The image apps build FROM, with its health check (closes #45)

The Dockerfile's last stage is now the image of "Deployment" in SPEC.md: Ubuntu 26.04 with ca-certificates, nix-bin and runit from a dated snapshot whose InRelease files are checked by hash, nixpkgs from its release file checked by SHA-256, runsvinit built at a fixed commit, and smallwebwaf as a runit service. smallwebwaf answers /_smallwebwaf/healthz, and `smallwebwaf healthcheck` is the image's HEALTHCHECK. script/example-app builds an app on the image and checks it end to end. The Nix profile comes last on the PATH: first, busybox from nixpkgs replaced runit's own runsvdir and sv. SPEC.md is corrected to match what was built. Model: opus-5-5
2026-10-04 07:07:24 +00:00
parent 0750879e58
commit 74ba64235c
17 changed files with 584 additions and 71 deletions
@@ -0,0 +1,88 @@
+#!/bin/sh
+# script/example-app: build the image, and on it the example app in
+# deploy/example-app, then run the app's container and check that the
+# health check passes, that a request is served through smallwebwaf,
+# that `sv stop` stops smallwebwaf in order, and that `docker stop`
+# stops the container without having to kill it. The container and both
+# images are removed however the script ends. Building the app needs
+# network access, for nixpkgs' binary cache. script/check does not run
+# this.
+set -eu
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
+
+# Named after this run, so that runs in other clones on the same host
+# never touch each other's.
+NAME="$("$SCRIPT_DIR/projectname")-example-$$"
+IMAGE="$NAME-base"
+APP_IMAGE="$NAME-app"
+CONTAINER="$NAME"
+
+cleanup() {
+    docker rm --force "$CONTAINER" >/dev/null 2>&1 || true
+    docker rmi --force "$APP_IMAGE" "$IMAGE" >/dev/null 2>&1 || true
+}
+
+fail() {
+    echo "example-app: $*; the container's output:" >&2
+    docker logs "$CONTAINER" >&2 || true
+    exit 1
+}
+
+# wait_for <what fails> <command>...: run the command every second until
+# it succeeds, for at most a minute.
+wait_for() {
+    failure="$1"
+    shift
+    tries=0
+    until "$@"; do
+        tries=$((tries + 1))
+        [ "$tries" -lt 60 ] || fail "$failure"
+        sleep 1
+    done
+}
+
+healthy() {
+    status="$(docker inspect --format '{{.State.Health.Status}}' "$CONTAINER")"
+    [ "$status" = healthy ]
+}
+
+# logged <text>: the container's output holds text.
+logged() {
+    docker logs "$CONTAINER" 2>&1 | grep -qF "$1"
+}
+
+main() {
+    cd "$ROOT"
+    trap cleanup EXIT
+    trap 'exit 1' HUP INT TERM
+
+    docker build --no-cache -t "$IMAGE" .
+    docker build --no-cache --build-arg SMALLWEBWAF_IMAGE="$IMAGE" \
+        -t "$APP_IMAGE" deploy/example-app
+
+    docker run --detach --name "$CONTAINER" --publish 127.0.0.1::8080 \
+        "$APP_IMAGE" >/dev/null
+    wait_for "the health check did not pass" healthy
+    echo "example-app: the health check passes"
+
+    address="$(docker port "$CONTAINER" 8080/tcp)"
+    page="$(curl --fail --silent --show-error --max-time 10 "http://$address/")" ||
+        fail "no answer on port 8080"
+    [ "$page" = "hello from the example app" ] || fail "port 8080 answered $page"
+    wait_for "smallwebwaf logged no request it forwarded" logged '"action":"forward"'
+    echo "example-app: smallwebwaf passes a request to the app and its answer back"
+
+    docker exec "$CONTAINER" sv stop smallwebwaf >/dev/null ||
+        fail "sv stop smallwebwaf failed"
+    wait_for "smallwebwaf did not stop in order" logged '"msg":"stopped"'
+    echo "example-app: sv stop stops smallwebwaf in order"
+
+    docker stop "$CONTAINER" >/dev/null
+    status="$(docker inspect --format '{{.State.ExitCode}}' "$CONTAINER")"
+    [ "$status" = 0 ] || fail "docker stop left exit status $status"
+    echo "example-app: docker stop stops the container in order"
+}
+
+main "$@"