Plural ensures the state of all installed applications are stored in a git repository, under a common format. A typical workspace should have a similar layout to the following example (Please click to expand):
📦installation-repository
┣ 📂app-one
┃ ┣ 📂.plural
┃ ┃ ┣ 📜NONCE┃ ┃ ┗ 📜ONCE
┃ ┣ 📂crds
┃ ┃ ┣ 📜app-one-crds.yaml┃ ┣ 📂helm
┃ ┃ ┗ 📂app-one
┃ ┃ ┃ ┣ 📂charts
┃ ┃ ┃ ┃ ┣ 📜app-one-0.1.0.tgz┃ ┃ ┃ ┣ 📂templates
┃ ┃ ┃ ┃ ┣ 📜license.yaml┃ ┃ ┃ ┃ ┣ 📜NOTES.txt
┃ ┃ ┃ ┃ ┣ 📜application.yaml
┃ ┃ ┃ ┃ ┗ 📜secret.yaml
┃ ┃ ┃ ┗ 📜values.yaml
┃ ┣ 📂terraform
┃ ┃ ┣ 📂app-one-tf-module
┃ ┃ ┃ ┣ 📜main.tf┃ ┃ ┃ ┣ 📜outputs.tf
┃ ┃ ┃ ┣ 📜variables.tf
┃ ┃ ┗ 📜outputs.tf
┃ ┣ 📜build.hcl
┃ ┣ 📜deploy.hcl
┃ ┣ 📜diff.hcl
┃ ┣ 📜manifest.yaml
┃ ┗ 📜output.yaml
┣ 📂app-two
┃ ┣ 📂.plural
┃ ┃ ┣ 📜NONCE┃ ┃ ┗ 📜ONCE
┃ ┣ 📂crds
┃ ┃ ┣ 📜app-two-crds.yaml┃ ┣ 📂helm
┃ ┃ ┗ 📂app-two
┃ ┃ ┃ ┣ 📂charts
┃ ┃ ┃ ┃ ┣ 📜app-two-0.1.0.tgz┃ ┃ ┃ ┣ 📂templates
┃ ┃ ┃ ┃ ┣ 📜license.yaml┃ ┃ ┃ ┃ ┣ 📜NOTES.txt
┃ ┃ ┃ ┃ ┣ 📜application.yaml
┃ ┃ ┃ ┃ ┗ 📜secret.yaml
┃ ┃ ┃ ┗ 📜values.yaml
┃ ┣ 📂terraform
┃ ┃ ┣ 📂app-two-tf-module
┃ ┃ ┃ ┣ 📜main.tf┃ ┃ ┃ ┣ 📜outputs.tf
┃ ┃ ┃ ┣ 📜variables.tf
┃ ┃ ┗ 📜outputs.tf
┃ ┣ 📜build.hcl
┃ ┣ 📜deploy.hcl
┃ ┣ 📜diff.hcl
┃ ┣ 📜manifest.yaml
┃ ┗ 📜output.yaml
┣ 📜.gitignore
┣ 📜context.yaml
┗ 📜workspace.yaml
This is where the results to all bundle installs are stored. It can also be manually extended if there's some customization that a user wants to apply beyond what the bundle provided.
Stores base cloud provider setup for this repository. It uses a general format modeled after GCP, but the mapping to the resources in other clouds is pretty straightforward.
On each app installation, you have the option of inheriting this setup, or reconfiguring for the specific app.
The git attributes file specifies the filters that drive secret encryption. This file should not be tampered with, unless the user is confident they know what they're doing.
We'll also add additional .gitattributes as different modules add or create secrets that might be stored in the repo (eg ssh keys).
When installing an application with Plural, the Kubernetes resources are deployed using Helm. The Plural CLI creates a wrapper Helm chart in the deployment workspace for each application that wraps the chart(s) downloaded from the Plural API.
The values.yaml file contains all the configurations specific for this deployment.
The values.yaml file is created during the plural build command by the template engine
within the Plural CLI using (among other things) the user inputs from the
plural bundle install <app> <bundle> command.
The cloud resources required for an application installed through Plural are created using Terraform.
The main entrypoint for the terraform configuration is the terraform/main.tf.
Similar to the values.yaml file for Helm, the terraform/main.tf is created during the
plural build command by the template engine within the Plural CLI.
The build/deploy/diff files manage two things:
- the steps needed to build or apply a specific repository in plural
- change detection between runs
We'll automatically sha whatever subtree is needed to run any stage in the file, and if there's no detectable change, ignore the command. This is especially useful for avoiding slow, unneeded terraform commands
This file tells the Plural CLI to ignore certain paths during change detection,
is similar to a .gitignore file for Git.
Metadata about the plural application.
Outputs from various tools (Terraform, Helm, etc) that can be imported and used in other applications.
The crds directory contains all the CRDs for the Helm chart.
We manage these through the Plural CLI rather than Helm so we can do more advanced change detection.
The .plural folder within each application folder container two files: ONCE and NONCE.
These files are used as targets for change detection by the Plural CLI.
The NONCE file is used for commands that should be executed a single time after a plural build command.
The ONCE file is used for commands that should only be executed the first time an application is deployed.