Image Rendering

Grafana supports rendering of panels and dashboards as PNG-images.

When an image is being rendered the PNG-image is temporary written to the filesystem, i.e. a sub-directory of Grafana’s data directory named png.

A background job runs each 10 minutes and will remove temporary images. You can configure how long time an image should be stored before being removed by configuring the temp-data-lifetime setting.

Requirements

Rendering images may require quite a lot of memory, mainly because there are “browser instances” started in the background responsible for the actual rendering. Further, if multiple images are being rendered in parallel it most certainly has a bigger memory footprint. Minimum free memory recommendation is 1GB.

Depending on rendering method you would need that memory available in the system where the rendering process is running. For Grafana Image renderer plugin and PhantomJS it’s the system which Grafana is installed on. For Remote rendering service it is the system where that’s installed.

Rendering methods

Grafana image renderer plugin

This plugin currently does not work if it is installed in the Grafana docker image. See Install in Grafana docker image.

The Grafana image renderer plugin is a plugin that runs on the backend and handles rendering panels and dashboards as PNG-images using headless chrome.

You can install it using grafana-cli:

grafana-cli plugins install grafana-image-renderer

For further information and instructions refer to troubleshooting and the plugin details.

Install in Grafana docker image

This plugin is not compatible with the current Grafana Docker image without installing further system-level dependencies. We recommend setting up another Docker container for rendering and using remote rendering, see Remote rendering service for reference.

If you still want to install the plugin in the Grafana docker image we provide instructions for how to build a custom Grafana image, see Installing using Docker.

Remote rendering service

The Grafana image renderer plugin can also be run as a remote HTTP rendering service. In this setup Grafana will render an image by making a HTTP request to the remote rendering service, which in turn render the image and returns it back in the HTTP response to Grafana.

You can run the remote HTTP rendering service using Docker or as a standalone Node.js application.

Using Docker:

The following example describes how to run Grafana and the remote HTTP rendering service in two separate docker containers using Docker Compose.

Create a docker-compose.yml with the following content.

version: '2'

services:
  grafana:
    image: grafana/grafana:master
    ports:
     - "3000:3000"
    environment:
      GF_RENDERING_SERVER_URL: http://renderer:8081/render
      GF_RENDERING_CALLBACK_URL: http://grafana:3000/
      GF_LOG_FILTERS: rendering:debug
  renderer:
    image: grafana/grafana-image-renderer:latest
    ports:
      - 8081

and finally run:

docker-compose up

Running as standalone Node.js application:

The following example describes how to build and run the remote HTTP rendering service as a standalone node.js application and configure Grafana appropriately.

  1. Git clone the Grafana image renderer plugin repository.
  2. Install dependencies and build:
yarn install --pure-lockfile
yarn run build
  1. Run the server
node build/app.js server --port=8081
  1. Update Grafana configuration:

    [rendering]
    server_url = http://localhost:8081/render
    callback_url = http://localhost:3000/
    
  2. Restart Grafana

For further information and instructions refer to troubleshooting and the plugin details.

PhantomJS

PhantomJS is deprecated since Grafana v6.4 and will be removed in a future release. Please migrate to Grafana image renderer plugin or remote rendering service.

PhantomJS have been the only supported and default image renderer since Grafana v2.x and is shipped with Grafana.

PhantomJS binaries are included for Linux (x64), Windows (x64) and Darwin (x64). For Linux you should ensure that any required libraries, e.g. libfontconfig1, are available.

Please note that PhantomJS binaries are not included for ARM. To support this you will need to ensure that a phantomjs binary is available under tools/phantomjs/phantomjs.

Alerting and render limits

Alert notifications can include images, but rendering many images at the same time can overload the server where the renderer is running. For instructions of how to configure this, see concurrent_render_limit.

Troubleshooting

Enable debug log messages for rendering in the Grafana configuration file and inspect the Grafana server log.

[log]
filters = rendering:debug

Grafana image renderer plugin and remote rendering service

The plugin and rendering service uses Chromium browser which depends on certain libraries. If you don’t have all of those libraries installed in your system you may encounter errors when trying to render an image, e.g.

Rendering failed: Error: Failed to launch chrome!/var/lib/grafana/plugins/grafana-image-renderer/chrome-linux/chrome:
error while loading shared libraries: libX11.so.6: cannot open shared object file: No such file or directory\n\n\nTROUBLESHOOTING: https://github.com/GoogleChrome/puppeteer/blob/master/docs/troubleshooting.md

In general you can use the ldd utility to figure out what shared libraries are missing/not installed in your system:

$ cd <grafana-image-render plugin directiry>
$ ldd chrome-linux/chrome
        linux-vdso.so.1 (0x00007fff1bf65000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f2047945000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f2047924000)
        librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f204791a000)
        libX11.so.6 => not found
        libX11-xcb.so.1 => not found
        libxcb.so.1 => not found
        libXcomposite.so.1 => not found
        ...

Ubuntu:

On Ubuntu 18.10 the following dependencies have been confirmed as needed for the image rendering to function.

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 libgtk-3-0 libasound2

Centos:

On a minimal Centos install the following dependencies have been confirmed as needed for the image rendering to function.

libXcomposite libXdamage libXtst cups libXScrnSaver pango atk adwaita-cursor-theme adwaita-icon-theme at at-spi2-atk at-spi2-core cairo-gobject colord-libs dconf desktop-file-utils ed emacs-filesystem gdk-pixbuf2 glib-networking gnutls gsettings-desktop-schemas gtk-update-icon-cache gtk3 hicolor-icon-theme jasper-libs json-glib libappindicator-gtk3 libdbusmenu libdbusmenu-gtk3 libepoxy liberation-fonts liberation-narrow-fonts liberation-sans-fonts liberation-serif-fonts libgusb libindicator-gtk3 libmodman libproxy libsoup libwayland-cursor libwayland-egl libxkbcommon m4 mailx nettle patch psmisc redhat-lsb-core redhat-lsb-submod-security rest spax time trousers xdg-utils xkeyboard-config

Using custom Chrome/Chromium

As a last resort, if you already have Chrome or Chromium installed on your system you can configure Grafana Image renderer plugin to use this instead of the pre-packaged version of Chromium.

Please note that this is not recommended since you may encounter problems if the installed version of Chrome/Chromium is not is compatible with the Grafana Image renderer plugin.

To override the path to the Chrome/Chromium executable you can set an environment variable and make sure that it’s available for the Grafana process, e.g.

export GF_RENDERER_PLUGIN_CHROME_BIN="/usr/bin/chromium-browser"