Using cpolar for Intranet Penetration to Debug SpringBoot APIs

1. Local Environment Setup

Install JDK 1.8, IDEA, SpringBoot, Maven, Tomcat 9.0 and Postman.

2. Build SpringBoot Service

Create a SpringBoot project and implement a POST interface for demonstration.

2. Intranet Penetration with cpolar

Download and install cpolar, register an account, and log in via the client.

2.1 Install and configure cpolar

Visit https://www.cpolar.com/ , download the client for Windows or Linux and follow the official guide.

2.2 Create tunnel mapping local port

After installation, open http://localhost:9200 in a browser, log in, then create an HTTP tunnel for the local Tomcat 8080 port, specifying tunnel name, protocol, local address, domain type (random), and region.

Copy the generated public address.

2.3 Test public address

Use Postman to send a POST request to the public address plus the API path, with JSON parameters, and verify the request reaches the service.

3. Fixed Public Address

Reserve a sub‑domain in cpolar (requires at least the basic plan), configure the tunnel to use the reserved sub‑domain, and update the tunnel settings.

Test the fixed address with Postman to ensure successful calls.

4. cpolar Listener

Enable the listener feature (http://localhost:4040) in the tunnel’s advanced settings to view request logs, replay requests, and debug more efficiently.