O-RAN O2 Application¶

About this task

In the context of hosting a RAN Application on StarlingX, the O-RAN O2 Application provides and exposes the IMS and DMS service APIs of the O2 interface between the O-Cloud (StarlingX) and the Service Management & Orchestration (SMO), in the O-RAN Architecture.

The O2 interfaces enable the management of the O-Cloud (StarlingX) infrastructure and the deployment life-cycle management of O-RAN cloudified NFs that run on O-Cloud (StarlingX). For more information see:

O-RAN O2 complies with the specifications of INF O2 IMS and DMS Spec Compliance.

Note

This O-RAN specification on O2 IMS support for alarm acknowledgment and clearing was defined in G Release. See Welcome to INF O2 documentation. This feature is not supported in r8 release, therefore the r8 release follows the older specification which does not have this API definition.
INF O2 Services API.

The O-RAN O2 application is integrated into StarlingX as a system application. The O-RAN O2 application package is saved in StarlingX during system installation, but it is not applied by default.

System administrators can follow the procedures below to install and uninstall the O-RAN O2 application.

Install ¶

Prerequisites

Configure the internal Ceph storage for the O2 application persistent storage, see StarlingX Storage Configuration and Management: Configure the Internal Ceph Storage Backend.

Enable PVC support in oran-o2 namespace, see StarlingX Storage Configuration and Management: Enable ReadWriteOnce PVC Support in Additional Namespaces.

Procedure

You can install O-RAN O2 application on StarlingX from the command line.

Locate the O2 application tarball in /usr/local/share/applications/helm.

For example:
```
/usr/local/share/applications/helm/oran-o2-<version>.tgz
```
Download admin_openrc.sh from the StarlingX admin dashboard.
- Visit https://<oam-floating-ip-address>:8443/project/api_access/
- Click the Download OpenStack RC File”/”OpenStack RC File button
Copy the file to the controller host.

Source the platform environment.

$ source ./admin_openrc.sh
~(keystone_admin)]$

Upload the application.

~(keystone_admin)]$ system application-upload /usr/local/share/applications/helm/oran-o2-<version>.tgz

Prepare the override yaml file.
1. Create a client on the OAuth server.
  
  Assuming you have a 3rd-party OAuth 2 server, you have permission to create a client on your OAuth server, and the O2 application API required to get a token from the OAuth server in each requst from SMO.
  
  When you create a client, you will get a client ID and client secret.
```
OAUTH2_TOKEN_ENDPOINT=http://<3rd-party OAuth Server Address>:8080/realms/master/protocol/openid-connect/token
OAUTH2_CLIENT_ID=<oran-o2-client-id>
OAUTH2_CLIENT_SECRET=<oran-o2-client-secret>
```
  Note
  
  The reference to the 3rd-party OAuth Server (Keycloak)
2. Prepare the OAuth 2 variables to authenticate the updates.
  
  When using JWT with shared key, the following attributes need to be configured. For example:
```
~(keystone_admin)]$ OAUTH2_ALGORITHM=RS256
~(keystone_admin)]$ OAUTH2_PUB_KEY=<3rd-party OAuth Server Public Key>
```
  For token introspection, for example:
```
~(keystone_admin)]$ OAUTH2_INTROSPECTION_ENDPOINT=http://<3rd-party OAuth Server Address>:8080/realms/master/protocol/openid-connect/token/introspect
~(keystone_admin)]$ OAUTH2_CLIENT_ID=<oran-o2-client-id>
~(keystone_admin)]$ OAUTH2_CLIENT_SECRET=<oran-o2-client-secret>
```
3. Create certificates for the O2 service.
  
  Obtain an intermediate or Root CA-signed certificate and key from a trusted intermediate or Root Certificate Authority (CA). Refer to the documentation for the external Root CA that you are using on how to create a public certificate and private key pairs signed by an intermediate or Root CA for HTTPS.
  
  For lab purposes, see StarlingX Security: Create Certificates Locally using openssl to create an Intermediate or test Root CA certificate and key, and use it to locally sign test certificates.
  
  The resulting files, from either an external CA or locally generated for the lab with openssl, should be:
  - Local CA certificate - my-root-ca-cert.pem
  - Server certificate - my-server-cert.pem
  - Server key - my-server-key.pem
  Note
  
  If using a server certificate signed by a local CA (i.e. lab scenario above), this local CA certificate (e.g. my-root-ca-cert.pem from lab scenario above) must be shared with the SMO application for the O2 server certificate verification.
  
  Prepare client certificate for mTLS (Mutual TLS).
  
  When you request the O2 application from SMO, it needs the certificate for mTLS. We assume you have the CA certificate and CA key of the SMO client. It can be used to generate the client certificate and key.
  - SMO CA certificate - smo-ca-cert.pem
  - SMO CA key - smo-ca-key.pem
  - Client certificate - client-cert.pem
  - Client key - client-key.pem
  The reference command to generate the client certificate is below. For example:
```
openssl genrsa -out client-key.pem 2048
openssl req -new -key client-key.pem -out client.csr
openssl x509 -req -in client.csr -CA smo-ca.pem -CAkey smo-ca-key.pem -CAcreateserial -out client-cert.pem -days 365
```
4. Prepare the O2 service application configuration file.
  
