Thanos Defined Routes Documentation

This documentation provides an overview of routes defined in the Thanos codebase, focusing on the implementation within the Golang source files. It outlines specific function calls, middleware, and configurations that dictate how routes are managed.

Route Configuration

In Thanos, routes can be prefixed for easier routing and management through various components. The --web.route-prefix flag allows users to define a prefix for all routes. According to the documentation, changing the route prefix can be accomplished via:

func (q *QuerierBuilder) WithRoutePrefix(routePrefix string) *QuerierBuilder {
q.routePrefix = routePrefix
return q
}

This function is part of the QuerierBuilder, which is essential for configuring the querier’s accessible routes (source: test/e2e/e2ethanos/services.go).

Middleware and Routing Structure

Thanos employs middleware for HTTP client-side operations which integrate with the routing mechanism. This involves defining a structure that enables different handlers to be wrapped around routes:

// Tripperware is a signature for all http client-side middleware.
type Tripperware func(http.RoundTripper) http.RoundTripper

Middleware is pivotal in modifying the request or response, enhancing the routing capabilities of the application (source: internal/cortex/querier/queryrange/roundtrip.go).

Example Registering of Routes

Defining new routes for query handling involves using a router, as evident in the following example:

func (q *Query) Register(r *route.Router, ins extpromhttp.InstrumentationMiddleware) {
registerReactApp(r, ins, q.BaseUI)
}

This method registers routes associated with the query page of the Thanos UI, indicating the importance of maintaining appropriate routing for frontend components (source: pkg/ui/query.go).

Testing Route Functionality

Route functionality is tested in various components, ensuring that route prefixes and external prefixes work as intended. An example test case illustrates this process:

func TestQueryExternalPrefixAndRoutePrefix(t *testing.T) {
externalPrefix := "thanos"
routePrefix := "test"

q := e2ethanos.NewQuerierBuilder(e, "1").
WithRoutePrefix(routePrefix).
WithExternalPrefix(externalPrefix).
Init()
...
querierURL := urlParse(t, "http://"+q.Endpoint("http")+"/"+routePrefix)
...
}

Here, the test case demonstrates the use of both route and external prefixes in establishing the correct endpoint structure during testing (source: test/e2e/query_test.go).

Conclusion

The Thanos codebase provides various mechanisms for defining, registering, and testing routes. These features showcase a flexible routing framework that allows developers to customize how components interact over HTTP. Careful management of routes through middleware and builder patterns is essential for maintaining a robust service infrastructure.

Refer to the provided source snippets for further exploration and understanding of Thanos’ routing capabilities.