Question 37822 in Ubuntu Question posted in
The official Ubuntu documentation can be found here.

What is the usage of local-exec provisioner? – Ubuntu

I am getting familiar with Terraform and Ansible through books. Could someone enlighten me about the following block of code?

provisioner "local-exec" { 
    command = "ansible-playbook -u ubuntu --key-file ansible-key.pem -T 300 -i '${self.public_ip},', app.yml" 
  }
Tags:

2

Answers


  1. 0

    I would interpret that as Terraform should execute a local command on the Control Node.

    Reading the documentation about local-exec Provisioner it turns out that

    The local-exec provisioner invokes a local executable after a (annot.: remote) resource is created. This invokes a process on the machine running Terraform …

    and not on the Remote Resource.

    So after Terraform has in example created a Virtual Machine, it calls an Ansible playbook to proceed further on it.

    Login or Signup to reply.
  2. 0

    The short answer is local-exec is for anything you want to do on your local machine instead of the remote machine.

    You can do a bunch of different things:

    • write an ssh key into your ~/.ssh to access the server
    • run a sleep 30 or something to make sure the next commands wait a bit for your machine to provision
    • write logs to your local directory (last run, date completed, etc.)
    • write some env_vars to your local machine you can use to access the machine
    • the ansible example you provided

    FYI, hashicorp hates local- and remote- exec. If you talk to one of their devs, they will tell you that it is a necessary evil. Other than maybe a sleep or write this or that, avoid it for any stateful data.

    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search