ci: build lkm only if needed while building manager

.github/workflows/build-manager.yml

@@ -12,9 +12,79 @@ on:
     paths:
       - 'manager/**'
   workflow_call:
+  workflow_dispatch:
+    inputs:
+      build_lkm:
+        required: true
+        type: choice
+        default: "auto"
+        options:
+          - "true"
+          - "false"
+          - "auto"
+        description: "Whether to build lkm"
+      upload_lkm:
+        required: true
+        type: boolean
+        default: false
+        description: "Whether to upload lkm"
 
 jobs:
+  check-build-lkm:
+    runs-on: ubuntu-latest
+    outputs:
+      build_lkm: ${{ steps.check-build.outputs.build_lkm }}
+      upload_lkm: ${{ steps.check-build.outputs.upload_lkm }}
+    steps:
+      - name: check build
+        id: check-build
+        run: |
+          if [ "${{ github.event_name }}" == "workflow_dispatch" ] && [ "${{ inputs.build_lkm }}" != "auto" ]; then
+            kernel_changed="${{ inputs.build_lkm }}"
+          else
+            kernel_changed=true
+            mkdir tmp
+            cd tmp
+            git config --global init.defaultBranch bot
+            git config --global user.name 'Bot'
+            git config --global user.email 'bot@github.5ec1cff.io'
+            git init .
+            git remote add origin https://github.com/${{ github.repository }}
+            CURRENT_COMMIT="${{ github.event.head_commit.id }}"
+            git fetch origin $CURRENT_COMMIT --depth=1
+            git fetch origin lkm --depth=1
+            LKM_COMMIT="$(git log --format=%B -n 1 origin/lkm | head -n 1)"
+            LKM_COMMIT="${LKM_COMMIT#Upload LKM from }"
+            LKM_COMMIT=$(echo "$LKM_COMMIT" | tr -d '[:space:]')
+            echo "LKM_COMMIT=$LKM_COMMIT"
+            git fetch origin "$LKM_COMMIT" --depth=1
+            git diff --quiet "$LKM_COMMIT" "$CURRENT_COMMIT" -- kernel :!kernel/setup.sh .github/workflows/build-lkm.yml .github/workflows/build-kernel-*.yml && kernel_changed=false
+            cd ..
+            rm -rf tmp
+          fi
+          if [ "${{ github.event_name }}" == "push" ] && [ "${{ github.ref }}" == 'refs/heads/main' ]; then
+            need_upload=true
+          elif [ "${{ github.event_name }}" == "workflow_dispatch" ]; then
+            need_upload="${{ inputs.upload_lkm }}"
+          else
+            need_upload=false
+          fi
+          echo "kernel changed: $kernel_changed"
+          echo "need upload: $need_upload"
+          echo "build_lkm=$kernel_changed" >> "$GITHUB_OUTPUT"
+          echo "upload_lkm=$need_upload" >> "$GITHUB_OUTPUT"
+
+  build-lkm:
+    needs: check-build-lkm
+    uses: ./.github/workflows/build-lkm.yml
+    if: ${{ needs.check-build-lkm.outputs.build_lkm == 'true' }}
+    with:
+      upload: ${{ needs.check-build-lkm.outputs.upload_lkm == 'true' }}
+    secrets: inherit
+
   build-ksud:
+    if: ${{ always() }}
+    needs: [ check-build-lkm, build-lkm ]
     strategy:
       matrix:
         include:
@@ -27,8 +97,10 @@ jobs:
       target: ${{ matrix.target }}
       os: ${{ matrix.os }}
       pack_lkm: true
+      pull_lkm: ${{ needs.check-build-lkm.outputs.build_lkm != 'true' }}
 
   build-manager:
+    if: ${{ always() }}
     needs: build-ksud
     runs-on: ubuntu-latest
     defaults: