c12s-kubespray/contrib/terraform/aws/README.md
Jean-Marie F ca8a9c600a Terraform - Remove the need for region specific reference data (#1962)
* Dynamically retrieve aws_bastion_ami latest reference by querying AWS rather than hard coded

* Dynamically retrieve the list of availability_zones instead of needing to have them hard coded

* Limit availability zones to first 2, using slice extrapolation function

* Replace the need for hardcoded variable "aws_cluster_ami" by the data provided by Terraform

* Move ami choosing to vars, so people don't need to edit create infrastructure if they want another vendor image (as suggested by @atoms)

* Make name of the data block agnostic of distribution, given there are more than one distribution supported

* Add documentation about other distros being supported and what to change in which location to make these changes
2017-11-30 15:27:52 +00:00

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## Kubernetes on AWS with Terraform
**Overview:**
This project will create:
* VPC with Public and Private Subnets in # Availability Zones
* Bastion Hosts and NAT Gateways in the Public Subnet
* A dynamic number of masters, etcd, and worker nodes in the Private Subnet
* even distributed over the # of Availability Zones
* AWS ELB in the Public Subnet for accessing the Kubernetes API from the internet
**Requirements**
- Terraform 0.8.7 or newer
**How to Use:**
- Export the variables for your AWS credentials or edit `credentials.tfvars`:
```
export AWS_ACCESS_KEY_ID="www"
export AWS_SECRET_ACCESS_KEY ="xxx"
export AWS_SSH_KEY_NAME="yyy"
export AWS_DEFAULT_REGION="zzz"
```
- Rename `contrib/terraform/aws/terraform.tfvars.example` to `terraform.tfvars`
- Update `contrib/terraform/aws/terraform.tfvars` with your data. By default, the Terraform scripts use CoreOS as base image. If you want to change this behaviour, see note "Using other distrib than CoreOs" below.
- Allocate a new AWS Elastic IP. Use this for your `loadbalancer_apiserver_address` value (below)
- Create an AWS EC2 SSH Key
- Run with `terraform apply --var-file="credentials.tfvars"` or `terraform apply` depending if you exported your AWS credentials
Example:
```commandline
terraform apply -var-file=credentials.tfvars -var 'loadbalancer_apiserver_address=34.212.228.77'
```
- Terraform automatically creates an Ansible Inventory file called `hosts` with the created infrastructure in the directory `inventory`
- Ansible will automatically generate an ssh config file for your bastion hosts. To connect to hosts with ssh using bastion host use generated ssh-bastion.conf.
Ansible automatically detects bastion and changes ssh_args
```commandline
ssh -F ./ssh-bastion.conf user@$ip
```
- Once the infrastructure is created, you can run the kubespray playbooks and supply inventory/hosts with the `-i` flag.
Example (this one assumes you are using CoreOS)
```commandline
ansible-playbook -i ./inventory/hosts ./cluster.yml -e ansible_ssh_user=core -e bootstrap_os=coreos -b --become-user=root --flush-cache
```
***Using other distrib than CoreOs***
If you want to use another distribution than CoreOS, you can modify the search filters of the 'data "aws_ami" "distro"' in variables.tf.
For example, to use:
- Debian Jessie, replace 'data "aws_ami" "distro"' in variables.tf with
data "aws_ami" "distro" {
most_recent = true
filter {
name = "name"
values = ["debian-jessie-amd64-hvm-*"]
}
filter {
name = "virtualization-type"
values = ["hvm"]
}
owners = ["379101102735"]
}
- Ubuntu 16.04, replace 'data "aws_ami" "distro"' in variables.tf with
data "aws_ami" "distro" {
most_recent = true
filter {
name = "name"
values = ["ubuntu/images/hvm-ssd/ubuntu-xenial-16.04-amd64-*"]
}
filter {
name = "virtualization-type"
values = ["hvm"]
}
owners = ["099720109477"]
}
- Centos 7, replace 'data "aws_ami" "distro"' in variables.tf with
data "aws_ami" "distro" {
most_recent = true
filter {
name = "name"
values = ["dcos-centos7-*"]
}
filter {
name = "virtualization-type"
values = ["hvm"]
}
owners = ["688023202711"]
}
**Troubleshooting**
***Remaining AWS IAM Instance Profile***:
If the cluster was destroyed without using Terraform it is possible that
the AWS IAM Instance Profiles still remain. To delete them you can use
the `AWS CLI` with the following command:
```
aws iam delete-instance-profile --region <region_name> --instance-profile-name <profile_name>
```
***Ansible Inventory doesnt get created:***
It could happen that Terraform doesnt create an Ansible Inventory file automatically. If this is the case copy the output after `inventory=` and create a file named `hosts`in the directory `inventory` and paste the inventory into the file.
**Architecture**
Pictured is an AWS Infrastructure created with this Terraform project distributed over two Availability Zones.
![AWS Infrastructure with Terraform ](docs/aws_kubespray.png)