Fix reading logs from remote Docker daemon with TLS

[longsleep]

The Docker daemon can listen with TLS encryption and thus the Docker client needs to make HTTPS requests when the configured Docker host has https scheme configured. Furthermore other HTTP client related settings when the Docker daemon is using http or https protocol. This change initializes the Docker client HTTP support from the scraping configuration to let TLS connections succeed.

Fixes: https://github.com/grafana/loki/issues/6894

This is more or less a trivial fix, as most of the details are already implemented by Prometheus. Though the details required extending the targetGroup struct as did not pass through the required configuration. With some refactoring the change could probably be made more elegant. This is a quick fix which works for me

Checklist

• [ ] Documentation added
• [ ] Tests updated
• [ ] Is this an important fix or new feature? Add an entry in the CHANGELOG.md.
• [ ] Changes that require user attention or interaction to upgrade are documented in docs/sources/upgrading/_index.md

[CLAassistant]

All committers have signed the CLA.

[grafanabot]

./tools/diff_coverage.sh ../loki-main/test_results.txt test_results.txt ingester,distributor,querier,querier/queryrange,iter,storage,chunkenc,logql,loki

Change in test coverage per package. Green indicates 0 or positive change, red indicates that test coverage for a package fell.

+           ingester	0%
+        distributor	0%
+            querier	0%
+ querier/queryrange	0%
+               iter	0%
+            storage	0%
+           chunkenc	0%
+              logql	0%
+               loki	0%

[stale[bot]]

Hi! This issue has been automatically marked as stale because it has not had any activity in the past 30 days.

We use a stalebot among other tools to help manage the state of issues in this project. A stalebot can be very useful in closing issues in a number of cases; the most common is closing issues or PRs where the original reporter has not responded.

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[longsleep]

Thanks for the reply, will pick this up again asap.

[jeschkies]

@longsleep should we take over? 😊

[longsleep]

@longsleep should we take over?

@jeschkies if you can please do. I can't tell when I will have the time to come back to this yet (but it is not forgotten).

[jeschkies]

@longsleep could you give me permissions to push to you branch?

[longsleep]

@longsleep could you give me permissions to push to you branch?

@jeschkies sure I invited you to my fork, let me know if that is not enough. Thanks!

[jeschkies]

Thanks, @longsleep. Could you also sign the CLA?

[longsleep]

Thanks, @longsleep. Could you also sign the CLA?

Sure, done!