multiple arch CI build

.drone.yml

@@ -3,19 +3,37 @@ kind: pipeline
 name: unit
 
 steps:
-- name: build
+  # -------------------- tests (host arch only) --------------------
-  image: golang
+  - name: test
-  pull: if-not-exists
+    image: golang:1.22-alpine
-  commands:
+    pull: if-not-exists
-  - go test
+    commands:
-  - go build
+      - go test ./...
+
+  # -------------------- build + push multi-arch image --------------------
+  - name: publish
+    image: plugins/docker:latest
+    privileged: true         # needed for docker/buildx 
+    settings:
+      username:
+        from_secret: docker-user
+      password:
+        from_secret: docker-pw
+      repo:
+        from_secret: docker-repo
+
+      # build context & dockerfile
+      context: .
+      dockerfile: Dockerfile
+
+      # enable buildx / multi-arch
+      buildx: true
+      platforms:
+        - linux/amd64
+        - linux/arm64
+        - linux/arm/v7
+
+      # tags to push (all as a single multi-arch manifest)
+      tags:
+        - latest
 
-- name: publish
-  image: plugins/docker:latest
-  settings:
-    username:
-      from_secret: docker-user
-    password:
-      from_secret: docker-pw
-    repo:
-      from_secret: docker-repo