This is simple PoC using Terraform to bring up a number of EC2 servers to run Docker with a contrived containerized RESTful API. Nothing particularly original here, just a combination of various tutorials/projects to help me get familiar with these technologies.
Get an AWS account.
Ensure your workstations has Terraform installed.
You can install terraform using Homebrew on a Mac using brew update && brew install terraform.
Terraform e.g. brew install terraform.
See Terraform Getting Started Guide for more details.
You need an SSH key to access AWS EC2 instances. Use the chmod command to make sure your private key file isn't publicly viewable. For example, if the name of your private key file is my-key-pair.pem, use the following command:
chmod 400 /path/my-key-pair.pem
Once Terraform has done it's job you'll be able to use the ssh command to connect to EC2 instances. You'll specify the private key (.pem) file and user_name@public_dns_name. For Amazon Linux, the user name is ec2-user. For RHEL5, the user name is either root or ec2-user. For Ubuntu, the user name is ubuntu. For Fedora, the user name is either fedora or ec2-user. For SUSE Linux, the user name is either root or ec2-user. Otherwise, if ec2-user and root don't work, check with your AMI provider.
The terraform provider for AWS will need credentials, these can be read from the following environment variables:
AWS_ACCESS_KEY_ID
AWS_SECRET_ACCESS_KEK
We will set these as specific variables in terraform.tfvars
Copy terraform.tfvars.example to terraform.tfvars and set the variables to specific values for your AWS account and applicaiton details, as appropriate.
I am using an Amazon ECS-Optimized Amazon Linux AMI - EC2 charges for Micro instances are free for up to 750 hours a month if you qualify for the AWS Free Tier
To check what resources will be created:
$ terraform plan
To create EC2 instances and their dependencies:
$ terraform apply
To destroy all:
$ terraform destroy
_If you run into issues the output can often be a little opaque - well it is when you're starting out. Terraform has detailed logs which can be enabled by setting the TF_LOG environmental variable to any value. This will cause detailed logs to appear on stderr.
You can set TF_LOG to one of the log levels TRACE, DEBUG, INFO, WARN or ERROR to change the verbosity of the logs. TRACE is the most verbose and it is the default if TF_LOG is set to something other than a log level name_
Paul Feaviour 2015