Add tuxreaperd micro-init and in-container zombie-reaping tests for 0.2

tests/test_tuxreaperd.sh

@@ -0,0 +1,170 @@
+#!/bin/sh
+
+# In-container tests for tuxreaperd, the tux-dock micro init system.
+#
+# tuxreaperd is container-tailored: tux-dock mounts it into created containers
+# where it runs as PID 1, acting as a subreaper (PR_SET_CHILD_SUBREAPER) with a
+# SIGCHLD reaper loop so orphaned descendants never linger as zombies.
+#
+# These tests drive tuxreaperd the same way the app does (bind-mounted, PID 1)
+# and verify zombie reaping, exit-status propagation, and signal forwarding.
+
+set -eu
+
+image=${TUX_DOCK_TEST_IMAGE:-debian:forky}
+reaper_bin=${1:-build/tuxreaperd}
+reaper_src=${2:-}
+name="tux-reaper-test-$$-$(date +%s)"
+cleanup_status=0
+failures=0
+
+run_raw() {
+    command_name=$1
+    shift
+    started=$(date +%s)
+    printf '%s\n' "[TEST OUTPUT BEGIN] $command_name"
+    set +e
+    "$@" 2>&1
+    command_status=$?
+    set -e
+    elapsed=$(( $(date +%s) - started ))
+    printf '%s\n' "[TEST OUTPUT END] $command_name"
+    printf '%s\n' "[TEST RESULT] command=$command_name status=$command_status elapsed=${elapsed}s"
+    return "$command_status"
+}
+
+cleanup() {
+    if docker container inspect "$name" >/dev/null 2>&1; then
+        printf '%s\n' "[TUI] Cleanup: Remove Container"
+        if ! docker rm -f "$name" >/dev/null 2>&1; then
+            cleanup_status=1
+        fi
+        printf '%s\n' "[TUI] Complete: Container removed"
+    fi
+}
+trap cleanup EXIT INT TERM
+
+# Resolve an absolute path for the bind mount (docker requires absolute paths).
+if [ ! -f "$reaper_bin" ]; then
+    if command -v gcc >/dev/null 2>&1 && [ -n "$reaper_src" ]; then
+        printf '%s\n' "[TUI] tuxreaperd binary not found, building $reaper_bin"
+        mkdir -p "$(dirname "$reaper_bin")"
+        gcc -O2 -static -Wall -Wextra "$reaper_src" -o "$reaper_bin"
+    else
+        printf '%s\n' "tuxreaperd binary not found at $reaper_bin (run ./compile.sh)" >&2
+        exit 1
+    fi
+fi
+reaper_dir=$(CDPATH= cd "$(dirname "$reaper_bin")" && pwd)
+reaper_bin=$reaper_dir/$(basename "$reaper_bin")
+
+if ! docker image inspect "$image" >/dev/null 2>&1; then
+    printf '%s\n' "[TUI] Pull Docker Image: $image"
+    run_raw "docker pull $image" docker pull "$image"
+else
+    printf '%s\n' "[TUI] Image available: $image"
+fi
+
+printf '%s\n' "[TUI] Create container with tuxreaperd as PID 1"
+run_raw "docker create tuxreaperd container" \
+    docker create --name "$name" -v "$reaper_bin:/usr/local/bin/tuxreaperd:ro" \
+    "$image" /usr/local/bin/tuxreaperd sleep infinity
+run_raw "docker start $name" docker start "$name"
+
+printf '%s\n' "[TUI] Verify tuxreaperd is PID 1"
+if [ "$(docker exec "$name" cat /proc/1/comm 2>/dev/null)" = "tuxreaperd" ]; then
+    printf '%s\n' "[PASS] tuxreaperd is PID 1 in the container"
+else
+    printf '%s\n' "[FAIL] PID 1 is not tuxreaperd"
+    failures=$((failures + 1))
+fi
+
+printf '%s\n' "[TUI] Spawn orphaned grandchildren inside the container"
+# Each inner shell backgrounds a short-lived sleep and exits; the orphaned
+# sleep reparents to PID 1 (tuxreaperd, the subreaper) and becomes a zombie on
+# exit unless the SIGCHLD reaper loop reaps it.
+docker exec "$name" sh -c '
+    i=0
+    while [ "$i" -lt 20 ]; do
+        sh -c "sleep 0.1 &"
+        i=$((i + 1))
+    done
+    sleep 2
+'
+printf '%s\n' "[TUI] Count zombie processes under PID 1"
+zombie_count() {
+    docker exec "$name" sh -c '
+        zombies=0
+        for f in /proc/[0-9]*/stat; do
+            [ -r "$f" ] || continue
+            line=
+            IFS= read -r line < "$f" || continue
+            rest=${line##*) }
+            set -- $rest
+            [ "$1" = Z ] && zombies=$((zombies + 1))
+        done
+        printf "%s\n" "$zombies"
+    '
+}
+zombies=999
+attempt=0
+while [ "$attempt" -lt 10 ]; do
+    zombies=$(zombie_count)
+    [ "$zombies" -eq 0 ] && break
+    attempt=$((attempt + 1))
+    sleep 1
+done
+if [ "$zombies" -eq 0 ]; then
+    printf '%s\n' "[PASS] No zombie processes remain under tuxreaperd"
+else
+    printf '%s\n' "[FAIL] $zombies zombie process(es) not reaped"
+    failures=$((failures + 1))
+fi
+
+printf '%s\n' "[TUI] Verify exit-status propagation from the reaped child"
+status=0
+run_raw "docker run tuxreaperd exit-status" \
+    docker run --rm -v "$reaper_bin:/usr/local/bin/tuxreaperd:ro" \
+    "$image" /usr/local/bin/tuxreaperd sh -c 'exit 42' || status=$?
+if [ "$status" -eq 42 ]; then
+    printf '%s\n' "[PASS] Exit status 42 propagated from the child workload"
+else
+    printf '%s\n' "[FAIL] Expected exit status 42, got $status"
+    failures=$((failures + 1))
+fi
+
+printf '%s\n' "[TUI] Verify SIGTERM forwarding through docker stop"
+if docker stop "$name" >/dev/null 2>&1; then
+    code=$(docker wait "$name")
+    if [ "$code" = "143" ]; then
+        printf '%s\n' "[PASS] SIGTERM forwarded to workload, clean shutdown (exit 143)"
+    else
+        printf '%s\n' "[FAIL] Expected container exit 143, got $code"
+        failures=$((failures + 1))
+    fi
+else
+    printf '%s\n' "[FAIL] docker stop failed (did tuxreaperd fail to forward SIGTERM?)"
+    failures=$((failures + 1))
+fi
+
+trap - EXIT INT TERM
+if [ "$failures" -gt 0 ]; then
+    printf '%s\n' "tuxreaperd tests failed: $failures failure(s)" >&2
+    exit 1
+fi
+
+printf '%s\n' "[TUI] Remove Container: $name"
+run_raw "docker rm -f $name" docker rm -f "$name"
+printf '%s\n' "[TUI] Complete: Container removed"
+
+printf '%s\n' "[TUI] Verify removal: docker container inspect $name"
+if run_raw "docker container inspect $name" docker container inspect "$name"; then
+    printf '%s\n' "Container still exists after removal" >&2
+    exit 1
+else
+    printf '%s\n' "[TUI] Complete: Removal verified"
+fi
+
+
+printf '%s\n' "tuxreaperd tests passed"
+exit "$cleanup_status"