# Development Environment [DigitalOcean][] is the recommended development environment for Deis project contributors. [Provision a new DO cluster](../installing-deis/digitalocean.md) and then continue to follow the instructions below to get started hacking. !!! important Are you a new contributor to Deis? Your first [Pull Request][pr] could earn you credit at [DigitalOcean][]! Submit your changes and then email . When your PR is merged, the maintainer team will send you a DigitalOcean credit based on the value of your contribution. This document is for developers who are interested in working directly on the Deis codebase. In this guide, we walk you through the process of setting up a local development environment. While there are many ways to set up your Deis environment, this document covers a specific setup: - Developing on **Mac OSX** or **Linux** - Managing virtualization with **Vagrant/Virtualbox** - Hosting a docker registry with **docker-machine** (Mac) We try to make it simple to hack on Deis. However, there are necessarily several moving pieces and some setup required. We welcome any suggestions for automating or simplifying this process. If you're just getting into the Deis codebase, look for GitHub issues with the label [easy-fix][]. These are more straightforward or low-risk issues and are a great way to become more familiar with Deis. ## Prerequisites You can develop on any supported platform including your laptop, cloud providers or on bare metal. We strongly recommend a minimum 3-node cluster. We strongly suggest using Vagrant and VirtualBox for your virtualization layer during development. At a glance, you will need: - Python 2.7 or later (with `pip`) - virtualenv (`sudo pip install virtualenv`) - Go 1.5 or later, with support for compiling to `linux/amd64` - [Godep](https://github.com/tools/godep) - VirtualBox latest - Vagrant 1.5 or later On Mac, you will also want [Docker Machine][machine]. Additionally, you may need: - [shellcheck](https://github.com/koalaman/shellcheck) - [golint](https://github.com/golang/lint) In most cases, you should simply install according to the instructions. There are a few special cases, though. We cover these below. ### Configuring Go If your local workstation does not support the `linux/amd64` target environment, you will have to install Go from source with cross-compile support for that environment. This is because some of the components are built on your local machine and then injected into a docker container. Homebrew users can just install with cross compiling support: $ brew install go --with-cc-common It is also straightforward to build Go from source: $ sudo su $ curl -sSL https://golang.org/dl/go1.5.src.tar.gz | tar -v -C /usr/local -xz $ cd /usr/local/go/src $ # compile Go for our default platform first, then add cross-compile support $ ./make.bash --no-clean $ GOOS=linux GOARCH=amd64 ./make.bash --no-clean Once you can compile to `linux/amd64`, you should be able to compile Deis' components as normal. ### Configuring Docker Machine (Mac) Deis needs a Docker registry running independently of the Deis cluster. On OS X, you will need [Docker Machine][machine] to run the registry inside of a VirtualBox image. !!! note Previously, Deis used boot2docker to run the registry. However, Docker has deprecated boot2docker in favor of Docker Machine. Install Docker Machine according to the normal installation instructions. Then create a new image for hosting your Deis Docker registry: $ docker-machine create --driver virtualbox --virtualbox-disk-size=100000 \ --engine-insecure-registry=192.168.0.0/16 deis-registry This will create a new virtual machine named `deis-registry` that will take up as much as 100,000 MB of disk space. Registries tend to be large, so allocating a big disk is a good idea. Once the deis-registry machine exists, source its values into your environment so your docker client knows how to use the new machine. $ eval "$(docker-machine env deis-registry)" !!! note Because the registry that we create will not have a valid SSL certificate, we run the local registry as an insecure (HTTP, not HTTPS) registry. Each time Docker Machine reboots, the registry will get a new IP address somewhere in the `192.168.0.0/16` range. We must declare that explicitly when configuring Docker Machine. At this point, our `deis-registry` VM can now serve as a registry for Deis' Docker images. Later we will return to this. ## Fork the Deis Repository Once the prerequisites have been met, we can begin to work with Deis. To get Deis running for development, first [fork the Deis repository][fork], then clone your fork of the repository. Since Deis is predominantly written in Go, the best place to put it is in `$GOPATH/src/github.com/deis/`. $ mkdir -p $GOPATH/src/github.com/deis $ cd $GOPATH/src/github.com/deis $ git clone git@github.com:/deis.git $ cd deis !!! note By checking out the forked copy into the namespace `github.com/deis/deis`, we are tricking the Go toolchain into seeing our fork as the "official" Deis tree. If you are going to be issuing pull requests and working with official Deis repository, we suggest configuring Git accordingly. There are various strategies for doing this, but the [most common](https://help.github.com/articles/fork-a-repo/) is to add an `upstream` remote: $ git remote add upstream https://github.com/deis/deis.git For the sake of simplicity, you may want to point an environment variable to your Deis code: $ export DEIS=$GOPATH/src/github.com/deis/deis Throughout the rest of this document, `$DEIS` refers to that location. ### Alternative: Forking with a Pushurl A number of Deis developers prefer to pull directly from `deis/deis`, but push to `/deis`. If that workflow suits you better, you can set it up this way: $ git clone git@github.com:deis/deis.git $ cd deis $ git config remote.origin.pushurl git@github.com:/deis.git In this setup, fetching and pulling code will work directly with the upstream repository, while pushing code will send changes to your fork. This makes it easy to stay up to date, but also make changes and then issue pull requests. ## Build deisctl `deisctl` is used for interacting with the Deis cluster. While you can use an existing `deisctl` binary, we recommend that developers