Add CircleCi config

.circleci/config.yml

@@ -0,0 +1,19 @@
+# Use the latest 2.1 version of CircleCI pipeline process engine.
+# See: https://circleci.com/docs/configuration-reference
+version: 2.1
+
+# Define a job to be invoked later in a workflow.
+# See: https://circleci.com/docs/configuration-reference/#jobs
+jobs:
+  build:
+    working_directory: image
+    machine:
+      image: cimg/base
+    resource_class: arm.medium
+    steps:
+      - checkout
+      - setup_remote_docker
+      - run:
+          name: Build application Docker image
+          command: |
+            cd base && docker buildx build . --load --platform linux/arm64 --tag discourse/base:build_slim -f slim.Dockerfile