add dns items for coredns

Posted 2021-06-12 lvmxh

 add a dns item as follow:

# $(kubectl get cm coredns -n kube-system  -o json | jq .data.Corefile |grep -o host）

function add_coredns_host(){
CM=${CM:-coredns}
 
kubectl get cm $CM -n kube-system  -o json | jq .data.Corefile |grep -o host
ret=$?

if [[ $ret != 0 ]]; then
  # str=`kubectl get cm $CM -n kube-system -o json | jq .data.Corefile | \\
  #      sed -e \'0,/prometheus/s/prometheus/host {\\\\\\n \'"$item"\'\\\\\\n }\\\\\\n /\'`
  str=$(kubectl get cm $CM -n kube-system -o json | jq .data.Corefile |
           sed -e \'0,/prometheus/s/prometheus/host {\\\\n       \'"$1"\'\\\\n    }\\\\n    prometheus/\')
else
  str=$(kubectl get cm $CM -n kube-system -o json | jq .data.Corefile |
           sed -e \'s/\\(host {\\)/\\1\\\\n       \'"$1"\'/\')
fi

NATPATH="/data/Corefile"
kubectl patch cm $CM -n kube-system --type=\'json\' -p \'[
{"op":"replace","path":"\'"$NATPATH"\'","value": \'"$str"\'},
]\'
}


item="172.16.30.4 gateway.sdwam.opennes"
add_coredns_host  "$item"