nginx resolves the api/web service names to a container IP once, at
its own worker-process startup. docker compose up -d only recreates
containers whose image/config changed, so nginx keeps proxying to the
old, now-dead IP after a deploy rebuilds those containers - every
request 502s, which shows up in the browser as a misleading CORS
error since the bare 502 carries no Access-Control-Allow-Origin
header. Confirmed live: this caused a real multi-hour production
outage after the last two deploys.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
sakshamandClaude Sonnet 5
8ec7ca0881