CI: use latest main build of efW

Use the latest successful build of the main branch of eBPF for
Windows. This makes more sense than using tagged versions since
most of the changes we need are yet to be upstreamed.

Staying on a tagged release would mean waiting six weeks for a
new release, on average.

Signed-off-by: Lorenz Bauer <[email protected]>

.github/workflows/ci.yml

@@ -235,38 +235,96 @@ jobs:
     strategy:
       matrix:
         version:
-          - "0.20.0"
+          - "main"
     env:
       # Fix slow Go compile and cache restore
       # See https://github.com/actions/setup-go/pull/515
       GOCACHE: D:\gocache
       GOMODCACHE: D:\gomodcache
-      GOTMPDIR: D:\gotmp
+      # Avoid putting temp on slow C:
+      TEMP: D:\temp
 
     steps:
-      # Go requires gotmp to be present
-      - run: mkdir D:\gotmp
+      - run: mkdir D:\temp
         shell: pwsh
 
+      - name: Get eBPF for Windows download URL
+        id: determine-url
+        uses: actions/github-script@v6
+        with:
+          script: |
+            if ("${{ matrix.version }}" != "main") {
+              // TODO: Workflow artifact and release artifact don't have the
+              // same folder structure.
+              core.setFailed('Installing tagged versions is not supported');
+              return;
+            }
+
+            // Get the latest successful merge_group run
+            const workflow_runs = await github.rest.actions.listWorkflowRuns({
+              owner: 'microsoft',
+              repo: 'ebpf-for-windows',
+              workflow_id: 'cicd.yml',
+              event: 'merge_group',
+              status: 'success',
+              per_page: 1
+            });
+
+            if (workflow_runs.data.workflow_runs.length === 0) {
+              core.setFailed('No successful merge_group workflow runs found');
+              return;
+            }
+
+            // Get artifacts from this run
+            const run_id = workflow_runs.data.workflow_runs[0].id;
+            const artifacts = await github.rest.actions.listWorkflowRunArtifacts({
+              owner: 'microsoft',
+              repo: 'ebpf-for-windows',
+              run_id: run_id
+            });
+
+            // Find the specific artifact
+            const artifact = artifacts.data.artifacts.find(a => a.name === 'Build-x64-Debug');
+
+            if (!artifact) {
+              console.log('Available artifacts:', artifacts.data.artifacts.map(a => a.name));
+              core.setFailed('Build-x64-Debug artifact not found in the workflow run');
+              return;
+            }
+
+            // Get the download URL via redirect
+            const response = await github.rest.actions.downloadArtifact({
+              owner: 'microsoft',
+              repo: 'ebpf-for-windows',
+              artifact_id: artifact.id,
+              archive_format: 'zip',
+              request: {
+                redirect: 'manual'
+              }
+            });
+
+            // Extract the location header which contains the actual download URL
+            const download_url = response.headers.location;
+
+            if (!download_url) {
+              core.setFailed('Failed to get redirect URL from headers');
+              return;
+            }
+
+            core.setOutput('download_url', download_url);
+
       - name: Download and Install eBPF for Windows
         shell: pwsh
         run: |
-          Invoke-WebRequest -Uri "https://github.com/microsoft/ebpf-for-windows/releases/download/Release-v${{ matrix.version }}/Build-x64.Debug.zip" -OutFile "$env:TEMP\efw.zip"
-          Expand-Archive -Path "$env:TEMP\efw.zip" -DestinationPath "$env:TEMP\ebpf"
-          Set-Location "$env:TEMP\ebpf"
-          # setup-ebpf.ps1 can't handle spaces in the path to the MSI.
-          mv "Build-x64 Debug" "debug"
-          $setupScript = Get-ChildItem -Path . -Filter "setup-ebpf.ps1" -Recurse | Select-Object -First 1
+          Invoke-WebRequest -Uri "${{ steps.determine-url.outputs.download_url }}" -OutFile "$env:TEMP\efw.zip"
+          Expand-Archive -Path "$env:TEMP\efw.zip" -DestinationPath "$env:TEMP"
+          Expand-Archive -Path "$env:TEMP\build-Debug.zip" -DestinationPath "$env:TEMP\ebpf"
+          $setupScript = Get-ChildItem -Path "$env:TEMP\ebpf" -Filter "setup-ebpf.ps1" -Recurse | Select-Object -First 1
           if ($setupScript) {
             Write-Host "Found setup script: $($setupScript.FullName)"
             Set-Location -Path $setupScript.DirectoryName
             Write-Host "Changed directory to: $(Get-Location)"
             & $setupScript.FullName
-
-            # Change service account to SYSTEM, until https://github.com/microsoft/ebpf-for-windows/pull/4095 is in a release.
-            Write-Host "Changing ebpfsvc to run as SYSTEM"
-            sc.exe config ebpfsvc obj= "LocalSystem"
-            sc.exe start ebpfsvc
           } else {
             Write-Error "Setup script not found in the extracted package"
             exit 1