Terraform Provider Development

The ins and outs of developping a custom Terraform Provider

Presentation given at the Belgium Hashicorp User Group Meeting on Wednesday 28 March 2018

1. Terraform Provider Development Ringo De Smet Maintainer of terraform-provider-xenserver
2. Agenda • Runtime Model • Bootstrapping a plugin • Datasources & Resources • Code structuring • Testing • Distribution • Some pointers … and one more thing!
3. Runtime Model All v0.10 and up!
4. Runtime Model: tf init terraform terraform-provider-xenserver terraform-provider-mysql Download Download
5. Runtime Model: tf plan terraform terraform-provider-xenserver terraform-provider-mysql RPC RPC
6. Bootstrapping a plugin
7. Exposing all config options for the provider block supported datasources supported resources callback function to configure the provider, e.g. connection
8. Provider Initialisation
9. Provider Initialisation
10. Provider Initialisation
11. Datasources & Resources
12. Datasources
13. Datasources
14. Resources
15. Resources
16. Code structuring Split client SDK from Terraform provider sources, e.g. AWS https://github.com/aws/aws-sdk-go https://github.com/terraform-providers/terraform-provider-aws XenServer https://github.com/ringods/go-xen-api-client https://github.com/ringods/terraform-provider-xenserver
17. Testing • No unit testing • Terraform core is unit tested • Your client SDK is (or should be) tested • Acceptance Testing • Starts the provider under test • Real resources in use, possibly cost involved (AWS, …) • System Testing • kitchen-terraform • test full Terraform setups with tools like serverspec
18. Acceptance Testing
19. Acceptance Testing
20. Acceptance Testing
21. Distribution • Supported providers are automatically downloaded • Not yet so for third-party providers • Download manually • Put in ~/.terraform.d/plugins • Versioning: terraform-provider-vX.Y.Z • Support discussed in hashicorp/terraform#15252
22. Information Pointers • Terraform Internals • Terraform Providers • Terraform Provider Versioning • Chat: https://gitter.im/hashicorp-terraform/Lobby
23. How to keep 3rd party providers well maintained?
24. https://github.com/voxpupuli Community to maintain Puppet modules
25. https://github.com/chef-cookbooks Community to maintain Chef cookbooks
26. Where is the Terraform community?
27. https://github.com/terra-farm New community to maintain
 Terraform providers & modules
28. github.com/terra-farm Join us! Reach out via the issues on
 github.com/terra-farm/meta