feat(observability): add Prometheus/Grafana/Loki/Alertmanager/Alloy stack and remove legacy Monitoring UI

backend/src/media_library_viewer_api/jobs.py

@@ -52,6 +52,42 @@ JOB_TEMPLATES: dict[str, JobTemplate] = {
         description="Lists empty directories under the selected path. Does not delete anything.",
         command_template="find {path} -type d -empty -print",
     ),
+    "install_node_exporter": JobTemplate(
+        name="Install Node Exporter",
+        description="Downloads and installs prometheus-node-exporter via package manager (apt/dnf/yum/zypper).",
+        command_template=(
+            "set -e; "
+            "if command -v apt-get >/dev/null 2>&1; then "
+            "sudo apt-get update && sudo apt-get install -y prometheus-node-exporter; "
+            "elif command -v dnf >/dev/null 2>&1; then "
+            "sudo dnf install -y prometheus-node-exporter; "
+            "elif command -v yum >/dev/null 2>&1; then "
+            "sudo yum install -y prometheus-node-exporter; "
+            "elif command -v zypper >/dev/null 2>&1; then "
+            "sudo zypper install -y prometheus-node-exporter; "
+            "else echo 'No supported package manager found' >&2; exit 1; "
+            "fi; "
+            "sudo systemctl enable --now prometheus-node-exporter; "
+            "echo installed at {path}"
+        ),
+    ),
+    "restart_node_exporter": JobTemplate(
+        name="Restart Node Exporter",
+        description="Restarts the prometheus-node-exporter systemd service.",
+        command_template="sudo systemctl restart prometheus-node-exporter; echo restarted at {path}",
+    ),
+    "node_exporter_status": JobTemplate(
+        name="Node Exporter status",
+        description="Checks whether prometheus-node-exporter is installed, enabled, and running.",
+        command_template=(
+            "systemctl status prometheus-node-exporter --no-pager || true; "
+            "echo '---'; "
+            "command -v node_exporter >/dev/null 2>&1 "
+            "&& node_exporter --version 2>&1 | head -1 "
+            "|| echo 'node_exporter binary not found'; "
+            "echo checked {path}"
+        ),
+    ),
 }