> Samples > Domains > Domain on PV > Prerequisites

Prerequisites

Prerequisites for WLS and JRF domain types
Additional prerequisites for JRF domains

Prerequisites for WLS and JRF domain types

Choose the type of domain you’re going to use throughout the sample, WLS or JRF.
The JAVA_HOME environment variable must be set and must reference a valid JDK 8 or 11 installation.
Get the operator source and put it in /tmp/weblogic-kubernetes-operator.

For example:
```
$ cd /tmp
```
```
$ git clone --branch v4.2.9
 https://github.com/oracle/weblogic-kubernetes-operator.git
```
NOTE: We will refer to the top directory of the operator source tree as /tmp/weblogic-kubernetes-operator; however, you can use a different location.

For additional information about obtaining the operator source, see the Developer Guide Requirements.
Copy the Domain on PV sample to a new directory; for example, use directory /tmp/sample.
```
$ mkdir -p /tmp/sample
```
```
$ cp -r /tmp/weblogic-kubernetes-operator/kubernetes/samples/scripts/create-weblogic-domain/domain-on-pv/* /tmp/sample
```
NOTE: We will refer to this working copy of the sample as /tmp/sample; however, you can use a different location.

Copy the wdt-artifacts directory of the sample to a new directory; for example, use directory /tmp/sample/wdt-artifacts.

$ mkdir -p /tmp/sample/wdt-artifacts

$ cp -r /tmp/weblogic-kubernetes-operator/kubernetes/samples/scripts/create-weblogic-domain/wdt-artifacts/* /tmp/sample/wdt-artifacts

Download the latest WebLogic Deploy Tooling (WDT) and WebLogic Image Tool (WIT) installer ZIP files to your /tmp/sample/wdt-artifacts directory. Both WDT and WIT are required to create the images.

$ cd /tmp/sample/wdt-artifacts

$ curl -m 120 -fL https://github.com/oracle/weblogic-deploy-tooling/releases/latest/download/weblogic-deploy.zip \
  -o /tmp/sample/wdt-artifacts/weblogic-deploy.zip

$ curl -m 120 -fL https://github.com/oracle/weblogic-image-tool/releases/latest/download/imagetool.zip \
  -o /tmp/sample/wdt-artifacts/imagetool.zip

To set up the WebLogic Image Tool, run the following commands:
```
$ cd /tmp/sample/wdt-artifacts
```
```
$ unzip imagetool.zip
```
```
$ ./imagetool/bin/imagetool.sh cache deleteEntry --key wdt_latest
```
```
$ ./imagetool/bin/imagetool.sh cache addInstaller \
  --type wdt \
  --version latest \
  --path /tmp/sample/wdt-artifacts/weblogic-deploy.zip
```
Note that the WebLogic Image Tool cache deleteEntry command does nothing if the wdt_latest key doesn’t have a corresponding cache entry. It is included because the WIT cache lookup information is stored in the $HOME/cache/.metadata file by default, and if the cache already has a version of WDT in its --type wdt --version latest location, then the cache addInstaller command would fail. For more information about the WIT cache, see the WIT Cache documentation.

These steps will install WIT to the /tmp/sample/wdt-artifacts/imagetool directory, plus put a wdt_latest entry in the tool’s cache which points to the WDT ZIP file installer. You will use WIT and its cached reference to the WDT installer later in the sample for creating model images.
To set up the WebLogic Deploy Tooling that we will use later for the archive helper, run the following command:
```
$ unzip /tmp/sample/wdt-artifacts/weblogic-deploy.zip
```
Make sure an operator is set up to manage the namespace, sample-domain1-ns. Also, make sure a Traefik ingress controller is managing the same namespace and listening on port 30305. To do this, follow the same steps as the Quick Start guide up through the Prepare for a domain step.

Make sure you stop when you complete the “Prepare for a domain” step and then resume following these instructions.
Set up ingresses that will redirect HTTP from the Traefik port 30305 to the clusters in this sample’s WebLogic domains.
- Run kubectl apply -f on each of the ingress YAML files that are already included in the sample source directory:
```
$ kubectl apply -f https://raw.githubusercontent.com/oracle/weblogic-kubernetes-operator/release/4.2/kubernetes/samples/scripts/create-weblogic-domain/ingresses/traefik-ingress-sample-domain1-admin-server.yaml
$ kubectl apply -f https://raw.githubusercontent.com/oracle/weblogic-kubernetes-operator/release/4.2/kubernetes/samples/scripts/create-weblogic-domain/ingresses/traefik-ingress-sample-domain1-cluster-cluster-1.yaml
```
NOTE: We give each cluster ingress a different host name that is decorated using both its operator domain UID and its cluster name. This makes each cluster uniquely addressable even when cluster names are the same across different clusters. When using curl to access the WebLogic domain through the ingress, you will need to supply a host name header that matches the host names in the ingress.

For more information on ingresses and load balancers, see Ingress.
Obtain the WebLogic 12.2.1.4 image that is referenced by the sample’s Domain resource YAML.

a. Use a browser to access the Oracle Container Registry.

b. Choose an image location: for JRF domains, select Middleware, then fmw-infrastructure; for WLS domains, select Middleware, then weblogic.

c. Select Sign In and accept the license agreement.

d. Use your terminal to log in to the container registry: docker login container-registry.oracle.com.

e. Later in this sample, when you run WebLogic Image Tool commands, the tool will use the image as a base image for creating model images. Specifically, the tool will implicitly call docker pull for one of the previous licensed images as specified in the tool’s command line using the --fromImage parameter. For JRF, this sample specifies container-registry.oracle.com/middleware/fmw-infrastructure:12.2.1.4, and for WLS, the sample specifies container-registry.oracle.com/middleware/weblogic:12.2.1.4.

