Build amd64/arm64 multiarch images

Signed-off-by: Adam Dodman <adam@adam-ant.co.uk>
Signed-off-by: Joe Groocock <me@frebib.net>

.drone.star

@@ -1,15 +1,37 @@
-def main(ctx):
-  return [
-    step("3.15"),
-    step("3.16",["latest"]),
-    step("edge"),
-  ]
+repo = "spritsail/alpine"
+archs = ["amd64", "arm64"]
+versions = ["edge", "3.14", "3.15", "3.16"]
+branches = ["master"]
 
-def step(alpinever,tags=[]):
-  vertest = "grep -q '%s' /etc/alpine-release && " % alpinever if alpinever != "edge" else ""
+def main(ctx):
+  builds = []
+
+  for ver in versions:
+    depends_on = []
+    srctpl = "drone/%s/${DRONE_BUILD_NUMBER}:%s-ARCH" % (ctx.repo.slug, ver)
+    for arch in archs:
+      key = "build-%s-%s" % (ver, arch)
+      tmprepo = "drone/%s/${DRONE_BUILD_NUMBER}:%s-%s" % (ctx.repo.slug, ver, arch)
+      builds.append(step(ver, arch, key, tmprepo))
+      depends_on.append(key)
+
+    if ctx.build.branch in branches:
+      tags = []
+      if ver == versions[-1]:
+        tags.append("latest")
+      builds.append(publish(ver, srctpl, depends_on, tags))
+
+  return builds
+
+def step(ver, arch, key, tmprepo):
+  vertest = "grep -q '%s' /etc/alpine-release && " % ver if ver != "edge" else ""
   return {
     "kind": "pipeline",
-    "name": "build-%s" % alpinever,
+    "name": key,
+    "platform": {
+      "os": "linux",
+      "arch": arch,
+    },
     "steps": [
       {
         "name": "build",
@@ -17,8 +39,9 @@ def step(alpinever,tags=[]):
         "pull": "always",
         "settings": {
           "build_args": [
-            "ALPINE_TAG=%s" % alpinever,
+            "ALPINE_TAG=%s" % ver,
           ],
+          "repo": tmprepo,
         },
       },
       {
@@ -27,6 +50,7 @@ def step(alpinever,tags=[]):
         "pull": "always",
         "settings": {
           "run": vertest + "su-exec nobody apk --version",
+          "repo": tmprepo,
         },
       },
       {
@@ -34,16 +58,49 @@ def step(alpinever,tags=[]):
         "image": "spritsail/docker-publish",
         "pull": "always",
         "settings": {
-          "repo": "spritsail/alpine",
-          "tags": [alpinever] + tags,
-          "username": {"from_secret": "docker_username"},
-          "password": {"from_secret": "docker_password"},
+          "from": tmprepo,
+          "repo": tmprepo,
+          "registry": {"from_secret": "registry_url"},
+          "username": {"from_secret": "registry_username"},
+          "password": {"from_secret": "registry_password"},
         },
         "when": {
-          "branch": ["master"],
+          "branch": branches,
           "event": ["push"],
         },
       },
     ]
   }
 
+def publish(ver, srctpl, depends, tags=[]):
+  return {
+    "kind": "pipeline",
+    "name": "publish-%s" % ver,
+    "depends_on": depends,
+    "platform": {
+      "os": "linux",
+    },
+    "steps": [
+      {
+        "name": "publish",
+        "image": "spritsail/docker-multiarch-publish",
+        "pull": "always",
+        "settings": {
+          "src_template": srctpl,
+          "src_registry": {"from_secret": "registry_url"},
+          "src_username": {"from_secret": "registry_username"},
+          "src_password": {"from_secret": "registry_password"},
+          "dest_repo": repo,
+          "dest_username": {"from_secret": "docker_username"},
+          "dest_password": {"from_secret": "docker_password"},
+          "tags": [ver] + tags,
+        },
+        "when": {
+          "branch": branches,
+          "event": ["push"],
+        },
+      },
+    ]
+  }
+
+# vim: ft=python sw=2