Add controller development docs (kubernetes-sigs#2101)

CONTRIBUTING.md

@@ -6,7 +6,7 @@ _As contributors and maintainers of this project, and in the interest of fosteri
 
 ## Getting Started
 
-[`BUILDING.md`](/docs/BUILDING.md) has instructions on how to build the project.
+[Controller developement documentation](/docs/controller-devel.md) has instructions on how to build the project.
 We also have more documentation on how to get started contributing here:
 
 - [Contributor License Agreement](https://git.k8s.io/community/CLA.md) Kubernetes projects require that you sign a Contributor License Agreement (CLA) before we can accept your pull requests

docs/controller-devel.md

@@ -0,0 +1,119 @@
+# AWS Load Balancer Controller Development Guide
+
+We'll walk you through the setup to start contributing to the AWS Load Balancer
+Controller project. No matter if you're contributing code or docs,
+follow the steps below to set up your development environment.
+
+!!! tip "Issue before PR"
+    Of course we're happy about code drops via PRs, however, in order to give
+    us time to plan ahead and also to avoid disappointment, consider creating
+    an issue first and submit a PR later. This also helps us to coordinate
+    between different contributors and should in general help keeping everyone
+    happy.
+
+
+## Prerequisites
+
+Please ensure that you have [properly installed Go][install-go].
+
+[install-go]: https://golang.org/doc/install
+
+!!! note "Go version"
+    We recommend to use a Go version of `1.14` or above for development.
+
+## Fork upstream repository
+
+The first step in setting up your AWS Load Balancer controller development
+environment is to fork the upstream AWS Load Balancer controller repository to your
+personal Github account.
+
+
+## Ensure source code organization directories exist
+
+Make sure in your `$GOPATH/src` that you have directories for the
+`sigs.k8s.io` organization:
+
+```bash
+mkdir -p $GOPATH/src/github.com/sigs.k8s.io
+```
+
+
+## `git clone` forked repository and add upstream remote
+
+For the forked repository, you will `git clone` the repository into
+the appropriate folder in your `$GOPATH`. Once `git clone`'d, you will want to
+set up a Git remote called "upstream" (remember that "origin" will be pointing
+at your forked repository location in your personal Github space).
+
+You can use this script to do this for you:
+
+```bash
+GITHUB_ID="your GH username"
+
+cd $GOPATH/src/github.com/sigs.k8s.io
+git clone git@github.com:$GITHUB_ID/aws-load-balancer-controller
+cd aws-load-balancer-controller/
+git remote add upstream git@github.com:kubernetes-sigs/aws-load-balancer-controller
+git fetch --all
+
+```
+
+## Create your local branch
+
+Next, you create a local branch where you work on your feature or bug fix.
+Let's say you want to enhance the docs, so set `BRANCH_NAME=docs-improve` and
+then:
+
+```
+git fetch --all && git checkout -b $BRANCH_NAME upstream/main
+```
+
+## Commit changes
+
+Make your changes locally, commit and push using:
+
+```
+git commit -a -m "improves the docs a lot"
+
+git push origin $BRANCH_NAME
+```
+
+## Create a pull request
+
+Finally, submit a pull request against the upstream source repository.
+
+We monitor the GitHub repo and try to follow up with comments within a working
+day.
+
+
+## Building the controller
+
+To build the controller binary, run the following command.
+
+```bash
+make controller
+```
+
+To install CRDs into a Kubernetes cluster, run the following command.
+
+```bash
+make install
+```
+
+To uninstall CRD from a Kubernetes cluster, run the following command.
+
+```bash
+make uninstall
+```
+
+To build the container image for the controller and push to a container registry, run the following command.
+
+```bash
+make docker-push
+```
+
+To deploy the CRDs and the container image to a Kubernetes cluster, run the following command.
+
+```bash
+make deploy
+```