Without a resolver directive, nginx resolves upstream hostnames once at
startup and caches the IP forever. When the API container restarts it gets
a new Docker-assigned IP, causing 502 Bad Gateway until nginx is reloaded.
Fix:
- Add 'resolver 127.0.0.11 valid=10s' (Docker embedded DNS)
- Use a variable in proxy_pass ('set \ api') so nginx
re-resolves on every request using the resolver above
- Variable proxy_pass passes the full request URI as-is, so /api/...
correctly maps to http://api:8000/api/... without double-pathing
- poller/docker-entrypoint.sh: convert from CRLF+BOM to LF (UTF-8 no BOM)
Windows saved the file with a UTF-8 BOM which made the Linux kernel
reject the shebang with 'exec format error', crashing the poller.
- infrastructure/openbao/init.sh: same CRLF -> LF fix
- poller/Dockerfile: add sed to strip CRLF and BOM at image build time
as a defensive measure for future Windows edits
- docker-compose.override.yml: add 'restart: on-failure' to api and poller
so they recover from the postgres startup race (TimescaleDB restarts
postgres after initdb, briefly causing connection refused on first boot)
- .gitattributes: enforce LF for all text/script/code files so git
normalises line endings on checkout and prevents this class of bug
