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titleCasablanca

This installation step is required for Beijing onlyCasablanca in order to enable automatic DNS updates on failover.

Setup required to test DnsSwitch functionality

These steps are used to test DNSSwitch functionality within PROM POD

1. Place dnsSwitch.bash on core-dns master under /home/ubuntu

2. Place sdnc.dnsswitch and site.conf on respective sites under /home/ubuntu

3. Make sure that site.conf is properly configured on site-A and site-B

Code Block e.g. as follows- a) for site A siteIP="10.147.112.139" ----- IP Addresss of Site A app="sdnc" --- app name is sdnc corednsHost="10.147

.

114.7" ----- IP address of core-dns master b) for site B siteIP="10.147.113.136" ----- IP Addresss of Site B app="sdnc" --- app name is sdnc corednsHost="10.147.114.7" ----- IP address of core-dns master

4.Following are the steps to create ssh key for remote core-dns connection

Code Block
    a. ExecuteAs a root user, execute below command /home/ubuntu on coredns master (make sure to use the key name as coredns.key) :
          $ ssh-keygen -t rsa -f coredns.key  - This creates two files- coredns.key and coredns.key.pub under /home/ubuntu
	b. Copy above two key files on site A and site B and execute below command.
           sudo ssh-copy-id -i coredns.key root@<corednsHost>
    c(hit Enter key for the prompts)
	
	This creates two files: coredns.key and coredns.key.pub
    b. verify below command works for root user without any prompts(because the key was added with root user):
           ssh -i /home/ubuntu/coredns.key root@<corednsHost>
5

	c. Copy coredns.key and coredns.key.pub files to /dockerdata-nfs/coredns on all Master sites	   


3. Make sure kubectl works on core-dns master

Code Block
#kubernetes cluster was installed using ubuntu, hence below does not work
root@core-dns-master:/home/ubuntu# kubectl get pods -n onap
The connection to the server localhost:8080 was refused - did you specify the right host or port?

#copy kube config using root user to /root to make it work
root@core-dns-master:/home/ubuntu# cp /home/ubuntu/.kube/ /root


#verify kubectl works from root user
root@core-dns-master:~# kubectl get pods --all-namespaces
NAMESPACE     NAME                                      READY     STATUS    RESTARTS   AGE
kube-system   coredns-7fd6694686-dnwt7                  1/1       Running   2          11d
kube-system   coredns-7fd6694686-jrj92                  1/1       Running   2          11d
kube-system   etcd-core-dns-master                      1/1       Running   2          12d
kube-system   kube-apiserver-core-dns-master            1/1       Running   10         12d
kube-system   kube-controller-manager-core-dns-master   1/1       Running   8          12d
kube-system   kube-proxy-j4wlv                          1/1       Running   2          12d
kube-system   kube-proxy-q74fc                          1/1       Running   2          12d
kube-system   kube-scheduler-core-dns-master            1/1       Running   7          12d
kube-system   tiller-deploy-84f4c8bb78-skvlp            1/1       Running   2          12d
kube-system   weave-net-lq4ls                           2/2       Running   7          12d
kube-system   weave-net-rm6z4                           2/2       Running   15         12d


6. Execute sdnc.dnsswitch makeActive script from Site A or Site BB  to trigger manual failover and DNSSwitch

Code Block
root@k8s-master:/home/ubuntu# ./sdnc.dnsswitch
Note :- execute sdnc.dnsswitch as rootmakeActive


7. You may verify the logs on core-dns master :

Code Block
root@core-dns-master:~$ ll *.log
-rw-r--r-- 1 root root 12002 May  1 11:28 dnsSwitch.log
root@core-dns-master:~$

root@core-dns-master:~$ cat dnsSwitch.log
Fri Apr 27 09:16:10 EDT 2018 script called from site: 10.147.113.136
Fri Apr 27 09:16:10 EDT 2018 logging current dns entry
Server:         10.96.0.10
Address:        10.96.0.10#53

Name:   sdnc.example.com
Address: 10.147.112.139

Fri Apr 27 09:16:10 EDT 2018 editing dns zone
Fri Apr 27 09:16:10 EDT 2018 verify if dns domain address exist in configuration for given app: sdnc
Fri Apr 27 09:16:10 EDT 2018 dns domain address was found
Fri Apr 27 09:16:10 EDT 2018 dns zone file edited
Fri Apr 27 09:16:10 EDT 2018 editing coredns configmap
configmap "coredns" deleted
configmap "coredns" created
Fri Apr 27 09:16:11 EDT 2018 coredns configmap edited
Fri Apr 27 09:16:11 EDT 2018 waiting for dns cache time
Fri Apr 27 09:17:01 EDT 2018 sending refresh signal for coredns configmap
Fri Apr 27 09:17:01 EDT 2018 Completed executing sdnc.dnsswitch on host: core-dns-master