Migrate deploy workflow to OpenBao SSH CA

.gitea/workflows/ci.yml

@@ -215,12 +215,34 @@ jobs:
 
   deploy:
     if: github.event_name == 'push' && github.ref == 'refs/heads/main'
-    runs-on: deploy
+    runs-on:
+      - ubuntu-latest
+      - agent-workspace
+    env:
+      BAO_TOKEN_FILE: /run/openbao-agent-ci_runner/token
     steps:
+      - name: Configure SSH via OpenBao CA
+        shell: bash
+        run: |
+          set -euo pipefail
+          : "${OPENBAO_ADDR:?OPENBAO_ADDR must be set by the runner environment}"
+          mkdir -p ~/.ssh && chmod 700 ~/.ssh
+          ssh-keygen -t ed25519 -f ~/.ssh/id_ed25519 -N "" -q
+          BAO_TOKEN="$(<"$BAO_TOKEN_FILE")"
+          SIGNED_KEY=$(curl -fsS \
+            -H "X-Vault-Token: $BAO_TOKEN" \
+            -H "X-Vault-Request: true" \
+            -X POST \
+            -d "{\"public_key\": \"$(cat ~/.ssh/id_ed25519.pub)\", \"valid_principals\": \"${{ vars.DEPLOY_USER }}\"}" \
+            "${OPENBAO_ADDR}/v1/ssh/sign/${{ vars.DEPLOY_SSH_ROLE }}" \
+            | jq -r '.data.signed_key')
+          [ -n "$SIGNED_KEY" ] && [ "$SIGNED_KEY" != "null" ] \
+            || { echo "ERROR: failed to sign SSH key via OpenBao CA" >&2; exit 1; }
+          printf '%s\n' "$SIGNED_KEY" > ~/.ssh/id_ed25519-cert.pub
+          unset BAO_TOKEN SIGNED_KEY
+
+      - name: Add deploy host to known_hosts
+        run: ssh-keyscan -H "${{ vars.DEPLOY_HOST }}" >> ~/.ssh/known_hosts 2>/dev/null
+
       - name: Deploy to lintel-prod-01
-        uses: appleboy/ssh-action@v1
+        run: ssh "${{ vars.DEPLOY_USER }}@${{ vars.DEPLOY_HOST }}" "bash /srv/sum/nohype/app/deploy/deploy.sh"
-        with:
-          host: ${{ secrets.PROD_SSH_HOST }}
-          username: deploy
-          key: ${{ secrets.PROD_SSH_KEY }}
-          script: bash /srv/sum/nohype/app/deploy/deploy.sh