Add docs for GitHub action (#32)

Author: mszostok

README.md

@@ -15,6 +15,48 @@ The Codeowners Validator project validates the GitHub [CODEOWNERS](https://help.
 
 ![usage](./docs/assets/usage.svg)
 
+## Usage
+
+#### Docker
+
+```bash
+export GH_TOKEN=<your_token>
+docker run --rm -v $(pwd):/repo -w /repo \
+  -e REPOSITORY_PATH="." \
+  -e GITHUB_ACCESS_TOKEN="$GH_TOKEN" \
+  -e EXPERIMENTAL_CHECKS="notowned" \
+  -e OWNER_CHECKER_REPOSITORY="org-name/rep-name" \
+  mszostok/codeowners-validator:v0.4.0
+```
+
+#### Command line
+
+```bash
+export GH_TOKEN=<your_token>
+env REPOSITORY_PATH="." \
+    GITHUB_ACCESS_TOKEN="$GH_TOKEN" \
+    EXPERIMENTAL_CHECKS="notowned" \
+    OWNER_CHECKER_REPOSITORY="org-name/rep-name" \
+  codeowners-validator
+```
+
+#### GitHub Action
+
+```yaml
+- uses: mszostok/codeowners-validator@v0.4.0
+  with:
+    checks: "files,owners,duppatterns"
+    experimental_checks: "notowned"
+    # GitHub access token is required only if the `owners` check is enabled
+    github_access_token: "${{ secrets.OWNERS_VALIDATOR_GITHUB_SECRET }}"
+```
+
+Check [this](./docs/gh-action.md) document for more information about GitHub Action.
+
+----
+
+Check the [Configuration](#configuration) section for more info on how to enable and configure given checks.
+
 ## Installation
 
 It's highly recommended to install a fixed version of ` codeowners-validator`. Releases are available on the [releases page](https://github.com/mszostok/codeowners-validator/releases).
@@ -47,38 +89,6 @@ You can install `codeowners-validator` with `env GO111MODULE=on go get -u github
 
 This will put `codeowners-validator` in `$(go env GOPATH)/bin`
 
-## Usage
-
-#### Docker
-
-```bash
-export GH_TOKEN=<your_token>
-docker run --rm -v $(pwd):/repo -w /repo \
-  -e REPOSITORY_PATH="." \
-  -e GITHUB_ACCESS_TOKEN="$GH_TOKEN" \
-  -e EXPERIMENTAL_CHECKS="notowned" \
-  -e OWNER_CHECKER_REPOSITORY="org-name/rep-name" \
-  mszostok/codeowners-validator:v0.4.0
-```
-
-#### Command line
-
-```bash
-export GH_TOKEN=<your_token>
-env REPOSITORY_PATH="." \
-    GITHUB_ACCESS_TOKEN="$GH_TOKEN" \
-    EXPERIMENTAL_CHECKS="notowned" \
-    OWNER_CHECKER_REPOSITORY="org-name/rep-name" \
-  codeowners-validator
-```
-
-#### GitHub Action
-
-Coming soon 😎 Stay tuned!
-
-
-Check the [Configuration](#configuration) section for more info on how to enable and configure given checks.
-
 ## Configuration
 
 Use the following environment variables to configure the application:

action.yml

@@ -4,7 +4,7 @@ author: "szostok.mateusz@gmail.com"
 
 inputs:
   github_access_token:
-    description: "The GitHub access token. Instruction for creating a token can be found here. If not provided then validating owners functionality could not work properly, e.g. you can reach the API calls quota or if you are setting GitHub Enterprise base URL then an unauthorized error can occur."
+    description: "The GitHub access token. Instruction for creating a token can be found here: https://help.github.com/articles/creating-a-personal-access-token-for-the-command-line/#creating-a-token. If not provided then validating owners functionality could not work properly, e.g. you can reach the API calls quota or if you are setting GitHub Enterprise base URL then an unauthorized error can occur."
     required: false
 
   github_base_url:

docs/assets/action-output.png

@@ -0,0 +1,49 @@
+<p align="center">
+  <h3 align="center">GitHub Action for CODEOWNERS Validator</h3>
+  <p align="center">Ensures the correctness of your CODEOWNERS file.</p>
+  <p align="center">
+    <a href="/LICENSE"><img alt="Software License" src="https://img.shields.io/badge/license-Apache-brightgreen.svg?style=flat-square"></a>
+  </p>
+</p>
+
+---
+
+The [Codeowners Validator](https://github.com/mszostok/codeowners-validator) is available as a GitHub Action.
+                                                                                   
+<p align="center">
+    <img src="https://raw.githack.com/mszostok/codeowners-validator/master/docs/assets/action-output.png" width="600px" alt="demo">
+</p>
+
+
+## Usage
+ 
+Create a workflow (eg: `.github/workflows/sanity.yml` see [Creating a Workflow file](https://help.github.com/en/articles/configuring-a-workflow#creating-a-workflow-file))
+
+```yaml
+name: "Codeowners Validator"
+
+on:
+  schedule:
+    # Runs at 08:00 UTC every day
+    - cron:  '0 8 * * *'
+
+jobs:
+  sanity:
+    runs-on: ubuntu-latest
+    steps:
+      # Checks-out your repository, which is validated in the next step
+      - uses: actions/checkout@v2
+      - name: GitHub CODEOWNERS Validator
+        uses: mszostok/codeowners-validator@v0.4.0
+        with:
+          checks: "files,owners,duppatterns"
+          experimental_checks: "notowned"
+          # GitHub access token is required only if the `owners` check is enabled
+          github_access_token: "${{ secrets.OWNERS_VALIDATOR_GITHUB_SECRET }}"
+```
+
+The best is to run this as a cron job and not only if you applying changes to CODEOWNERS file itself, e.g. the CODEOWNERS file can be invalidate when you removing someone from the organization.
+
+> **Note**: To execute `owners` check you need to create a [GitHub token](https://help.github.com/articles/creating-a-personal-access-token-for-the-command-line/#creating-a-token) and store it as a secret in your repository, see ["Creating and storing encrypted secrets."](https://help.github.com/en/actions/configuring-and-managing-workflows/creating-and-storing-encrypted-secrets). Token requires only read-only scope for your repository.
+
+<!--- example repository when failed -->