Environment Discovery

Managing your IaC through env0 provides many advantages, but manual Environment creation and deployment can be tedious and error-prone at scale. Environment Discovery eliminates these pain points by automatically creating and destroying environments based on your pull requests. Leverage preconfigured directory structures to streamline your workflow, save time, and reduce errors, allowing your team to focus on innovation.

Setting Up an Environment Discovery

Get started

In this example, we will create a Terragrunt configuration based on Terragrunt Infrastructure Example repository.

First things first, you will need to create a one time configuration of your discovery settings. This is a per Project configuration.

Under Project Settings select Environment Discovery tab. To continue, click Get Started.

Choose The Infrastructure

Just like setting up a Template, you will have to pick the type of infrastructure you are using, and click Next

Configure Your Repository

Next, choose the desired Git provider, and configure the repository you would like to discover from and click Next

Configure the Environment Mapping

The final step is crucial as it defines the structure of your project. In this section, you will specify the layout of your project, including which Environments will be created, how they will be named, and where they will be located within env0

Let's break it down step by step:

Match Environments Glob

You will need to define your project structure using a multi-glob pattern. Any match to this pattern will trigger the creation and planning of an environment in env0. In this example, we aim to create an env0 Environment for any terragrunt.hcl file that is not located under the _envcommon folder

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Glob pattern

Glob patterns specify sets of filenames with wildcard characters. For example, \*.tf or prod/\*\*

For example, you can configure pattern like src/prod/**/*.tf
In this case, we will create new env0 Environments only if the new main.tf is located under src/prod/...

We also support extglob patterns with that you can write pattern which ignores files or use a list of folders.
Note that for extglob, when using OR/AND statements, make sure to wrap each option with parentheses, for example:

• !(prod/us-east-1/\*\*)+(dev/us-east-1/**|dev/us-west-2/main.tf)
  This means we will listen to any change in dev/us-east-1 and dev/us-west-2/main.tf, and ignore changes under prod/us-east-1. (Recommend including exclusions first.)
• +(Terraform/!(prod)**|Terragrunt/dev/**)
  Listen for any changes in Terraform or Terragrunt/dev but ignore any changes in Terraform/prod

Root Path

The root path configuration defines the starting point from which env0 will generate environments. For instance, if the glob pattern is set to src/prod/storage/*_/_.tf, and the discovered file is src/prod/storage/environment0/main.tf, with the root path configured as src/prod, env0 will exclude the root path from the full path of the discovered main.tf file. Therefore, it will be treated as storage/environment0/main.tf when determining where to place the environment.

Deploy Discovered Environments on

In the next section, you'll be able to set the Continuous Deployment and PR Plan settings which your Environments will be created with.

Changes on Template Directory files - The Environment will only plan / deploy on changes to the directory matched by the main glob pattern

Changes by file filter pattern - The Environment will plan / deploy on changes matching the given multi glob pattern.

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Custom Glob Variables

We also support using custom string templates that are set during runtime -

• env0_template_dir_path - The entire template path.
• env0_template_dir_name - The name of the directory of the template files.
• env0_template_dir_ancestors - Will be interpolated with each ancestor directory up the template path, and is meant to be used in an extended glob expression. It is most useful for picking up configuration files up the path, like in a Terragrunt style repository. ** NOTE: this should NOT be used with a file extension
  e.g: If the template directory is non-prod/us-east-1/dev/postgres, then it will be interpolated as `non-prod/|non-prod/us-east-1/|non-prod/us-east-1/dev/|non-prod/us-east-1/dev/postgres/*`.

example usage:
+((_envcommon/${env0_template_dir_name}/**)|(${env0_template_dir_path}/**)|${env0_template_dir_ancestors}) which means match everything under the path defined in the environment's template and match any changes under _envcommon matching the template dir name, and any files changes in the ancestors (or parent) folders.

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Heads Up

In case the even that the environment creation glob and the environment CD / PR plan glob do not match, it is possible that the changes that trigger the Environment creation won't trigger the initial PR Plan (see section below for more info)

In our example, we would like other changes to trigger a plan, and not only those under the Template Directory.

Environment Placement

This section will let you choose the Environment placement strategy within your project.

Let's consider a env0 Project hierarchy of

- environment-discovery
- - prod
- - non-prod

Create Environments in this project - Will not consider Sub-Projects when creating the environments. In our case, a PR to change prod/us-east-1/prod/mysql will create an Environment called us-east-1/prod/mysql

Create Environments in the closest matching Sub-Project path, matching the directory path - Will consider the closest Sub-Project to match the path, for example a PR to change prod/us-east-1/prod/mysql will create an Environment called us-east-1/prod/mysql on prod Sub-Project

Workspace Naming

Here we can choose to either use default as the workspace names or derive it from the Environment's name

Click Done and you should be greeted with the success screen if all went well.

Using Environment Discovery

After configured, using environment discovery is easy as opening and merging a pull request.

1. Create a branch with desired changes and open a PR.

   

2. Navigate to the relevant Project or Sub-Project in env0 or click the env0 bot comment (Remember: multiple environments can be created via a single PR)

   

3. In the Deployments tab, you'll be able to see the initial PR Plan env0 ran on your code.

   

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   Closing a PR

   Closing a PR will archive the Never Deployed Environment. Note, that for Bitbucket Cloud and Bitbucket Server automatic archival is not supported, and you will have to do so manually.

4. After the plan has been reviewed and merged, env0 will trigger a deployment for that Environment.