Add polling Docker deployments

Co-authored-by: Heaust Azure <heaust.azure@gmail.com>

README.md

@@ -41,6 +41,16 @@ prebuilt package assets, Monaco, and the persistent SQLite volume. Configure the
 path in `compose.yaml`. The default port binding is private to the VPS at `127.0.0.1:5002`; put
 Caddy or nginx in front of it for HTTPS. Follow logs with `docker compose logs -f yawn`.
 
+To check for new pushes every minute, add this entry with `crontab -e`:
+
+```cron
+* * * * * $HOME/yawn/server/poll-deploy.sh >> $HOME/yawn-deploy.log 2>&1
+```
+
+The poller compares `origin/main` with the last healthy deployed revision and does nothing when they
+match. A shared lock prevents overlapping manual and scheduled deployments. Failed deployments do
+not update the revision marker, so the next poll retries them.
+
 Run the previous VitePress documentation site with `npm start`.
 
 Run `npm run coredocs` for the raw worker-message, shared-memory, and render-graph reference intended for custom handles, editors, and direct SAB clients.

server/deploy-docker.sh

@@ -3,13 +3,16 @@ set -euo pipefail
 
 repository="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
 expected_repository="$HOME/yawn"
+state_directory="$HOME/.local/state/yawn"
+deployed_revision_file="$state_directory/deployed-revision"
+compose=(docker compose --project-name yawn --project-directory "$repository" --file "$repository/compose.yaml")
 
 if [[ "$repository" != "$expected_repository" ]]; then
     printf 'Expected the repository at %s, found %s\n' "$expected_repository" "$repository" >&2
     exit 1
 fi
 
-for command in git docker; do
+for command in git docker flock; do
     if ! command -v "$command" >/dev/null 2>&1; then
         printf 'Missing required command: %s\n' "$command" >&2
         exit 1
@@ -20,6 +23,13 @@ if ! docker compose version >/dev/null 2>&1; then
     exit 1
 fi
 
+mkdir -p "$state_directory"
+exec 9>"$state_directory/deploy.lock"
+if ! flock -n 9; then
+    printf 'Another Yawn deployment is already running.\n'
+    exit 0
+fi
+
 cd "$repository"
 
 if [[ "$(git branch --show-current)" != "main" ]]; then
@@ -41,10 +51,10 @@ if [[ "$(git rev-parse HEAD)" != "$fetched" ]]; then
 fi
 
 printf 'Building the production image...\n'
-docker compose build --pull yawn
+"${compose[@]}" build --pull yawn
-docker compose up -d --remove-orphans yawn
+"${compose[@]}" up -d --remove-orphans yawn
 
-container="$(docker compose ps -q yawn)"
+container="$("${compose[@]}" ps -q yawn)"
 if [[ -z "$container" ]]; then
     printf 'Docker Compose did not create the Yawn container.\n' >&2
     exit 1
@@ -55,11 +65,14 @@ for _ in {1..60}; do
     status="$(docker inspect --format '{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}' "$container")"
     case "$status" in
         healthy)
+            temporary_revision="$(mktemp "$state_directory/deployed-revision.XXXXXX")"
+            git rev-parse HEAD >"$temporary_revision"
+            mv -f -- "$temporary_revision" "$deployed_revision_file"
             printf 'The Yawn container is healthy.\n'
             exit 0
             ;;
         unhealthy | exited | dead)
-            docker compose logs --tail 50 yawn >&2
+            "${compose[@]}" logs --tail 50 yawn >&2
             exit 1
             ;;
     esac
@@ -67,5 +80,5 @@ for _ in {1..60}; do
 done
 
 printf 'Yawn did not become healthy before the timeout.\n' >&2
-docker compose logs --tail 50 yawn >&2
+"${compose[@]}" logs --tail 50 yawn >&2
 exit 1

server/poll-deploy.sh

@@ -0,0 +1,67 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repository="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
+expected_repository="$HOME/yawn"
+state_directory="$HOME/.local/state/yawn"
+deployed_revision_file="$state_directory/deployed-revision"
+compose=(docker compose --project-name yawn --project-directory "$repository" --file "$repository/compose.yaml")
+
+if [[ "$repository" != "$expected_repository" ]]; then
+    printf 'Expected the repository at %s, found %s\n' "$expected_repository" "$repository" >&2
+    exit 1
+fi
+
+for command in git docker flock; do
+    if ! command -v "$command" >/dev/null 2>&1; then
+        printf 'Missing required command: %s\n' "$command" >&2
+        exit 1
+    fi
+done
+if ! docker compose version >/dev/null 2>&1; then
+    printf 'Docker Compose v2 is required.\n' >&2
+    exit 1
+fi
+
+mkdir -p "$state_directory"
+exec 9>"$state_directory/deploy.lock"
+if ! flock -n 9; then
+    printf 'Another Yawn deployment is already running.\n'
+    exit 0
+fi
+
+cd "$repository"
+if [[ "$(git branch --show-current)" != "main" ]]; then
+    printf 'Deployments must run from the main branch.\n' >&2
+    exit 1
+fi
+if [[ -n "$(git status --porcelain --untracked-files=normal)" ]]; then
+    printf 'Refusing to deploy a checkout with local changes.\n' >&2
+    exit 1
+fi
+
+git fetch origin main
+remote_revision="$(git rev-parse FETCH_HEAD)"
+current_revision="$(git rev-parse HEAD)"
+deployed_revision=""
+if [[ -f "$deployed_revision_file" ]]; then
+    read -r deployed_revision <"$deployed_revision_file"
+fi
+
+container="$("${compose[@]}" ps -q yawn 2>/dev/null || true)"
+container_status="missing"
+if [[ -n "$container" ]]; then
+    container_status="$(docker inspect --format '{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}' "$container" 2>/dev/null || true)"
+fi
+
+if [[ "$current_revision" == "$remote_revision" &&
+    "$deployed_revision" == "$remote_revision" &&
+    "$container_status" == "healthy" ]]; then
+    printf 'Yawn is already running revision %s.\n' "${remote_revision:0:12}"
+    exit 0
+fi
+
+printf 'Deploying revision %s...\n' "${remote_revision:0:12}"
+flock -u 9
+exec 9>&-
+"$repository/server/deploy-docker.sh"