fix(unbound): unbound-exporter installation

Applications/PiHole/add-unbound.md

@@ -30,6 +30,9 @@ server:
     # logfile: "/var/log/unbound/unbound.log"
     verbosity: 0
 
+    # view more statistics
+    extended-statistics: yes
+
     interface: 127.0.0.1
     port: 5335
     do-ip4: yes

Applications/PiHole/install-unbound-prometheus-exporter.md

@@ -0,0 +1,54 @@
+# Install the Unbound Prometheus Exporter
+
+## Install
+
+### Install golang & compile the exporter
+
+```bash
+sudo apt update -y
+sudo apt install golang
+```
+
+Clone, compile & move the exporter to the correct location
+
+```bash
+git clone https://github.com/letsencrypt/unbound_exporter.git
+cd unbound_exporter
+go build
+sudo install -o root -g root -m 0755 unbound_exporter /usr/local/bin/unbound-exporter
+cd ..
+rm -rf unbound_exporter
+```
+
+### Create a systemd service
+
+```bash
+cat << EOF > /etc/systemd/system/unbound-exporter.service
+[Unit]
+Description=Unbound Prometheus Exporter
+After=network.target
+
+[Service]
+Type=simple
+User=root
+Group=root
+Restart=always
+ExecStart=/usr/local/bin/unbound-exporter -web.listen-address ":9167" -web.telemetry-path "/metrics"
+
+[Install]
+WantedBy=multi-user.target
+EOF
+```
+
+### Start the service
+
+```bash
+sudo systemctl daemon-reload
+sudo systemctl enable --now unbound-exporter.service
+```
+
+### Test the exporter
+
+```bash
+curl localhost:9167/metrics
+```