Docker: Upgrade to Ubuntu 20.04 in Dockerfiles (#23852)

* Chore: Upgrade to Ubuntu 20.04
Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>

.circleci/config.yml

@@ -50,7 +50,7 @@ commands:
       - run:
           name: "Install Grafana build pipeline tool"
           command: |
-            VERSION=0.2.10
+            VERSION=0.2.11
             curl -fLO https://grafana-downloads.storage.googleapis.com/grafana-build-pipeline/v${VERSION}/grabpl
             chmod +x grabpl
             mv grabpl /tmp

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Breaking changes
 
 - **Removed PhantomJS**: PhantomJS was deprecated in [Grafana v6.4](https://grafana.com/docs/grafana/latest/guides/whats-new-in-v6-4/#phantomjs-deprecation) and starting from Grafana v7.0.0, all PhantomJS support has been removed. This means that Grafana no longer ships with a built-in image renderer, and we advise you to install the [Grafana Image Renderer plugin](https://grafana.com/grafana/plugins/grafana-image-renderer).
+- **Docker**: Our Ubuntu based images have been upgraded to Ubuntu [20.04 LTS](https://releases.ubuntu.com/20.04/).
 
 # 6.7.3 (2020-04-23)
 

Dockerfile.ubuntu

@@ -30,7 +30,7 @@ COPY emails emails
 ENV NODE_ENV production
 RUN ./node_modules/.bin/grunt build
 
-FROM ubuntu:19.10
+FROM ubuntu:20.04
 
 LABEL maintainer="Grafana team <hello@grafana.com>"
 EXPOSE 3000

packaging/docker/build.sh

@@ -64,7 +64,7 @@ docker_build () {
   else
     libc=""
     dockerfile="ubuntu.Dockerfile"
-    base_image="${base_arch}ubuntu:19.10"
+    base_image="${base_arch}ubuntu:20.04"
   fi
 
   grafana_tgz="grafana-latest.linux-${arch}${libc}.tar.gz"

packaging/docker/ubuntu.Dockerfile

-ARG BASE_IMAGE=ubuntu:19.10
+ARG BASE_IMAGE=ubuntu:20.04
 FROM ${BASE_IMAGE} AS grafana-builder
 
 ARG GRAFANA_TGZ="grafana-latest.linux-x64.tar.gz"

scripts/build/ci-build/Dockerfile

-FROM ubuntu:18.04 as toolchain
+FROM ubuntu:20.04 as toolchain
 
 ENV OSX_SDK_URL=https://s3.dockerproject.org/darwin/v2 \
     OSX_SDK=MacOSX10.10.sdk \
@@ -70,7 +70,7 @@ RUN cd /tmp && \
     rm -rf /tmp/crosstool-ng-${CTNG}
 
 # base image to crossbuild grafana
-FROM ubuntu:18.04
+FROM ubuntu:20.04
 
 ENV GOVERSION=1.14.1 \
     PATH=/usr/local/go/bin:$PATH \