Add node to cluster

Once a test chef-bach cluster is up and running users can manually add new nodes to the cluster by following these steps.

• On the hypervisor host run only the function create_cluster_VMs in vbox_create.sh script file with these changes.
• Update the for look in the function to include the new node names. For e.g. if bcpc-vm4 need to be added to the cluster as a new node change the for loop to

for vm in bcpc-vm4; do ... 

which is originally coded as

for vm in bcpc-vm1 bcpc-vm2 bcpc-vm3; do ...

• Comment the following lines at the end of vbox_create.sh script.

...
if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
  ##download_VM_files
  ##create_bootstrap_VM
  create_cluster_VMs
  ##install_cluster
fi
...

• The assumption is that the user will be executing from the chef-bcpc directory from where the original cluster was created from and there has been no changes.
• Execute the modified vbox_create.sh script which will create the new virtual machine(s).
• We need to identify the id of NIC 1 of the newly created VM(s)
• Using bcpc-vm4 as example, run vboxmanage showvminfo bcpc-vm4 | grep 'NIC 1' on the hypervisor host which will generate the output similar to the following

NIC 1:           MAC: 0800276DB8F7, Attachment: Host-only Interface 'vboxnet0', Cable connected: on, Trace: off (file: none), Type: 82543GC, Reported speed: 0 Mbps, Boot priority: 0, Promisc Policy: deny, Bandwidth group: none

• Note the MAC: value for NIC 1 and logon to the bootstrap host for the cluster.
• Update the cluster.txt file in the bootstrap node with the details for the new VM(s). In the case of BCPC-VM4 which is going to be a single node ZooKeeper & Kafka server, the following will be the new entry in cluster.txt

bcpc-vm4 08:00:27:6D:B8:F7 10.0.100.14 - bcpc.example.com role[BCPC-Kafka-Head-Zookeeper],role[BCPC-Kafka-Head-Server] 

• On the bootstrap node, run the cluster-enroll-cobbler.sh to add new nodes to cobbler

cluster-enroll-cobbler.sh add bcpc-vm4 

• Once the VM(s) are enrolled, power on the VM(s) which need to be done from the hypervisor host. For e.g.

vboxmanage startvm bcpc-vm4 --type=headless 

• When the VM(s) are up which take a bit of time since OS gets installed the first time, run cluster assign roles script from the bootstrap node to install the required components on the VMs through chef-client.

cluster-assign-roles.sh Test-Laptop hadoop bcpc-vm4 

This will get a new VM node added to the cluster.