cf-example-golang-hello-world

# Welcome

So, you've decided to try Codefresh? Welcome on board!

Using this repository we'll help you get up to speed with basic functionality such as: *compiling*, *testing* and *building Docker images*.

This project uses `golang` (or just `go`) to build an application which will eventually become a distributable Docker image.

## Example application

We'll use https://github.com/nuveo/prest[pREST] as an example application. pREST allows you to serve a RESTful API from any PostgreSQL database.
Have a look at the README.pREST.md file for more information about pREST.

## Looking around

In the root of this repository you'll find a file named `codefresh.yml`, this is our https://docs.codefresh.io/docs/what-is-the-codefresh-yaml[build descriptor] and it describes the different steps that comprise our process.
Let's quickly review the contents of this file:

### Testing

To test our code we use Codefresh's https://docs.codefresh.io/docs/steps#section-freestyle[Freestyle step].

The Freestyle step basically let's you say "Hey, Codefresh! Here's a Docker image. Create a new container and run these commands for me, will ya?"

```
  perform_tests:
    image: golang:latest
    working_directory: ${{main_clone}}
    description: Performing unit tests...
    commands:
      # Need to have the source in the correct GOPATH folder - let's do that
      - mkdir -p /go/src/github.com/${{CF_REPO_OWNER}}
      - ln -s /codefresh/volume/${{CF_REPO_NAME}} /go/src/github.com/${{CF_REPO_OWNER}}/${{CF_REPO_NAME}}
      - cd /go/src/github.com/${{CF_REPO_OWNER}}/${{CF_REPO_NAME}} && go get
      - cd /go/src/github.com/${{CF_REPO_OWNER}}/${{CF_REPO_NAME}} && go test
```

The `image` field states which image should be used when creating the container (Similar to Travis CI's `language` or CircleCI`s `machine`).

The `commands` field is how you specify all the commands that you'd like to execute

### Building

To bake our application into a Docker image we use Codefresh's https://docs.codefresh.io/docs/steps#section-build[Build step].

The Build is a simplified abstraction over the Docker build command.

```
  build_image:
    type: build
    description: Building the image...
    image_name: ${{CF_REPO_OWNER}}/${{CF_REPO_NAME}}
    tag: '${{CF_BRANCH}}'
```

Use the `image_name` field to declare the name of the resulting image (don't forget to change the image owner name from `${{CF_REPO_OWNER}}` to your own!).

### Launching

This is where it gets real! Let's use Codefresh's https://docs.codefresh.io/docs/steps#section-launch-composition[Launch Composition step] to run our composition within Codefresh!

Launching compositions within Codefresh means you have your very own staging area, at a click of a button!
```
  launch_composition:
    type: launch-composition
    description: Launching an environment from a composition...
    composition:
      version: '2'
      services:
        prest:
          image: '${{CF_REPO_OWNER}}/${{CF_REPO_NAME}}:${{CF_BRANCH}}'
          environment:
            - PREST_PG_HOST=postgres
            - PREST_PG_USER=prest
            - PREST_PG_PASS=prest
            - PREST_PG_DATABASE=prest
            - PREST_PG_PORT=5432
          depends_on:
            - postgres
          ports:
            - '3000'
        postgres:
          image: mbrung/postgres-no-volume
          environment:
            - POSTGRES_USER=prest
            - POSTGRES_DB=prest
            - POSTGRES_PASSWORD=prest
          ports:
            - '5432'
```

Using the `composition` field, we direct Codefresh to the location if the `docker-compose` file in our repository.

Once the Launch Composition step has completed successfully, you'll be able to review and share your running composition in the https://docs.codefresh.io/docs/share-environment-with-your-test[Environments page].

You'll now be able to either connect directly to pREST to perform RESTful opreations, or to the ephemereal Postgres database to create new schemas and tables for pREST to work with.

Now that we've gotten a grip on the flow, let's get cracking!

## Using This Example

To use this example:

. Fork this repository to your own Github account. (If you want to make changes and get the CI working on new commits)
. Log in to Codefresh using your Github account.
. Click the `Add Service` button.
. Select the forked repository. (Or paste in the the original repository's URL.)
. Select the `I have a codefresh.yml file` option.
. Complete the wizard.
. Rejoice!