fix: handle multiple nginx-proxy replicas sharing a label

[JamBalaya56562]

What

Handle the case where the nginx-proxy (or docker-gen) detection label matches more than one container. Closes #1006.

Why

labeled_cid returns one container ID per line, so when several nginx replicas share the same label, get_nginx_proxy_container returns multiple newline-separated IDs. Code that treated that as a single ID embedded it directly in the Docker API URL and broke: the health check reported ... isn't running, the reload reached no replica, and the startup check failed with can't get docker-gen container id for multiple all-in-one replicas.

How

• check_nginx_proxy_container_run: read the IDs into an array; the proxy is considered up if any matched container is running.
• reload_nginx: iterate over every docker-gen and nginx-proxy ID (SIGHUP, or docker exec for the all-in-one path).
• entrypoint.sh startup check: new nginx_proxy_is_docker_gen helper iterates the IDs to detect a bundled docker-gen, instead of passing the whole string to is_docker_gen_container.

With a single matching container everything behaves as before (one iteration), so the docker_api / docker_api_legacy tests are unchanged.

Test

New nginx_replicas integration test covers both paths: (1) separate docker-gen + two labeled nginx replicas — both receive SIGHUP and the health check passes; (2) two all-in-one nginx-proxy replicas — the companion starts instead of failing the docker-gen check.

Verified locally

Two labeled replicas: get_nginx_proxy_container returns 2 IDs, the health check passes, reload_nginx sends SIGHUP to both, and the companion starts cleanly with two all-in-one replicas (the old single-arg check failed there).

Out of scope

docker_restart (LETSENCRYPT_<cid>_RESTART_CONTAINER) targets proxied app containers, not nginx replicas, so it is unaffected.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR fixes nginx-proxy/docker-gen detection and reload behavior when the detection label matches multiple containers (e.g., Swarm replicas), preventing newline-separated container IDs from breaking Docker API calls and startup checks (closes #1006).

Changes:

• Update check_nginx_proxy_container_run to treat the proxy as “up” if any matched replica is running.
• Update reload_nginx to iterate over all matched docker-gen and nginx-proxy container IDs (SIGHUP or all-in-one docker exec path).
• Add an integration test (nginx_replicas) and wire it into the test suite and CI matrix.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
app/functions.sh	Iterates over multiple matched container IDs for health checks, reloads, and bundled docker-gen detection.
app/entrypoint.sh	Uses the new helper to detect bundled docker-gen across multiple nginx-proxy replicas.
test/tests/nginx_replicas/run.sh	Adds an integration test covering separate docker-gen + multiple nginx replicas and multiple all-in-one replicas.
test/config.sh	Registers the new nginx_replicas test in the global test list.
.github/workflows/test.yml	Adds nginx_replicas to the GitHub Actions matrix.

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[JamBalaya56562]

Addressed the Copilot review (grammar fix: "an nginx-proxy container ID").

[buchdag]

@JamBalaya56562 please flag AI-generated PR explicitly in the PR description (ie "🤖 Generated with Claude Code" like in this PR) and add the AI agent as co-author of the commits.

[JamBalaya56562]

@buchdag done, added Claude Code as co-author on the commits. The AI-generated flag is already in the PR description.