Propagate SIGTERM for graceful shutdown #110
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 process receiving the signal is PID 1, it gets special treatment by the kernel; if it hasn't registered a handler for the signal, the kernel won't fall back to default behavior, and nothing happens. Prior to this patch, the entrypoint script is PID 1 in the container, and by default, shell does not register SIGTERM handler. As a result, `docker stop` will not work properly when trying to gracefully shutdown the container. This patch adds `tini` to be the PID 1 in the container to do PID 1 things, and correctly propagate the SIGTERM signal.
|
Why not just update https://github.com/mintel/dex-k8s-authenticator/blob/master/entrypoint.sh#L9 to use: |
|
@jimmidyson using exec is still not ideal. the go program might just assume using the default SIGTERM handler, which would kill itself if it's not PID1. But that behavior is not the case if it's running as PID 1. Plus, normally, a program won't do PID 1 things like reaping processes that reparented to it. |
jimmidyson
approved these changes
Oct 22, 2019
|
Thanks both - bit of an oversight on my part to not use this originally. 👍 |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
If the process receiving the signal is PID 1, it gets special treatment
by the kernel; if it hasn't registered a handler for the signal, the
kernel won't fall back to default behavior, and nothing happens. Prior
to this patch, the entrypoint script is PID 1 in the container, and by
default, shell does not register SIGTERM handler. As a result,
docker stopwill not work properly when trying to gracefully shutdown thecontainer.
This patch adds
tinito be the PID 1 in the container to do PID 1things, and correctly propagate the SIGTERM signal.