110 lines
3.8 KiB
Markdown
110 lines
3.8 KiB
Markdown
![]() |
# Simple Websocket Example
|
||
|
|
||
|
Any websocket server will suffice; however, for the purpose of demonstration, we'll use the gorilla/websocket package in a Go process.
|
||
|
|
||
|
### Build
|
||
|
```shell
|
||
|
➜ CGO_ENABLED=0 go build -o wsserver
|
||
|
```
|
||
|
|
||
|
### Containerize
|
||
|
```shell
|
||
|
➜ docker build -t nicksardo/websocketexample .
|
||
|
Sending build context to Docker daemon 6.134 MB
|
||
|
Step 1 : FROM alpine:3.5
|
||
|
---> 4a415e366388
|
||
|
Step 2 : COPY wsserver /wsserver
|
||
|
---> 8002887d752d
|
||
|
Removing intermediate container 7772a3e76155
|
||
|
Step 3 : CMD /wsserver
|
||
|
---> Running in 27c8ff226267
|
||
|
---> eecd0574e5d1
|
||
|
Removing intermediate container 27c8ff226267
|
||
|
Successfully built eecd0574e5d1
|
||
|
|
||
|
➜ docker push nicksardo/websocketexample:latest
|
||
|
...
|
||
|
```
|
||
|
|
||
|
### Deploy
|
||
|
Either update the image in the `Deployment` to your newly created image or continue using `nicksardo/websocketexample.`
|
||
|
```shell
|
||
|
➜ vi deployment.yaml
|
||
|
# Change image to your own
|
||
|
```
|
||
|
|
||
|
```shell
|
||
|
➜ kubectl create -f deployment.yaml
|
||
|
deployment "ws-example" created
|
||
|
service "ws-example-svc" created
|
||
|
ingress "ws-example-ing" created
|
||
|
|
||
|
```
|
||
|
|
||
|
### Test
|
||
|
Retrieve the ingress external IP:
|
||
|
```shell
|
||
|
➜ kubectl get ing/ws-example-ing
|
||
|
NAME HOSTS ADDRESS PORTS AGE
|
||
|
ws-example-ing * xxx.xxx.xxx.xxx 80 3m
|
||
|
```
|
||
|
|
||
|
Wait for the loadbalancer to be created and functioning. When you receive a successful response, you can proceed.
|
||
|
```
|
||
|
➜ curl http://xxx.xxx.xxx.xxx
|
||
|
Websocket example. Connect to /ws%
|
||
|
```
|
||
|
|
||
|
The binary we deployed does not have any html/javascript to demonstrate thwe websocket, so we'll use websocket.org's client.
|
||
|
|
||
|
Visit http://www.websocket.org/echo.html. It's important to use `HTTP` instead of `HTTPS` since we assembled an `HTTP` load balancer. Browsers may prevent `HTTP` websocket connections as a security feature.
|
||
|
Set the `Location` to
|
||
|
```
|
||
|
ws://xxx.xxx.xxx.xxx/ws
|
||
|
```
|
||
|
Click 'Connect' and you should see messages received from server:
|
||
|

|
||
|
|
||
|
|
||
|
### Change backend timeout
|
||
|
|
||
|
At this point, the websocket connection will be destroyed by the HTTP(S) Load Balancer after 30 seconds, which is the default timeout. Note: this timeout is not an idle timeout - it's a timeout on the connection lifetime.
|
||
|
|
||
|
Currently, the GCE ingress controller does not provide a way to set this timeout via Ingress specification. You'll need to change this value either through the GCP Cloud Console or through gcloud CLI.
|
||
|
|
||
|
|
||
|
```shell
|
||
|
➜ kubectl describe ingress/ws-example-ing
|
||
|
Name: ws-example-ing
|
||
|
Namespace: default
|
||
|
Address: xxxxxxxxxxxx
|
||
|
Default backend: ws-example-svc:80 (10.48.10.12:8080,10.48.5.14:8080,10.48.7.11:8080)
|
||
|
Rules:
|
||
|
Host Path Backends
|
||
|
---- ---- --------
|
||
|
* * ws-example-svc:80 (10.48.10.12:8080,10.48.5.14:8080,10.48.7.11:8080)
|
||
|
Annotations:
|
||
|
target-proxy: k8s-tp-default-ws-example-ing--52aa8ae8221ffa9c
|
||
|
url-map: k8s-um-default-ws-example-ing--52aa8ae8221ffa9c
|
||
|
backends: {"k8s-be-31127--52aa8ae8221ffa9c":"HEALTHY"}
|
||
|
forwarding-rule: k8s-fw-default-ws-example-ing--52aa8ae8221ffa9c
|
||
|
Events:
|
||
|
FirstSeen LastSeen Count From SubObjectPath Type Reason Message
|
||
|
--------- -------- ----- ---- ------------- -------- ------ -------
|
||
|
12m 12m 1 loadbalancer-controller Normal ADD default/ws-example-ing
|
||
|
11m 11m 1 loadbalancer-controller Normal CREATE ip: xxxxxxxxxxxx
|
||
|
11m 9m 5 loadbalancer-controller Normal Service default backend set to ws-example-svc:31127
|
||
|
```
|
||
|
|
||
|
Retrieve the name of the backend service from within the annotation section.
|
||
|
|
||
|
Update the timeout field for every backend that needs a higher timeout.
|
||
|
|
||
|
```shell
|
||
|
➜ export BACKEND=k8s-be-31127--52aa8ae8221ffa9c
|
||
|
➜ gcloud compute backend-services update $BACKEND --global --timeout=86400 # seconds
|
||
|
Updated [https://www.googleapis.com/compute/v1/projects/xxxxxxxxx/global/backendServices/k8s-be-31127--52aa8ae8221ffa9c].
|
||
|
```
|
||
|
|
||
|
Wait up to twenty minutes for this change to propagate.
|