feat: improve HTTP API logging, honor no-startup-message

[jinnatar]

They provide little useful information outside debugging and anything at
Info level is broadcast over shoutrrr.

[codecov]

Codecov Report

Merging #1091 (ac8ad56) into main (4a66a69) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1091   +/-   ##
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  Coverage   61.96%   61.96%           
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  Files          22       22           
  Lines        1438     1438           
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  Hits          891      891           
  Misses        463      463           
  Partials       84       84           

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[piksel]

I don't think it is that straight forward. It essentially replaces the startup message and when --debug isn't passed, there is no output from starting watchtower at all which might be confusing for some users. That being said, the startup message should probably be displayed, but incorporating whether the API is enabled. That way you could disable it as well using --no-startup-message.

[simskij]

I agree with @piksel on this.

[jinnatar]

ACK, reworking it to use --no-startup-message

[jinnatar]

@piksel PTAL. I left the runHTTPServer logging as Debug since it's of questionable value to a user, and changed the Info level log to contain the listen port so it's more useful in indicating the API is functioning and where to find it.

Example run:

%> ./watchtower daemon --http-api-update --http-api-token foo --http-api-periodic-polls --no-startup-message
INFO[0001] Watchtower v0.0.0-unknown                     notify=no
INFO[0001] Using no notifications                        notify=no
INFO[0001] Only checking containers with name "daemon"   notify=no
INFO[0001] Scheduling first run: 2021-10-24 16:29:02 +0300 EEST  notify=no
INFO[0001] Note that the first check will be performed in 23 hours, 59 minutes, 59 seconds  notify=no
INFO[0001] The HTTP API is enabled at :8080.             notify=no

[jinnatar]

There is still a slight annoyance left where watchtower is very silent and unhelpful, but I believe this is a deeper issue than I can resolve here:

%> ./watchtower daemon --http-api-update --http-api-token foo 
<absolutely no output produced>

i.e. if the API mode is enabled but no periodic updates are enabled as is the default, startup messages aren't processed at all since the call is blocked. Probably they should still happen, but then the flow needs to be changed a bit and my Go isn't exactly that good to do it in this PR without undue risk to general stability. :-)

Edit: nvm, found a clean way to fix this issue at the same time.

[piksel]

Looks good, except for a few smaller things.

The API parts are messy and should be redone (ref #939). But this should be sufficient for now. Just take a look at the comments.

[jinnatar]

I agree with @piksel on this.

I believe these have been addressed but GitHub still marks this comment as blocking merge for some reason.