Add workflow To comment links of artifacts in PRs

When users request  o build or get the artifacts with some specific
version, they can simply open a PR with the specific VERSION and this
workflow will post the links to where to find the artifacts.

Signed-off-by: Charalampos Mainas <charalampos.mainas@gmail.com>

Author: cmainas

.github/workflows/build-trigger.yaml

@@ -0,0 +1,127 @@
+name: Find or build artifacts from PRs
+
+on:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - qemu/**
+      - solo5/**
+      - firecracker/**
+      - virtiofsd/**
+
+jobs:
+  get-versions:
+    name: Get the versions of all artifacts from their respeective VERSION files
+    runs-on: ubuntu-latest
+    outputs:
+      qemu_version: ${{ steps.versions.outputs.qemu_version }}
+      solo5_version: ${{ steps.versions.outputs.solo5_version }}
+      firecracker_version: ${{ steps.versions.outputs.firecracker_version }}
+      virtiofsd_version: ${{ steps.versions.outputs.virtiofsd_version }}
+
+    steps:
+      - name: Harden the runner (Audit all outbound calls)
+        uses: step-security/harden-runner@ec9f2d5744a09debf3a187a3f4f675c53b671911 # v2.13.0
+        with:
+          egress-policy: audit
+
+      - name: Checkout code
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          fetch-depth: 0
+
+      - name: Get versions to build
+        id: versions
+        run: |
+          QEMU_VERSION="$(cat qemu/VERSION)"
+          SOLO5_VERSION="$(cat solo5/VERSION)"
+          FIRECRACKER_VERSION="$(cat firecracker/VERSION)"
+          VIRTIOFSD_VERSION="$(cat virtiofsd/VERSION)"
+          echo "qemu_version=$QEMU_VERSION" >> $GITHUB_OUTPUT
+          echo "solo5_version=$SOLO5_VERSION" >> $GITHUB_OUTPUT
+          echo "firecracker_version=$FIRECRACKER_VERSION" >> $GITHUB_OUTPUT
+          echo "virtiofsd_version=$VIRTIOFSD_VERSION" >> $GITHUB_OUTPUT
+          echo "$QEMU_VERSION"
+          echo "$SOLO5_VERSION"
+          echo "$FIRECRACKER_VERSION"
+          echo "$VIRTIOFSD_VERSION"
+
+  build-Qemu-artifacts:
+    name: Check and build missing Qemu artifacts
+    needs: [get-versions]
+    uses: ./.github/workflows/qemu_build.yaml
+    with:
+      qemu_version: ${{ needs.get-versions.outputs.qemu_version }}
+      arch: '["amd64", "arm64"]'
+    secrets: inherit
+
+  build-Solo5-artifacts:
+    name: Check and build missing Solo5 artifacts
+    needs: [get-versions]
+    uses: ./.github/workflows/solo5_build.yaml
+    with:
+      solo5_version: ${{ needs.get-versions.outputs.solo5_version }}
+      arch: '["amd64", "arm64"]'
+    secrets: inherit
+
+  build-Virtiofsd-artifacts:
+    name: Check and build missing Virtiofsd artifact
+    needs: [get-versions]
+    uses: ./.github/workflows/virtiofsd_build.yaml
+    with:
+      virtiofsd_version: ${{ needs.get-versions.outputs.virtiofsd_version }}
+      arch: '["amd64", "arm64"]'
+    secrets: inherit
+
+  comment-artifact-links:
+    name: Post links for artifacts
+    needs: [get-versions,build-Qemu-artifacts,build-Solo5-artifacts,build-Virtiofsd-artifacts]
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+    steps:
+
+      - name: Harden the runner (Audit all outbound calls)
+        uses: step-security/harden-runner@ec9f2d5744a09debf3a187a3f4f675c53b671911 # v2.13.0
+        with:
+          egress-policy: audit
+
+      - name: Set download links
+        id: links
+        run: |
+          RUNS_URL="https://github.com/${{ github.repository }}/actions/runs"
+          QEMU_LINK="${RUNS_URL}/${{ needs.build-Qemu-artifacts.outputs.artifact_run_id }}"
+          SOLO5_LINK="${RUNS_URL}/${{ needs.build-Solo5-artifacts.outputs.artifact_run_id }}"
+          VIRTIOFSD_LINK="${RUNS_URL}/${{ needs.build-Virtiofsd-artifacts.outputs.artifact_run_id }}"
+
+          FC_RELEASE_URL="https://github.com/firecracker-microvm/firecracker/releases"
+          FC_LINK="${FC_RELEASE_URL}/download/${{ needs.get-versions.outputs.firecracker_version }}"
+          echo "qemu=${QEMU_LINK}" >> $GITHUB_OUTPUT
+          echo "solo5=${SOLO5_LINK}" >> $GITHUB_OUTPUT
+          echo "virtiofsd=${VIRTIOFSD_LINK}" >> $GITHUB_OUTPUT
+          echo "firecracker=${FC_LINK}" >> $GITHUB_OUTPUT
+
+      - name: Add ccomment
+        uses: actions/github-script@v8
+        env:
+          QEMU_TEXT: "Qemu ${{ needs.build-Qemu-artifacts.outputs.artifact_suffix }}: ${{ steps.links.outputs.qemu }}"
+          SOLO5_TEXT: "Solo5 ${{ needs.build-Solo5-artifacts.outputs.artifact_suffix }}: ${{ steps.links.outputs.solo5 }}"
+          VFS_TEXT: "Virtiofsd ${{ needs.build-Virtiofsd-artifacts.outputs.artifact_suffix }}: ${{ steps.links.outputs.virtiofsd }}"
+          FC_TEXT: "Firecracker ${{ needs.get-versions.outputs.firecracker_version }}: ${{ steps.links.outputs.firecracker }}"
+        with:
+          script: |
+            const body = `
+            Links to download artifacts for amd64 and aarch64 architectures:
+            - ${process.env.QEMU_TEXT}
+            - ${process.env.SOLO5_TEXT}
+            - ${process.env.VFS_TEXT}
+            - ${process.env.FC_TEXT}
+            `;
+            await github.rest.issues.createComment({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body
+            })