Get previous build ID

1 files changed, 52 insertions, 20 deletions

diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 28ec742..db11c70 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -8,9 +8,57 @@ jobs:
     vmImage: 'Ubuntu-16.04'
 
   steps:
+    - script: |
+        REQUEST_URL="https://dev.azure.com/\
+        python-discord/${SYSTEM_TEAMPROJECTID}/_apis/build/builds?\
+        queryOrder=finishTimeDescending&\
+        resultFilter=succeeded&\
+        \$top=1&\
+        repositoryType=${BUILD_REPOSITORY_PROVIDER}&\
+        repositoryId=${BUILD_REPOSITORY_NAME}&\
+        branchName=${BUILD_SOURCEBRANCH}&\
+        api-version=5.0"
+
+        printf '%s\n' "Retrieving latest successful build using ${REQUEST_URL}"
+        response="$(curl -sSL "${REQUEST_URL}")"
+
+        prev_build="$(printf '%s' "${response}" | jq -re '.value[0].id')"
+        printf '%s\n' "Most recent successful build found: ${prev_build}"
+        printf '%s\n' "##vso[task.setvariable variable=PREV_BUILD]${prev_build}"
+
+        if [[ "${BUILD_REASON}" = "PullRequest" ]]; then
+            prev_commit="$(printf '%s' "${response}" | jq -re '.value[0]."pr.sourceSha"')"
+
+            if [[ -z "${prev_commit}" ]]; then
+                echo "Could not retrieve the previous build's commit. \
+                Falling back to the head of the target branch."
+
+                prev_commit="origin/${SYSTEM_PULLREQUEST_TARGETBRANCH}"
+            fi
+        else
+            prev_commit="$(printf '%s' "${response}" | jq -re '.value[0].sourceVersion')"
+        fi
+
+        printf '%s\n' "##vso[task.setvariable variable=PREV_COMMIT]${prev_commit}"
+      displayName: 'Get Previous Successful Build'
+
+    - task: DownloadPipelineArtifact@1
+      inputs:
+        source: 'specific'
+        project: $(System.TeamProject)
+        pipeline: $(System.DefinitionId)
+        runVersion: 'specific'
+        buildId: $(PREV_BUILD)
+        artifactName: 'BaseId'
+      displayName: 'Download Base ID Artifact'
+
+    - script: |
+        base_id="$(cat "${SYSTEM_ARTIFACTSDIRECTORY}"/base.sha256)"
+        printf '%s\n' "##vso[task.setvariable variable=BASE_ID]${base_id}"
+      displayName: 'Write Base ID to Variable'
+
     - script: docker build -t pythondiscord/snekbox-base:latest -f docker/base.Dockerfile .
       displayName: 'Build Base Image'
-      enabled: false
 
     - script: |
         id="$(docker images -q --no-trunc pythondiscord/snekbox-base:latest)"
@@ -20,26 +68,10 @@ jobs:
         fi
 
         printf '%s' "${id}" >> base.sha256
-      displayName: 'Create Digest Artifact'
-      enabled: false
+      displayName: 'Create Base ID Artifact'
 
     - task: PublishPipelineArtifact@1
       inputs:
         path: base.sha256
-        artifact: base_id
-      enabled: false
-
-    - task: DownloadPipelineArtifact@1
-      inputs:
-        buildType: 'specific'
-        project: $(System.TeamProject)
-        pipeline: $(System.DefinitionId)
-        buildVersionToDownload: 'specific'
-        buildId: 2434
-        artifactName: 'base_id'
-
-    - script: |
-        ls -la $(System.ArtifactsDirectory)
-
-    - script: |
-        cat $(System.ArtifactsDirectory)/base.sha256
+        artifact: BaseId
+      displayName: 'Publish Base ID Artifact'