feat: adds fly deploy github action

.github/renovate.json5

@@ -29,6 +29,12 @@
       "matchStrings": [
         "datasource=(?<datasource>.*?) depName=(?<depName>.*?)\\sARG .*?_VERSION=(?<currentValue>v.*)\\s"
       ]
+    },
+    {
+      "fileMatch": ["^\\.github\\/workflows\\/fly-deploy\\.yaml$"],
+      "matchStrings": [
+        "datasource=(?<datasource>.*?) depName=(?<depName>.*?)\\sversion:\\s(?<currentValue>.*)\\s"
+      ]
     }
   ]
 }

.github/workflows/fly-deploy.yaml

@@ -0,0 +1,51 @@
+name: Deploy to Fly
+
+on:
+  workflow_dispatch: {}
+  push:
+    branches:
+      - main
+    paths:
+      - Dockerfile
+      - fly.toml
+      - config/**
+      - scripts/**
+
+jobs:
+  check-fly-secret:
+    runs-on: ubuntu-latest
+    outputs:
+      fly-secret-exists: ${{ steps.fly-secret-check.outputs.defined }}
+    steps:
+      - name: Check for Fly secrets availability
+        id: fly-secret-check
+        # perform secret check & put boolean result as an output
+        shell: bash
+        run: |
+          if [ "${{ secrets.FLY_API_TOKEN }}" != '' ] && [ "${{ secrets.FLY_APP }}" != '' ]; then
+            echo "defined=true" >> $GITHUB_OUTPUT;
+          else
+            echo "defined=false" >> $GITHUB_OUTPUT;
+          fi
+
+  deploy:
+    name: Deploy app
+    runs-on: ubuntu-latest
+    needs: [check-fly-secret]
+    if: needs.check-fly-secret.outputs.fly-secret-exists == 'true'
+    steps:
+      - uses: actions/checkout@v2
+      - uses: superfly/flyctl-actions/setup-flyctl@master
+        with:
+          version: 0.1.54
+      - name: Install Task
+        uses: arduino/setup-task@v1
+        with:
+          # renovate: datasource=github-releases depName=go-task/task
+          version: 3.27.1
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Deploy app
+        run: flyctl deploy --remote-only -a $FLY_APP
+        env:
+          FLY_APP: ${{ secrets.FLY_APP }}
+          FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}