Provision log nodes with the terraform

For log infrastructure we have following vms:

elasticsearch (3 nodes):

• Standard DS4 v2 (8 cores, 28 GB memory)
• 8x1023GB disks

logstash+kibana:

• Standard DS14 v2 (16 cores, 112 GB memory)
• 5x1024GB disks

Unfortunately, all logs are collected via public IP.