add a table for more convenient access to docker container environment

[nabilschear]

All the docker container environment variables are joined with a comma and embedded into a single field in the docker_containers table. This makes it hard to construct queries against individual variables. This change introduces a new table called docker_container_envs that splits these environment variables out in separate rows so that they can be used in a similar manner to the process_envs table.

Structured in a similar manner to the docker_container_labels table and re-using the variable parsing code from process_envs

[mike-myers-tob]

Hi @nabilschear !

It looks like the integration test is commented out, was this intentional?

[nabilschear]

@mike-myers-tob nearly all the docker_* tables have this very simple structure for their tests. They are basically smoketests to make sure that the query can run (but don't check any returned values). See https://github.com/osquery/osquery/blob/master/tests/integration/tables/docker_image_labels.cpp as an example. In my case, I copied from this file: https://github.com/osquery/osquery/blob/master/tests/integration/tables/docker_container_labels.cpp

[nabilschear]

any updates on this one?

[directionless]

This is not indexed.

It might need additional since it's part of the row's primary key.

[nabilschear]

I removed indexed from key. It now has a similar structure to the process_envs table, which I think is right (replacing pid for id)

[directionless]

While I'm not totally sure we need it, it seems reasonably in keeping with the rest of the docker tables. Approved, pending CI

[mike-myers-tob]

I'm going to close and reopen this PR to try to rerun the CI workflows

[directionless]

I suspect the build failures are because of the LE cert expiration. That should be fixed on HEAD. Can you rebase please?

[Smjert]

I suspect the build failures are because of the LE cert expiration. That should be fixed on HEAD. Can you rebase please?

Closing and reopening the PR (as Mike previously did) automatically updates the temporary merge branch that Github uses with the CI behind the curtains, aligning it to master. It should be fine now.