Intercepts

When intercepting a service, the Telepresence Traffic Manager ensures that a Traffic Agent has been injected into the intercepted workload. The injection is triggered by a Kubernetes Mutating Webhook and will only happen once. The Traffic Agent is responsible for redirecting intercepted traffic to the developer's workstation.

An intercept is either global or personal.

Global intercet

This intercept will intercept alltcp and/or udp traffic to the intercepted service and send all of that traffic down to the developer's workstation. This means that a global intercept will affect all users of the intercepted service.

Personal intercept

This intercept will intercept specific HTTP requests, allowing other HTTP requests through to the regular service. The selection is based on http headers or paths, and allows for intercepts which only intercept traffic tagged as belonging to a given developer.

There are two ways of configuring an intercept:

• one from the CLI directly
• one from an Intercept Specification

Intercept behavior when using single-user versus team mode.

Switching the Traffic Manager from single-user mode to team mode changes the Telepresence defaults in two ways.

First, in team mode, Telepresence will require that the user is logged in to Ambassador Cloud, or is using an api-key. The team mode aldo causes Telepresence to default to a personal intercept using --http-header=auto --http-path-prefix=/. Personal intercepts are important for working in a shared cluster with teammates, and is important for the preview URL functionality below. See telepresence intercept --help for information on using the --http-header and --http-path-xxx flags to customize which requests that are intercepted.

Secondly, team mode causes Telepresence to default to--preview-url=true. This tells Telepresence to take advantage of Ambassador Cloud to create a preview URL for this intercept, creating a shareable URL that automatically sets the appropriate headers to have requests coming from the preview URL be intercepted.

Supported workloads

Kubernetes has various workloads. Currently, Telepresence supports intercepting (installing a traffic-agent on) Deployments, ReplicaSets, and StatefulSets.