WeOS Rest Endpoint Request Flow

This shows what happens with an incoming request to an endpoint

flowchart LR
    Start --> runPreMiddleware[[Run Pre Middleware]] --> getRoute[[Get Route]] --> runMiddleware[[Run Middleware]] --> runController[[Run Controller]]-->End([End])

Pre Middleware

We have standard middleware that we typically use

• RequestID - Generate request id
• Recover - Return friendly error when there is a panic
• ZapLogger - Switches to using Zap logger instead of echo logger

Get Route

Uses echo framework functionality.

Run Middleware

Middleware are run in the order in which they are configured on the path.

Context Middleware

By default a Context Middleware is set which adds values in the request based on the parameters configured on that path in the OpenAPI spec.

flowchart TD
    Start --> request[/Request/] --> getAccountID[/Get Account ID/] --> hasUnprocessedParams{Has\nUnprocessed\nParams}
    hasUnprocessedParams -->|No|End([End])
    hasUnprocessedParams -->|Yes|getParamFromRequest[[Get Param From Request]]-->requestHasParam{Request\nHas\nParam}
    requestHasParam -->|Yes|addToContext[Add param and request value to context] --> End
    requestHasParam -->|No|End

Run Controller

The controller that is run is either explicitly set using the x-controller extension or automatically configured.

Standard Create Controller

flowchart TD
    Start --> request[/Request/] --> addContentTypeToContext[Add Content Type to Context] -->|Context| contextWithContentType[/Name: Content Type\n Schema: Some Open API Schema/]
    contextWithContentType --> dispatchCommand[[Dispatch Command]] --> errorReturned{Error\nReturned}
    errorReturned-->|No|getItem[Get Item from Projection] --> createEtag[Create Etag] --> Etag[/ETag/] --> End
    errorReturned-->|Yes|returnError[Return Error]-->End