1 files changed, 31 insertions, 0 deletions
diff --git a/scripts/check_dockerfiles.sh b/scripts/check_dockerfiles.sh
new file mode 100755
index 0000000..07e76f8
--- /dev/null
+++ b/scripts/check_dockerfiles.sh
@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+
+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"
+echo "Retrieving previous build's commit using $REQUEST_URL"
+RESPONSE="$(curl -sSL "${REQUEST_URL}")"
+
+if [[ $BUILD_REASON = "PullRequest" ]]; then
+    PREV_COMMIT="$(echo "${RESPONSE}" | grep -Po '"pr\.sourceSha"\s*:\s*"\K.*?[^\\](?="\s*[,}])')"
+    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="$(echo "${RESPONSE}" | grep -Po '"sourceVersion"\s*:\s*"\K.*?[^\\](?="\s*[,}])')"
+fi
+
+if [[ -n $PREV_COMMIT ]]; then
+    echo "Using $PREV_COMMIT to compare diffs."
+
+    if [[ -z "$(git diff $PREV_COMMIT -- docker/base.Dockerfile)" ]]; then
+        echo "No changes detected in docker/base.Dockerfile. The base image will not be built."
+        echo "##vso[task.setvariable variable=BASE_CHANGED]false"
+    fi
+
+    if [[ -z "$(git diff $PREV_COMMIT -- docker/venv.Dockerfile Pipfile*)" ]]; then
+        echo "No changes detected in docker/venv.Dockerfile or the Pipfiles. The venv image will not be built."
+        echo "##vso[task.setvariable variable=VENV_CHANGED]false"
+    fi
+else
+    echo "No previous commit was retrieved. Either the previous build is too old and was deleted or the branch was empty before this build. All images will be built."
+fi