Is there a way to learn the Ambassador service prefix at runtime in my microservice in Kubernetes?
Taking this config example:
---
apiVersion: ambassador/v1
kind: Mapping
name: myservice_get_mapping
prefix: /myprefix/
service: myservice
From within my docker container, I would like to get the '/myprefix/'. Either via some env variable to the deployment or programmatically if cannot be done using env variable.
Thanks.
Assuming the fact that Ambassador Mapping resource associates REST resources with Kubernetes services, you can fetch annotation metadata via JSONPath and then parse prefix: field, if I understand your question correctly.
Example for k8s service from Ambassador documentation:
kind: Service
metadata:
name: httpbin
annotations:
getambassador.io/config: |
---
apiVersion: ambassador/v1
kind: Mapping
name: tour-ui_mapping
prefix: /test/
service: http://tour
spec:
ports:
- name: httpbin
port: 80
Command line to fetch prefix: field value:
$ kubectl get svc httpbin -o jsonpath='{.metadata.annotations}'| grep -w "prefix:"| awk '{print $2}'
/test/
Update:
Alternatively, you might also consider to retrieve the same result through the direct call to REST API through Bearer token authentication method:
curl -k -XGET -H "Authorization : Bearer $MY_TOKEN" 'https://<API-server_IP>/api/v1/namespaces/default/services/httpbin' -H "Accept: application/yaml"| grep -w "prefix:"| awk '{print $2}
$MY_TOKEN variable has to be supplied with appropriate token which is entitled to perform above query against REST API as I've already pointed out in my former answer.