build it from source. $ cd $DEIS/deisctl $ make build $ make install # optionally This will build just the `deisctl` portion of Deis. Running `make install` will install the `deisctl` command in `$GOPATH/bin/deisctl`. You can verify that `deisctl` is correctly built and installed by running `deisctl -h`. That should print the help text and exit. ## Configure SSH Tunneling for deisctl To connect to the cluster using `deisctl`, you must add the private key to `ssh-agent`. For example, when using Vagrant: $ ssh-add ~/.vagrant.d/insecure_private_key Set `$DEISCTL_TUNNEL` so the `deisctl` client on your workstation can connect to one of the hosts in your cluster: $ export DEISCTL_TUNNEL=172.17.8.100 !!! note A number of times during this setup, tools will suggest that you export various environment variables. You may find it convenient to store these in your shell's RC file (`~/.bashrc` or `~/.zshrc`). ## Install the Deis Client The `deis` client is also written in Go. Your Deis client should match your server's version. Like `deisctl`, we recommend that developers build `deis` from source: $ cd $DEIS/client $ make build $ make install # optionally $ ./deis Usage: deis [...] ## Start Up a Development Cluster Our host system is now configured for controlling a Deis cluster. The next thing to do is begin standing up a development cluster. When developing locally, we want deisctl to check our local unit files so that any changes are reflected in our Deis cluster. The easiest way to do this is to set an environment variable telling deisctl where to look. Assuming the variable `$DEIS` points to the location if the deis source code, we want something like this: $ export DEISCTL_UNITS=$DEIS/deisctl/units To start up and configure a local vagrant cluster for development, you can use the `dev-cluster` target. $ make dev-cluster This may take a while to run the first time. At the end of the process, you will be prompted to run `deisctl start platform`. Hold off on that task for now. We will come back to it later. To verify that the cluster is running, you should be able to connect to the nodes on your Deis cluster: $ vagrant status Current machine states: deis-01 running (virtualbox) deis-02 running (virtualbox) deis-03 running (virtualbox) $ vagrant ssh deis-01 Last login: Tue Jun 2 18:26:30 2015 from 10.0.2.2 * * * ***** ddddd eeeeeee iiiiiii ssss * * * * * * d d e e i s s * * ***** ***** d d e i s ***** * * * d d e i s * * * * * * d d eee i sss ***** * * ***** d d e i s * ***** * * d d e i s * * * * * * d d e e i s s ***** ***** * * ddddd eeeeeee iiiiiii ssss Welcome to Deis Powered by CoreOS With a dev cluster now running, we are ready to set up a local Docker registry. ## Configure a Docker Registry The development workflow requires Docker Registry set at the `$DEIS_REGISTRY` environment variable. If you're developing locally you can use the `dev-registry` target to spin up a quick, disposable registry inside a Docker container. The target `dev-registry` prints the registry's address and port when using `docker-machine`; otherwise, use your host's IP address as returned by `ifconfig` with port 5000 for `$DEIS_REGISTRY`. $ make dev-registry To configure the registry for local Deis development: export DEIS_REGISTRY=192.168.59.103:5000 It is important that you export the `$DEIS_REGISTRY` environment variable as instructed. If you are developing elsewhere, you must set up a registry yourself. Make sure it meets the following requirements: 1. You can push Docker images from your workstation 2. Hosts in the cluster can pull images with the same URL !!! note If the development registry is insecure and has an IP address in a range other than `10.0.0.0/8`, `172.16.0.0/12`, or `192.168.0.0/16`, you'll have to modify `contrib/coreos/user-data.example` and whitelist your development registry so the daemons can pull your custom components. ## Initial Platform Build The full environment is prepared. You can now build Deis from source code and then run the platform. We'll do three steps together: - Build the source (`make build`) - Update our local cluster with a dev release (`make dev-release`) - Start the platform (`deisctl start platform`) Conveniently, we can accomplish all three in one step: $ make deploy Running `deisctl list` should display all of the services that your Deis cluster is currently running. You can now use your Deis cluster in all of the usual ways. At this point, you are running Deis from the code in your Git clone. But since rebuilding like this is time consuming, Deis has a simplified developer workflow more suited to daily development. ## Development Workflow Deis includes `Makefile` targets designed to simplify the development workflow. This workflow is typically: 1. Update source code and commit your changes using `git` 2. Use `make -C build` to build a new Docker image 3. Use `make -C dev-release` to push a snapshot release 4. Use `make -C restart` to restart the component This can be shortened to a one-liner using the `deploy` target: ```console $ make -C controller deploy ``` You can also use the same tasks on the root `Makefile` to operate on all components at once. For example, `make deploy` will build, dev-release, and restart all components on the cluster. !!! important In order to cut a dev-release, you must commit changes using `git` to increment the SHA used when tagging Docker images. ## Test Your Changes Deis ships with a comprehensive suite of automated tests, most written in Go. See [testing][] for instructions on running the tests. ## Useful Commands Once your controller is running, here are some helpful commands. ### Tail Logs $ kubectl logs -f deis-controller ### Django Shell $ kubectl exec -it deis-controller python manage.py shell Have commands other Deis developers might find useful? Send us a PR! ## Pull Requests Please read [Submitting a Pull Request](submitting-a-pull-request.md). It contains a checklist of things you should do when proposing a change to Deis. [digitalocean]: https://www.digitalocean.com/ [easy-fix]: https://github.com/deis/deis/issues?labels=easy-fix&state=open [fork]: https://github.com/deis/deis/fork [machine]: http://docs.docker.com/machine/install-machine/ [pr]: https://github.com/deis/deis/pulls [testing]: testing.md