feat: Add pull request workflow with SSH host validation and deployment checks

- Created `.github/workflows/pull_request.yml` to handle pull request events on the `main` branch.
- Integrated matrix strategy to test across macOS, Ubuntu, and Windows platforms.
- Added `check.sh` to verify the existence of a populated `known_hosts` file before deployment.
- Added `post_check.sh` to ensure the `known_hosts` file is removed after the job for security.
- Included test deployment of a `whoami` container to validate Docker host setup.
- Utilized `pyTooling/Actions/with-post-step` to streamline pre- and post-check scripts.
- Added support for private SSH keys and `known_hosts` configuration using the custom SSH action.

Author: warnyul

.github/workflows/pull_request.yml

@@ -0,0 +1,39 @@
+on:
+  pull_request:
+    branches: 
+      - main
+jobs:
+  test:
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - macos-15
+          - ubuntu-24.04
+          - windows-2025
+    runs-on: ${{ matrix.os }}      
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - name: Setup SSH key
+        uses: ./
+        with:
+          ssh-private-key: ${{ secrets.SSH_PRIVATE_KEY }}
+          ssh-known-hosts: ${{ secrets.SSH_KNOWN_HOSTS }}
+          log-public-key: false
+      - name: Check known hosts
+        uses: pyTooling/Actions/with-post-step@9ceefdbf5dceae8c441fc393ed82344c7ca8bbdb # v3.1.1
+        with:
+          main: |
+            ./check.sh
+          post: |
+            ./post_check.sh
+      - name: Deploy over SSH
+        shell: bash
+        env:
+          DOCKER_HOST: ${{ secrets.DOCKER_HOST }}
+        run: |
+          # renovate: datasource=docker depname=traefik/whoami versioning=docker
+          WHOAMI_VERSION="v1.10"
+          docker run -d -P --name whoami traefik/whoami:v1.10
+          docker stop whoami
+          docker rm whoami

check.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+if [ ! -s ~/.ssh/known_hosts ]; then
+    echo "::error file=$(basename "$0"),line=${LINENO},endLine=${LINENO},title=Assertion Error::\
+~/.ssh/known_hosts is missing or empty."
+    exit 1
+fi

post_check.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+if [ -s ~/.ssh/known_hosts ]; then
+    echo "::error file=$(basename "$0"),line=${LINENO},endLine=${LINENO},title=Assertion Error::\
+~/.ssh/known_hosts file should not exist after the job."
+    exit 1
+fi