Troubleshooting of k8s implementation problems in the development and testing environment-internal network DNS resolution

I believe many of my friends have already used k8s in the testing or production environment to solve their own business problems. The following are some of our practices in the testing environment. We direct all services and pods to developers and testers (without ingress, nodeport, and lb, we directly use Static Routing + NAT ), in this way, our testing and developers can directly access SVC and pod. We will discuss it separately later. Most of us are mobile native developers, so most of us need to use WiFi + DNS servers to test our apps. However, if there are many Intranet sites and many services, you need to maintain the DNS server frequently. Can you automatically maintain our DNS server based on our service.

Ideas:
1. obtain all services under all namespaces in the k8s container cloud, and set rules. For example, all web services use the complete domain name as the service name, for example, in api.abc.com, the service name is API-ABC-com, and Kube-system is filtered out.
2. Write the obtained namespace, domain name, And clusterip to the DNS configuration file in the corresponding folder. If yes, delete the file and add it. If no, add it automatically.
3. Load the DNS configuration files for each namespace

#!/bin/bashsvc=$(kubectl get svc --all-namespaces|awk ‘/-/ && NR!=1 && !/kube-system/ {print $1,$2,$4}‘|sed ‘s#-#.#g‘)echo "$svc"|while read linedo        namespace=`echo $line|awk ‘{print $1}‘`        [ -d $namespace ] || mkdir -p ${namespace}        [ -f ${namespace}/dns ] || touch ${namespace}/dns        domain=`echo $line|awk ‘{print $2}‘`        dns_record=`echo $line|awk ‘{print $2"="$3}‘`        [ `grep ${dns_record} ${namespace}/dns|wc -l` ] && sed -i "/${domain}/d" ${namespace}/dns && echo ${dns_record}>>${namespace}/dns        names=`cat ${namespace}/dns | grep -v ‘^#|^//‘ | tr ‘\n‘ ‘,‘|sed ‘s/,$//g‘`        sed "s#{namespace}#${namespace}#g" ~/yaml/dns/deploy.yaml | sed "s#{names}#${names}#g"|kubectl apply -f -done

View the deploy-svc.yaml of DNS

Apiversion: extensions/v1beta1kind: deploymentmetadata: Name: DNS namespace: {namespace} SPEC: selector: matchlabels: Name: DNS replicas: 1 template: Metadata: labels: Name: dns spec: containers:-Name: bind image: cytopia/Bind ports:-containerport: 53 Protocol: TCP name: dnstcp-containerport: 53 Protocol: UDP name: dnsudp env:-Name: extra_hosts value: "{names}"-Name: dns_forwarder value: "114.114.114.144, 8.8.4.4" # This is an Internet DNS server --- apiversion: v1kind: servicemetadata: Name: DNS namespace: {namespace} labels: Name: dnsspec: ports:-Protocol: TCP port: 53 targetport: 53 name: dnstcp-Protocol: UDP port: 53 targetport: 53 name: dnsudp selector: name: DNS

Troubleshooting of k8s implementation problems in the development and testing environment-internal network DNS resolution