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FAQ

List of questions and answers relating to abcdesktop.io

A Kubernetes Cloud provider can be Amazon EKS, DigitalOcean DOKS, Azur AKS, Google GKE, or any of others cloud provider with a Kubernetes service.

Networking

This list of questions and answers is relating network, talking about

  • port-forward
  • NodePort
  • LoadBalancer
  • Ingress Controler
  • WebSocket timeout

How can I reach my new service on a Kubernetes cloud provider ?

I was attempting to deploy the ABCDesktop (kubernetes-version-3.0) for testing my setup with a few of my own desktop applications. Everything worked fine when tested locally in my Ubuntu (22.04) machine. I then thought to deploy the setup in a Kubernetes cloud provider with 3 nodes cluster. How can I reach my new hosted service on a Kubernetes cloud provider (Amazon EKS, Digital Ocean, Azur AKS, Google GKE) ?

We use the kubectl port-forward to the nginx pod 

NGINX_POD_NAME=$(kubectl get pods -l run=nginx-od -o jsonpath={.items..metadata.name} -n abcdesktop)
kubectl port-forward $NGINX_POD_NAME --address 0.0.0.0 80:80 -n abcdesktop

Then open your web browser to reach the http://localhost

Then open your web browser, you get the home page, login using LDAP auth or Anonymous auth.

Screenshot 2023-05-06 at 12 32 45

Then login, and you get a pod user.

For the first time, you may get a timeout error, if container images can't be downloaded in less than 180 seconds on the worker node.

Screenshot 2023-05-06 at 12 33 55

How can I expose my new service with an external IP address ?

I was attempting to deploy the abcesktop (kubernetes-version-3.0) for testing my setup with a few of my own desktop applications. Everything worked fine when tested locally in my Ubuntu (22.04) machine. I then thought to deploy the setup in a Kubernetes cloud provider with 3 nodes cluster. How can I expose my new service with an external IP address ?

To expose the service with an external IP address, we need to update the nginx service type. The default type on your own desktop is type: NodePort, the nginx service type on a Kubernetes cloud provider becomes type: LoadBalancer.

Delete the previous abcdesktop's nginx service 

kubectl delete service nginx -n abcdesktop

Create a new nginx service yaml file named nginx-lb.yaml The new nginx service type is LoadBalancer

kind: Service
apiVersion: v1
metadata:
  name: nginx
  namespace: abcdesktop
spec:
  type: LoadBalancer
  selector:
    run: nginx-od
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
    name: http

Apply the nginx service type LoadBalancer

kubectl apply -f nginx-lb.yaml
service/nginx created

Wait for an EXTERNAL-IP from you kubernetes cloud provider

kubectl get service nginx -n abcdesktop
NAME    TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
nginx   LoadBalancer   10.245.105.75   <pending>     80:31581/TCP   64s

You get the EXTERNAL-IP for your LoadBalancer

kubectl get service nginx -n abcdesktop
NAME        TYPE           CLUSTER-IP       EXTERNAL-IP    PORT(S)           AGE
nginx       LoadBalancer   10.245.172.53    161.35.246.4   80:30443/TCP      2m36s

In case, the LoadBalancer service returns the EXTERNAL-IP 161.35.246.4 Then open your web browser to reach this EXTERNAL-IP 161.35.246.4.

abcdesktop homepage

Login using Philip J. Fry

abcdesktop login

And you should get the fry desktop

abcdesktop desktop

How can I expose my new service with Ingress Controller ?

A Kubernetes Ingress Controller acts as a reverse proxy.

In the Ingress, define a path to the abcdesktop's nginx service.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-demo
  namespace: abcdesktop
spec:
  rules:
    - host: demo.digital.pepins.net
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: nginx
                port:
                  number: 80
  ingressClassName: nginx

The request path: / is proxyfied to service named nginx in abcdesktop namespace.

How to prevent the connection from closing after 60 seconds of inactivity ?

My desktop is disconnected after 60 seconds of inactivity, and the message "Your abcdesktop session has been disconnected. Please reload this page" appears.

abcdesktop session has been disconnected

The message Your abcdesktop session has been disconnected. Please reload this page appears when the websockify websocket is disconnected.

