feat: continuous deployment — server restarts on new image

deploy/bbledger-autodeploy.service

@@ -0,0 +1,17 @@
+# /etc/systemd/system/bbledger-autodeploy.service — continuous deployment:
+# pull :latest and restart the bot only when CI has published a new image.
+# Pull-based on purpose: CI never gets credentials for the server.
+[Unit]
+Description=bbledger: restart the bot when a new image is published
+After=docker.service
+Requires=docker.service
+
+[Service]
+Type=oneshot
+# $$ keeps systemd from eating the shell's $; a failed pull (offline, GHCR
+# down) fails the unit visibly and the timer simply tries again
+ExecStart=/bin/sh -ec '\
+    docker pull -q ghcr.io/schroedingberg/bbledger:latest >/dev/null; \
+    new=$$(docker image inspect -f "{{.Id}}" ghcr.io/schroedingberg/bbledger:latest); \
+    cur=$$(docker inspect -f "{{.Image}}" bbledger-bot 2>/dev/null || true); \
+    [ "$$new" = "$$cur" ] || systemctl restart bbledger-bot'

deploy/bbledger-autodeploy.timer

@@ -0,0 +1,10 @@
+# /etc/systemd/system/bbledger-autodeploy.timer
+[Unit]
+Description=Check for a new bbledger image every 5 minutes
+
+[Timer]
+OnBootSec=5min
+OnUnitActiveSec=5min
+
+[Install]
+WantedBy=timers.target

infra/README.md

@@ -67,7 +67,9 @@ Security → SSH keys) — every project key is installed on the server.
 3. Send `12,30 Test` in the Telegram group; expect the ✓ — and the entry
    commit appearing in the data repo moments later.
 
-Redeploying app versions never touches infra: CI pushes a new image and
-`ssh root@<ip> systemctl restart bbledger-bot` picks it up (IP is in the
-apply output). `destroy` is safe for the ledger: every entry is pushed to
-the data repo, and the next `apply` resumes from the clone.
+Redeploying app versions never touches infra: merging to main releases a
+new image, and the server's `bbledger-autodeploy.timer` pulls it and
+restarts the bot within ~5 minutes (pull-based on purpose — CI holds no
+server credentials). `bb deploy` / `bb restart` cover the impatient case.
+`destroy` is safe for the ledger: every entry is pushed to the data repo,
+and the next `apply` resumes from the clone.

infra/cloud-init.yaml

@@ -32,6 +32,12 @@ write_files:
   - path: /etc/systemd/system/bbledger-push.path
     content: |
       ${indent(6, push_path)}
+  - path: /etc/systemd/system/bbledger-autodeploy.service
+    content: |
+      ${indent(6, autodeploy_unit)}
+  - path: /etc/systemd/system/bbledger-autodeploy.timer
+    content: |
+      ${indent(6, autodeploy_timer)}
 
 runcmd:
   - systemctl enable --now docker
@@ -48,4 +54,4 @@ runcmd:
       echo '${ghcr_token}' | docker login ghcr.io -u '${ghcr_user}' --password-stdin
     fi
   - systemctl daemon-reload
-  - systemctl enable --now bbledger-bot.service bbledger-summary.timer bbledger-push.path
+  - systemctl enable --now bbledger-bot.service bbledger-summary.timer bbledger-push.path bbledger-autodeploy.timer

infra/main.tf

@@ -75,16 +75,18 @@ resource "hcloud_server" "bot" {
   firewall_ids = [hcloud_firewall.ssh_only.id]
 
   user_data = templatefile("${path.module}/cloud-init.yaml", {
-    bot_token       = var.bot_token
-    data_repo       = var.data_repo
-    data_deploy_key = var.data_deploy_key
-    ghcr_user       = var.ghcr_user
-    ghcr_token      = var.ghcr_token
-    bot_unit        = file("${path.module}/../deploy/bbledger-bot.service")
-    summary_unit    = file("${path.module}/../deploy/bbledger-summary.service")
-    summary_timer   = file("${path.module}/../deploy/bbledger-summary.timer")
-    push_unit       = file("${path.module}/../deploy/bbledger-push.service")
-    push_path       = file("${path.module}/../deploy/bbledger-push.path")
+    bot_token        = var.bot_token
+    data_repo        = var.data_repo
+    data_deploy_key  = var.data_deploy_key
+    ghcr_user        = var.ghcr_user
+    ghcr_token       = var.ghcr_token
+    bot_unit         = file("${path.module}/../deploy/bbledger-bot.service")
+    summary_unit     = file("${path.module}/../deploy/bbledger-summary.service")
+    summary_timer    = file("${path.module}/../deploy/bbledger-summary.timer")
+    push_unit        = file("${path.module}/../deploy/bbledger-push.service")
+    push_path        = file("${path.module}/../deploy/bbledger-push.path")
+    autodeploy_unit  = file("${path.module}/../deploy/bbledger-autodeploy.service")
+    autodeploy_timer = file("${path.module}/../deploy/bbledger-autodeploy.timer")
   })
 
   # an edited cloud-init must not silently rebuild a running VM — recreate