fix: harden stall-detection enumeration and timestamp parsing

Post-merge review of GRM-168 found three defects: the docker ps
feeding the probe loop lacked a failure guard, so a slow daemon would
abort the healthcheck under pipefail exactly when diagnostics matter;
CreatedAt contains spaces so whitespace-splitting read only captured
the date and broke the 15-minute age gate (GNU date also rejects the
+0000 UTC suffix); and head -200 could truncate the inspect State
block the spec requires. Pipe-separated fields, guarded enumeration,
stripped UTC suffix, and full inspect output fix all three.

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

ansible/roles/gitea_runner/templates/runner-healthcheck.sh.j2

@@ -38,10 +38,15 @@ fi
 STALL_MINUTES={{ gitea_runner_stall_minutes }}
 DIAG_DIR="{{ gitea_runner_config_dir }}"
 now_epoch=$(date +%s)
-timeout 15 docker ps --filter "name=GITEA-ACTIONS-TASK" \
-    --format '{% raw %}{{.ID}} {{.Names}} {{.CreatedAt}}{% endraw %}' 2>/dev/null \
-    | while read -r cid cname ccreated _rest; do
-    created_epoch=$(date -d "$ccreated" +%s 2>/dev/null || echo 0)
+# Implements: REQ-1 — guard the enumeration: a slow/dead daemon must not
+# abort the healthcheck under pipefail; an empty list just skips probing.
+# Implements: REQ-2 — pipe-separate fields: CreatedAt contains spaces, so
+# whitespace-splitting `read` only captured the date and broke the age gate.
+{ timeout 15 docker ps --filter "name=GITEA-ACTIONS-TASK" \
+    --format '{% raw %}{{.ID}}|{{.Names}}|{{.CreatedAt}}{% endraw %}' 2>/dev/null || true; } \
+    | while IFS='|' read -r cid cname ccreated _rest; do
+    # GNU date rejects the redundant " +0000 UTC" suffix — drop it.
+    created_epoch=$(date -d "${ccreated% UTC}" +%s 2>/dev/null || echo 0)
     age_min=$(( (now_epoch - created_epoch) / 60 ))
     [[ "$age_min" -lt "$STALL_MINUTES" ]] && continue
     marker="$DIAG_DIR/.stall-diag-$cid"
@@ -52,7 +57,7 @@ timeout 15 docker ps --filter "name=GITEA-ACTIONS-TASK" \
             echo "=== stall diagnostics for $cname ($cid), age ${age_min}m ==="
             echo "--- exec probe: TIMEOUT (>10s) ---"
             echo "--- docker inspect ---"
-            timeout 15 docker inspect "$cid" 2>/dev/null | head -200
+            timeout 15 docker inspect "$cid" 2>/dev/null
             echo "--- docker top ---"
             timeout 15 docker top "$cid" 2>/dev/null
             echo "--- docker stats --no-stream ---"

docs/specs/GRM-170.md

@@ -0,0 +1,69 @@
+# GRM-170: Fix stall-detection robustness bugs in runner healthcheck
+
+## Problem
+
+Post-merge review of the GRM-168 stall-detection block in
+`runner-healthcheck.sh.j2` found three defects:
+
+1. **Missing `|| true` on the container enumeration.** `timeout 15
+   docker ps … | while …` runs under `set -euo pipefail`. If the daemon
+   is unresponsive — precisely the condition the section exists to
+   diagnose — `docker ps` exits nonzero, pipefail propagates it, and the
+   healthcheck dies mid-run before reaching the runner-service check.
+   Every other docker call in the script is guarded; this one is not.
+
+2. **CreatedAt split bug.** `docker ps --format '{{.ID}} {{.Names}}
+   {{.CreatedAt}}'` emits a timestamp containing spaces
+   (`2026-09-18 10:30:00 +0000 UTC`), but `read -r cid cname ccreated
+   _rest` only captures `2026-09-18` — the date part. `date -d` then
+   computes age from midnight: containers created today always appear
+   ≥N hours old, so the 15-minute gate effectively never filters.
+
+3. **`head -200` truncates `docker inspect`.** Inspect output is ~300+
+   lines and the `State` block (OOMKilled, Pid, times) the spec requires
+   can be cut off.
+
+## Approach
+
+REQ-1: Wrap the enumeration so a failed `docker ps` yields empty input
+instead of aborting the script: `{ timeout 15 docker ps … || true; } |
+while …`.
+
+REQ-2: Emit fields separated by `|` (`{{.ID}}|{{.Names}}|{{.CreatedAt}}`)
+and parse with `IFS='|' read -r cid cname ccreated _rest` so the full
+timestamp reaches `date -d`; also strip the redundant ` UTC` suffix
+because GNU date rejects `+0000 UTC` together. The age gate then
+compares real minutes.
+
+REQ-3: Remove the `head -200` truncation on `docker inspect` output so
+the full State block is captured in the diagnostics bundle.
+
+REQ-4: Diagnostics-only constraint unchanged — no kills, no restarts.
+
+## Test Plan
+
+- Render the template and run `bash -n` on the output.
+- Shell-simulate: feed a fake `docker ps` line with spaced CreatedAt and
+  verify `date -d` computes minutes correctly (manual check).
+- `make lint-all` (ansible-lint, actionlint, ruff) passes.
+- Molecule gitea_runner scenario converges with the template change.
+
+## Deploy Plan
+
+Merge via auto-merge → release (fix: commit bumps patch) → infra
+dependency-bump PR picks up the new role version → runner role applied
+on next infra run. This PR also carries the merged-but-unreleased
+GRM-168 healthcheck into the release.
+
+## Rollback Plan
+
+Revert the three-line change set; the section degrades to the GRM-168
+behavior (still diagnostics-only, just less robust).
+
+## Acceptance Criteria
+
+- [x] `docker ps` enumeration guarded against nonzero exit.
+- [x] Full CreatedAt timestamp parsed via `|` separator.
+- [x] `docker inspect` captured without truncation.
+- [x] Rendered script passes `bash -n`.
+- [x] `make lint-all` passes.