Extend Docker setup to support ARM

.github/workflows/build.yml

@@ -27,9 +27,16 @@ jobs:
       - uses: actions/checkout@v6
       - run: nix build --print-build-logs .#homeConfigurations.samueles.activationPackage
 
-  hm-docker:
+  hm-docker-x86:
     runs-on: ubuntu-24.04
     steps:
       - uses: cachix/install-nix-action@v31
       - uses: actions/checkout@v6
-      - run: nix build --print-build-logs .#homeConfigurations.agent.activationPackage
+      - run: nix build --print-build-logs .#homeConfigurations.agent-amd64.activationPackage
+
+  hm-docker-arm:
+    runs-on: ubuntu-24.04-arm
+    steps:
+      - uses: cachix/install-nix-action@v31
+      - uses: actions/checkout@v6
+      - run: nix build --print-build-logs .#homeConfigurations.agent-arm64.activationPackage

.github/workflows/update.yml

@@ -55,7 +55,7 @@ jobs:
           name: flake.lock
       - run: nix build --print-build-logs .#homeConfigurations.samueles.activationPackage
 
-  hm-docker:
+  hm-docker-x86:
     needs: lock
     runs-on: ubuntu-24.04
     steps:
@@ -64,15 +64,27 @@ jobs:
       - uses: actions/download-artifact@v7
         with:
           name: flake.lock
-      - run: nix build --print-build-logs .#homeConfigurations.agent.activationPackage
+      - run: nix build --print-build-logs .#homeConfigurations.agent-amd64.activationPackage
+
+  hm-docker-arm:
+    needs: lock
+    runs-on: ubuntu-24.04-arm
+    steps:
+      - uses: cachix/install-nix-action@v31
+      - uses: actions/checkout@v6
+      - uses: actions/download-artifact@v7
+        with:
+          name: flake.lock
+      - run: nix build --print-build-logs .#homeConfigurations.agent-arm64.activationPackage
 
   pr:
     needs:
       - lock
       - nixos
       - hm-nixos
       - hm-macos
-      - hm-docker
+      - hm-docker-x86
+      - hm-docker-arm
     runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v6

Dockerfile

@@ -1,17 +1,18 @@
 FROM ubuntu
+ARG TARGETARCH
 RUN apt-get update \
     && apt-get upgrade -y \
     && apt-get install -y curl git sudo xz-utils
-RUN useradd -m -s /bin/bash agent \
-    && usermod -aG sudo agent \
+RUN useradd -m -s /bin/bash agent-${TARGETARCH} \
+    && usermod -aG sudo agent-${TARGETARCH} \
     && mkdir -m 0755 /nix \
-    && chown agent /nix
-USER agent
+    && chown agent-${TARGETARCH} /nix
+USER agent-${TARGETARCH}
 RUN curl --proto '=https' --tlsv1.2 -L https://nixos.org/nix/install | sh -s -- --no-daemon \
     && mkdir -p ~/.config/nix \
     && echo 'experimental-features = nix-command flakes' > ~/.config/nix/nix.conf
-ENV USER=agent
-ENV PATH=/home/agent/.nix-profile/bin:$PATH
+ENV USER=agent-${TARGETARCH}
+ENV PATH=/home/agent-${TARGETARCH}/.nix-profile/bin:$PATH
 RUN git clone https://github.com/samestep/env.git ~/github/samestep/env \
     && ln -fsT ~/github/samestep/env ~/.config/home-manager \
     && nix run ~/github/samestep/env#home-manager -- init --switch -b backup

README.md

@@ -72,9 +72,9 @@ ln -fsT ~/github/samestep/env ~/.config/home-manager
 nix run ~/github/samestep/env#home-manager -- init --switch --impure
 ```
 
-## [Docker](docker)
+## Docker ([x86](docker-x86) and [ARM](docker-arm))
 
-This repo also contains a dedicated Home Manager config for use in an x86 Ubuntu Docker container; for instance:
+This repo also contains dedicated Home Manager configs for use in an Ubuntu Docker container; for instance:
 
 ```sh
 docker build . -t agent

docker/home-manager/home.nix → docker-arm/home-manager/home.nix

@@ -1,8 +1,4 @@
-{
-  config,
-  pkgs,
-  ...
-}:
+{ config, pkgs, ... }:
 let
   util = import ../../util.nix { inherit config pkgs; };
 in
@@ -13,13 +9,13 @@ in
     # # https://nix-community.github.io/home-manager/release-notes.xhtml
     stateVersion = "25.11";
 
-    username = "agent";
-    homeDirectory = "/home/agent";
+    username = "agent-arm64";
+    homeDirectory = "/home/agent-arm64";
 
     packages = util.packages;
 
     file = util.file // {
-      ".codex/config.toml" = util.symlink "docker/codex/config.toml";
+      ".codex/config.toml" = util.symlink "codex/config.toml";
     };
   };
 

docker-x86/home-manager/home.nix

@@ -0,0 +1,25 @@
+{ config, pkgs, ... }:
+let
+  util = import ../../util.nix { inherit config pkgs; };
+in
+{
+  nixpkgs = util.nixpkgs;
+
+  home = {
+    # # https://nix-community.github.io/home-manager/release-notes.xhtml
+    stateVersion = "25.11";
+
+    username = "agent-amd64";
+    homeDirectory = "/home/agent-amd64";
+
+    packages = util.packages;
+
+    file = util.file // {
+      ".codex/config.toml" = util.symlink "codex/config.toml";
+    };
+  };
+
+  programs = util.programs // {
+    bash.enable = true; # Necessary for aliases and Starship to work.
+  };
+}

flake.nix

@@ -102,15 +102,25 @@
           };
           modules = [ ./ubuntu/home-manager/home.nix ];
         };
-        "agent" = home-manager.lib.homeManagerConfiguration {
+        "agent-amd64" = home-manager.lib.homeManagerConfiguration {
           pkgs = import nixpkgs {
             system = "x86_64-linux";
             overlays = [
               npc.overlays.default
               moss.overlays.default
             ];
           };
-          modules = [ ./docker/home-manager/home.nix ];
+          modules = [ ./docker-x86/home-manager/home.nix ];
+        };
+        "agent-arm64" = home-manager.lib.homeManagerConfiguration {
+          pkgs = import nixpkgs {
+            system = "aarch64-linux";
+            overlays = [
+              npc.overlays.default
+              moss.overlays.default
+            ];
+          };
+          modules = [ ./docker-arm/home-manager/home.nix ];
         };
       };
       devShells =