaphore. Because we started sharing that semaphore across multiple-platform builds, builds for other platforms would stall completely, and the whole build would stall. Make the results channel into a buffered channel to allow it to not stall there. Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
openshift-ci
bot
added
kind/bug
|
/approve |
|
[APPROVALNOTIFIER] This PR is APPROVED This pull-request has been approved by: nalind, rhatdan The full list of commands accepted by this bot can be found here. The pull request process is described here
Needs approval from an approver in each of these files:
Approvers can indicate their approval by writing |
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
What type of PR is this?
/kind bug
What this PR does / why we need it:
If the build for a single stage fails, we break out of the loop that's iterating through all of the stages over in its own goroutine, and start cleaning up after the stages that were already completed.
Because the function that launched that goroutine also calls its cleanup function in non-error cases, the cleanup function sets the map that's used to keep track of what needs to be cleaned up to
nilafter the function finishes iterating through the map, so that we won't try to clean up (a given thing that needs to be cleaned up) more than once.Because the loop that's iterating through all of the stages is running in its own goroutine, it doesn't stop when the function that started it returns in error cases, so it would still attempt to build subsequent stages. Have it check for cases where the map variable has already been cleared, or if one of the stages that it's already run returned an error. If the function that it calls to build the stage, using the map variable as a parameter, is already running at that point, it'll have a non-
nilmap, so it won't crash, but it might not be cleaned up correctly, either.If such a stage finishes, either successfully or with an error, the goroutine would try to pass the result back to its parent(?) goroutine over a channel that was no longer being read from, and it would stall, never releasing the jobs semaphore. Because we started sharing that semaphore across multiple-platform builds, builds for other platforms would stall completely, and the whole build would stall. Make the results channel into a buffered channel to allow it to not stall there.
How to verify it
New integration test!
Which issue(s) this PR fixes:
None
Special notes for your reviewer:
Does this PR introduce a user-facing change?