  As per the Cloudification and Orchestration use case defined in O-RAN Working Group 6, the following information should be generated by SMO:
  - O-Cloud Gload ID - OCLOUD_GLOBAL_ID
  - SMO Register URL - SMO_REGISTER_URL
  See O-RAN Cloudification and Orchestration Use Cases and Requirements for O-RAN Virtualized RAN.
```
API_HOST_EXTERNAL_FLOATING=$(echo ${OS_AUTH_URL} | awk -F / '{print $3}' | cut -d: -f1)

cat <<EOF > app.conf
[DEFAULT]

ocloud_global_id = ${OCLOUD_GLOBAL_ID}
smo_register_url = ${SMO_REGISTER_URL}

[OCLOUD]
OS_AUTH_URL = ${OS_AUTH_URL}
OS_USERNAME = ${OS_USERNAME}
OS_PASSWORD = ${OS_PASSWORD}
API_HOST_EXTERNAL_FLOATING = ${API_HOST_EXTERNAL_FLOATING}

[OAUTH2]
oauth2_verify_type = jwt
oauth2_public_key = ${OAUTH2_PUB_KEY}
oauth2_algorithm = ${OAUTH2_ALGORITHM}

# required if oauth2_verify_type = introspection
#oauth2_verify_type = introspection
#oauth2_introspection_endpoint = ${OAUTH2_INTROSPECTION_ENDPOINT}
#oauth2_client_id = ${OAUTH2_CLIENT_ID}
#oauth2_client_secret = ${OAUTH2_CLIENT_SECRET}

[API]

[WATCHER]

[PUBSUB]
EOF
```
5. Retrieve the CA certificate from your SMO vendor.
  
  If the SMO application provides service via HTTPS, and the server certificate is self-signed, the CA certificate should be retrieved from the SMO.
  
  This procedure assumes that the name of the certificate is smo-ca.pem
6. Populate the override yaml file.
  
  Refer to the previous step for the required override values.
```
APPLICATION_CONFIG=$(base64 app.conf -w 0)
SERVER_CERT=$(base64 my-server-cert.pem -w 0)
SERVER_KEY=$(base64 my-server-key.pem -w 0)
SMO_CA_CERT=$(base64 smo-ca.pem -w 0)

cat <<EOF > o2service-override.yaml

applicationconfig: ${APPLICATION_CONFIG}
servercrt: ${SERVER_CERT}
serverkey: ${SERVER_KEY}
smocacrt: ${SMO_CA_CERT}

EOF
```
  To deploy other versions of an image required for a quick solution, to have early access to the features (eg. oranscinf/pti-o2imsdms:2.0.4), and to authenticate images that are hosted by a private registry, follow the steps below:
  1. Create a docker-registry secret in oran-o2 namespace.
    export O2SERVICE_IMAGE_REG=<docker-server-endpoint> kubectl create secret docker-registry private-registry-key \ --docker-server=${O2SERVICE_IMAGE_REG} --docker-username=${USERNAME} \ --docker-password=${PASSWORD} -n oran-o2
  2. Refer to the imagePullSecrets in override file.
```
cat <<EOF > o2service-override.yaml
imagePullSecrets:
  - private-registry-key

o2ims:
  serviceaccountname: admin-oran-o2
  images:
    tags:
      o2service: ${O2SERVICE_IMAGE_REG}/docker.io/oranscinf/pti-o2imsdms:2.0.4
      postgres: ${O2SERVICE_IMAGE_REG}/docker.io/library/postgres:9.6
      redis: ${O2SERVICE_IMAGE_REG}/docker.io/library/redis:alpine
    pullPolicy: IfNotPresent
  logginglevel: "DEBUG"

applicationconfig: ${APPLICATION_CONFIG}
servercrt: ${SERVER_CERT}
serverkey: ${SERVER_KEY}
smocacrt: ${SMO_CA_CERT}

EOF
```

Update the overrides for the oran-o2 application.

~(keystone_admin)]$ system helm-override-update oran-o2 oran-o2 oran-o2 --values o2service-override.yaml

# Check the overrides
~(keystone_admin)]$ system helm-override-show oran-o2 oran-o2 oran-o2

Run the system application-apply command to apply the updates.
```
~(keystone_admin)]$ system application-apply oran-o2
```

Monitor the status using the command below.

~(keystone_admin)]$ watch -n 5 system application-list

~(keystone_admin)]$ watch kubectl get all -n oran-o2

Results

You have launched services in the above namespace.

Postrequisites

You will need to integrate StarlingX with an SMO application that performs management of O-Cloud infrastructure and the deployment life cycle management of O-RAN cloudified NFs. See the following API reference for details:

API O-RAN O2 interface

Note

O-RAN O2 interface limitations:

In the StarlingX r8 version, in the GET：/o2ims-infrastructureMonitoring/v1/alarm API resource, alarm clearing events are not recorded.

Uninstall ¶

Procedure

You can uninstall the O-RAN O2 application on StarlingX from the command line.

Uninstall the application.

Remove O2 application related resources.
```
~(keystone_admin)]$ system application-remove oran-o2
```
Delete the application.

Remove the uninstalled O2 application’s definition, including the manifest and helm charts and helm chart overrides, from the system.
```
~(keystone_admin)]$ system application-delete oran-o2
```

Results

You have uninstalled the O2 application from the system.