solve the concrete problem for git branch name that starts with #

metasfresh-docker metasfresh/metasfresh-docker#23

Jenkinsfile

@@ -2,6 +2,16 @@
 // the "!#/usr/bin... is just to to help IDEs, GitHub diffs, etc properly detect the language and do syntax highlighting for you.
 // thx to https://github.com/jenkinsci/pipeline-examples/blob/master/docs/BEST_PRACTICES.md
 
+/**
+ * According to the documentation at https://docs.docker.com/engine/reference/commandline/tag/ :
+ * A tag name must be valid ASCII and may contain lowercase and uppercase letters, digits, underscores, periods and dashes. A tag name may not start with a period or a dash and may contain a maximum of 128 characters.
+ */
+ def String mkDockerTag(String input)
+ {
+ 	return input
+ 		.replaceFirst('^[#\\.]', '') // delete the first letter if it is a period or dash
+ 		.replaceAll('[^a-zA-Z0-9_#\\.]', '_'); // replace everything that's not allowed with an underscore
+ }
 
 def boolean isRepoExists(String repoId)
 {
@@ -256,8 +266,8 @@ node('agent && linux && dejenkinsnode001') // shall only run on a jenkins agent
 							docker.withRegistry('https://index.docker.io/v1/', 'dockerhub_metasfresh')
 							{
 								def app = docker.build 'metasfresh/metasfresh-admin', 'src/main/docker';
-								app.push "${MF_UPSTREAM_BRANCH}-latest";
-								app.push "${MF_UPSTREAM_BRANCH}-${BUILD_VERSION}";
+								app.push mkDockerTag("${MF_UPSTREAM_BRANCH}-latest");
+								app.push mkDockerTag("${MF_UPSTREAM_BRANCH}-${BUILD_VERSION}");
 							}
             }
 		}