github.com/jim-minter/rp

Notice

For information relating to the generally available Azure Red Hat OpenShift v3 service, please see the following links:

• https://azure.microsoft.com/en-us/services/openshift/
• https://www.openshift.com/products/azure-openshift
• https://docs.microsoft.com/en-us/azure/openshift/
• https://docs.openshift.com/aro/welcome/index.html

Quickstarts

• If you have a whitelisted subscription and want to use az aro to create a cluster, follow using az aro.

• If you want to deploy a development RP, follow deploy development RP.

Repository map

• .github/workflows: CI workflows using GitHub Actions.

• cmd/rp: RP entrypoint.

• deploy: ARM templates to deploy RP in development and production.

• docs: Documentation.

• hack: Build scripts and utilities.

• pkg: RP source code:

  • pkg/api: RP internal and external API definitions.

  • pkg/backend: RP backend workers.

  • pkg/client: Autogenerated ARO service Go client.

  • pkg/database: RP CosmosDB wrapper layer.

  • pkg/deploy: /deploy ARM template generation code.

  • pkg/env: RP environment-specific shims for running in production, development or test

  • pkg/frontend: RP frontend webserver.

  • pkg/install: OpenShift installer wrapper layer.

  • pkg/swagger: /swagger Swagger specification generation code.

  • pkg/util: Utility libraries.

• python: Autogenerated ARO service Python client and az aro client extension.

• swagger: Autogenerated ARO service Swagger specification.

• test: End-to-end tests.

• vendor: Vendored Go libraries.

Basic architecture

• pkg/frontend is intended to become a spec-compliant RP web server. It is backed by CosmosDB. Incoming PUT/DELETE requests are written to the database with an non-terminal (Updating/Deleting) provisioningState.

• pkg/backend reads documents with non-terminal provisioningStates, asynchronously updates them and finally updates document with a terminal provisioningState (Succeeded/Failed). The backend updates the document with a heartbeat - if this fails, the document will be picked up by a different worker.

• As CosmosDB does not support document patch, care is taken to correctly pass through any fields in the internal model which the reader is unaware of (see github.com/ugorji/go/codec.MissingFielder). This is intended to help in upgrade cases and (in the future) with multiple microservices reading from the database in parallel.

• Care is taken to correctly use optimistic concurrency to avoid document corruption through concurrent writes (see RetryOnPreconditionFailed).

• The pkg/api architecture differs somewhat from github.com/openshift/openshift-azure: the intention is to fix the broken merge semantics and try pushing validation into the versioned APIs to improve error reporting.

• Everything is intended to be crash/restart/upgrade-safe, horizontally scaleable, upgradeable...

Useful links

• https://github.com/Azure/azure-resource-manager-rpc

• https://github.com/microsoft/api-guidelines

• https://docs.microsoft.com/en-gb/rest/api/cosmos-db

• https://github.com/jim-minter/go-cosmosdb