metarouter

Polaris Metadata Routing Plugin

Forward requests to the target metadata service node based on the ArcticStar metadata in the request parameters.

Use Cases

When user A applies to use service S, the backend service S receives the request and creates a separate container A, allocating the corresponding resources. Container A registers its address information and label A with ArcticStar. Subsequently, all requests from user A will be scheduled to container A and provided with the corresponding service.

Service S is generally a heavy-duty service that consumes a significant amount of resources, such as the popular AIGC recently.

Technical Solution

Parse the ArcticStar metadata in the request and set it in calleeMetadata.

Plugin Usage

• Upstream client configuration needs to disable service routing by setting disable_servicerouter: true.
• It is recommended to add a prefix identifier to the metadata key to avoid key conflicts.
• For security reasons, if using user identification as metadata, you can parse the user identification through a business authentication plugin and set it in the request.

Import the Plugin in the main.go file of the gateway project

• Add import statements

import (
    _ "trpc.group/trpc-go/trpc-gateway/plugin/polaris/metarouter"
)

• Configure the tRPC framework file to enable the metarouter interceptor.

global:                             # Global configuration
server:                             # Server configuration
  filter:                          # Interceptor list for all service handler functions
  service:                         # Business services provided, can have multiple
    - name: trpc.inews.trpc.gateway      # Route name for the service
      filter:
        - metarouter: # Gateway plugin registered in the service's filter, allowing dynamic loading in router.yaml
plugins:                            # Plugin configuration
  log:                              # Log configuration
  gateway:                          # Plugin type is gateway
    metarouter:                     # Metadata routing plugin

Note: Make sure to register it in server.service.filter, not server.filter.

Configure the Plugin in the gateway routing configuration router.yaml file

Plugins at different levels will only be executed once, with the priority order as follows: router plugin > service plugin > global plugin

router: # Router configuration
  - method: /v1/user/info
    id: "xxxxxx"
    target_service:
      - service: trpc.user.service
    plugins:
      - name: metarouter
        props:
          meta_key_list: # List of ArcticStar metadata keys
            - you-meta-key
client: # Upstream service configuration, consistent with the tRPC protocol
  - name: trpc.user.service
    plugins:
      - name: metarouter
        props:
          meta_key_list: # ArcticStar metadata key
            - you-meta-key
plugins: