From d104ae871170e5d1dac644921815bcce8496f23c Mon Sep 17 00:00:00 2001
From: Alex Auvolat <alex@adnab.me>
Date: Mon, 26 Sep 2022 17:19:21 +0200
Subject: [PATCH] Add step to generate multi-arch Docker container in CI

---
 .drone.yml            | 13 ++++++++++++-
 nix/manifest-tool.nix | 23 +++++++++++++++++++++++
 shell.nix             | 30 ++++++++++++++++++++++++++++++
 3 files changed, 65 insertions(+), 1 deletion(-)
 create mode 100644 nix/manifest-tool.nix

diff --git a/.drone.yml b/.drone.yml
index 277bfbc2..f5ac6179 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -245,6 +245,17 @@ node:
   nix-daemon: 1
 
 steps:
+  - name: multiarch-docker
+    image: nixpkgs/nix:nixos-22.05
+    environment:
+      DOCKER_AUTH:
+        from_secret: docker_auth
+      HOME: "/root"
+    commands:
+      - mkdir -p /root/.docker
+      - echo $DOCKER_AUTH > /root/.docker/config.json
+      - export CONTAINER_TAG=${DRONE_TAG:-$DRONE_COMMIT}
+      - nix-shell --attr release --run "multiarch_docker"
   - name: refresh-index
     image: nixpkgs/nix:nixos-22.05
     environment:
@@ -269,6 +280,6 @@ trigger:
 
 ---
 kind: signature
-hmac: 362639b4c9541ad9bd06ff7f72b5235b2b0216bcb16eececd25285b6fe94ba6f
+hmac: 103a04785c98f5376a63ce22865c2576963019bbc4d828f200d2a470a3c821ea
 
 ...
diff --git a/nix/manifest-tool.nix b/nix/manifest-tool.nix
new file mode 100644
index 00000000..182ccc0e
--- /dev/null
+++ b/nix/manifest-tool.nix
@@ -0,0 +1,23 @@
+pkgs:
+pkgs.buildGoModule rec {
+  pname = "manifest-tool";
+  version = "2.0.5";
+
+  src = pkgs.fetchFromGitHub {
+    owner = "estesp";
+    repo = "manifest-tool";
+    rev = "v${version}";
+    sha256 = "hjCGKnE0yrlnF/VIzOwcDzmQX3Wft+21KCny/opqdLg=";
+  } + "/v2";
+
+  vendorSha256 = null;
+
+  checkPhase = "true";
+
+  meta = with pkgs.lib; {
+    description = "Command line tool to create and query container image manifest list/indexes";
+    homepage = "https://github.com/estesp/manifest-tool";
+    license = licenses.asl20;
+    platforms = platforms.linux;
+  };
+}
diff --git a/shell.nix b/shell.nix
index ea5d6356..e82bce78 100644
--- a/shell.nix
+++ b/shell.nix
@@ -10,6 +10,7 @@ let
     overlays = [ cargo2nixOverlay ];
   };
   kaniko = (import ./nix/kaniko.nix) pkgs;
+  manifest-tool = (import ./nix/manifest-tool.nix) pkgs;
   winscp = (import ./nix/winscp.nix) pkgs;
 
 in
@@ -84,6 +85,34 @@ function to_docker {
     --verbosity=debug
 }
 
+function multiarch_docker {
+        manifest-tool push from-spec <(cat <<EOF
+image: dxflrs/garage:''${CONTAINER_TAG}
+manifests:
+  -
+    image: dxflrs/arm64_garage:''${CONTAINER_TAG}
+    platform:
+      architecture: arm64
+      os: linux
+  -
+    image: dxflrs/amd64_garage:''${CONTAINER_TAG}
+    platform:
+      architecture: amd64
+      os: linux
+  -
+    image: dxflrs/386_garage:''${CONTAINER_TAG}
+    platform:
+      architecture: 386
+      os: linux
+  -
+    image: dxflrs/arm_garage:''${CONTAINER_TAG}
+    platform:
+      architecture: arm
+      os: linux
+EOF
+        )
+}
+
 function refresh_index {
   aws \
       --endpoint-url https://garage.deuxfleurs.fr \
@@ -113,6 +142,7 @@ function refresh_index {
       nativeBuildInputs = [
         pkgs.awscli2
         kaniko 
+        manifest-tool
       ];
     };
   }