prometheus-terraform

This project is comprised of a terraform script which when run will create the necessary infrastructure for a prometheus instance

Prerequisites

• Terraform; tested with version v0.12.31,
• AWS Command Line Interface 1.16.155+

AWS Credentials

AWS credentials are selected based on the value of the AWS_PROFILE environmental variable and AWS CLI profile configuration. It is not possible to run the Terraform scripts without this variable set. Either export this in your current shell environment or permanently add it to your ~/.bash_profile or equivalent.

Terraform

These scripts make use of Infrastructure as Code (IaC) and depend on Terraform as the primary tool for managing and applying infrastructural changes. Documentation can be found for this tool on the Terraform Guides webpage.

Configuration

Terraform Variables

The following variables are required:

Variable	Description	Examples
aws_region	AWS region to create the infrastructure	eu-west-2
environment	AWS environment in which to create the infrastructure	development
instance_count	How many instances you want	1
prometheus_metrics_port	The desired port	9999
ssh_keyname	The keyname of the ssh profile you want to use	my-environment
tag_name_regex	Prometheus tag	my-instance-tag
dns_zone_id	The DNS zone id you want to use	12345
dns_zone_name	The DNS zone name you want to use	myzone.abc.com

State

Terraform state is stored remotely in an S3 bucket. The region, state bucket name, and workspace prefix are determined dynamically based on the configuration of the host environment and the AWS_PROFILE environment variable.

Environment-specific configuration

Environment-specific configuration tasks are performed after instance launch using cloud-init directives from user data. Terraform templates have been setup for individual files that require provisioning after instance launch and suitable variable interpolations have been added where required.

The following structure has been implemented for cloud-init configuration for each applicable Terraform module:

groups
  ├── prometheus
  │    ├── module-prometheus       - directory for EC2 configuration, including cloud-init
  │    │    ├── cloud-init         
  │    │    │   ├── files          - directory for YAML files that contain no variable interpolations
  │    │    │   └── templates      - directory for templates that include variable interpolations
  │    │    ├── cloud-init.tf      - main cloud-init configuration definition for this module
  │    │    ├── ec2.tf             - configuration file for ec2 instances
  │    │    ├── route53.tf         - configuration file for route 53 records
  │    │    ├── security-groups.tf - configuration file for security groups
  │    │    └── variables          - module variables definitions
  │    └── profiles                - folder for profile configuration  
  └── ...


## Applying infrastructure changes

The Prometheus-terraform scripts can be run using the Terraform-runner.

View usage instructions for the terraform-runner on the internal Confluence site