# This example shows how to add environment variables to container from ConfigMap, Secret and
# downwards API (node: name and IP; pod: namespace, name and IP; resources: requests and limits).

# ConfigMap
apiVersion: v1
kind: ConfigMap
metadata:
  name: config-environment-all
data:
  CONFIG_VARIABLE1: config-value1
  CONFIG_VARIABLE2: config-value2
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: config-environment-custom
data:
  config_custom_variable1: config-custom-value1
  config_custom_variable2: config-custom-value2
---
# Secret
apiVersion: v1
kind: Secret
type: Opaque
metadata:
  name: secret-environment-all
data:
  SECRET_VARIABLE1: c2VjcmV0LXZhbHVlMQ==
  SECRET_VARIABLE2: c2VjcmV0LXZhbHVlMg==
---
apiVersion: v1
kind: Secret
type: Opaque
metadata:
  name: secret-environment-custom
data:
  secret_custom_variable1: c2VjcmV0LWN1c3RvbS12YWx1ZTE=
  secret_custom_variable2: c2VjcmV0LWN1c3RvbS12YWx1ZTI=
---
# Deployment
apiVersion: apps/v1
kind: Deployment
metadata:
  name: environment-variables
spec:
  selector:
    matchLabels:
      app: environment-variables
  template:
    metadata:
      labels:
        app: environment-variables
    spec:
      # Don't wait (SIGTERM) just kill (SIGKILL)
      terminationGracePeriodSeconds: 0
      containers:
        - name: alpine
          image: alpine:latest
          command: ["/bin/sh", "-c", "--"]
          args:
            - >
              while true; do
                now=$(TZ=UTC date +"%Y-%m-%d %H:%M:%S UTC");

                echo "--";
                echo "Time: ${now}";

                echo "NODE_NAME: $NODE_NAME, NODE_IP: $NODE_IP";
                echo "POD_NAMESPACE: $POD_NAMESPACE, POD_NAME: $POD_NAME, POD_IP: $POD_IP";
                echo "SERVICE_ACCOUNT: $SERVICE_ACCOUNT";

                echo "REQUESTS_CPU: $REQUESTS_CPU, REQUESTS_MEMORY: $REQUESTS_MEMORY"
                echo "LIMITS_CPU: $LIMITS_CPU, LIMITS_MEMORY: $LIMITS_MEMORY";

                echo "CONFIG_VARIABLE1: $CONFIG_VARIABLE1, CONFIG_VARIABLE2: $CONFIG_VARIABLE2";
                echo "CONFIG_CUSTOM_VARIABLE1: $CONFIG_CUSTOM_VARIABLE1"
                echo "CONFIG_CUSTOM_VARIABLE2: $CONFIG_CUSTOM_VARIABLE2";

                echo "SECRET_VARIABLE1: $SECRET_VARIABLE1, SECRET_VARIABLE2: $SECRET_VARIABLE2";
                echo "SECRET_CUSTOM_VARIABLE1: $SECRET_CUSTOM_VARIABLE1"
                echo "SECRET_CUSTOM_VARIABLE2: $SECRET_CUSTOM_VARIABLE2";

                sleep 5;
              done
          env:
            # Downwards API (see: https://kubernetes.io/docs/concepts/workloads/pods/downward-api/)
            - name: NODE_NAME
              valueFrom:
                fieldRef:
                  fieldPath: spec.nodeName
            - name: NODE_IP
              valueFrom:
                fieldRef:
                  fieldPath: status.hostIP
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_IP
              valueFrom:
                fieldRef:
                  fieldPath: status.podIP
            - name: SERVICE_ACCOUNT
              valueFrom:
                fieldRef:
                  fieldPath: spec.serviceAccountName
            - name: REQUESTS_CPU
              valueFrom:
                resourceFieldRef:
                  resource: requests.cpu
            - name: REQUESTS_MEMORY
              valueFrom:
                resourceFieldRef:
                  resource: requests.memory
            - name: LIMITS_CPU
              valueFrom:
                resourceFieldRef:
                  resource: limits.cpu
            - name: LIMITS_MEMORY
              valueFrom:
                resourceFieldRef:
                  resource: limits.memory
            # Config (custom)
            - name: CONFIG_CUSTOM_VARIABLE1
              valueFrom:
                configMapKeyRef:
                  name: config-environment-custom
                  key: config_custom_variable1
            - name: CONFIG_CUSTOM_VARIABLE2
              valueFrom:
                configMapKeyRef:
                  name: config-environment-custom
                  key: config_custom_variable2
            # Secret (custom)
            - name: SECRET_CUSTOM_VARIABLE1
              valueFrom:
                secretKeyRef:
                  name: secret-environment-custom
                  key: secret_custom_variable1
            - name: SECRET_CUSTOM_VARIABLE2
              valueFrom:
                secretKeyRef:
                  name: secret-environment-custom
                  key: secret_custom_variable2
          envFrom:
            # Config (all)
            - configMapRef:
                name: config-environment-all
            # Secret (all)
            - secretRef:
                name: secret-environment-all
          resources:
            requests:
              cpu: 50m
              memory: 128Mi
            limits:
              cpu: 100m
              memory: 256Mi