fix: healthcheck printf returns 0

[ruggi99]

What kind of change does this PR introduce?

Bug fix and feature

What is the current behavior?

Currently healthchecks based on printf return always 0 and are false-positive.

Healthcheck config (the port is wrong in order to test, rest has 3000 open, 4000 is closed):

$ docker inspect -f '{{json .Config.Healthcheck }}' supabase-rest
{"Test":["CMD","printf","\\0",">","/dev/tcp/localhost/4000"],"Interval":5000000000,"Timeout":5000000000,"Retries":3}

$ docker inspect -f '{{json .State.Health.Log }}' supabase-rest
[{"Start":"2023-01-20T17:51:21.136686444Z","End":"2023-01-20T17:51:21.203277311Z","ExitCode":0,"Output":"\u0000printf: warning: ignoring excess arguments, starting with '>'\n"},{"Start":"2023-01-20T17:51:26.211514237Z","End":"2023-01-20T17:51:26.279377587Z","ExitCode":0,"Output":"\u0000printf: warning: ignoring excess arguments, starting with '>'\n"},{"Start":"2023-01-20T17:51:31.286512431Z","End":"2023-01-20T17:51:31.350657173Z","ExitCode":0,"Output":"\u0000printf: warning: ignoring excess arguments, starting with '>'\n"},{"Start":"2023-01-20T17:51:36.362020785Z","End":"2023-01-20T17:51:36.424323443Z","ExitCode":0,"Output":"\u0000printf: warning: ignoring excess arguments, starting with '>'\n"},{"Start":"2023-01-20T17:51:41.43299977Z","End":"2023-01-20T17:51:41.50987106Z","ExitCode":0,"Output":"printf: warning: ignoring excess arguments, starting with '>'\n\u0000"}]

Exit code is always 0

What is the new behavior?

$ docker inspect -f '{{json .Config.Healthcheck }}' supabase-rest
{"Test":["CMD","bash","-c","printf \\0 > /dev/tcp/localhost/4000"],"Interval":5000000000,"Timeout":5000000000,"Retries":3}

$ docker inspect -f '{{json .State.Health.Log }}' supabase-rest
[{"Start":"2023-01-20T18:01:32.979767241Z","End":"2023-01-20T18:01:33.042339059Z","ExitCode":1,"Output":"bash: connect: Cannot assign requested address\nbash: /dev/tcp/localhost/4000: Cannot assign requested address\n"},{"Start":"2023-01-20T18:01:38.04912028Z","End":"2023-01-20T18:01:38.094944501Z","ExitCode":1,"Output":"bash: connect: Cannot assign requested address\nbash: /dev/tcp/localhost/4000: Cannot assign requested address\n"}]

Additional context

Added Healthcheck to PostgREST also

[coveralls]

Pull Request Test Coverage Report for Build 3970099738

• 7 of 7 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.04%) to 62.39%

---

Totals
Change from base Build 3965757735:	0.04%
Covered Lines:	3618
Relevant Lines:	5799

---

💛 - Coveralls

[github-actions]

🎉 This PR is included in version 1.34.4 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[sweatybridge]

Btw I don't think PostgREST exposes a shell so we need to revert that health check

[ruggi99]

You're partially right.
PostgREST ships with a shell on ARM64, but not on AMD64.
Sorry about that.