Passing environment variables to Flink job on Flink Kubernetes Cluster

I'm using Flink Kubernetes Operator 1.3.0 and need to pass some environment variables to a Python job. I have followed the official documentation and the example runs fine. How can I inject environment variables so that I can use it inside the python file?

EDIT:

Here's the yaml file that I've used. Its straight from the example link above:

apiVersion: flink.apache.org/v1beta1
kind: FlinkDeployment
metadata:
  name: python-example
spec:
  image: localhost:32000/flink-python-example:1.16.0
  flinkVersion: v1_16
  flinkConfiguration:
    taskmanager.numberOfTaskSlots: "1"
  serviceAccount: flink
  jobManager:
    resource:
      memory: "2048m"
      cpu: 1
  taskManager:
    resource:
      memory: "2048m"
      cpu: 1
  job:
    jarURI: local:///opt/flink/opt/flink-python_2.12-1.16.0.jar # Note, this jarURI is actually a placeholder
    entryClass: "org.apache.flink.client.python.PythonDriver"
    args: ["-pyclientexec", "/usr/local/bin/python3", "-py", "/opt/flink/usrlib/python_demo.py"]
    parallelism: 1
    upgradeMode: stateless

As you can see it's a custom resource of kind FlinkDeployment. And here's the python code:

import logging
import sys

from pyflink.datastream import StreamExecutionEnvironment
from pyflink.table import StreamTableEnvironment


def python_demo():
    env = StreamExecutionEnvironment.get_execution_environment()
    env.set_parallelism(1)

    t_env = StreamTableEnvironment.create(stream_execution_environment=env)
    t_env.execute_sql("""
    CREATE TABLE orders (
      order_number BIGINT,
      price        DECIMAL(32,2),
      buyer        ROW<first_name STRING, last_name STRING>,
      order_time   TIMESTAMP(3)
    ) WITH (
      'connector' = 'datagen'
    )""")

    t_env.execute_sql("""
        CREATE TABLE print_table WITH ('connector' = 'print')
          LIKE orders""")
    t_env.execute_sql("""
        INSERT INTO print_table SELECT * FROM orders""")


if __name__ == '__main__':
    logging.basicConfig(stream=sys.stdout, level=logging.INFO, format="%(message)s")
    python_demo()

Found the solution.

This is not detailed in the reference https://nightlies.apache.org/flink/flink-kubernetes-operator-docs-release-0.1/docs/custom-resource/reference

or example Flink Deployment https://nightlies.apache.org/flink/flink-kubernetes-operator-docs-release-0.1/docs/custom-resource/pod-template/

But here it says: https://nightlies.apache.org/flink/flink-kubernetes-operator-docs-release-0.1/docs/custom-resource/reference/#jobmanagerspec JobManager pod template. It will be merged with FlinkDeploymentSpec.podTemplate

So I just added envFrom from the example in which shows you how to extend the FlinkDeployment CRD:

https://nightlies.apache.org/flink/flink-kubernetes-operator-docs-release-0.1/docs/custom-resource/pod-template/

Confirmed this is working as I had to get this work for my own application now

apiVersion: flink.apache.org/v1beta1
kind: FlinkDeployment
metadata:
  name: python-example
spec:
  image: localhost:32000/flink-python-example:1.16.0
  flinkVersion: v1_16
  flinkConfiguration:
    taskmanager.numberOfTaskSlots: "1"
  serviceAccount: flink
  jobManager:
    resource:
      memory: "2048m"
      cpu: 1
    podTemplate:
      apiVersion: v1
      kind: Pod
      metadata:
       name: pod-template
      spec:
        serviceAccount: flink
        containers:
        # Do not change the main container name
          - name: flink-main-container
            envFrom:
            - secretRef:
                name: <SECRET RESOURCE NAME>
  taskManager:
    resource:
      memory: "2048m"
      cpu: 1
  job:
    jarURI: local:///opt/flink/opt/flink-python_2.12-1.16.0.jar # Note, this jarURI is actually a placeholder
    entryClass: "org.apache.flink.client.python.PythonDriver"
    args: ["-pyclientexec", "/usr/local/bin/python3", "-py", "/opt/flink/usrlib/python_demo.py"]
    parallelism: 1
    upgradeMode: stateless