# Lab 4

A key aspect of providing an application means sharing with others. Sharing can be direct counsumption (by users or in CI/CD pipelines) or as a dependency for other charts. If people can't find your app then they can't use it.

A means of sharing is a chart repository, which is a location where packaged charts can be stored and shared. As the chart repository only applies to Helm, we will just look at the usage and storage of Helm charts.

## Using charts from a public repository

Helm charts can be available on a remote repository or in a local environment/repository. The remote repositories can be public like [Bitnami Charts](https://github.com/bitnami/charts) or [IBM Helm Charts](https://github.com/IBM/charts), or hosted repositories like on Google Cloud Storage or GitHub. Refer to [Helm Chart Repository Guide](https://helm.sh/docs/topics/chart_repository/) for more details. You can learn more about the structure of a chart repository by examining the [chart index file](https://github.com/IBM/cloudpakforapplications-appmod-workshop/tree/0b5c028d4b3fd68daae432ea13599239db96d638/workshop/generatedContent/index.yaml) in this lab.

In this part of the lab, we show you how to install the `guestbook` chart from the [Helm101 repo](https://ibm.github.io/helm101/).

1. Check the repositories configured on your system:

   ```
   helm repo list
   ```

   The output should be similar to the following:

   ```
   $ helm repo list
   Error: no repositories to show
   ```

   > Note: Chart repositories are not installed by default with Helm v3. It is expected that you add the repositories for the charts you want to use. The [Helm Hub](https://hub.helm.sh) provides a centralized search for publicly available distributed charts. Using the hub you can identify the chart with its hosted repository and then add it to your local respoistory list. The [Helm chart repository](https://github.com/helm/charts) like Helm v2 is in "maintenance mode" and will be deprecated by November 13, 2020. See the [project status](https://github.com/helm/charts#status-of-the-project) for more details.
2. Add `helm101` repo:

   ```
   helm repo add helm101 https://ibm.github.io/helm101/
   ```

   Should generate an output as follows:

   ```
   $ helm repo add helm101 https://ibm.github.io/helm101/
   "helm101" has been added to your repositories
   ```

   You can also search your repositories for charts by running the following command:

   ```
   helm search repo helm101
   ```

   ```
   $ helm search repo helm101
   NAME              CHART VERSION  APP VERSION DESCRIPTION
   helm101/guestbook 0.2.1                      A Helm chart to deploy Guestbook three tier web...
   ```
3. Install the chart

   As mentioned we are going to install the `guestbook` chart from the [Helm101 repo](https://ibm.github.io/helm101/). As the repo is added to our local respoitory list we can reference the chart using the `repo name/chart name`, in other words `helm101/guestbook`. To see this in action, you will install the application to a new namespace called `repo-demo`.

   If the `repo-demo` namespace does not exist, create it using:

   ```
   kubectl create namespace repo-demo
   ```

   Now install the chart using this command:

   ```
   helm install guestbook-demo helm101/guestbook --namespace repo-demo
   ```

   The output should be similar to the following:

   ```
   $helm install guestbook-demo helm101/guestbook --namespace repo-demo
   NAME: guestbook-demo
   LAST DEPLOYED: Tue Feb 25 15:40:17 2020
   NAMESPACE: repo-demo
   STATUS: deployed
   REVISION: 1
   TEST SUITE: None
   NOTES:
   1. Get the application URL by running these commands:
     NOTE: It may take a few minutes for the LoadBalancer IP to be available.
           You can watch the status of by running 'kubectl get svc -w guestbook-demo --namespace repo-demo'
     export SERVICE_IP=$(kubectl get svc --namespace repo-demo guestbook-demo -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
     echo http://$SERVICE_IP:3000
   ```

   Check that release deployed as expected as follows:

   ```
   $ helm list -n repo-demo
   NAME           NAMESPACE   REVISION UPDATED                                   STATUS   CHART            APP VERSION
   guestbook-demo repo-demo   1        2020-02-25 15:40:17.627745329 +0000 UTC   deployed guestbook-0.2.1
   ```

## Conclusion

This lab provided you with a brief introduction to the Helm repositories to show how charts can be installed. The ability to share your chart means ease of use to both you and your consumers.


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