How to: Service invocation across namespaces

In this article, you’ll learn how you can call between services deployed to different namespaces. By default, service invocation supports invoking services within the same namespace by simply referencing the app ID (nodeapp):

localhost:3500/v1.0/invoke/nodeapp/method/neworder

Service invocation also supports calls across namespaces. On all supported hosting platforms, Dapr app IDs conform to a valid FQDN format that includes the target namespace. You can specify both:

• The app ID (nodeapp), and
• The namespace the app runs in (production).

Example 1

Call the neworder method on the nodeapp in the production namespace:

localhost:3500/v1.0/invoke/nodeapp.production/method/neworder

When calling an application in a namespace using service invocation, you qualify it with the namespace. This proves useful in cross-namespace calls in a Kubernetes cluster.

Example 2

Call the ping method on myapp scoped to the production namespace:

https://localhost:3500/v1.0/invoke/myapp.production/method/ping

Example 3

Call the same ping method as example 2 using a curl command from an external DNS address (in this case, api.demo.dapr.team) and supply the Dapr API token for authentication:

MacOS/Linux:

curl -i -d '{ "message": "hello" }' \
     -H "Content-type: application/json" \
     -H "dapr-api-token: ${API_TOKEN}" \
     https://api.demo.dapr.team/v1.0/invoke/myapp.production/method/ping