The example base images are General Availability (GA) images that are suitable for demonstration and development purposes only where the environments are not available from the public Internet; they are not acceptable for production use. In production, you should always use CPU (patched) images from OCR or create your images using the WebLogic Image Tool (WIT) with the --recommendedPatches option. For more guidance, see Apply the Latest Patches and Updates in Securing a Production Environment for Oracle WebLogic Server.

Additional prerequisites for JRF domains

NOTE: If you’re using a Domain on PV, WLS domain type, skip this section and continue on to Build the domain creation image for the Domain on PV sample.

JRF prerequisites

Introduction to JRF setups
Set up and initialize an infrastructure database
Important considerations for RCU model attributes, Domain fields, and secrets

Introduction to JRF setups

NOTE: The requirements in this section are in addition to Prerequisites for WLS and JRF domain types.

A JRF domain requires an infrastructure database, and configuring your domain to access this database. For more details, see JRF domains in the user documentation. You must perform all these steps before you create your domain.

Set up and initialize an infrastructure database

A JRF domain requires an infrastructure database and requires initializing this database with a schema and a set of tables for each different domain. The following example shows how to set up a database. The database is set up with the following attributes:

Attribute	Value
database Kubernetes namespace	`default`
database Kubernetes pod	`oracle-db`
database image	`container-registry.oracle.com/database/enterprise:12.2.0.1-slim`
database password	MY_DBA_PASSWORD
infrastructure schema prefix	`FMW1` (for domain1)
infrastructure schema password	MY_RCU_SCHEMA_PASSWORD
database URL	`oracle-db.default.svc.cluster.local:1521/devpdb.k8s`

Ensure that you have access to the database image, and then create a deployment using it:
- Use a browser to log in to https://container-registry.oracle.com, select Database -> enterprise and accept the license agreement.
- Get the database image:
  - In the local shell, docker login container-registry.oracle.com.
  - In the local shell, docker pull container-registry.oracle.com/database/enterprise:12.2.0.1-slim.
- Deploy a secret named oracle-db-secret with your desired Oracle DBA password for its SYS account.
  - In the local shell:
```
$ kubectl -n default create secret generic oracle-db-secret \
  --from-literal='password=MY_DBA_PASSWORD'
```
  - Replace MY_DBA_PASSWORD with your desired value.
  - Oracle Database passwords can contain upper case, lower case, digits, and special characters. Use only _ and # as special characters to eliminate potential parsing errors in Oracle connection strings.
  - NOTE: Record or memorize the value you chose for MY_DBA_PASSWORD. It will be be needed again in other parts of this sample.
- Use the sample script in /tmp/weblogic-kubernetes-operator/kubernetes/samples/scripts/create-oracle-db-service to create an Oracle database running in the pod, oracle-db.
```
$ cd /tmp/weblogic-kubernetes-operator/kubernetes/samples/scripts/create-oracle-db-service
```
```
$ start-db-service.sh
```
  This script will deploy a database in the default namespace with the connect string oracle-db.default.svc.cluster.local:1521/devpdb.k8s, and administration password MY_DBA_PASSWORD.
  
  This step is based on the steps documented in Run a Database.
  
  NOTE: If your Kubernetes cluster nodes do not all have access to the database image in a local cache, then deploy a Kubernetes docker secret to the default namespace with login credentials for container-registry.oracle.com, and pass the name of this secret as a parameter to start-db-service.sh using -s your-image-pull-secret. Alternatively, copy the database image to each local Docker cache in the cluster. For more information, see the Cannot pull image FAQ.
  
  WARNING: The Oracle Database images are supported only for non-production use. For more details, see My Oracle Support note: Oracle Support for Database Running on Docker (Doc ID 2216342.1).

Important considerations for RCU model attributes, Domain fields, and secrets

To allow the operator to access the database and OPSS wallet, you must create an RCU access secret containing the database connect string, user name, and password that’s referenced from your model and an OPSS wallet password secret that’s referenced from your Domain before deploying your domain. It’s also necessary to define an RCUDbInfo stanza in your model.

The sample includes examples of JRF models and Domain YAML files in the /tmp/sample/wdt-artifacts/wdt-model-files and /tmp/sample/domain-resources directories, and instructions in the following sections will describe setting up the RCU and OPSS secrets.

When you follow the instructions in the samples, avoid instructions that are WLS only, and substitute JRF for WLS in the corresponding model image tags and Domain YAML file names.

For example, in this sample:

JRF Domain YAML file has an configuration.opss.walletPasswordSecret field that references a secret named sample-domain1-opss-wallet-password-secret, with a walletPassword of your choice.
JRF domain creation image models have the following domainInfo -> RCUDbInfo stanza that references a sample-domain1-rcu-access secret with the appropriate values for attributes, rcu_prefix, rcu_schema_password, and rcu_db_conn_string, for accessing the Oracle database that you deployed to the default namespace as one of the prerequisite steps.

    RCUDbInfo:
        rcu_prefix: '@@SECRET:@@ENV:DOMAIN_UID@@-rcu-access:rcu_prefix@@'
        rcu_schema_password: '@@SECRET:@@ENV:DOMAIN_UID@@-rcu-access:rcu_schema_password@@'
        rcu_db_conn_string: '@@SECRET:@@ENV:DOMAIN_UID@@-rcu-access:rcu_db_conn_string@@'

For important JRF domain information, refer to JRF domains.