Docker Desktop's VM can't resolve tailnet hostnames. Work around this by:
1. Starting a Tailscale container that joins the tailnet
2. Building the image with docker build
3. Saving to tarball with docker save
4. Pushing via skopeo inside the Tailscale container
Uses TS_CI_GATEWAY_AUTHKEY repository secret for authentication.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
## Summary
- Add `containers/nettest/` with Alpine-based Dockerfile and connectivity test script
- Add `.forgejo/workflows/build-nettest.yaml` workflow triggered by `nettest-v*` tags
- Test script checks DNS resolution and HTTPS connectivity to forge and registry
## Deployment and Testing
- [ ] Merge PR to main
- [ ] Run `mise run container-release nettest v0.1.0` to trigger first build
- [ ] Verify workflow runs successfully and container can reach tailnet services
- [ ] Manually test from minikube: `kubectl run nettest --rm -it --image=registry.tail8d86e.ts.net/blumeops/nettest:v0.1.0`
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Reviewed-on: https://forge.tail8d86e.ts.net/eblume/blumeops/pulls/52
