DevOps Classroom Series – 10/Apr/2020

Scenario: Add two more chef-client nodes to the hosted chef

• To do the bootstrap from workstation
  • Machine with ipaddress, username and password
    • Ensure you have a Valid chef-repo, to verify cd into chef repo and execute knife node list
    • Build a knife bootstrap command

    knife bootstrap <ipaddress> -U <username> -P <password> --sudo -N '<name of node>
    

  • Machine with ipaddress, username and pem file
    • Ensure you have a Valid chef-repo, to verify cd into chef repo and execute knife node list
    • Build a knife bootstrap command

     knife bootstrap <ipaddress> -U <username> -i <path to identity file> --sudo -N '<name of node>
    

• To verify the chef-client on the node, execute the following commands

sudo chef-client

• Once the bootstrap is done, chef-client nodes communicate with chef server every 30 mins. The process where nodes communicate with chef server and do the work assigned is called as convergance.

• During convergance internally sudo chef-client command is executed

• A typical convergance run looks as shown below

• What acutally happens during convergance (Not a complete story)?

  • Chef server is communicated by chef node
  • Chef server replies back on what has to be executed on that node (run_list)
  • Chef Server maintains a list of what recipes have to be executed on every node and that list is called as run list
  • Chef Client gets the recipes and executes them