feat: Add platform arg to force building a specific architecture

.github/workflows/build-pr.yml

@@ -258,6 +258,58 @@ jobs:
           grep -q 'ARG IMAGE_REGISTRY=ghcr.io/blue-build' Containerfile || exit 1
           bluebuild build --retry-push -B docker -I docker -S sigstore --push -vv recipes/recipe.yml recipes/recipe-39.yml
 
+  arm64-build:
+    timeout-minutes: 60
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+      id-token: write
+    needs:
+      - build
+    if: needs.build.outputs.push == 'true'
+
+    steps:
+      - name: Maximize build space
+        uses: ublue-os/remove-unwanted-software@v6
+
+      - uses: sigstore/[email protected]
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+        with:
+          install: true
+
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          ref: ${{github.event.pull_request.head.ref}}
+          repository: ${{github.event.pull_request.head.repo.full_name}}
+
+      - name: Install bluebuild
+        run: |
+          cargo install --path . --debug --all-features
+
+      - name: Expose GitHub Runtime
+        uses: crazy-max/ghaction-github-runtime@v3
+
+      - name: Run Build
+        env:
+          GH_TOKEN: ${{ github.token }}
+          GH_PR_EVENT_NUMBER: ${{ github.event.number }}
+          COSIGN_PRIVATE_KEY: ${{ secrets.TEST_SIGNING_SECRET }}
+          BB_BUILDKIT_CACHE_GHA: true
+        run: |
+          cd integration-tests/test-repo
+          bluebuild build \
+            --retry-push \
+            --platform linux/arm64 \
+            --push \
+            -vv \
+            recipes/recipe-arm64.yml
+
   docker-build-external-login:
     timeout-minutes: 60
     runs-on: ubuntu-latest

integration-tests/test-repo/recipes/recipe-arm64.yml

@@ -0,0 +1,38 @@
+name: cli/test
+description: This is my personal OS image.
+base-image: quay.io/fedora/fedora-silverblue
+image-version: 40
+alt_tags:
+  - arm64
+stages:
+modules:
+  - from-file: akmods.yml
+  - from-file: flatpaks.yml
+
+  - type: files
+    files:
+      - usr: /usr
+
+  - type: script
+    scripts:
+      - example.sh
+
+  - type: rpm-ostree
+    repos:
+      - https://copr.fedorainfracloud.org/coprs/atim/starship/repo/fedora-%OS_VERSION%/atim-starship-fedora-%OS_VERSION%.repo
+    install:
+      - micro
+      - starship
+    remove:
+      - firefox
+      - firefox-langpacks
+
+  - type: signing
+
+  - type: test-module
+
+  - type: containerfile
+    containerfiles:
+      - labels
+    snippets:
+      - RUN echo "This is a snippet" && ostree container commit

process/drivers/buildah_driver.rs

@@ -50,6 +50,7 @@ impl BuildDriver for BuildahDriver {
         let command = cmd!(
             "buildah",
             "build",
+            if let Some(platform) = opts.platform => format!("--platform={platform}"),
             "--pull=true",
             format!("--layers={}", !opts.squash),
             "-f",

process/drivers/docker_driver.rs

@@ -130,6 +130,7 @@ impl BuildDriver for DockerDriver {
         let status = cmd!(
             "docker",
             "build",
+            if let Some(platform) = opts.platform => format!("--platform={platform}"),
             "-t",
             &*opts.image,
             "-f",
@@ -235,6 +236,7 @@ impl BuildDriver for DockerDriver {
             },
             "build",
             "--pull",
+            if let Some(platform) = opts.platform => format!("--platform={platform}"),
             "-f",
             &*opts.containerfile,
             // https://github.com/moby/buildkit?tab=readme-ov-file#github-actions-cache-experimental

process/drivers/opts/build.rs

@@ -2,6 +2,8 @@ use std::{borrow::Cow, path::Path};
 
 use bon::Builder;
 
+use crate::drivers::types::Platform;
+
 use super::CompressionType;
 
