example of handling environment variables using oc patch

patch-openshift-enviroment-variable.sh

## SET variable with the name of dc that you want to change
PROJETO=xxxx

# If you need a replacement a suggest you remove and them add

### to remove you can do this
oc set env dc/${PROJETO} KUBERNETES_NAMESPACE-

## add the deployment config with new item
oc patch dc/${PROJETO} --type=json --patch '
[
  { 
    "op": "add",
    "path": "/spec/template/spec/containers/0/env/-",
    "value": {
      "name": "KUBERNETES_NAMESPACE",
      "valueFrom": {
          "fieldRef": {
              "fieldPath": "metadata.namespace"
          }
      }
    }
  }
]
'

## GET the value updated
KUBERNETES_NAMESPACE=$(oc get dc/${PROJETO} -o=jsonpath="{.spec.template.spec.containers[0].env[?(@.name=='KUBERNETES_NAMESPACE')].value}")

Was very helpefull this link to test the JSON - https://json8.github.io/patch/demos/apply/