ca8a9c600a
* 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
125 lines
3.9 KiB
Markdown
125 lines
3.9 KiB
Markdown
## Kubernetes on AWS with Terraform
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**Overview:**
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This project will create:
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* VPC with Public and Private Subnets in # Availability Zones
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* Bastion Hosts and NAT Gateways in the Public Subnet
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* A dynamic number of masters, etcd, and worker nodes in the Private Subnet
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* even distributed over the # of Availability Zones
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* AWS ELB in the Public Subnet for accessing the Kubernetes API from the internet
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**Requirements**
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- Terraform 0.8.7 or newer
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**How to Use:**
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- Export the variables for your AWS credentials or edit `credentials.tfvars`:
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```
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export AWS_ACCESS_KEY_ID="www"
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export AWS_SECRET_ACCESS_KEY ="xxx"
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export AWS_SSH_KEY_NAME="yyy"
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export AWS_DEFAULT_REGION="zzz"
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```
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- Rename `contrib/terraform/aws/terraform.tfvars.example` to `terraform.tfvars`
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- 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.
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- Allocate a new AWS Elastic IP. Use this for your `loadbalancer_apiserver_address` value (below)
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- Create an AWS EC2 SSH Key
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- Run with `terraform apply --var-file="credentials.tfvars"` or `terraform apply` depending if you exported your AWS credentials
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Example:
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```commandline
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terraform apply -var-file=credentials.tfvars -var 'loadbalancer_apiserver_address=34.212.228.77'
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```
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- Terraform automatically creates an Ansible Inventory file called `hosts` with the created infrastructure in the directory `inventory`
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- 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.
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Ansible automatically detects bastion and changes ssh_args
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```commandline
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ssh -F ./ssh-bastion.conf user@$ip
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```
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- Once the infrastructure is created, you can run the kubespray playbooks and supply inventory/hosts with the `-i` flag.
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Example (this one assumes you are using CoreOS)
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```commandline
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ansible-playbook -i ./inventory/hosts ./cluster.yml -e ansible_ssh_user=core -e bootstrap_os=coreos -b --become-user=root --flush-cache
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```
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***Using other distrib than CoreOs***
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If you want to use another distribution than CoreOS, you can modify the search filters of the 'data "aws_ami" "distro"' in variables.tf.
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For example, to use:
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- Debian Jessie, replace 'data "aws_ami" "distro"' in variables.tf with
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data "aws_ami" "distro" {
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most_recent = true
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filter {
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name = "name"
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values = ["debian-jessie-amd64-hvm-*"]
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}
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filter {
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name = "virtualization-type"
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values = ["hvm"]
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}
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owners = ["379101102735"]
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}
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- Ubuntu 16.04, replace 'data "aws_ami" "distro"' in variables.tf with
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data "aws_ami" "distro" {
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most_recent = true
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filter {
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name = "name"
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values = ["ubuntu/images/hvm-ssd/ubuntu-xenial-16.04-amd64-*"]
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}
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filter {
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name = "virtualization-type"
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values = ["hvm"]
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}
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owners = ["099720109477"]
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}
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- Centos 7, replace 'data "aws_ami" "distro"' in variables.tf with
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data "aws_ami" "distro" {
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most_recent = true
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filter {
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name = "name"
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values = ["dcos-centos7-*"]
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}
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filter {
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name = "virtualization-type"
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values = ["hvm"]
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}
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owners = ["688023202711"]
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}
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**Troubleshooting**
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***Remaining AWS IAM Instance Profile***:
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If the cluster was destroyed without using Terraform it is possible that
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the AWS IAM Instance Profiles still remain. To delete them you can use
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the `AWS CLI` with the following command:
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```
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aws iam delete-instance-profile --region <region_name> --instance-profile-name <profile_name>
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```
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***Ansible Inventory doesnt get created:***
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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.
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**Architecture**
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Pictured is an AWS Infrastructure created with this Terraform project distributed over two Availability Zones.
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