Step by Step Guide

In this guide we will deploy an application with tilt and namespace in remote OpenShift cluster

Clone this sample repo Nordmart-review
Install following tools:

Required for local development:
- Tilt v0.22.11 or above
- Docker 20.10.8 or above
- Helm 3 or above
- oc binaries
Required by this application:
- Java 11
- Maven 3
You should have a namespace in remote/local cluster; If you are in SAAP then enable sandbox namespace/project/environment for your tenant; you can read more here
Login to cluster

Login into OpenShift and then copy login command

Then click Display Token

Then copy the login token

And then run this command in the terminal
```
oc login --token=<TOKEN> --server=<SERVER>
```
Switch project to sandbox namespace/project/environment
```
oc project <MY-SANDBOX>
```
Login to OpenShift internal docker registry

First get the OpenShift internal docker registry URL and set in HOST variable name
```
HOST=image-registry-openshift-image-registry.apps.[CLUSTER-NAME].[CLUSTER-ID].kubeapp.cloud
```
NOTE: Ask Customer Admin or Cluster Admin to provide you the OpenShift internal registry route

Then login into docker registry with following command:
```
docker login -u $(oc whoami) -p $(oc whoami -t) $HOST
```
If you get this error x509: certificate signed by unknown authority then you need to update your /etc/docker/daemon.json file and add the insecure registry
```
{
    "insecure-registries" : [ "HOST" ]
}
```

(Optional) Add Helm chart repos

If you reference Helm charts from private registry then you first need to add it

cd deploy

# Helm credentials can be found in Vault or in a secret in build namespace
helm repo add stakater-nexus <private repo URL> --username helm-user-name --password ********; 

cd ..

Update Helm dependencies

cd deploy

helm dependency update

cd ..

Go through the Tiltfile of the application
Check the local_resource section in the Tiltfile
Create tilt_options.json file

Remove .template from the file named tilt_options.json.template

And then fill up all three things
1. namespace: your sandbox environment name
2. default_registry: the OpenShift internal registry route (you have set in step # 6 in HOST above) and then add your namespace name after /
3. allow_k8s_contexts: given you are logged in the cluster; then run oc config current-context to get the value for allow_k8s_contexts
  
  e.g.
```
{
    "namespace": "tilt-username-sandbox",
    "default_registry": "image-registry-openshift-image-registry.apps.[CLUSTER-NAME].[CLUSTER-ID].kubeapp.cloud/tilt-username-sandbox",
    "allow_k8s_contexts": "tilt-username-sandbox/api-[CLUSTER-NAME]-[CLUSTER-ID]-kubeapp-cloud:6443/user@email.com"
}
```

Go through the .gitigore and check tilt and Helm specific ignores

# Tilt
tilt_options.json
tilt_modules/

# Helm
/deploy/charts

Go through .tiltignore
```
**/charts
**/tmpcharts
```

Go through values-local.yaml in a tilt folder in base application directory.

values-local.yaml should contain the following content. Make sure that replica count should always be 1.

application:

  deployment:
    imagePullSecrets: null

    # Tilt live update only supports one replica
    replicas: 1

    image:
      tag: null

Validate this application is not running already
Run tilt up at base directory

Open the tilt browser; just hit the space

If everything is green then the application will be deployed in the cluster

Press space key to view the progress in Tilt web UI. The application should be running in the namespace used in tilt_options.json file.
Lets browse through some reviews. Go to routes:

Click on the review route:

In the end of the route add /api/review/329199

Review the JSON output:
Lets make one change; we will update the first review text to "Tilt Demo"

Switch back to tilt browser and you will see it has started picking up changes

Within few seconds the change will be deployed; and you can refresh the route to see the change

Awesome! you made it
Run tilt down to delete the application and related configuration from the namespace