github: make use of LXD's actions/lp-snap-build in build job

Signed-off-by: Simon Deziel <[email protected]>

.github/workflows/builds.yml

@@ -16,51 +16,30 @@ jobs:
     name: Trigger snap build
     runs-on: ubuntu-24.04
     if: ${{ github.repository == 'canonical/lxd-pkg-snap' && github.actor != 'dependabot[bot]' }}
+    env:
+      SSH_AUTH_SOCK: /tmp/ssh_agent.sock
+      PACKAGE: "lxd"
+      REPO: "git+ssh://[email protected]/~canonical-lxd/lxd"
+      BRANCH: ${{ github.ref_name }}
     steps:
       - name: Checkout code
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683  # v4.2.2
 
-      - name: Install Go
-        uses: actions/setup-go@3041bf56c941b39c61721a86cd11f3bb1338122a  # v5.2.0
+      - uses: ./.github/actions/lp-snap-build
         with:
-          go-version: 'stable'
-
-      - name: Setup Launchpad SSH access
-        env:
-          SSH_AUTH_SOCK: /tmp/ssh_agent.sock
-          LAUNCHPAD_LXD_BOT_KEY: ${{ secrets.LAUNCHPAD_LXD_BOT_KEY }}
-        run: |
-          set -eux
-          mkdir -m 0700 -p ~/.ssh/
-          ssh-agent -a "${SSH_AUTH_SOCK}" > /dev/null
-          ssh-add - <<< "${{ secrets.LAUNCHPAD_LXD_BOT_KEY }}"
-          ssh-add -L > ~/.ssh/id_ed25519.pub
-          # In ephemeral environments like GitHub Action runners, relying on TOFU isn't providing any security
-          # so require the key obtained by `ssh-keyscan` to match the expected hash from https://help.launchpad.net/SSHFingerprints
-          ssh-keyscan git.launchpad.net >> ~/.ssh/known_hosts
-          ssh-keygen -qlF git.launchpad.net | grep -xF 'git.launchpad.net RSA SHA256:UNOzlP66WpDuEo34Wgs8mewypV0UzqHLsIFoqwe8dYo'
+          ssh-key: "${{ secrets.LAUNCHPAD_LXD_BOT_KEY}}"
 
       - name: Trigger Launchpad snap build
         env:
-          SSH_AUTH_SOCK: /tmp/ssh_agent.sock
-          TARGET: ${{ github.ref_name }}
         run: |
           set -eux
-          git config --global transfer.fsckobjects true
-          git config --global user.name "Canonical LXD Bot"
-          git config --global user.email "[email protected]"
-          git config --global commit.gpgsign true
-          git config --global gpg.format "ssh"
-          git config --global user.signingkey ~/.ssh/id_ed25519.pub
           localRev="$(git rev-parse HEAD)"
-          go install github.com/canonical/lxd-ci/lxd-snapcraft@latest
-          git clone -b "${TARGET}" git+ssh://[email protected]/~canonical-lxd/lxd ~/lxd-pkg-snap-lp
           # XXX: `ver` contains an array with the 2 versions
-          ver=($(lxd-snapcraft -package lxd -get-version -file ~/lxd-pkg-snap-lp/snapcraft.yaml))
-          rsync -a --exclude .git --delete . ~/lxd-pkg-snap-lp/
-          cd ~/lxd-pkg-snap-lp
+          ver=($(lxd-snapcraft -package "${PACKAGE}" -get-version -file ~/"${PACKAGE}-pkg-snap-lp/snapcraft.yaml"))
+          rsync -a --exclude .git --delete . ~/"${PACKAGE}-pkg-snap-lp"/
+          cd ~/"${PACKAGE}-pkg-snap-lp"
           lxd-snapcraft -package lxd -set-version "${ver[0]}" -set-source-commit "${ver[1]}"
           git add --all
-          git commit --all --quiet -s --allow-empty -m "Automatic upstream build (${TARGET})" -m "Upstream commit: ${localRev}"
+          git commit --all --quiet -s --allow-empty -m "Automatic upstream build (${BRANCH})" -m "Upstream commit: ${localRev}"
           git show
           git push --quiet