Merge pull request #15 from natrontech/docs/docker-secrets

add docs for docker-secrets & improve error handling

README.md

@@ -65,6 +65,20 @@ You can use the following flags to configure the exporter. All flags can also be
 | `pbs.metrics-path`       | `PBS_METRICS_PATH`   | Path under which to expose metrics                   | `/metrics`                                             |
 | `pbs.web.listen-address` | `PBS_LISTEN_ADDRESS` | Address to listen on for web interface and telemetry | `:9101`                                                |
 
+### Docker secrets
+
+If you are using [Docker secrets](https://docs.docker.com/engine/swarm/secrets/), you can use the following environment variables to set the path to the secrets:
+
+| Environment Variable      | Description                     |
+| ------------------------- | ------------------------------- |
+| `PBS_API_TOKEN_FILE`      | Path to the API token file      |
+| `PBS_API_TOKEN_NAME_FILE` | Path to the API token name file |
+| `PBS_USERNAME_FILE`       | Path to the username file       |
+
+See an example of how to use Docker secrets with Docker Compose in the [docker-compose-secrets.yaml](docker-compose-secrets.yaml) file.
+
+The variables `PBS_API_TOKEN`, `PBS_API_TOKEN_NAME`, and `PBS_USERNAME` take precedence over the secret files.
+
 ## Multiple Proxmox Backup Servers
 
 If you want to monitor multiple Proxmox Backup Servers, you can use the `targets` parameter in the query string. Instead of setting the `pbs.endpoint` flag (or `PBS_ENDPOINT` env), you can use the `target` parameter in the query string to specify the Proxmox Backup Server to monitor. You would then use following URL to scrape metrics: `http://localhost:9101/metrics?target=http://10.10.10.10:8007`.

docker-compose-secrets.yaml

@@ -0,0 +1,29 @@
+version: '3.8'
+services:
+  pbs-exporter:
+    build: .
+    # image: ghcr.io/natrontech/pbs-exporter:latest
+    container_name: pbs-exporter
+    user: '65534'
+    restart: always
+    ports:
+      - "9101:9101"
+    environment:
+      - PBS_ENDPOINT=https://pbs-server:8007
+      - PBS_INSECURE=false
+      - PBS_USERNAME_FILE=/run/secrets/proxmoxbackup-username
+      - PBS_API_TOKEN_NAME_FILE=/run/secrets/proxmoxbackup-api-token-name
+      - PBS_API_TOKEN_FILE=/run/secrets/proxmoxbackup-api-token
+    secrets:
+    - proxmoxbackup-username
+    - proxmoxbackup-api-token-name
+    - proxmoxbackup-api-token
+
+secrets:
+  # example with secret files in .secrets folder
+  proxmoxbackup-username:
+    file: "./.secrets/proxmoxbackup_username.secret"
+  proxmoxbackup-api-token-name:
+    file: "./.secrets/proxmoxbackup_api_token_name.secret"
+  proxmoxbackup-api-token:
+    file: "./.secrets/proxmoxbackup_api_token.secret"

main.go

@@ -764,14 +764,19 @@ func main() {
 
 		// debug
 		if *loglevel == "debug" {
-			log.Printf("DEBUG: ----Using connection endpoint %s", target)
+			log.Printf("DEBUG: Using connection endpoint %s", target)
 		}
 
 		exporter := NewExporter(target, *username, *apitoken, *apitokenname)
-		prometheus.MustRegister(exporter)
+
+		// catch if register of exporter fails
+		err := prometheus.Register(exporter)
+		if err != nil {
+			// if register fails, we log the error and return
+			log.Printf("ERROR: %s", err)
+		}
 		promhttp.Handler().ServeHTTP(w, r) // Serve the metrics
 		prometheus.Unregister(exporter)    // Clean up after serving
-
 	})
 
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {

prometheus/static-config/multiple-targets.yaml

@@ -1,7 +1,11 @@
 # Use Case: multiple Proxmox Backup Server, all have the same authentication user/token
+#           important: env PBS_ENDPOINT not set!
 #
-# important: env PBS_ENDPOINT NOT SET!
-#
+# Setup:
+# - exporter instance: pbs-exporter:9101
+# - first PBS target: https://10.10.10.10:8007
+# - second PBS target: https://10.10.10.11:8007
+
 scrape_configs:
 - job_name: 'pbs-exporter'
   honor_timestamps: true