use printf to replace printenv

Signed-off-by: Weiping Cai <[email protected]>

Author: Weiping Cai

content/en/docs/tasks/inject-data-application/define-interdependent-environment-variables.md

@@ -53,12 +53,10 @@ Pod:
     kubectl logs pod/dependent-envars-demo
     ```
     ```
-    SERVICE_ADDRESS
-    https://172.17.0.1:80
-    UNCHANGED_REFERENCE
-    $(PROTOCOL)://172.17.0.1:80
-    ESCAPED_REFERENCE
-    $(PROTOCOL)://172.17.0.1:80
+
+    UNCHANGED_REFERENCE=$(PROTOCOL)://172.17.0.1:80
+    SERVICE_ADDRESS=https://172.17.0.1:80
+    ESCAPED_REFERENCE=$(PROTOCOL)://172.17.0.1:80
     ```
 
 As shown above, you have defined the correct dependency reference of `SERVICE_ADDRESS`, bad dependency reference of `UNCHANGED_REFERENCE` and skip dependent references of `ESCAPED_REFERENCE`.

content/en/examples/pods/inject/dependent-envars.yaml

@@ -4,23 +4,23 @@ metadata:
   name: dependent-envars-demo
 spec:
   containers:
-  - name: dependent-envars-demo
-    args:
-    - while true; do echo -en '\n'; echo SERVICE_ADDRESS;printenv SERVICE_ADDRESS;echo UNCHANGE_REFERENCE;printenv UNCHANGE_REFERENCE;echo ESCAPED_REFERENCE;printenv ESCAPED_REFERENCE; sleep 30; done;
-    command:
+    - name: dependent-envars-demo
+      args:
+        - while true; do echo -en '\n'; printf UNCHANGED_REFERENCE=$UNCHANGED_REFERENCE'\n'; printf SERVICE_ADDRESS=$SERVICE_ADDRESS'\n';printf ESCAPED_REFERENCE=$ESCAPED_REFERENCE'\n'; sleep 30; done;
+      command:
         - sh
         - -c
-    image: busybox
-    env:
-    - name: SERVICE_PORT
-      value: "80"
-    - name: SERVICE_IP
-      value: "172.17.0.1"
-    - name: UNCHANGED_REFERENCE
-      value: "$(PROTOCOL)://$(SERVICE_IP):$(SERVICE_PORT)"
-    - name: PROTOCOL
-      value: "https"
-    - name: SERVICE_ADDRESS
-      value: "$(PROTOCOL)://$(SERVICE_IP):$(SERVICE_PORT)"
-    - name: ESCAPED_REFERENCE
-      value: "$$(PROTOCOL)://$(SERVICE_IP):$(SERVICE_PORT)"
+      image: busybox
+      env:
+        - name: SERVICE_PORT
+          value: "80"
+        - name: SERVICE_IP
+          value: "172.17.0.1"
+        - name: UNCHANGED_REFERENCE
+          value: "$(PROTOCOL)://$(SERVICE_IP):$(SERVICE_PORT)"
+        - name: PROTOCOL
+          value: "https"
+        - name: SERVICE_ADDRESS
+          value: "$(PROTOCOL)://$(SERVICE_IP):$(SERVICE_PORT)"
+        - name: ESCAPED_REFERENCE
+          value: "$$(PROTOCOL)://$(SERVICE_IP):$(SERVICE_PORT)"