.. Copyright 2014 tsuru authors. All rights reserved.
   Use of this source code is governed by a BSD-style
   license that can be found in the LICENSE file.

+++++++++++++++++++++++++
Deploying Go applications
+++++++++++++++++++++++++

Overview
========

This document is a hands-on guide to deploying a simple Go web application in
tsuru.

Creating the app
================

To create an app, you use the command `app create`:

.. highlight:: bash

::

    $ tsuru app create <app-name> <app-platform>

For Go, the platform name is ``go``! Let's be over creative and develop a hello
world tutorial-app, let's call it "helloworld":

.. highlight:: bash

::

    $ tsuru app create helloworld go

To list all available platforms, use the command `platform list`.

You can see all your applications using the command  `app list`:

.. highlight:: bash

::

    $ tsuru app list
    +-------------+-------------------------+--------------------------------+
    | Application | Units State Summary     | Address                        |
    +-------------+-------------------------+--------------------------------+
    | helloworld  | 0 of 0 units in-service | helloworld.192.168.50.4.nip.io |
    +-------------+-------------------------+--------------------------------+

Application code
================

A simple web application in Go `main.go`:

.. highlight:: go

::

    package main

    import (
        "fmt"
        "net/http"
        "os"
    )

    func main() {
        http.HandleFunc("/", hello)
        fmt.Println("listening...")
        err := http.ListenAndServe(":" + os.Getenv("PORT"), nil)
        if err != nil {
            panic(err)
        }
    }

    func hello(res http.ResponseWriter, req *http.Request) {
        fmt.Fprintln(res, "hello, world!")
    }

Deployment
==========

You can just run tsuru app deploy command and your project will be deployed:

.. highlight:: console

::

    $ tsuru app deploy -a helloworld .
     tar: Removing leading `/' from member names
     /

     ---- Building application image ----
      ---> Sending image to repository (5.57MB)
      ---> Cleaning up

     ---- Starting 1 new unit ----
      ---> Started unit b21298a64e...

     ---- Binding and checking 1 new units ----
      ---> Bound and checked unit b21298a64e

     ---- Adding routes to 1 new units ----
      ---> Added route to unit b21298a64e

     OK


Now you can check your deployed app running `tsuru app info`

.. highlight:: bash

::

    $ tsuru app info -a helloworld
    Application: helloworld
    Platform: go
    Teams: admin
    Address: helloworld.192.168.50.4.nip.io
    Owner: admin@example.com
    Team owner: admin
    Deploys: 1
    Pool: theonepool
    Units: 1
    +---------------------------------+---------+
    | Unit                            | State   |
    +---------------------------------+---------+
    | helloworld-web-b21298a64e-8a64e | started |
    +---------------------------------+---------+

    App Plan:
    +---------------+--------+-----------+---------+
    | Name          | Memory | Cpu Share | Default |
    +---------------+--------+-----------+---------+
    | autogenerated | 0 MB   | 100       | false   |
    +---------------+--------+-----------+---------+

Handling dependencies
=====================

If your app is split in packages, you should set the `GO_PKG_PATH` environment
variable with the package name of your app:

.. highlight:: bash

::

    $ tsuru env-set GO_PKG_PATH=github.com/tsuru/helloworld --app helloworld

If you have external dependencies, you should add them as vendored packages.
An alternative solution is building your app locally and deploying it using
the app deploy command. In this case, you would also need a Procfile:

.. highlight:: bash

::

    $ CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o helloworld
    $ echo "web: ./helloworld" > ./Procfile
    $ tsuru app deploy --app helloworld ./helloworld ./Procfile

If your app has other files to include in the deploy command, like tsuru.yaml,
include them as parameters in the above command as well.

Running the application
=======================

tsuru will compile and run the application automatically, but it's possible to
customize how tsuru compiles and runs the application. For more details, check
the README of the Go platform:
https://github.com/tsuru/basebuilder/blob/master/go/README.md.

Now that the app is deployed, you can access it from your browser, getting the
IP or host listed in ``app list`` and opening it. For example,
in the list below:

::

    $ tsuru app list
    +-------------+-------------------------+--------------------------------+
    | Application | Units State Summary     | Address                        |
    +-------------+-------------------------+--------------------------------+
    | helloworld  | 1 of 1 units in-service | helloworld.192.168.50.4.nip.io |
    +-------------+-------------------------+--------------------------------+

It's done! Now we have a simple go project deployed on tsuru.

Now we can access your app in the URL displayed in `app list`
("helloworld.192.168.50.4.nip.io" in this case).

Going further
=============

For more information, you can dig into `tsuru docs <http://docs.tsuru.io>`_, or
read `complete instructions of use for the tsuru command
<https://tsuru-client.readthedocs.org>`_.