Hi Ingo, Thanks a lot for this proposal!
We had a related discussion recently in the context of FLINK-19520 (randomizing tests configuration) [1]. I believe other scenarios will benefit as well. For the end users, I think substitution in configuration files is preferable over parsing env vars in Flink code. And for cases without such a file, we could have a default one on the classpath with all substitutions defined (and then merge everything from the user-supplied file). [1] https://issues.apache.org/jira/browse/FLINK-19520 Regards, Roman On Mon, Jan 18, 2021 at 11:11 AM Ingo Bürk <i...@ververica.com> wrote: > Hi everyone, > > in Ververica Platform we offer a feature to use environment variables in > the Flink configuration¹, e.g. > > ``` > s3.access-key: ${S3_ACCESS_KEY} > ``` > > We've been discussing internally whether contributing such a feature to > Flink directly would make sense and wanted to start a discussion on this > topic. > > An alternative way to do so from the above would be parsing those directly > based on their name, so instead of having it defined in the Flink > configuration as above, it would get automatically set if something like > $FLINK_CONFIG_S3_ACCESS_KEY was set in the environment. This is somewhat > similar to what e.g. Spring does, and faces similar challenges (dealing > with "."s etc.) > > Although I view both of these approaches as mostly orthogonal, supporting > both very likely wouldn't make sense, of course. So I was wondering what > your opinion is in terms of whether the project would benefit from > environment variable support for the Flink configuration, and whether there > are tendencies as to which approach to go with. > > ¹ > > https://docs.ververica.com/user_guide/application_operations/deployments/configure_flink.html#environment-variables > > Best regards > Ingo >
