Feature/matrix docker container (#173)

* use matrix for Docker container

* update badge

.github/workflows/verify-on-container.yml

@@ -1,6 +1,6 @@
 # https://help.github.com/en/articles/workflow-syntax-for-github-actions
 
-name: Docker container on Ubuntu 20.04
+name: Docker container
 
 on:
 - push
@@ -8,8 +8,19 @@ on:
 jobs:
   ssh-pem:
     name: Connect to github.com (PEM format)
-    runs-on: ubuntu-20.04
-    container: ubuntu:20.04
+    runs-on: ${{ matrix.os }}
+    container: ${{ matrix.container }}
+    strategy:
+      matrix:
+        os:
+        - ubuntu-16.04
+        - ubuntu-18.04
+        - ubuntu-20.04
+        container:
+        - ubuntu:16.04
+        - ubuntu:18.04
+        - ubuntu:20.04
+      fail-fast: false
     steps:
     - name: Install packages
       run: |
@@ -28,8 +39,19 @@ jobs:
       run: git clone git@github.com:shimataro/ssh-key-action.git tmp
   ssh-pkcs8:
     name: Connect to github.com (PKCS8 format)
-    runs-on: ubuntu-20.04
-    container: ubuntu:20.04
+    runs-on: ${{ matrix.os }}
+    container: ${{ matrix.container }}
+    strategy:
+      matrix:
+        os:
+        - ubuntu-16.04
+        - ubuntu-18.04
+        - ubuntu-20.04
+        container:
+        - ubuntu:16.04
+        - ubuntu:18.04
+        - ubuntu:20.04
+      fail-fast: false
     steps:
     - name: Install packages
       run: |
@@ -48,8 +70,19 @@ jobs:
       run: git clone git@github.com:shimataro/ssh-key-action.git tmp
   ssh-rfc4716:
     name: Connect to github.com (RFC4716 format)
-    runs-on: ubuntu-20.04
-    container: ubuntu:20.04
+    runs-on: ${{ matrix.os }}
+    container: ${{ matrix.container }}
+    strategy:
+      matrix:
+        os:
+        - ubuntu-16.04
+        - ubuntu-18.04
+        - ubuntu-20.04
+        container:
+        - ubuntu:16.04
+        - ubuntu:18.04
+        - ubuntu:20.04
+      fail-fast: false
     steps:
     - name: Install packages
       run: |

README.md

@@ -140,8 +140,8 @@ See [CHANGELOG.md](CHANGELOG.md).
 [link-verify-ubuntu-1804]: https://github.com/shimataro/ssh-key-action/actions?query=workflow%3A%22Ubuntu+18.04%22
 [image-verify-ubuntu-1604]: https://github.com/shimataro/ssh-key-action/workflows/Ubuntu%2016.04/badge.svg?event=push&branch=v2
 [link-verify-ubuntu-1604]: https://github.com/shimataro/ssh-key-action/actions?query=workflow%3A%22Ubuntu+16.04%22
-[image-verify-docker-container]: https://github.com/shimataro/ssh-key-action/workflows/Docker%20container%20on%20Ubuntu%2020.04/badge.svg?event=push&branch=v2
-[link-verify-docker-container]: https://github.com/shimataro/ssh-key-action/actions?query=workflow%3A%22Docker+container+on+Ubuntu+20.04%22
+[image-verify-docker-container]: https://github.com/shimataro/ssh-key-action/workflows/Docker%20container/badge.svg?event=push&branch=v2
+[link-verify-docker-container]: https://github.com/shimataro/ssh-key-action/actions?query=workflow%3A%22Docker+container%22
 [image-release]: https://img.shields.io/github/release/shimataro/ssh-key-action.svg
 [link-release]: https://github.com/shimataro/ssh-key-action/releases
 [image-license]: https://img.shields.io/github/license/shimataro/ssh-key-action.svg