Embedded Browser

Simfra includes an embedded Chromium browser that runs inside Docker. It has DNS resolution and CA trust pre-configured, so it can reach all Simfra services - including private resources that are not accessible from the host.

Prerequisites

  • SIMFRA_DOCKER=true

Accessing the Browser

Click the globe icon in the web console navigation bar, or navigate to /browser in the Simfra UI.

How It Works

The browser runs Chromium in a Docker container with VNC streamed to your browser via a noVNC WebSocket connection.

Because it runs inside the Docker network:

  • DNS is pre-configured - Service DNS names (ALB endpoints, RDS hostnames, CloudFront distributions) resolve correctly without any host DNS setup.
  • CA trust is pre-configured - The Simfra root CA is injected into the container's trust store, so HTTPS connections to Simfra-issued certificates work without warnings.
  • Private resources are reachable - Internal load balancers, private RDS instances, and other VPC-only resources that don't publish ports to the host are directly accessible.

Per-Account Containers

Each account gets its own browser container, auto-created on first use. Containers are recycled after 10 minutes of idle time to conserve resources.

Use Cases

  • Internal ALBs: Browse applications behind internal load balancers that have no host port mapping.
  • Cognito Hosted UI: Test the full OAuth2 login flow through Cognito's hosted sign-in page.
  • S3 Static Websites: View S3-hosted websites using their bucket website endpoint.
  • CloudFront Distributions: Access CloudFront-served content with proper domain resolution.
  • API Gateway: Test APIs through their custom domain names.

Limitations

  • VNC latency: The display is streamed over VNC, so there is some visual latency compared to a native browser.
  • No clipboard sharing: Copy/paste between the embedded browser and your host clipboard is not supported.
  • No file downloads: Files downloaded in the embedded browser stay inside the container - they cannot be saved to the host filesystem.
  • Docker required: The embedded browser is only available when Docker is enabled.