terraform-provider-sshcommand

SSH Command Terraform Provider

This provider allow to execute commands remotely via SSH and capture the output from them.

This provider uses built-in crypto/ssh Golang library to act as a SSH Client. Currently the implementation is very limited, but can be easily extended.

Table of contents

• Requirements
• Building
• Installing the provider
• Resources
• Example usage
• Authors

Requirements

• Terraform 0.11.x
• Go 1.11.x

Building

For testing builds, simply run docker build ., which will download all dependencies, run build, test and linter.

For local builds, simply follow the steps from Dockerfile.

Installing the provider

After building the provider, install it using the Terraform instructions for installing a third party provider.

Resources

sshcommand_command

This resource executes given command on remote system and stores it's output in Terraform.

Parameters

• host - Hostname to connect.
• private_key - SSH private key used for authentication (SSH Agent support is not implemented).
• command - Command to execute.
• user - User used for SSH log in. Defaults value is root.
• port - Port to open SSH connection. Defaults is 22.
• connection_timeout - Timeout for opening TCP connection. This should be decreased when using retry. Defaults is 5m.
• retry - If this is set to true, plugin will retry to connect/execute command until retry_timeout is reached. Defaults to 'false'.
• retry_timeout - Time after which retry logic should time out. Defaults to 5m.
• retry_interval - Specifies how long to wait between each attempt. Defaults to 5s.
• ignore_execute_errors - If true, resource will be created even if executed command returns non 0 exit code. Defaults to false.

Attributes

• result - Output of executed command.

Example usage

provider "sshcommand" {
  version = "~> 0.1.0"
}

output "example" {
  value = "\n${sshcommand_command.ssh_host_fingerprints.result}"
}

resource "sshcommand_command" "ssh_host_fingerprints" {
  host               = "example"
  command            = "ssh-keygen -r $(hostname -f) | cut -d' ' -f4-6"
  private_key        = file(".ssh/id_rsa")
}

# Reboot server after OS installation
resource "sshcommand_command" "reboot" {
  host                  = var.node_ip
  command               = "reboot"
  private_key           = var.ssh_private_key
  ignore_execute_errors = true
  depends_on            = [ "null_resource.os_install" ]
}

# Make sure you SSH into correct system
resource "sshcommand_command" "wait_for_os" {
  host           = var.node_ip
  command        = "grep ID=flatcar /etc/os-release"
  private_key    = var.ssh_private_key
  # If grep fails or SSH connection gets refused, resource will be trying again.
  retry          = true
  retry_interval = "1s"
}

Authors

• Mateusz Gozdek - Initial work - invidian