Docker: Custom dockerfiles, docker and image rendering docs update (#20492)

Adds support for using custom dockerfiles to pre-install image 
renderer plugins.
Updates docs for docker and image rendering.

Fixes #20241

Co-Authored-By: Leonard Gram <leo@xlson.com>

packaging/docker/build-enterprise.sh

@@ -31,7 +31,7 @@ if [ ${UBUNTU_BASE} = "0" ]; then
   DOCKERFILE="Dockerfile"
 else
   TAG_SUFFIX="-ubuntu"
-  DOCKERFILE="Dockerfile.ubuntu"
+  DOCKERFILE="ubuntu.Dockerfile"
 fi
 
 echo "Building and deploying ${_docker_repo}:${_grafana_tag}${TAG_SUFFIX}"

packaging/docker/build.sh

@@ -63,7 +63,7 @@ docker_build () {
     base_image="${base_arch}alpine:3.10"
   else
     libc=""
-    dockerfile="Dockerfile.ubuntu"
+    dockerfile="ubuntu.Dockerfile"
     base_image="${base_arch}ubuntu:18.10"
   fi
 

packaging/docker/custom/Dockerfile

@@ -2,8 +2,31 @@ ARG GRAFANA_VERSION="latest"
 
 FROM grafana/grafana:${GRAFANA_VERSION}
 
+USER root
+
+ARG GF_INSTALL_IMAGE_RENDERER_PLUGIN="false"
+
+RUN if [ $GF_INSTALL_IMAGE_RENDERER_PLUGIN = "true" ]; then \
+    echo "http://dl-cdn.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories && \
+    echo "http://dl-cdn.alpinelinux.org/alpine/edge/main" >> /etc/apk/repositories && \
+    echo "http://dl-cdn.alpinelinux.org/alpine/edge/testing" >> /etc/apk/repositories && \
+    apk --no-cache  upgrade && \
+    apk add --no-cache udev ttf-opensans chromium && \
+    rm -rf /tmp/* && \
+    rm -rf /usr/share/grafana/tools/phantomjs; \
+fi
+
 USER grafana
 
+ENV GF_RENDERER_PLUGIN_CHROME_BIN="/usr/bin/chromium-browser"
+
+RUN if [ $GF_INSTALL_IMAGE_RENDERER_PLUGIN = "true" ]; then \
+    grafana-cli \
+        --pluginsDir "$GF_PATHS_PLUGINS" \
+        --pluginUrl https://github.com/grafana/grafana-image-renderer/releases/latest/download/plugin-linux-x64-glibc-no-chromium.zip \
+        plugins install grafana-image-renderer; \
+fi
+
 ARG GF_INSTALL_PLUGINS=""
 
 RUN if [ ! -z "${GF_INSTALL_PLUGINS}" ]; then \

packaging/docker/custom/ubuntu.Dockerfile

@@ -0,0 +1,41 @@
+ARG GRAFANA_VERSION="latest-ubuntu"
+
+FROM grafana/grafana:${GRAFANA_VERSION}-ubuntu
+
+USER root
+
+# Set DEBIAN_FRONTEND=noninteractive in environment at build-time
+ARG DEBIAN_FRONTEND=noninteractive
+
+ARG GF_INSTALL_IMAGE_RENDERER_PLUGIN="false"
+
+RUN if [ $GF_INSTALL_IMAGE_RENDERER_PLUGIN = "true" ]; then \
+    apt-get update && \
+    apt-get upgrade -y && \
+    apt-get install -y chromium-browser && \
+    apt-get autoremove -y && \
+    rm -rf /var/lib/apt/lists/* && \
+    rm -rf /usr/share/grafana/tools/phantomjs; \
+fi
+
+USER grafana
+
+ENV GF_RENDERER_PLUGIN_CHROME_BIN="/usr/bin/chromium-browser"
+
+RUN if [ $GF_INSTALL_IMAGE_RENDERER_PLUGIN = "true" ]; then \
+    grafana-cli \
+        --pluginsDir "$GF_PATHS_PLUGINS" \
+        --pluginUrl https://github.com/grafana/grafana-image-renderer/releases/latest/download/plugin-linux-x64-glibc-no-chromium.zip \
+        plugins install grafana-image-renderer; \
+fi
+
+ARG GF_INSTALL_PLUGINS=""
+
+RUN if [ ! -z "${GF_INSTALL_PLUGINS}" ]; then \
+    OLDIFS=$IFS; \
+        IFS=','; \
+    for plugin in ${GF_INSTALL_PLUGINS}; do \
+        IFS=$OLDIFS; \
+        grafana-cli --pluginsDir "$GF_PATHS_PLUGINS" plugins install ${plugin}; \
+    done; \
+fi