Ports
Container Ports
The Ports tab provides general information about container port accessibility, default platform routing and the options available for exposing additional application ports.
Default Open Ports
The platform opens a predefined set of ports for HTTP and SSL traffic. These ports are proxied through the shared load balancer to the corresponding backend port inside the container.
| Port on Shared Load Balancer | Backend Port | Frontend SSL | Backend SSL |
|---|---|---|---|
| 80, 8080, 8086 | 80 | No | No |
| 4848 | 4848 | Yes | Yes |
| 8443 | 8443 | Yes | Yes |
| 4901–4910 | 4901–4910 | Yes | Yes |
| 443 | 80 | Yes | No |
| 4949 | 4949 | Yes | No |
| 7979 | 7979 | Yes | No |
Traffic routing
Ports 80, 8080 and 8086 route HTTP traffic to backend port 80. Port 443 terminates SSL at the frontend and forwards traffic to backend port 80.
Open Additional Ports
Ports that are not available through the default shared load-balancer mapping can be exposed using one of the following methods:
After selecting the preferred access method, bind the application listener to the provided internal or external address and the required port.
Ports Auto-Redirect
The platform automatically redirects incoming requests to an application running inside the container. During node creation, it detects ports with active TCP listeners and excludes ports commonly used by standard services such as SSH, mail and databases.
The first remaining active port becomes the container entry point. Incoming requests are forwarded to this port through the embedded shared load balancer. The detection runs whenever the container is launched, so the application can become accessible without manual port configuration.
When manual configuration may be required
Change the automatic behavior when the detected port is incorrect or when the selected entry point exposes a private administration interface.
Configure Auto-Redirect Variables
Open the container Variables section and add the required platform variable to control the auto-redirect behavior.
JELASTIC_EXPOSE
JELASTIC_PRIORITY_PORTS
Use this variable to define a comma-separated list of preferred ports. The platform checks the ports in the specified order and configures the first active service as the entry point.
This method can reduce startup time because the platform checks only the listed ports before using the full default scan.
Variable priority rules
- If an exact port is defined through JELASTIC_EXPOSE, the JELASTIC_PRIORITY_PORTS value is ignored.
- If none of the priority ports has an active service, the platform uses its default port-detection process.
- Node.js containers can use REDIRECT_EXCLUDE_PORTS to exclude selected ports from automatic redirection.
REDIRECT_EXCLUDE_PORTS for Node.js
For a Node.js application server, use REDIRECT_EXCLUDE_PORTS to prevent specified ports from being selected by the auto-redirect algorithm.
For more detailed control over inbound and outbound access, configure the container firewall rules.
Expected Result
The application is accessible through the required default or custom port. Incoming traffic is routed through the shared load balancer, an endpoint or a public IP according to the selected configuration.
Important Notes
- Confirm that the application is actively listening on the intended container port.
- Use endpoints when only selected ports need to be exposed.
- Use a public IP when direct access to multiple or all container ports is required.
- Do not expose administrative or internal service ports unless necessary.
- An exact JELASTIC_EXPOSE value overrides the priority-port list.
- Review firewall rules when the service remains inaccessible after port configuration.