# Lab 2 - Deploying Guestbook Application

The Guestbook app is a sample app for users to leave comments. It consists of a web front end, Redis master for storage, and a replicated set of Redis slaves. We will also integrate the app with Watson Tone Analyzer which detects the sentiment in users' comments and replies with emoticons.

![Guestbook applicaiton topology](https://2816711705-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M1Bh2a26msY5M4vW3R9%2Fsync%2F98618e2d64b3a65ec04598219907401deb83fd31.jpg?generation=1593194636541956\&alt=media)

## Download the Guestbook app

1.  Clone the Guestbook app into the `workshop` directory.

    ```
     git clone -b kubecon2019 https://github.com/IBM/guestbook
    ```
2.  Navigate into the app directory.

    ```
     cd guestbook/v2
    ```

## Enable the automatic sidecar injection for the default namespace

In Kubernetes, a sidecar is a utility container in the pod, and its purpose is to support the main container. For Istio to work, Envoy proxies must be deployed as sidecars to each pod of the deployment. There are two ways of injecting the Istio sidecar into a pod: manually using the istioctl CLI tool or automatically using the Istio sidecar injector. In this exercise, we will use the automatic sidecar injection provided by Istio.

1.  Annotate the default namespace to enable automatic sidecar injection:

    ```
     kubectl label namespace default istio-injection=enabled
    ```
2.  Validate the namespace is annotated for automatic sidecar injection:

    ```
     kubectl get namespace -L istio-injection
    ```

    Sample output:

    ```
     NAME             STATUS   AGE    ISTIO-INJECTION
     default          Active   271d   enabled
     istio-system     Active   5d2h
     ...
    ```

## Create a Redis database

The Redis database is a service that you can use to persist the data of your app. The Redis database comes with a master and slave modules.

1.  Create the Redis controllers and services for both the master and the slave.

    ```
     kubectl create -f redis-master-deployment.yaml
     kubectl create -f redis-master-service.yaml
     kubectl create -f redis-slave-deployment.yaml
     kubectl create -f redis-slave-service.yaml
    ```
2.  Verify that the Redis controllers for the master and the slave are created.

    ```
     kubectl get deployment
    ```

    Output:

    ```
     NAME           READY   UP-TO-DATE   AVAILABLE   AGE
     redis-master   1/1     1            1           2m16s
     redis-slave    2/2     2            2           2m15s
    ```
3.  Verify that the Redis services for the master and the slave are created.

    ```
     kubectl get svc
    ```

    Output:

    ```
     NAME           TYPE           CLUSTER-IP      EXTERNAL-IP     PORT(S)        AGE
     redis-master   ClusterIP      172.21.85.39    <none>          6379/TCP       5d
     redis-slave    ClusterIP      172.21.205.35   <none>          6379/TCP       5d
    ```
4.  Verify that the Redis pods for the master and the slave are up and running.

    ```
     kubectl get pods
    ```

    Output:

    ```
     NAME                            READY     STATUS    RESTARTS   AGE
     redis-master-4sswq              2/2       Running   0          5d
     redis-slave-kj8jp               2/2       Running   0          5d
     redis-slave-nslps               2/2       Running   0          5d
    ```

## Install the Guestbook app

1.  Inject the Istio Envoy sidecar into the guestbook pods, and deploy the Guestbook app on to the Kubernetes cluster. Deploy both the v1 and v2 versions of the app:

    ```
     kubectl apply -f ../v1/guestbook-deployment.yaml
     kubectl apply -f guestbook-deployment.yaml
    ```

    These commands deploy the Guestbook app on to the Kubernetes cluster. Since we enabled automation sidecar injection, these pods will be also include an Envoy sidecar as they are started in the cluster. Here we have two versions of deployments, a new version (`v2`) in the current directory, and a previous version (`v1`) in a sibling directory. They will be used in future sections to showcase the Istio traffic routing capabilities.
2.  Create the guestbook service.

    ```
     kubectl create -f guestbook-service.yaml
    ```
3.  Verify that the service was created.

    ```
     kubectl get svc
    ```

    Output:

    ```
     NAME           TYPE           CLUSTER-IP      EXTERNAL-IP     PORT(S)        AGE
     guestbook      LoadBalancer   172.21.36.181   169.61.37.140   80:32149/TCP   5d
     ...
    ```
4.  Verify that the pods are up and running.

    ```
     kubectl get pods
    ```

    Sample output:

    ```
     NAME                            READY   STATUS    RESTARTS   AGE
     guestbook-v1-98dd9c654-dz8dq    2/2     Running   0          30s
     guestbook-v1-98dd9c654-mgfv6    2/2     Running   0          30s
     guestbook-v1-98dd9c654-x8gxx    2/2     Running   0          30s
     guestbook-v2-8689f6c559-5ntgv   2/2     Running   0          28s
     guestbook-v2-8689f6c559-fpzb7   2/2     Running   0          28s
     guestbook-v2-8689f6c559-wqbnl   2/2     Running   0          28s
     redis-master-577bc6fbb-zh5v8    2/2     Running   0          4m47s
     redis-slave-7779c6f75b-bshvs    2/2     Running   0          4m46s
     redis-slave-7779c6f75b-nvsd6    2/2     Running   0          4m46s
    ```

    Note that each guestbook pod has 2 containers in it. One is the guestbook container, and the other is the Envoy proxy sidecar.

Great! Your guestbook app is up and running. In the next exercise you will expose the Istio service mesh with the Ingress Gateway
