add super-linter GitHub presubmit action (#1)

* add super-linter GitHub presubmit action
* disable running kubeval linter
* fix MD lint problems

Author: vorburger

.github/linters/.markdown-lint.yaml

@@ -0,0 +1,10 @@
+# https://github.com/DavidAnson/markdownlint#optionsconfig
+# https://github.com/DavidAnson/markdownlint/blob/main/schema/.markdownlint.yaml
+
+# Bare URL are OK
+MD034: false
+
+MD013:
+  line_length: 4096
+  strict: false
+  stern: false

.github/workflows/linter.yaml

@@ -0,0 +1,25 @@
+# https://github.com/github/super-linter
+name: Lint Code Base
+on:
+  push:
+  pull_request:
+    branches: [master]
+jobs:
+  build:
+    name: Lint Code Base
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+
+      - name: Lint Code Base
+        uses: github/super-linter@v4
+        env:
+          DEFAULT_BRANCH: master
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          MARKDOWN_CONFIG_FILE: .markdown-lint.yaml
+          # https://github.com/github/super-linter/issues/1601
+          VALIDATE_KUBERNETES_KUBEVAL: false

README.md

@@ -1,4 +1,4 @@
-# Learning Kubernetes Codelabs
+# Learning Kubernetes Codelabs [![GitHub Super-Linter](https://github.com/vorburger/LearningKubernetes-CodeLabs/workflows/Lint%20Code%20Base/badge.svg)](https://github.com/marketplace/actions/super-linter)
 
 This is a Code Lab style course for learning Kubernetes, with the following lessons:
 

TODO.md

@@ -1,3 +1,5 @@
+# ToDo
+
 - [ ] Lessons:
 
   - [ ] API: Build an Operator
@@ -39,8 +41,6 @@
       ssh: connect to host $IP port 22: Connection timed out
       ERROR: (gcloud.compute.ssh) [/usr/bin/ssh] exited with return code [255].
 
-- [ ] GitHub Action (pre-commit hook) to lint all markdown, check links, etc.
-
-- [ ] https://github.com/googlecodelabs/tools ? 
+- [ ] https://github.com/googlecodelabs/tools ?
 
 - [ ] https://codelabs.developers.google.com ?

docs/hello-world.md

@@ -10,4 +10,4 @@
 
     minikube dashboard
 
-If you run `minikube` inside a Virtual Machine (VM) instead of on your Laptop/Desktop workstation, then you'll need to set up some port forwarding to be able to access services in your local web browser.
+If you run `minikube` inside a Virtual Machine (VM) instead of on your Laptop/Desktop workstation, then you'll need to set up some port forwarding to be able to access services in your local web browser.

docs/install.md

@@ -8,7 +8,6 @@ To follow the lessons in this tutorial, you need to have the following prerequis
 
 There are several ways to set this up, see the options below. Alternatives include e.g. `kind`, `kubeadm`; or cloud hosted managed Kubernetes offerings like Google's GKE; or local distributions like k3s.io, k3s.io, OpenShift, et al. (We may add documentation about such other approaches later.)
 
-
 ## minikube Docker driver
 
 One of easiest ways to get started on a developer workstation is to use https://minikube.sigs.k8s.io/docs/start, and:
@@ -18,11 +17,10 @@ One of easiest ways to get started on a developer workstation is to use https://
 
 This creates a VM, and works equally well on Windows, Mac and Linux.
 
-
 ## minikube None driver
 
 To avoid creating a VM and run the Kubernetes control panel containers straight on the host,
-which is suitable e.g. inside a new Linux VM which isn't used for anything else, use the 
+which is suitable e.g. inside a new Linux VM which isn't used for anything else, use the
 _[Linux "none" (= bare-metal) driver](https://minikube.sigs.k8s.io/docs/drivers/none/)_,
 e.g. with Debian 10 simply:
 
@@ -36,13 +34,12 @@ e.g. with Debian 10 simply:
     sudo chown -R $(id -un):$(id -gn $(id -un)) /home/vorburger_google_com/.minikube/
     alias k="minikube kubectl -- "
 
-
 ## Test Installation
 
 The goal of each of the set-up options above, if successful, is that you should be able to run:
 
     k get pods -A
-    
+
 and see:
 
     NAMESPACE     NAME                               READY   STATUS    RESTARTS   AGE