Terraform Provisioner for Habitat

A Terraform provisioner to install and configure Habitat

This is a development repository for adding features to the provisioner. Primary goal at the moment is to add support for installation and configuration of Habitat on Windows.

Contents

• Installation
• Example
• Documentation

Installation

Requirements

This Habitat provisioner is based on Terraform, this means that you need

• Terraform >=0.11.11
• You must have winrm access to Windows machine with admin rights for installation

Installation from binaries (recommended)

The recommended way to install Habitat provisioner is to use the binary distributions from the Releases page. The packages are available for macOS, Windows and Linux.

Download and uncompress the latest release for your OS. This example uses the macOS binary.

> wget https://github.com/chef-partners/terraform-provisioner-habitat/releases/download/0.1/terraform-provisioner-habitat_dev_v0.1_darwin_amd64.tar.gz
> tar -xvf terraform-provisioner-habitat_dev*.tar.gz

Now copy the binary to the Terraform's plugins folder, if is your first plugin maybe isn't present.

> mkdir -p ~/.terraform.d/plugins/
> mv terraform-provisioner-habitat_dev*/terraform-provisioner-habitat_dev* ~/.terraform.d/plugins/

Build from source

If you wish to compile the provisioner from source code, you'll first need Go installed on your machine (version >=1.11.4 is required). You'll also need to correctly setup a GOPATH, as well as adding $GOPATH/bin to your $PATH. In addition you will need to install required Terraform packages on your machine from Hashicorp Terraform repository.

Clone Provisioner repository to: $GOPATH/src/github.com/chef-partners/terraform-provisioner-habitat

cd $GOPATH/src/github.com/chef-partners/
git clone https://github.com/chef-partners/terraform-provisioner-habitat.git
cd terraform-provisioner-habitat
go build -o terraform-provisioner-habitat_dev
mv ./terraform-provisioner-habitat_dev ~/.terraform.d/plugins/terraform-provisioner-habitat_dev
chmod +x ~/.terraform.d/plugins/terraform-provisioner-habitat_dev

Example

The following example shows how to install SQL Server Habitat service on a Windows machine

provisioner "habitat_dev" {
    peer = ""
    
    service {
      name = "core/sqlserver"
      topology = "standalone"
    }
    
    connection {
      type = "winrm"
      timeout = "10m"
      user = "${var.win_username}"
      password = "${var.win_password}"
    }
}

To attach this SQL server with an application as Habitat peer and establish service binding, the following can be used in the application server's provisioning

provisioner "habitat_dev" {
    peer = "${aws_instance.ms-hab-sqlserver.private_ip}"
    
    service {
      name = "mwrock/contosouniversity"
      topology = "standalone"
      binds = [
        "database:sqlserver.default"
      ]
    }

    connection {
      type = "winrm"
      timeout = "15m"
      user = "${var.win_username}"
      password = "${var.win_password}"
    }
  }

Documentation

Arguments

There are 2 configuration levels, supervisor and service. Values placed directly within the provisioner block are supervisor configs, and values placed inside a service block are service configs. Services can also take a bind block to configure runtime bindings.

Supervisor

• permanent_peer: Whether this supervisor should be marked as a permanent peer. Optional (Defaults to false)
• listen_gossip: IP and port to listen for gossip traffic. Optional (Defaults to "0.0.0.0:9638")
• listen_http: IP and port for the HTTP API service. Optional (Defaults to "0.0.0.0:9631")
• peer: IP or FQDN of a supervisor instance to peer with. Optional (Defaults to none)
• ring_key: Key for encrypting the supervisor ring traffic. Optional (Defaults to none)
• skip_install: Skips the installation Habitat, if it's being installed another way. Optional (Defaults to no)

Service

• name: A package identifier of the Habitat package to start (eg core/nginx, core/nginx/1.11.10 or core/nginx/1.11.10/20170215233218). Required.
• strategy: Update strategy to use. Possible values "at-once", "rolling" or "none". Optional (Defaults to "none")
• topology: Topology to start service in. Possible values "standalone" or "leader". Optional (Defaults to "standalone")
• channel: Channel in a remote depot to watch for package updates. Optional
• group: Service group to join. Optional (Defaults to "default")
• url: URL of the remote Depot to watch. Optional (Defaults to the public depot)
• binds: Array of binding statements (eg "backend:nginx.default"). Optional
• user_toml: TOML formatted user configuration for the service. Easiest to source from a file (eg user_toml = "${file("conf/redis.toml")}"). Optional

Bind

• service: The target service to bind.
• group: The target group to bind.
• alias: The alias for the binding.

**This format for declaring bindings is optional. It can be used in place of or along side the binds = ["alias:service.group"] method of declaring binds. This format might be easier to manage when populating one or more of the bind parameters dynamically.

Example:

service {
  name = "core/haproxy"
  group = "${var.environment}"

  bind {
    alias = "backend"
    service = "nginx"
    group = "${var.environment}"
  }
}

This block will generate the option --bind backend:nginx.default when starting the haproxy service.

Kudos & Prior Art

This provisioner is heavily inspired by prior art from nsdavidson/terraform-provision-habitat later added to Terraform.