Terra parity
Terra parity is made to improve productivity and quality for engineers utilizing Infrastructure as Code for building software systems.
You should be able to benefit from this extension, if the following applies to you:
- folder per environment: in infrastructure code as code repository each environment (
dev, test, prod etc.) has a dedicated folder, as opposed to approach with same code for many environments (for example when using terraform's tfvars or workspaces)
- dev/prod parity: you'd like to keep your environments as similar as possible (see https://12factor.net/dev-prod-parity)
Why? Because then the folder structure and resources code would have a lot of duplication across different environments and few for-a-good-reason differences.
Terra parity is aiming to help engineers make changes to such code a bit more robust by providing a way to quickly navigate, compare and align code of corresponding resources.
How to use
Environment paths is the only required setting. It is a set of relative paths to environments you'd like to have parity between.
Copy relative paths of your environments folders from Explorer
and add these to .vscode/settings.json:
{
"terra-parity.Environment paths": [
"path/to/dev",
"path/to/test",
"path/to/prod"
]
}
or use VS Code UI - Settings->Workspace->Extensions->Terra parity and add paths one by one with Add Item button
You could use User settings as opposed to the Workspace settings. Howeever using Workspace settings is handier in case you work with multiple IaC repositories, having different environments and paths.
Use
- Open one of the environment IaC files in Editor.
- Run Terra parity from command palette (
⇧⌘P) or use hotkey ⌃E for Mac OS or Ctrl+Alt+E for Windows & Linux.
- Terra parity will determine the opened file's environment (based on configured Environments paths) and the subpath and for every other environment will try to find the corresponding file - file located under same subpath of another environment path. Opened file's content will be compared with Corresponding file's content and the menu item will be rendered displaying the comparison result.
- In case the files contents are same, the menu will indicate it with text "Match".
Upon selection the corresponding resource file will be revealed in Explorer and opened in Editor:
- In case the files contents differ, the menu will indicate it with text "Different".
Upon selection the files comparison will be opened:
- In case the file doesn't exist on that environment, the menu will indicate it with text "Not found".
Upon selection the opened file will be copied to corresponding environment's location:
Why - Usage Example
You provision infrastructure for a web application that has three environments - dev, test and prod. Your infrastructure as code has folder dedicated to each environment. For example:
Below are examples of engineers workflows when Terra parity might be helpful
You work on feature which involves adding new resource2. After adding it on dev you'd typically want to navigate to test-env/eu-west-1/component1, create folder resource2 and create terragrunt.hcl file there.In this example this isn't a big issue to do it manually - the file could easily be found in the Explorer. However for the size of any real IaC repository navigating to the right folder, creating subfolders and file would take you some time and energy. Terra parity automates that. Upon invocation it will render menu informing you that the files are not found under on test and prod (test-env/eu-west-1/component1/resource2/terragrunt.hcl and prod-env/eu-west-1/component1/resource2/terragrunt.hcl). Choosing either menu will copy terragrunt.hcl to a corresponding location (with creation of missing folders) and open new file in Editor.
You work on feature that involves changing app1's resource1. Again, normally you'd want to first make change on dev and afterwards repeat it on test and ensure both are aligned - either are plain copied of each other or have few for-a-good-reason differences. And again, navigating to test (or prod) could be a time consuming routine, as well as calling a comparison window to ensure the change is copied properly. Terra parity automates that. Upon invocation it render menu informing you that dev-env/eu-west-1/component1/resource1/terragrunt.hcl differs from both other envifonment's corresponding resources - test-env/eu-west-1/component1/resource1/terragrunt.hcl and prod-env/eu-west-1/component1/resource1/terragrunt.hcl. Selecting either of the menus will open files comparison window, where the test or prod could be aligned with dev right in place.
When changes don't go smooth and involve multiple rounds of small changes to resource on multiple environments, you could use Terra parity to do a final alignment between corresponding resources ensure that all the needed changes are present where they need to. Invoke extension from any environment's resource to see the preview of its comparison with corresponding resource and navigate between them.
Finally you could use it to just quickly navigate between corresponding resources for whatever other reason.
