Iago

Iago (Infrastructure As GO) is an experimental software deployment framework. Iago scripts are written in Go. This means that Iago scripts can be compiled into a simple binary with no dependencies.

Basic API

Iago executes tasks on groups of hosts. Tasks describe actions to be performed to each individual host, and how to handle errors.

  // var g iago.Group; this is a set of iago.Host instances that the task will be applied to.
  g.Run(iago.Task{
    Name: "Example Task",
    // Here we specify the iago.Func action, which is an action that executes the function that we give it.
    // The function is executed concurrently for each host in the group.
    Action: iago.Func(func(ctx context.Context, host iago.Host) error {
      log.Println(host.Name())
      return nil
    }),
    // The OnError handler decides how any errors returned by the actions should be handled.
    // Any errors are automatically wrapped in a iago.TaskError before they are given to the handler.
    OnError: iago.Panic,
  })

We currently support connecting to remote hosts via SSH, but support for other connection methods can be added by implementing the iago.Host interface.

Example

The following example downloads a file from each remote host. This example uses the iagotest package, which spawns docker containers and connects to them with SSH for testing. The iago.DialSSH or iago.NewSSHGroup can be used to connect to existing SSH servers.

func TestIago(t *testing.T) {
  dir, _ := os.Getwd()

  // The iagotest package provides a helper function that automatically
  // builds and starts docker containers with an exposed SSH port for testing.
  g := iagotest.CreateSSHGroup(t, 4)

  g.Run(iago.Task{
    Name: "Download files",
    Action: iago.Download{
      Src:  iago.P("/etc/os-release"),
      Dest: iago.P("os").RelativeTo(dir),
      Mode: 0644,
    },
    OnError: iago.Panic,
  })
}

TODO

• Improve the reading of ssh_config files
  • Should support reading the public key files (it doesn't look like the ssher package supports this fully)
• Prompt the user when verifying host keys?
• Improve logging
  • Logging for tasks as they are running
  • Progress -- how many hosts have finished a task