[FLINK-15792] Make Flink logs accessible via kubectl logs per default

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.10.0
• Fix Version/s: 1.12.0
• Component/s: Deployment / Kubernetes
• Labels: pull-request-available
• Assignee: Yang Wang
• Reporter: Till Rohrmann
• Created: 28/Jan/20 16:08
• Updated: 20/Jun/23 04:04
• Resolved: 07/Aug/20 06:10

Description

I think we should make Flink's logs accessible via kubectl logs per default. Firstly, this is the idiomatic way to obtain the logs from a container on Kubernetes. Secondly, especially if something does not work and the container cannot start/stops abruptly, there is no way to log into the container and look for the log.file. This makes debugging the setup quite hard.

I think the best way would be to create the Flink Docker image in such a way that it logs to stdout. In order to allow access to the log file from the web ui, it should also create a log file. One way to achieve this is to add a ConsoleAppender to the respective logging configuration. Another way could be to start the process in the console mode and then to teeing the stdout output into the log file.

Issue Links

• is blocked by: FLINK-17166 Modify the log4j-console.properties to also output logs into the files for WebUI
• relates to: FLINK-31234 Add an option to redirect stdout/stderr for flink on kubernetes
• links to: GitHub Pull Request #12240