fix: chromium memory leaks

[gulien]

Close #642.

⚠️ A single Chromium browser is now started, and it now works as the same manner as LibreOffice "stateful", i.e.:

• No concurrent conversions.
• If browser is not healthy, it is restarted before a conversion.

Flags

New:

• --chromium-restart-after - Number of conversions after which Chromium will automatically restart. Set to 0 to disable this feature (default 0).
• --chromium-auto-start - Automatically launch Chromium upon initialization if set to true; otherwise, Chromium will start at the time of the first conversion (default false).
• --chromium-start-timeout - Maximum duration to wait for Chromium to start or restart (default 10s).

Deprecated flag: chromium-failed-starts-threshold

Metrics

New:

• chromium_requests_queue_size - Current number of Chromium conversion requests waiting to be treated.
• chromium_restarts_count - Current number of Chromium restarts.

Deprecated:

• chromium_active_instances_count
• chromium_failed_starts_count

[codecov-commenter]

Codecov Report

Merging #705 (416e40b) into main (258876d) will increase coverage by 0.17%.
The diff coverage is 96.09%.

❗ Current head 416e40b differs from pull request most recent head 41cd16e. Consider uploading reports for the commit 41cd16e to get more accurate results

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@@            Coverage Diff             @@
##             main     #705      +/-   ##
==========================================
+ Coverage   93.24%   93.42%   +0.17%     
==========================================
  Files          36       40       +4     
  Lines        3138     3268     +130     
==========================================
+ Hits         2926     3053     +127     
- Misses        135      137       +2     
- Partials       77       78       +1     

Files	Coverage Δ
pkg/gotenberg/flags.go	100.00% <100.00%> (ø)
pkg/gotenberg/mocks.go	100.00% <100.00%> (ø)
pkg/gotenberg/supervisor.go	100.00% <100.00%> (ø)
pkg/modules/api/mocks.go	100.00% <100.00%> (ø)
pkg/modules/chromium/debug.go	100.00% <100.00%> (ø)
pkg/modules/chromium/mocks.go	100.00% <100.00%> (ø)
pkg/modules/chromium/routes.go	98.40% <100.00%> (-1.60%)	⬇️
pkg/modules/logging/logging.go	90.21% <100.00%> (ø)
pkg/modules/pdfcpu/pdfcpu.go	100.00% <100.00%> (ø)
pkg/modules/chromium/chromium.go	97.33% <97.18%> (+5.33%)	⬆️
... and 2 more

... and 1 file with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[gulien]

@petternordlanderhelo @JulienWeintraub

Image gulnap/gotenberg:chromium-memory-leaks-fix is available for your tests.

It will not solve the memory leaks on Chromium side, but at least it’s mitigated in Gotenberg. Also, faster unitary conversion.

[gulien]

This version is currently running (smoothly) on the demo instance. I'm going to merge this PR, but feel free to keep me informed if you notice anything 😉

[JulienWeintraub]

This version is currently running (smoothly) on the demo instance. I'm going to merge this PR, but feel free to keep me informed if you notice anything 😉

Thanks @gulien for the job !
I'll test it as soon as I have a moment

[gulien]

Thanks @JulienWeintraub! There is also now a gotenberg/gotenberg:edge version for testing purpose 👍
FYI, the memory is still growing, but less than before AFAIK.