fix jenkins ci/cd

Jenkinsfile

@@ -9,7 +9,6 @@ pipeline {
         // Replace with your image name
         IMAGE_NAME = 'oh-service'
         // Variable for Git commit hash
-        GIT_COMMIT_HASH = ''
     }
     
     stages {
@@ -36,6 +35,10 @@ pipeline {
             steps {
                 script {
                     // Build with commit hash tag
+                    if (!GIT_COMMIT_HASH) {
+                        GIT_COMMIT_HASH = sh(script: 'git rev-parse --short HEAD', returnStdout: true).trim()
+                    }
+                    
                     sh '''
                         docker build -t ${DOCKER_HUB_USERNAME}/${IMAGE_NAME}:${GIT_COMMIT_HASH} .
                         docker tag ${DOCKER_HUB_USERNAME}/${IMAGE_NAME}:${GIT_COMMIT_HASH} ${DOCKER_HUB_USERNAME}/${IMAGE_NAME}:latest