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9.3 Image Rendering

Usually, regular notifications through Grafana can be quite hard to read and understand. However, instead of receiving text-based Grafana Notifications through your alert channels, you can enable Grafana to render a picture of the metric, just as it is shown when logging in to the Grafana dashboard directly.

info

The following steps are performed on your 📟 node server.

Install Image Renderer​

To add the Image Rendering tool to your Grafana server, you have to install it's package.

1.1 Check Grafana Version: Verify which Grafana Version you have installed before breaking support.

grafana-server -v

1.2 Install Render Plugin: Use the built-in Grafana-CLI to install the suited image renderer for your Grafana installation.

sudo grafana-cli plugins install grafana-image-renderer 3.10.1

1.3 Enable Image Capturing: Add image captures to the global Grafana cofiguration file using your preferred text editor.

sudo vim /etc/grafana/grafana.ini

Then search for the following text section:

#################################### Unified Alerting ####################

[unified_alerting]

1.4 Set Image Capturing: Underneath the Unified Alerting section, add the screenshot settings and safe the file.

[unified_alerting.screenshots]
capture = true

The final section will look like this:

#################################### Unified Alerting ####################

[unified_alerting.screenshots]
capture = true

[unified_alerting]

1.5 Install Dependencies: Install all necessary packages for the image rendering software.

sudo apt install -y libx11-6 libx11-xcb1 libxcomposite1 libxcursor1 libxdamage1 libxext6 libxfixes3 libxi6 libxrender1 libxtst6 libglib2.0-0 libnss3 libcups2  libdbus-1-3 libxss1 libxrandr2 libgtk-3-0 libasound2 libxcb-dri3-0 libgbm1 libxshmfence1

1.6 Grant Permissions: Grant the Grafana service user all necessary rights to read and execute plugins.

sudo chown -R grafana-server-worker:grafana-server-worker /var/lib/grafana/plugins

1.7 Refresh Grafana: Restart your Grafana server for the dependency to show up.

sudo systemctl restart grafana-server

1.8 Verify Grafana Status: Check if the Grafana Server restarted correctly.

systemctl status grafana-server

The output should look similar to this:

● grafana-server.service - Grafana instance
     Loaded: loaded (/lib/systemd/system/grafana-server.service; enabled; vendo>
     Active: active (running) since [DATE]; [TIME] ago
       Docs: http://docs.grafana.org
   Main PID: 28472 (grafana)
      Tasks: 30 (limit: 38043)
     Memory: 150.4M
        CPU: 6min 59.027s
     CGroup: /system.slice/grafana-server.service
             ├─28472 /usr/share/grafana/bin/grafana server --config=/etc/grafan>
             └─28490 /var/lib/grafana/plugins/grafana-image-renderer/plugin_sta>

[DATE] [TIME] [USER] grafana-server[28472]: logger=context userId=1 orgI>...
...
tip

From now on, all notifications will automatically send graphs once the alert is triggered.

Revert Setup​

If something went wrong, you can disable image rendering or remove the plugin all together.

1. Disable Image Capturing: Open the Grafana configuration file and remove or comment out the screenshot settings.

vim /etc/grafana/grafana.ini

Locate and remove or comment out the following section:

[unified_alerting.screenshots]
capture = true

2. Remove the Render Plugin: Uninstall the image renderer plugin using the Grafana CLI.

sudo grafana-cli plugins uninstall grafana-image-renderer

3. Clean Up Plugin Directory: Manually ensure all images and cache are removed from the plugin directory.

sudo rm -rf /var/lib/grafana/plugins/grafana-image-renderer

4. Revert File Permissions: Reset ownership of the plugin folder if it was changed previously.

sudo chown -R root:root /var/lib/grafana/plugins

5. Restart Grafana: Restart Grafana to apply the changes.

sudo systemctl restart grafana-server

6. Verify Grafana Status: Ensure Grafana is running properly after reverting the changes.

systemctl status grafana-server

The output should look similar to this:

● grafana-server.service - Grafana instance
     Loaded: loaded (/lib/systemd/system/grafana-server.service; enabled; vendo>
     Active: active (running) since [DATE]; [TIME] ago
       Docs: http://docs.grafana.org
   Main PID: 28472 (grafana)
      Tasks: 30 (limit: 38043)
     Memory: 150.4M
        CPU: 6min 59.027s
     CGroup: /system.slice/grafana-server.service
             ├─28472 /usr/share/grafana/bin/grafana server --config=/etc/grafan>
             └─28490 /var/lib/grafana/plugins/grafana-image-renderer/plugin_sta>

[DATE] [TIME] [USER] grafana-server[28472]: logger=context userId=1 orgI>...
...
tip

Grafana will now stop rendering images in alert notifications and revert back to text-based alerts.