build-scx-scheds: Add a container image with system deps

.github/workflows/build-scx-builder.yaml

@@ -0,0 +1,43 @@
+name: Build scx-builder
+description: |
+  This workflow builds a ./build-scx-scheds/Dockerfile docker image,
+  which can be used for sched-ext build.
+  It is pushed to 'ghcr.io/libbpf/scx-builder'
+
+on:
+  pull_request:
+    paths:
+      - 'build-scx-scheds/**'
+  schedule:
+    - cron: '0 0 * * 0'
+  workflow_dispatch:
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository_owner }}/scx-builder
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Log in to Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v6
+        with:
+          context: build-scx-scheds
+          push: true
+          tags: |
+            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
+            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.sha }}

build-scx-scheds/Dockerfile

@@ -0,0 +1,7 @@
+FROM ubuntu:24.04
+
+RUN apt-get update -y && apt-get install -y --no-install-recommends sudo
+
+COPY install-dependencies.sh /tmp/install-dependencies.sh
+RUN /tmp/install-dependencies.sh
+

build-scx-scheds/action.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+set -xeuo pipefail
+
+docker run --rm \
+  -v "${GITHUB_WORKSPACE}:/workspace" \
+  -v "${GITHUB_ACTION_PATH}:/action" \
+  -v "${OUTPUT_DIR}:/output" \
+  -w /workspace \
+  -e OUTPUT_DIR=/output \
+  --entrypoint /action/build-scheds.sh \
+  ghcr.io/libbpf/scx-builder:latest
+
+# Fixup ownership of output files
+sudo chown -R "$(id -u):$(id -g)" "${OUTPUT_DIR}"
+

build-scx-scheds/action.yml

@@ -5,15 +5,12 @@ inputs:
     required: true
 
 runs:
-  using: "composite"
+  using: 'composite'
   steps:
-
-    - name: Install sched-ext/scx dependencies
+    - name: Build sched-ext/scx in container
       shell: bash
-      run: ${GITHUB_ACTION_PATH}/install-dependencies.sh
-
-    - name: Build sched-ext/scx
       env:
+        GITHUB_ACTION_PATH: ${{ github.action_path }}
+        GITHUB_WORKSPACE: ${{ github.workspace }}
         OUTPUT_DIR: ${{ inputs.output-dir }}
-      shell: bash
-      run: ${GITHUB_ACTION_PATH}/build-scheds.sh
+      run: ${{ github.action_path }}/action.sh

build-scx-scheds/build-scheds.sh

@@ -6,7 +6,7 @@ export SCX_ROOT=${SCX_ROOT:-}
 export SCX_REVISION=${SCX_REVISION:-main}
 
 if [[ -z "$SCX_ROOT" ]]; then
-    export SCX_ROOT=$(mktemp -d scx.XXXX)
+    export SCX_ROOT=$(mktemp -d /tmp/scx.XXXX)
     git clone --branch=main https://github.com/sched-ext/scx.git $SCX_ROOT
     pushd $SCX_ROOT
     git reset --hard $SCX_REVISION