Reduce repetition in CI pipeline.yml

Use YAML anchors and aliases to reduce the amount of repetition
in our CI pipeline YAML.

Closes gh-21716

ci/pipeline.yml

+anchors:
+  git-repo-resource-source: &git-repo-resource-source
+    uri: ((github-repo))
+    username: ((github-username))
+    password: ((github-password))
+    branch: ((branch))
+  docker-resource-source: &docker-resource-source 
+    username: ((docker-hub-username))
+    password: ((docker-hub-password))
+    tag: ((branch))
+  build-project-task-params: &build-project-task-params
+    privileged: true
+    timeout: ((task-timeout))
+    file: git-repo/ci/tasks/build-project.yml
+  github-task-params: &github-task-params
+    GITHUB_REPO: spring-boot
+    GITHUB_ORGANIZATION: spring-projects
+    GITHUB_PASSWORD: ((github-password))
+    GITHUB_USERNAME: ((github-username))
+    MILESTONE: ((milestone))
+  bintray-task-params: &bintray-task-params
+    BINTRAY_SUBJECT: ((bintray-subject))
+    BINTRAY_REPO: ((bintray-repo))
+    BINTRAY_USERNAME: ((bintray-username))
+    BINTRAY_API_KEY: ((bintray-api-key))
+  sontatype-task-params: &sonatype-task-params
+    SONATYPE_USER_TOKEN: ((sonatype-user-token))
+    SONATYPE_PASSWORD_TOKEN: ((sonatype-user-token-password))
+  artifactory-task-params: &artifactory-task-params
+    ARTIFACTORY_SERVER: ((artifactory-server))
+    ARTIFACTORY_USERNAME: ((artifactory-username))
+    ARTIFACTORY_PASSWORD: ((artifactory-password))
+  artifactory-repo-put-params: &artifactory-repo-put-params
+    repo: libs-snapshot-local
+    folder: distribution-repository
+    build_uri: "https://ci.spring.io/teams/${BUILD_TEAM_NAME}/pipelines/${BUILD_PIPELINE_NAME}/jobs/${BUILD_JOB_NAME}/builds/${BUILD_NAME}"
+    build_number: "${BUILD_PIPELINE_NAME}-${BUILD_JOB_NAME}-${BUILD_NAME}"
+    disable_checksum_uploads: true
+    exclude:
+    - "**/*.effective-pom"
+    artifact_set:
+    - include:
+      - "/**/spring-boot-docs-*.zip"
+      properties:
+        "zip.type": "docs"
+        "zip.deployed": "false"
 resource_types:
 - name: artifactory-resource
   type: docker-image
@@ -23,18 +69,12 @@ resources:
   type: git
   icon: github-circle
   source:
-    uri: ((github-repo))
-    username: ((github-username))
-    password: ((github-password))
-    branch: ((branch))
+    <<: *git-repo-resource-source
 - name: git-repo-windows
   type: git
   icon: github-circle
-  source:
-    uri: ((github-repo))
-    username: ((github-username))
-    password: ((github-password))
-    branch: ((branch))
+  source: 
+    <<: *git-repo-resource-source
     git_config:
     - name: core.autocrlf
       value: true
@@ -74,18 +114,14 @@ resources:
   type: docker-image
   icon: docker
   source:
+    <<: *docker-resource-source
     repository: ((docker-hub-organization))/spring-boot-ci-image
-    username: ((docker-hub-username))
-    password: ((docker-hub-password))
-    tag: ((branch))
 - name: spring-boot-jdk11-ci-image
   type: docker-image
   icon: docker
   source:
+    <<: *docker-resource-source
     repository: ((docker-hub-organization))/spring-boot-jdk11-ci-image
-    username: ((docker-hub-username))
-    password: ((docker-hub-password))
-    tag: ((branch))
 - name: artifactory-repo
   type: artifactory-resource
   icon: package-variant
@@ -149,22 +185,14 @@ jobs:
     - task: detect-jdk8-update
       file: git-repo/ci/tasks/detect-jdk-updates.yml
       params:
-        GITHUB_REPO: spring-boot
-        GITHUB_ORGANIZATION: spring-projects
-        GITHUB_PASSWORD: ((github-password))
-        GITHUB_USERNAME: ((github-username))
+        <<: *github-task-params
         JDK_VERSION: java8
-        MILESTONE: ((milestone))
       image: spring-boot-ci-image
     - task: detect-jdk11-update
       file: git-repo/ci/tasks/detect-jdk-updates.yml
       params:
-        GITHUB_REPO: spring-boot
-        GITHUB_ORGANIZATION: spring-projects
-        GITHUB_PASSWORD: ((github-password))
-        GITHUB_USERNAME: ((github-username))
+        <<: *github-task-params
         JDK_VERSION: java11
-        MILESTONE: ((milestone))
       image: spring-boot-ci-image
 - name: detect-ubuntu-image-updates
   plan:
@@ -176,11 +204,7 @@ jobs:
     - task: detect-ubuntu-image-updates
       file: git-repo/ci/tasks/detect-ubuntu-image-updates.yml
       params:
-        GITHUB_REPO: spring-boot
-        GITHUB_ORGANIZATION: spring-projects
-        GITHUB_PASSWORD: ((github-password))
-        GITHUB_USERNAME: ((github-username))
-        MILESTONE: ((milestone))
+        <<: *github-task-params
       image: spring-boot-ci-image
 - name: detect-docker-updates
   plan:
