Merge pull request #5 from gruntwork-io/yori-chart-development-proposal

RDD: Some initial guidelines on chart development

Author: yorinasub17

CONTRIBUTING.md

@@ -10,19 +10,22 @@ https://help.github.com/articles/about-pull-requests/) for contributions, subjec
 1. [Create a pull request](#create-a-pull-request)
 1. [Merge and release](#merge-and-release)
 
+
 ## File a GitHub issue
 
 Before starting any work, we recommend filing a GitHub issue in this repo. This is your chance to ask questions and
 get feedback from the maintainers and the community before you sink a lot of time into writing (possibly the wrong)
 code. If there is anything you're unsure about, just ask!
 
+
 ## Update the documentation
 
 We recommend updating the documentation *before* updating any code (see [Readme Driven
 Development](http://tom.preston-werner.com/2010/08/23/readme-driven-development.html)). This ensures the documentation
 stays up to date and allows you to think through the problem at a high level before you get lost in the weeds of
 coding.
 
+
 ## Update the tests
 
 We also recommend updating the automated tests *before* updating any code (see [Test Driven
@@ -33,6 +36,7 @@ functionality you're adding in your contribution. Check out the
 [tests](https://github.com/gruntwork-io/helm-kubernetes-services/tree/master/test) folder for instructions on running
 the automated tests.
 
+
 ## Update the code
 
 At this point, make your code changes and use your new test case to verify that everything is working. As you work,
@@ -59,6 +63,25 @@ Bear in mind that the Helm charts in this Module are used by real companies to r
 production, and certain types of changes could cause downtime. If downtime cannot be avoided, please make sure to call
 that out when you submit a pull request.
 
+### Code style
+
+We follow [the official Chart best practices](https://docs.helm.sh/chart_best_practices/) documented by the community.
+Please read through the guidelines if you have not already.
+
+Additionally, Gruntwork has a few extra guidelines not stated in the best practices guide:
+
+- Chart `values.yaml` should separate required inputs from optional inputs. Required inputs should be documented as
+  comments.
+- Provide example required inputs in a separate `linter_values.yaml` file so that `helm lint` can be used to lint the
+  charts.
+- Any input value that is rendered directly in the yaml templates (using `toYaml`) should be explicitly called out in
+  the `values.yaml` file.
+- Any input value that is a map should explicitly call out the expected fields. Additionally, the fields should be
+  labeled by type and whether or not the value is required.
+- Any required input that is a map, or optional input that is a map with an empty default, should have an example in the
+  comments.
+- Every chart should have both helm tests and terratests. The helm tests test if the chart came up successfully in an
+  install, while the terratest is used for integration testing of the chart before releasing the chart.
 
 ### Formatting and pre-commit hooks
 
@@ -70,7 +93,7 @@ using pre-commit hooks managed using [pre-commit](http://pre-commit.com/):
 1. Make sure you have the helm client installed. See [the official docs](https://docs.helm.sh/using_helm/#install-helm)
    for instructions.
 
-That's it! Now just write your code, and every time you commit, `helm lint` will be run on the charts that you modify.
+Now write your code, and every time you commit, `helm lint` will be run on the charts that you modify.
 
 
 ## Create a pull request
@@ -85,6 +108,7 @@ to include the following:
    test output so we can verify that everything is working.
 1. Any notes on backwards incompatibility or downtime.
 
+
 ## Merge and release
 
 The maintainers for this repo will review your code and provide feedback. If everything looks good, they will merge the

README.md

@@ -45,6 +45,39 @@ The following charts are available in this package:
 -->
 
 
+## How do you install the charts in this Package?
+
+The charts in this Package are distributed in the Gruntwork Helm Repo. You can access these charts by adding the
+Gruntwork Helm Repo to your client:
+
+```bash
+$ helm repo add gruntwork https://helmcharts.gruntwork.io
+```
+
+Then, you can access any of the charts under the `gruntwork` name. For example, you can find all the Gruntwork charts by
+searching for `gruntwork`:
+
+```bash
+$ helm search gruntwork
+```
+
+In general, each of the charts document the required and optional input values in the corresponding `values.yaml` file.
+You can access the `values.yaml` of a Chart either by inspecting this repository, or using the `helm inspect` command.
+For example, to see the values of the `k8s-service` chart, you can run:
+
+```bash
+$ helm inspect values gruntwork/k8s-service
+```
+
+Once you know what values the chart requires, you can install the chart by defining your own `values.yaml` file with the
+required values defined. Then, you can install the chart to your Kubernetes cluster using `helm install`:
+
+```bash
+$ helm install -f values.yaml gruntwork/k8s-service
+```
+
+See the `helm install` help text for more configuration options.
+
 
 ## What is Kubernetes?
 
@@ -80,6 +113,7 @@ release, the helm client essentially packages up the values and charts as a rele
 Tiller will then generate Kubernetes YAML files from the packaged release, and then apply the generated Kubernetes YAML
 file from the charts on the cluster.
 
+
 ## How do you run applications on Kubernetes?
 
 There are three different ways you can schedule your application on a Kubernetes cluster. In all three, your application