14-zero-downtime-deployment

Terraform Zero-Downtime Deployment example

This folder contains a zero-downtime deployment example of a Terraform installed on your computer file on AWS (Amazon Web Services).

It shows how to deploy a new AMI across the cluster when you have made changes to your code. In addition, you control the text the User Data script return from its one-liner HTTP server.

Furthermore, it shows how to develop (not duplicating code) web server clusters in different environments using a module.

The environments are:

• Staging (stage)
• Production (prod)

This is the file layout in this repo:

live
    ├── global
    │       └── s3/
    │           ├── main.tf
    │           └── (etc)
    │
    ├── stage
    │       ├── services/
    │       │   └── webserver-cluster/
    │       │       ├── main.tf
    │       │       └── (etc)
    │       └── data-stores/
    │           └── mysql/
    │               ├── main.tf
    │               └── (etc)
    │
    └── prod
            ├── services/
            │   └── webserver-cluster/
            │       ├── main.tf
            │       └── (etc)
            └── data-stores/
                └── mysql/
                    ├── main.tf
                    └── (etc)

modules
    └── services/
        └── webserver-cluster/
            ├── main.tf
            └── (etc)

It uses in common for both environments:

• Terraform Remote State example: live/global/s3
• Terraform Web Server Cluster module example: modules/services/webserver-cluster

It uses for staging environment:

• Terraform MySQL on RDS example (staging environment): live/stage/data-stores/mysql
• Terraform Web Server Cluster example (staging environment): live/stage/services/webserver-cluster

It uses for production environment:

• Terraform MySQL on RDS example (production environment): live/prod/data-stores/mysql
• Terraform Web Server Cluster example (production environment): live/prod/services/webserver-cluster

Requirements

• You must have Terraform installed on your computer.
• You must have an AWS (Amazon Web Services) account.
• It uses the Terraform AWS Provider that interacts with the many resources supported by AWS through its APIs.
• This code was written for Terraform 0.10.x.

Using the code

Configure your AWS access keys.

Use Terraform Remote State example for creating the remote state bucket. See: live/global/s3

Use Terraform module example for Web Server Cluster example in the staging environment and Web Server Cluster example in the production environment. See: modules/services/webserver-cluster

Use Terraform MySQL on RDS example for creating a MySQL database in the staging environment. See: live/stage/data-stores/mysql

Use Terraform Web Server Cluster example for creating a web server cluster in the staging environment. See: live/stage/services/webserver-cluster

Use Terraform MySQL on RDS example for creating a MySQL database in the production environment. See: live/prod/data-stores/mysql

Use Terraform Web Server Cluster example for creating a web server cluster in the production environment. See: live/prod/services/webserver-cluster