Add Docker tests for default config and $ZEBRA_CONF_PATH

[teor2345]

Motivation

We want to test that our Docker build scripts configure Zebra correctly:

• check that $ZEBRA_CONF_PATH works
• make sure the default Docker config works with the latest Zebra version

Suggested Solution

• move the default Docker config into a file
• add that file to the Zebra config test directory, all configs in this directory are automatically tested with Zebra:
  • https://github.com/ZcashFoundation/zebra/tree/main/zebrad/tests/common/configs
• add a Docker test for the default config
• add a Docker test for $ZEBRA_CONF_PATH

Here's one possible test script:

# make sure Zebra runs with the default docker config
docker run ... | grep --max-count=1 'estimated progress to chain tip.*BeforeOverwinter'
docker stop ...

# make sure Zebra runs with a custom docker config
TODO: copy the file into docker?
export ZEBRA_CONF_PATH=`zebra/zebrad/tests/common/configs/v1.0.0-rc.2.toml`
docker run ... | grep --max-count=1 'v1.0.0-rc.2.toml'
docker stop ...

Related Work

Originally posted by @teor2345 in #5163 (comment)

The test script depends on PR #5733 merging.

[mpguerra]

removing this one from the release candidate epic

[teor2345]

This isn't causing any problems for us right now, but we should test this new docker feature soon. (In the next sprint is ok.)

[teor2345]

I added some more details to this ticket, and a possible test script.

[teor2345]

@mpguerra I moved this ticket out of this sprint, because some devops tasks were still open from last sprint.

But feel free to move it back in!