makefile: Add goal to build the project in a linux container (#674)

Today our CI builds all of the linux code we have with musl and libc to
ensure everything is silky smooth. We should have a way to do the same
locally. This adds a new macOS only goal that spins up a container
(requires `container` to be installed) that builds an image with our
deps (libarchive and compression libs) and then builds the project. It
supports supplying whatever libc (musl or glibc) to verify they both
work.

Author: dcantah

.github/workflows/linux-build.yml

@@ -12,11 +12,28 @@ on:
       - release/*
 
 jobs:
+  swift-version:
+    name: Determine Swift version
+    runs-on: ubuntu-24.04
+    outputs:
+      image: ${{ steps.version.outputs.image }}
+    steps:
+      - name: Checkout .swift-version
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8  # v6
+        with:
+          sparse-checkout: .swift-version
+          sparse-checkout-cone-mode: false
+
+      - name: Read Swift version
+        id: version
+        run: echo "image=swift:$(cat .swift-version)-noble" >> "$GITHUB_OUTPUT"
+
   build:
     name: Linux compile check
+    needs: swift-version
     timeout-minutes: 30
     runs-on: ubuntu-24.04
-    container: swift:6.3-noble
+    container: ${{ needs.swift-version.outputs.image }}
 
     steps:
       - name: Checkout repository

Makefile

@@ -37,6 +37,27 @@ LIBARCHIVE_LOCAL_DIR := workdir/libarchive
 
 KATA_BINARY_PACKAGE := https://github.com/kata-containers/kata-containers/releases/download/3.17.0/kata-static-3.17.0-arm64.tar.xz
 
+SWIFT_VERSION := $(shell cat $(ROOT_DIR)/.swift-version)
+SWIFT_SDK_URL := $(shell grep '^SWIFT_SDK_URL' vminitd/Makefile | head -1 | sed 's/.*:= *//')
+SWIFT_SDK_CHECKSUM := $(shell grep '^SWIFT_SDK_CHECKSUM' vminitd/Makefile | head -1 | sed 's/.*:= *//')
+LINUX_DEV_IMAGE := containerization-dev:$(SWIFT_VERSION)
+
+# Run a command inside a Linux dev container.
+# Requires 'container' (https://github.com/apple/container).
+# Automatically builds the dev image if it doesn't exist.
+define linux_run
+	@if ! command -v container > /dev/null 2>&1; then \
+		echo "Error: 'container' CLI not found. Install from https://github.com/apple/container"; \
+		exit 1; \
+	fi
+	@if ! container image list -q 2>/dev/null | grep -q "$(LINUX_DEV_IMAGE)"; then \
+		echo "Building Linux dev container image..."; \
+		$(MAKE) linux-image; \
+	fi
+	@container run --memory 8gb --cpus 4 -v $(ROOT_DIR):/workspace -w /workspace $(LINUX_DEV_IMAGE) \
+		bash -c "$(1)"
+endef
+
 include Protobuf.Makefile
 .DEFAULT_GOAL := all
 
@@ -48,6 +69,28 @@ else
 	@echo "No additional dependencies required on $(UNAME_S)"
 endif
 
+ifeq ($(UNAME_S),Darwin)
+.PHONY: linux-image
+linux-image:
+	container build \
+		--progress plain \
+		-f images/linux-dev/Dockerfile \
+		--build-arg SWIFT_VERSION=$(SWIFT_VERSION) \
+		--build-arg SWIFT_SDK_URL=$(SWIFT_SDK_URL) \
+		--build-arg SWIFT_SDK_CHECKSUM=$(SWIFT_SDK_CHECKSUM) \
+		-t $(LINUX_DEV_IMAGE) \
+		.
+
+.PHONY: linux-build
+linux-build: LIBC ?= musl
+linux-build:
+ifeq ($(LIBC),all)
+	$(call linux_run,make containerization && make -C vminitd LIBC=glibc && make -C vminitd LIBC=musl)
+else
+	$(call linux_run,make containerization && make -C vminitd LIBC=$(LIBC))
+endif
+endif
+
 .PHONY: all
 all: containerization
 all: init

images/linux-dev/Dockerfile

@@ -0,0 +1,27 @@
+# Copyright © 2026 Apple Inc. and the Containerization project authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#   https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+ARG SWIFT_VERSION=6.3
+FROM swift:${SWIFT_VERSION}-noble
+
+RUN apt-get update \
+ && apt-get install -y make libarchive-dev libbz2-dev liblzma-dev libssl-dev \
+ && apt-get clean \
+ && rm -rf /var/lib/apt/lists/*
+
+ARG SWIFT_SDK_URL
+ARG SWIFT_SDK_CHECKSUM
+RUN if [ -n "$SWIFT_SDK_URL" ]; then \
+      swift sdk install "$SWIFT_SDK_URL" --checksum "$SWIFT_SDK_CHECKSUM"; \
+    fi

vminitd/.devcontainer/Dockerfile

@@ -1,4 +1,4 @@
-FROM swift:6.2
+FROM swift:6.3-noble
 
 RUN apt-get update \
 &&  apt-get install make \

vminitd/Makefile

@@ -27,7 +27,12 @@ else
 MUSL_ARCH := x86_64
 endif
 
-SWIFT_CONFIGURATION := --swift-sdk $(MUSL_ARCH)-swift-linux-musl $(SWIFT_WARNING_CONFIG) -Xlinker -s --disable-automatic-resolution
+LIBC ?= musl
+ifeq ($(LIBC),musl)
+SWIFT_SDK_FLAGS := --swift-sdk $(MUSL_ARCH)-swift-linux-musl
+endif
+
+SWIFT_CONFIGURATION := $(SWIFT_SDK_FLAGS) $(SWIFT_WARNING_CONFIG) -Xlinker -s --disable-automatic-resolution
 
 SWIFT_VERSION := 6.3
 SWIFT_SDK_URL := https://download.swift.org/swift-6.3-release/static-sdk/swift-6.3-RELEASE/swift-6.3-RELEASE_static-linux-0.1.0.artifactbundle.tar.gz