[diagramsnet container]: Prevent Chromium zombie processes from stacking

[al-cheb]

Issue:

When specifying low memory limits for a diagramsnet container in Kubernetes, chromium processes could remain in a zombie state if we send a lot of parallel requests.

The diagramsnet service just stopped working with following error, but the container is still alive.

Error 400: : An error occurred while converting the diagram: connect ECONNREFUSED 127.0.0.1:40619

E.g:

$  seq 10 | xargs -P 10 -I -- curl -k https://kroki.local/diagramsnet/svg/eNpLyUwvSizIUHBXqPZIzcnJ17ULzy_KSanlAgB1EAjQ
Error 400: Error: An error occurred while converting the diagram: Navigating frame was detached
Error: Navigating frame was detached
    at #onFrameDetached (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/LifecycleWatcher.js:100:47)
    at file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/third_party/mitt/mitt.js:36:7
    at Array.map (<anonymous>)
    at Object.emit (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/third_party/mitt/mitt.js:35:20)
    at CdpFrame.emit (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/common/EventEmitter.js:77:23)
    at #removeFramesRecursively (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/FrameManager.js:448:15)
    at #onClientDisconnect (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/FrameManager.js:91:42)Error 400: : An error occurred while converting the diagram: connect ECONNREFUSED 127.0.0.1:43847
Error 400: Error: An error occurred while converting the diagram: Navigating frame was detached
Error: Navigating frame was detached
    at #onFrameDetached (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/LifecycleWatcher.js:100:47)
    at file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/third_party/mitt/mitt.js:36:7
    at Array.map (<anonymous>)
    at Object.emit (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/third_party/mitt/mitt.js:35:20)
    at CdpFrame.emit (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/common/EventEmitter.js:77:23)
    at #removeFramesRecursively (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/FrameManager.js:448:15)
    at #onClientDisconnect (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/FrameManager.js:91:42)
    at runNextTicks (node:internal/process/task_queues:60:5)
    at listOnTimeout (node:internal/timers:540:9)
    at process.processTimers (node:internal/timers:514:7)Error 400: Error: An error occurred while converting the diagram: Navigating frame was detached
Error: Navigating frame was detached
    at #onFrameDetached (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/LifecycleWatcher.js:100:47)
    at file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/third_party/mitt/mitt.js:36:7
    at Array.map (<anonymous>)
    at Object.emit (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/third_party/mitt/mitt.js:35:20)
    at CdpFrame.emit (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/common/EventEmitter.js:77:23)
    at #removeFramesRecursively (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/FrameManager.js:448:15)
    at #onClientDisconnect (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/FrameManager.js:91:42)
    at runNextTicks (node:internal/process/task_queues:60:5)
    at listOnTimeout (node:internal/timers:540:9)
    at process.processTimers (node:internal/timers:514:7)Error 400: Error: An error occurred while converting the diagram: Navigating frame was detached
Error: Navigating frame was detached
    at #onFrameDetached (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/LifecycleWatcher.js:100:47)
    at file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/third_party/mitt/mitt.js:36:7
    at Array.map (<anonymous>)
    at Object.emit (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/third_party/mitt/mitt.js:35:20)
    at CdpFrame.emit (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/common/EventEmitter.js:77:23)
    at #removeFramesRecursively (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/FrameManager.js:448:15)
    at #onClientDisconnect (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/FrameManager.js:91:42)Error 400: : An error occurred while converting the diagram: connect ECONNREFUSED 127.0.0.1:43847
Error 400: : An error occurred while converting the diagram: connect ECONNREFUSED 127.0.0.1:43847
Error 400: : An error occurred while converting the diagram: connect ECONNREFUSED 127.0.0.1:43847
Error 400: : An error occurred while converting the diagram: connect ECONNREFUSED 127.0.0.1:43847
Error 400: Error: An error occurred while converting the diagram: Navigating frame was detached
Error: Navigating frame was detached
    at #onFrameDetached (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/LifecycleWatcher.js:100:47)
    at file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/third_party/mitt/mitt.js:36:7
    at Array.map (<anonymous>)
    at Object.emit (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/third_party/mitt/mitt.js:35:20)
    at CdpFrame.emit (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/common/EventEmitter.js:77:23)
    at #removeFramesRecursively (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/FrameManager.js:448:15)
    at #onClientDisconnect (file:///usr/local/kroki/node_modules/puppeteer-core/lib/esm/puppeteer/cdp/FrameManager.js:91:42)

Normal state:

/usr/local/kroki $ ps aux
PID   USER     TIME  COMMAND
    1 kroki     0:00 node src/index.js
   17 kroki     0:00 {chromium} /usr/lib/chromium/chrome --allow-pre-commit-input --disable-background-networking --disable-background-timer-throttl
   19 kroki     0:00 /usr/lib/chromium/chromium --type=zygote --no-zygote-sandbox --no-sandbox --headless --headless
   20 kroki     0:00 /usr/lib/chromium/chromium --type=zygote --no-sandbox --headless --headless
   36 kroki     0:00 /usr/lib/chromium/chromium --type=gpu-process --no-sandbox --disable-dev-shm-usage --disable-breakpad --headless --ozone-platfo
   42 kroki     0:00 /usr/lib/chromium/chromium --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=n
   46 kroki     0:00 /usr/lib/chromium/chromium --type=renderer --headless --first-renderer-process --no-sandbox --disable-dev-shm-usage --disable-b

Hanging Chromium processes in the zombie state:

/usr/local/kroki $ ps
PID   USER     TIME  COMMAND
    1 kroki     0:00 node src/index.js
   19 kroki     0:00 [chromium]
   20 kroki     0:00 [chromium]
   36 kroki     0:00 [chromium]
   42 kroki     0:00 [chromium]
   46 kroki     0:00 [chromium]
   76 kroki     0:00 sh -c clear; (bash || ash || sh)
   83 kroki     0:00 ash
  113 kroki     0:00 sh
  157 kroki     0:00 [chromium]
  162 kroki     0:00 [chromium]
  168 kroki     0:00 [chromium]
  174 kroki     0:00 [chromium]
  181 kroki     0:00 [chromium]
  243 kroki     0:00 ps

What did you expect to see?
The Chromium processes should be properly handled.

[ggrossetie]

We did something similar in Mermaid: d2ee78b