ci: add discord notifications to at build success

Signed-off-by: Jakub Sokołowski <jakub@status.im>

Jenkinsfile

@@ -32,6 +32,11 @@ pipeline {
       description: 'ID of Jenkins credential for Docker registry.',
       defaultValue: params.DOCKER_CRED_ID ?: 'MISSING'
     )
+    string(
+      name: 'DISCORD_WEBHOOK_CRED',
+      description: 'Name of cretential with Discord webhook',
+      defaultValue: params.DISCORD_WEBHOOK_CRED ?: "",
+    )
     booleanParam(
       name: 'PUBLISH',
       description: 'Publish built Docker images.',
@@ -61,6 +66,16 @@ pipeline {
           image.push(env.DOCKER_TAG)
         }
       } }
+      post {
+        success { script {
+          if (params.DISCORD_WEBHOOK_CRED) {
+            discordNotify(
+              header: 'SpiffWorkflow Docker image published!',
+              cred: params.DISCORD_WEBHOOK_CRED,
+            )
+          }
+        } }
+      }
     }
   } // stages
   post {
@@ -68,3 +83,43 @@ pipeline {
     cleanup { cleanWs() }
   } // post
 } // pipeline
+
+def discordNotify(Map args=[:]) {
+  def opts = [
+    header: args.header ?: 'Deployment successful!',
+    title:  args.title  ?: "${env.JOB_NAME}#${env.BUILD_NUMBER}",
+    cred:   args.cred   ?: null,
+  ]
+  def repo = [
+    url: GIT_URL.minus('.git'),
+    branch: GIT_BRANCH.minus('origin/'),
+    commit: GIT_COMMIT.take(8),
+    prev: (
+      env.GIT_PREVIOUS_SUCCESSFUL_COMMIT ?: env.GIT_PREVIOUS_COMMIT ?: 'master'
+    ).take(8),
+  ]
+  wrap([$class: 'BuildUser']) {
+    BUILD_USER_ID = env.BUILD_USER_ID
+  }
+  withCredentials([
+    string(
+      credentialsId: opts.cred,
+      variable: 'DISCORD_WEBHOOK',
+    ),
+  ]) {
+    discordSend(
+      link: env.BUILD_URL,
+      result: currentBuild.currentResult,
+      webhookURL: env.DISCORD_WEBHOOK,
+      title: opts.title,
+      description: """
+        ${opts.header}
+        Image: [`${params.DOCKER_NAME}:${params.DOCKER_TAG}`](https://hub.docker.com/r/${params.DOCKER_NAME}/tags?name=${params.DOCKER_TAG})
+        Branch: [`${repo.branch}`](${repo.url}/commits/${repo.branch})
+        Commit: [`${repo.commit}`](${repo.url}/commit/${repo.commit})
+        Diff: [`${repo.prev}...${repo.commit}`](${repo.url}/compare/${repo.prev}...${repo.commit})
+        By: [`${BUILD_USER_ID}`](${repo.url}/commits?author=${BUILD_USER_ID})
+      """,
+    )
+  }
+}