Docker-sonarqube: Use AdoptOpenJDK image as base instead of OpenJDK image

[michal-duda-sonarsource]

Right now, in our docker images we use Oracle's OpenJDK. The problem with this is docker images for OpenJDK that we use a base for our images are very large. Switching to AdoptOpenJDK would enable us to use alpine (or in some cases alpine-slim) versions of JDK images which are much smaller due to a much smaller system distribution.

[nixel2007]

Please consider the fact that alpine images are slower than debian/ubuntu images cause of different libc implementations and other system libs.

We switched from alpine to normal images for SQ cause of perfomance degradation at CE

[pierre-guillot-sonarsource]

Thanks for the feedback @nixel2007 , we will make sure to benchmark this 👍

[gosp]

Use JRE instead of JDK to reduce size. For example:

• alpine: adoptopenjdk/openjdk11:alpine-jre or azul/zulu-openjdk-alpine:11-jre
• debian:stretch: adoptopenjdk/openjdk11:debian-jre

[lg0killer]

Just be careful as some of the plugins break when a too lightweight version is being used.

Something like the svg badges depend on libfontmanager and since the current openjdk is the jre-slim, it causes the container to break since it is not included.

[pierre-guillot-sonarsource]

@michal-duda-sonarsource can we close this ?

[michal-duda-sonarsource]

Closing, since we switched to openjdk:11-jre-slim.