 /// Options for building
@@ -15,14 +17,13 @@ pub struct BuildOpts<'scope> {
 
     #[builder(into)]
     pub containerfile: Cow<'scope, Path>,
+    pub platform: Option<Platform>,
 }
 
 #[derive(Debug, Clone, Builder)]
+#[builder(on(Cow<'_, str>, into))]
 pub struct TagOpts<'scope> {
-    #[builder(into)]
     pub src_image: Cow<'scope, str>,
-
-    #[builder(into)]
     pub dest_image: Cow<'scope, str>,
 }
 
@@ -80,4 +81,7 @@ pub struct BuildTagPushOpts<'scope> {
     /// Run all steps in a single layer.
     #[builder(default)]
     pub squash: bool,
+
+    /// The platform to build the image on.
+    pub platform: Option<Platform>,
 }

process/drivers/podman_driver.rs

@@ -72,6 +72,7 @@ impl BuildDriver for PodmanDriver {
         let command = cmd!(
             "podman",
             "build",
+            if let Some(platform) = opts.platform => format!("--platform={platform}"),
             "--pull=true",
             format!("--layers={}", !opts.squash),
             "-f",

process/drivers/traits.rs

@@ -90,6 +90,7 @@ pub trait BuildDriver {
         let build_opts = BuildOpts::builder()
             .image(&full_image)
             .containerfile(opts.containerfile.as_ref())
+            .maybe_platform(opts.platform)
             .squash(opts.squash)
             .build();
 

process/drivers/types.rs

@@ -167,3 +167,25 @@ impl DetermineDriver<CiDriverType> for Option<CiDriverType> {
         )
     }
 }
+
+#[derive(Debug, Clone, Copy, ValueEnum)]
+pub enum Platform {
+    #[value(name = "linux/amd64")]
+    LinuxAmd64,
+
+    #[value(name = "linux/arm64")]
+    LinuxArm64,
+}
+
+impl std::fmt::Display for Platform {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            match *self {
+                Self::LinuxAmd64 => "linux/amd64",
+                Self::LinuxArm64 => "linux/arm64",
+            }
+        )
+    }
+}

scripts/exports.sh

@@ -46,6 +46,7 @@ color_string() {
 
 # Parse OS version and export it
 export OS_VERSION=$(grep -Po "(?<=VERSION_ID=)\d+" /usr/lib/os-release)
+export OS_ARCH=$(uname -m)
 
 # Export functions for use in sub-shells or sourced scripts
 export -f get_yaml_array

src/commands/build.rs

@@ -9,6 +9,7 @@ use blue_build_process_management::{
             BuildTagPushOpts, CheckKeyPairOpts, CompressionType, GenerateImageNameOpts,
             GenerateTagsOpts, SignVerifyOpts,
         },
+        types::Platform,
         BuildDriver, CiDriver, Driver, DriverArgs, SigningDriver,
     },
     logging::{color_str, gen_random_ansi_color},
@@ -58,6 +59,14 @@ pub struct BuildCommand {
     #[builder(default)]
     push: bool,
 
+    /// Build for a specific platform.
+    ///
+    /// NOTE: Building for a different architecture
+    /// than your hardware will require installing
+    /// qemu.
+    #[arg(long)]
+    platform: Option<Platform>,
+
     /// The compression format the images
     /// will be pushed in.
     #[arg(short, long, default_value_t = CompressionType::Gzip)]
@@ -268,6 +277,7 @@ impl BuildCommand {
         let opts = if let Some(archive_dir) = self.archive.as_ref() {
             BuildTagPushOpts::builder()
                 .containerfile(containerfile)
+                .maybe_platform(self.platform)
                 .archive_path(format!(
                     "{}/{}.{ARCHIVE_SUFFIX}",
                     archive_dir.to_string_lossy().trim_end_matches('/'),
@@ -279,6 +289,7 @@ impl BuildCommand {
             BuildTagPushOpts::builder()
                 .image(&image_name)
                 .containerfile(containerfile)
+                .maybe_platform(self.platform)
                 .tags(tags.to_cow_vec())
                 .push(self.push)
                 .retry_push(self.retry_push)