Bring back Slack notification for failed builds

Author: sdeleuze

ci/pipeline.yml

@@ -2,12 +2,29 @@ anchors:
   docker-hub-task-params: &docker-hub-task-params
     DOCKER_HUB_USERNAME: ((docker-hub-username))
     DOCKER_HUB_PASSWORD: ((docker-hub-password))
+  slack-fail-params: &slack-fail-params
+    text: >
+      :concourse-failed: <https://ci.spring.io/teams/${BUILD_TEAM_NAME}/pipelines/${BUILD_PIPELINE_NAME}/jobs/${BUILD_JOB_NAME}/builds/${BUILD_NAME}|${BUILD_PIPELINE_NAME} ${BUILD_JOB_NAME} failed!>
+    silent: true
+    icon_emoji: ":concourse:"
+    username: concourse-ci
+resource_types:
+  - name: slack-notification
+    type: docker-image
+    source:
+      repository: cfcommunity/slack-notification-resource
+      tag: latest
 resources:
   - name: spring-native
     type: git
     source:
       uri: https://github.com/spring-projects-experimental/spring-native
       branch: master
+  - name: slack-alert
+    type: slack-notification
+    icon: slack
+    source:
+      url: ((slack-webhook-url))
   - name: every-day
     type: time
     source: {interval: 24h}
@@ -97,6 +114,11 @@ jobs:
               - name: spring-native
             run:
               path: spring-native/ci/build-samples.sh
+        on_failure:
+          do:
+            - put: slack-alert
+              params:
+                <<: *slack-fail-params
   - name: build-master-java8-samples
     public: true
     plan: