Docker error : The network name cannot be found.

 If u get this error

deploying WSL2 distributions ensuring main distro is deployed: checking if main distro is up to date: checking main distro bootstrap version: getting main distro bootstrap version: open \\wsl$\docker-desktop\etc\wsl_bootstrap_version: The network name cannot be found. checking if isocache exists: CreateFile \\wsl$\docker-desktop-data\isocache\: The network name cannot be found.

 

Try the following to troubleshoot:

1. Stop Docker Desktop
2. Run the following command in your terminal wsl --unregister docker-desktop
3. Run Docker Desktop again (Will recreate the distro)

Note: I also start my Docker Desktop as Administrator each time, so you probably need to run your terminal/Powershell as Administrator like I did.

Enable ingress

https://blog.raulnq.com/testing-the-nginx-ingress-controller-locally-docker-desktop

 

helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
helm repo update
helm install nginx-ingress ingress-nginx/ingress-nginx

Run kubectl get ingressclass and kubectl get services to check the installation:

First Deployment 

kubectl create deployment web --image=gcr.io/google-samples/hello-app:1.0

kubectl expose deployment web --type=NodePort --port=8080 

 

Second Deployment  

kubectl create deployment web2 --image=gcr.io/google-samples/hello-app:2.0
kubectl expose deployment web2 --port=8080 --type=NodePort
 

 

 

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
spec:
  ingressClassName: nginx
  rules:
    - host: hello-world.example
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: web
                port:
                  number: 8080
                  
          - path: /v2
            pathType: Prefix
            backend:
              service:
                name: web2
                port:
                  number: 8080
                  
          - path: /v3
            pathType: Prefix
            backend:
              service:
                name: web
                port:
                  number: 8080

kubectl apply -f example-ingress.yaml 

kubectl get ingress

minikube up cluster

 

Start your cluster

 

 

minikube start

kubectl get po -A

minikube kubectl -- get po -A
 

minikube dashboard

start kube 

kubectl create deployment hello-minikube --image=kicbase/echo-server:1.0
kubectl expose deployment hello-minikube --type=NodePort --port=8080
 

kubectl get services hello-minikube

minikube service hello-minikube

kubectl port-forward service/hello-minikube 7080:8080


 

Install swoole on window

 

Not directly, but with Docker and WSL (Windows Subsystem for Linux).

1. Install Docker (https://www.docker.com/products/docker-desktop)
2. Setup WSL

Open PowerShell as Administrator and run

Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Windows-Subsystem-Linux

Updating/Install the WSL 2 Linux kernel (https://docs.microsoft.com/en-us/windows/wsl/wsl2-kernel)

3. Enable "Enable the experimental WSL 2 based engine" in Docker (General)
4. Build the Docker container

IMPORTANT! Don't use a path with spacebars like:

• C:\Users\ {FIRSTNAME}[SPACEBAR]{LASTNAME}\Desktop\docker)

Create a folder (D:\docker) and create with an Editor the Dockerfile (D:\docker\Dockerfile)

FROM php:7.4.2-cli

RUN apt-get update && apt-get install vim -y && \
    apt-get install openssl -y && \
    apt-get install libssl-dev -y && \
    apt-get install wget -y && \
    apt-get install git -y && \
    apt-get install procps -y && \
    apt-get install htop -y

RUN cd /tmp && git clone https://github.com/swoole/swoole-src.git && \
    cd swoole-src && \
    git checkout v4.4.15 && \
    phpize  && \
    ./configure  --enable-openssl && \
    make && make install

RUN touch /usr/local/etc/php/conf.d/swoole.ini && \
    echo 'extension=swoole.so' > /usr/local/etc/php/conf.d/swoole.ini

RUN wget -O /usr/local/bin/dumb-init https://github.com/Yelp/dumb-init/releases/download/v1.2.2/dumb-init_1.2.2_amd64
RUN chmod +x /usr/local/bin/dumb-init

RUN apt-get autoremove -y && rm -rf /var/lib/apt/lists/*

ENTRYPOINT ["/usr/local/bin/dumb-init", "--", "php"]

Open PowerShell navigate to your folder (D:\docker) to build the DockerImage

docker build -f ./Dockerfile -t swoole-php .

5. Add your swoole source code

As an example (D:\docker\server.php)

<?php
$http = new Swoole\HTTP\Server("0.0.0.0", 9501);

$http->on('start', function ($server) {
    echo "Swoole http server is started at http://127.0.0.1:9501\n";
});

$http->on('request', function ($request, $response) {
    $response->header("Content-Type", "text/plain");
    $response->end("Hello World\n");
});

$http->start();
?>

6. Start your swoole http server with the PowerShell

docker run --rm -p 9501:9501 -v D:/docker/:/app -w /app swoole-php server.php

Gradle does not have execution permission.

How to solve the problem

run this command in flutter android directory

chmod a+rx gradlew

Farmer Application

The idea is farmer advertise their vegetable online.. the customer get the vegetables directly form them without any retailers...

Configure Relay Postfix to send email via Gmail SMTP

1.     Create a file to store our credentials:

sudo vi /etc/postfix/sasl_passwd

2.     Add something like this:

smtp.gmail.com:587 sysnotify@umt.edu.my:00umt00

3.     Now run:

sudo postmap /etc/postfix/sasl_passwd

4.     Prepare the postfix main config file:

sudo vi /etc/postfix/main.cf

5.     Add/update these lines

relayhost=smtp.gmail.com:587
smtp_sasl_auth_enable=yes smtp_sasl_password_maps=hash:/etc/postfix/sasl_passwd
smtp_use_tls=yes
smtp_tls_security_level=encrypt
tls_random_source=dev:/dev/urandom
smtp_sasl_security_options = noanonymous
smtp_always_send_ehlo = yes
smtp_sasl_mechanism_filter = plain

6.     Stop/Start the service

sudo postfix reload

7.     Run command nim utk test

date | mail -s "Test Email" abdul.rahim@umt.edu.my

8.     Check the queue for any errors

mailq