Use the tini shim in all flavours

I was misled by the error message found in alpine,
but the move was actually not specific to alpine.

Author: batmat

Dockerfile

@@ -70,6 +70,7 @@ USER ${user}
 
 COPY jenkins-support /usr/local/bin/jenkins-support
 COPY jenkins.sh /usr/local/bin/jenkins.sh
+COPY tini-shim.sh /bin/tini
 ENTRYPOINT ["/sbin/tini", "--", "/usr/local/bin/jenkins.sh"]
 
 # from a derived Dockerfile, can use `RUN plugins.sh active.txt` to setup /usr/share/jenkins/ref/plugins from a support bundle

Dockerfile-slim

@@ -70,6 +70,7 @@ USER ${user}
 
 COPY jenkins-support /usr/local/bin/jenkins-support
 COPY jenkins.sh /usr/local/bin/jenkins.sh
+COPY tini-shim.sh /bin/tini
 ENTRYPOINT ["/sbin/tini", "--", "/usr/local/bin/jenkins.sh"]
 
 # from a derived Dockerfile, can use `RUN plugins.sh active.txt` to setup /usr/share/jenkins/ref/plugins from a support bundle

tini-shim.sh

@@ -2,9 +2,12 @@
 set -euo pipefail
 
 cat <<EOF
-Please update your scripts to use /sbin/tini going forward.
-Previous path has been preserved for backwards compatibility in Alpine 3.4,
-but WILL BE REMOVED in Alpine 3.5. (or Jenkins 2.107.1 or something like this for our case)
+***************************************************************************
+* WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING *
+***************************************************************************
+Please update your scripts to use /sbin/tini or simply tini going forward.
+Previous path has been preserved for backwards compatibility,
+but WILL BE REMOVED in the future. (around Jenkins >= 2.107.2+)
 
 Now sleeping 2 minutes...
 EOF