Add an heartbeat value to send a ping to the client every INTERVAL seconds

Edit the od.config file, add to the desktop.envlocal option 'WEBSOCKIFY_HEARTBEAT':'30'

desktop.envlocal: { 'WEBSOCKIFY_HEARTBEAT':'30', 'LIBOVERLAY_SCROLLBAR':'0', 'UBUNTU_MENUPROXY':'0', 'X11LISTEN':'tcp' }

In this case, the command /usr/bin/websockify sends a ping to the client every 30 seconds. This command runs in the user's pod.

Update the configmap abcdesktop-config

kubectl create -n abcdesktop configmap abcdesktop-config --from-file=od.config -o yaml --dry-run=client | kubectl replace -n abcdesktop -f -

Restart the pyos pod

kubectl delete pods -l run=pyos-od -n abcdesktop

To get more informations how to Keepalive in websockets

Timeout is a main feature to preserve from unnecessary network bandwidth.

How to prevent the connection from closing after 60 seconds of inactivity with an Ingress Controller ?

My desktop is disconnected after 60 seconds of inactivity, and the message Your abcdesktop session has been disconnected. Please reload this page appears.

To prevent the connection from closing after 60 seconds of inactivity through Ingress Controller, make sure the Ingress Controller isn't configured to automatically terminate long connections. The default value nginx's ingress controller is 60 seconds.

Update the default values for nginx.ingress.kubernetes.io/proxy-read-timeout and nginx.ingress.kubernetes.io/proxy-send-timeout annotations to more than 60 seconds.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-demo
  namespace: abcdesktop
  annotations:
    nginx.ingress.kubernetes.io/proxy-read-timeout: "3600"
    nginx.ingress.kubernetes.io/proxy-send-timeout: "3600"
spec:
  rules:
    - host: demo.digital.pepins.net
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: nginx
                port:
                  number: 80
  ingressClassName: nginx

Applications

This list of questions and answers is relating abcdesktop's applications, talking about

  • /API/manager/images endpoints

How to delete all applications ?

To delete all applications use the images endpoint, replace localhost:30443 by your own datas

curl -X DELETE -H 'Content-Type: text/javascript' http://localhost:30443/API/manager/images/

It returns a json list of all deleted applications

["abcdesktopio/2048-alpine.d:3.0", "abcdesktopio/2048-ubuntu.d:3.0", "abcdesktopio/apachedirectorystudio.d:3.0", "abcdesktopio/astromenace.d:3.0", "abcdesktopio/base.d:3.0", "abcdesktopio/beekeeperstudio.d:3.0", "abcdesktopio/blender.d:3.0", "abcdesktopio/bless.d:3.0", "abcdesktopio/blobby.d:3.0", "abcdesktopio/boxes.d:3.0", "abcdesktopio/calculator.d:3.0", "abcdesktopio/chess.d:3.0", "abcdesktopio/chimerax.d:dev", "abcdesktopio/chrome.d:3.0", "abcdesktopio/chromium.d:3.0", "abcdesktopio/citrix.d:3.0", "abcdesktopio/cloudfoundry.d:3.0", "abcdesktopio/cmd.exe.d:3.0", "abcdesktopio/corsix-th.d:3.0", "abcdesktopio/cuda.d:dev"]

How to add an application ?

To add an application : - get the json file of an application - push the json file to the abcdesktop's images endpoint

wget https://raw.githubusercontent.com/abcdesktopio/oc.apps/main/2048-alpine.d.3.0.json
curl -X POST -H 'Content-Type: text/javascript' http://localhost:30443/API/manager/image -d @2048-alpine.d.3.0.json

The first start will pull the 2048 image, so it can take a while.

How to get the json file of a containerized application ?

To get the json file of a containerized application, you can use docker command or crictl command

  • docker command
docker inspect abcdesktopio/2048-alpine.d:3.0 > 2048-alpine.json
  • crictl command
crictl inspecti abcdesktopio/2048-alpine.d:3.0 > 2048-alpine.json

My application doesn't start. How to get log files ?

Open the webshell and read the logs files.

The log files are /tmp/lastcmd.log, /tmp/lastcmdenv.log and /tmp/NAME OF THE APPLICATION.log.

  • /tmp/lastcmd.log the init command log file created by /composer/appli-docker-entrypoint.sh
  • /tmp/lastcmdenv.log the last environment variables file
  • /tmp/NAME OF THE APPLICATION.log the command log file for the application