# Branch Deploy Action 🚀

A GitHub Action to enable branch deployments using IssueOps!

## About 💡

Before we get into details, let's first define a few key terms below:

- **IssueOps** - Its like ChatOps but instead of using a chat bot, commands are invoked by commenting on a pull request (PRs are issues under the hood) - Example: commenting `.deploy` on a pull request
- **Branch Deployment** - A branch deploy is a deployment methodology that enables you to deploy a branch (or pull request) to a desired environment before merging to `main` or `master` - More on this below
- **PR** - Short for pull request

### IssueOps 🗨️

The best way to define IssueOps is to compare it to something similar, ChatOps. You may be familiar with the concept ChatOps already but in case you aren't here is a quick definition below:

> ChatOps is the process of interacting with a chat bot to execute commands directly in a chat platform. For example, with ChatOps you might do something like `.ping example.org` to check the status of a website

IssueOps adopts the same mindset but through a different medium. Rather than using a chat service to invoke the commands we use comments on a GitHub Issue or Pull Request. GitHub Actions is the runtime which executes our desired logic

### Branch Deployments 🌲

Branch deployments are a battle tested way of deploying your changes to a given environment for a variety of reasons. Branch deployments allow you to do the following:

- Deploy your changes to production **before** merging
- Deploy changes to a staging, QA, or non-production environment

#### Branch Deployment Core Concepts ⭐

> Note: The `main` branch is considered the base repository branch for all examples below

- The `main` branch is always considered to be a stable and deployable branch
- All changes are deployed to production before they are merged to the `main` branch
- To roll back a branch deployment, you deploy the `main` branch
- `noop` deployments should not make changes but rather report what they "would" have done

#### Why use branch deployments?

> To put the *merge -> deploy* model in the past!

What if your changes are bad and you broke production with the *merge -> deploy* model? Well now you have to revert your PR, get passing CI/builds, and then re-merge your changes to get back to a stable environment. With the **branch deploy** model, this is almost never the case. The `main` branch is considered to be always safe and stable

## Testing Locally 🔨

Test with [act](https://github.com/nektos/act) locally to simulate a GitHub Actions event

```bash
act issue_comment -e events/issue_comment_deploy.json -s GITHUB_TOKEN=faketoken -j test
```

## Create an action from this template

Click the `Use this Template` and provide the new repo details for your action

## Code in Main

> First, you'll need to have a reasonably modern version of `node` handy. This won't work with versions older than 9, for instance.

Install the dependencies  
```bash
$ npm install
```

Build the typescript and package it for distribution
```bash
$ npm run build && npm run package
```

Run the tests :heavy_check_mark:  
```bash
$ npm test

 PASS  ./index.test.js
  ✓ throws invalid number (3ms)
  ✓ wait 500 ms (504ms)
  ✓ test runs (95ms)

...
```

## Change action.yml

The action.yml defines the inputs and output for your action.

Update the action.yml with your name, description, inputs and outputs for your action.

See the [documentation](https://help.github.com/en/articles/metadata-syntax-for-github-actions)

## Change the Code

Most toolkit and CI/CD operations involve async operations so the action is run in an async function.

```javascript
import * as core from '@actions/core';
...

async function run() {
  try { 
      ...
  } 
  catch (error) {
    core.setFailed(error.message);
  }
}

run()
```

See the [toolkit documentation](https://github.com/actions/toolkit/blob/master/README.md#packages) for the various packages.

## Publish to a distribution branch

Actions are run from GitHub repos so we will checkin the packed dist folder. 

Then run [ncc](https://github.com/zeit/ncc) and push the results:
```bash
$ npm run package
$ git add dist
$ git commit -a -m "prod dependencies"
$ git push origin releases/v1
```

Note: We recommend using the `--license` option for ncc, which will create a license file for all of the production node modules used in your project.

Your action is now published! :rocket: 

See the [versioning documentation](https://github.com/actions/toolkit/blob/master/docs/action-versioning.md)

## Validate

You can now validate the action by referencing `./` in a workflow in your repo (see [test.yml](.github/workflows/test.yml))

```yaml
uses: ./
with:
  milliseconds: 1000
```

See the [actions tab](https://github.com/actions/typescript-action/actions) for runs of this action! :rocket:

## Usage:

After testing you can [create a v1 tag](https://github.com/actions/toolkit/blob/master/docs/action-versioning.md) to reference the stable and latest V1 action