ci: added option to sign git tags

DEVELOPMENT.md

@@ -52,7 +52,7 @@ Several base-image variants are maintained in order to offer choices in JDK prov
 The [docker-versions-create.sh](docker-versions-create.sh) script is configured with the branches to maintain and is used to merge changes from the master branch into the mulit-base variant branches. The script also manages git tagging the master branch along with the merged branches. So a typical use of the script would be like:
 
 ```shell script
-./docker-versions-create.sh -t 1.2.0
+./docker-versions-create.sh -s -t 1.2.0
 ```
 
 > Most often the major version will be bumped unless a bug or hotfix needs to be published in which case the patch version should be incremented.

docker-versions-create.sh

@@ -10,7 +10,7 @@ function TrapExit {
 
 batchMode=false
 
-while getopts "hbt:" arg
+while getopts "hbt:s" arg
 do
   case $arg in
     b)
@@ -19,6 +19,9 @@ do
     t)
       tag=${OPTARG}
       ;;
+    s)
+      tagArgs="-s -m 'Signed during docker-versions-create"
+      ;;
     h)
       echo "
 Usage $0 [options]
@@ -28,6 +31,7 @@ Options:
           when any merge fails
   -t TAG  tag and push the current revision on master with the given tag
           and apply respective tags to each branch
+  -s      enable signed tags
   -h      display this help and exit
 "
       exit