@@ -192,11 +216,7 @@ jobs:
     - task: detect-docker-updates
       file: git-repo/ci/tasks/detect-docker-updates.yml
       params:
-        GITHUB_REPO: spring-boot
-        GITHUB_ORGANIZATION: spring-projects
-        GITHUB_PASSWORD: ((github-password))
-        GITHUB_USERNAME: ((github-username))
-        MILESTONE: ((milestone))
+        <<: *github-task-params
       image: spring-boot-ci-image
 - name: build
   serial: true
@@ -209,10 +229,8 @@ jobs:
     params: { state: "pending", commit: "git-repo" }
   - do:
     - task: build-project
-      privileged: true
-      timeout: ((task-timeout))
+      <<: *build-project-task-params
       image: spring-boot-ci-image
-      file: git-repo/ci/tasks/build-project.yml
     - in_parallel:
       - task: build-samples
         timeout: ((task-timeout))
@@ -239,20 +257,8 @@ jobs:
   - put: repo-status-build
     params: { state: "success", commit: "git-repo" }
   - put: artifactory-repo
-    params: &artifactory-params
-      repo: libs-snapshot-local
-      folder: distribution-repository
-      build_uri: "https://ci.spring.io/teams/${BUILD_TEAM_NAME}/pipelines/${BUILD_PIPELINE_NAME}/jobs/${BUILD_JOB_NAME}/builds/${BUILD_NAME}"
-      build_number: "${BUILD_PIPELINE_NAME}-${BUILD_JOB_NAME}-${BUILD_NAME}"
-      disable_checksum_uploads: true
-      exclude:
-      - "**/*.effective-pom"
-      artifact_set:
-      - include:
-        - "/**/spring-boot-docs-*.zip"
-        properties:
-          "zip.type": "docs"
-          "zip.deployed": "false"
+    params:
+      <<: *artifactory-repo-put-params
     on_failure:
       do:
       - put: slack-alert
@@ -319,10 +325,8 @@ jobs:
     params: { state: "pending", commit: "git-repo" }
   - do:
     - task: build-project
-      privileged: true
-      timeout: ((task-timeout))
+      <<: *build-project-task-params
       image: spring-boot-jdk11-ci-image
-      file: git-repo/ci/tasks/build-project.yml
     - in_parallel:
       - task: build-samples
         timeout: ((task-timeout))
@@ -395,7 +399,7 @@ jobs:
       RELEASE_TYPE: M
   - put: artifactory-repo
     params:
-      <<: *artifactory-params
+      <<: *artifactory-repo-put-params
       repo: libs-staging-local
   - put: git-repo
     params:
@@ -413,7 +417,7 @@ jobs:
       RELEASE_TYPE: RC
   - put: artifactory-repo
     params:
-      <<: *artifactory-params
+      <<: *artifactory-repo-put-params
       repo: libs-staging-local
   - put: git-repo
     params:
@@ -431,7 +435,7 @@ jobs:
       RELEASE_TYPE: RELEASE
   - put: artifactory-repo
     params:
-      <<: *artifactory-params
+      <<: *artifactory-repo-put-params
       repo: libs-staging-local
   - put: git-repo
     params:
@@ -453,9 +457,7 @@ jobs:
     file: git-repo/ci/tasks/promote.yml
     params:
       RELEASE_TYPE: M
-      ARTIFACTORY_SERVER: ((artifactory-server))
-      ARTIFACTORY_USERNAME: ((artifactory-username))
-      ARTIFACTORY_PASSWORD: ((artifactory-password))
+      <<: *artifactory-task-params
   - task: generate-release-notes
     file: git-repo/ci/tasks/generate-release-notes.yml
     params:
@@ -484,9 +486,7 @@ jobs:
     file: git-repo/ci/tasks/promote.yml
     params:
       RELEASE_TYPE: RC
-      ARTIFACTORY_SERVER: ((artifactory-server))
-      ARTIFACTORY_USERNAME: ((artifactory-username))
-      ARTIFACTORY_PASSWORD: ((artifactory-password))
+      <<: *artifactory-task-params
   - task: generate-release-notes
     file: git-repo/ci/tasks/generate-release-notes.yml
     params:
@@ -515,13 +515,8 @@ jobs:
     file: git-repo/ci/tasks/promote.yml
     params:
       RELEASE_TYPE: RELEASE
-      ARTIFACTORY_SERVER: ((artifactory-server))
-      ARTIFACTORY_USERNAME: ((artifactory-username))
-      ARTIFACTORY_PASSWORD: ((artifactory-password))
-      BINTRAY_SUBJECT: ((bintray-subject))
-      BINTRAY_REPO: ((bintray-repo))
-      BINTRAY_USERNAME: ((bintray-username))
-      BINTRAY_API_KEY: ((bintray-api-key))
+      <<: *artifactory-task-params
+      <<: *bintray-task-params
 - name: sync-to-maven-central
   serial: true
   plan:
@@ -537,12 +532,8 @@ jobs:
     image: spring-boot-ci-image
     file: git-repo/ci/tasks/sync-to-maven-central.yml
     params:
-      BINTRAY_USERNAME: ((bintray-username))
-      BINTRAY_API_KEY: ((bintray-api-key))
-      SONATYPE_USER_TOKEN: ((sonatype-user-token))
-      SONATYPE_PASSWORD_TOKEN: ((sonatype-user-token-password))
-      BINTRAY_SUBJECT: ((bintray-subject))
-      BINTRAY_REPO: ((bintray-repo))
+      <<: *bintray-task-params
+      <<: *sonatype-task-params
   - task: generate-release-notes
     file: git-repo/ci/tasks/generate-release-notes.yml
     params: