Kong Gateway Licensing

Kong Gateway can be used with or without a license. For Enterprise functionality, Kong Gateway enforces the presence and validity of a Kong Konnect license file.

Deploying the license file

Hybrid mode deployment: The license file must be deployed to each control plane and data plane node. Apply the license through the Kong Admin API to the control plane. The control plane distributes the license to its data plane nodes. This is the only method that applies the license to data planes automatically.
Traditional deployment with no separate control plane: The license file must be deployed to each node running Kong Gateway.

License file checking is done independently by each node as the Kong process starts; no network connectivity is necessary to execute the license validation process.

There are multiple ways to configure a license file on a Kong Gateway node. These are defined below, in the order in which they are checked by Kong:

If present, the contents of the environmental variable KONG_LICENSE_DATA are used.
Kong will search in the default location /etc/kong/license.json.
If present, the contents of the file defined by the environment variable KONG_LICENSE_PATH is used.
Directly deploy a license using the /licenses Admin API endpoint.

In this manner, the license file can be deployed either as a file on the node filesystem, as an environmental variable, or through the /licenses Admin API endpoint. The simplest method is using the Admin API.

Note that unlike most other KONG_* environmental variables, the KONG_LICENSE_DATA and KONG_LICENSE_PATH cannot be defined in-line as part of any kong CLI commands. License file environmental variables must be exported to the shell in which the Nginx process will run, ahead of the kong CLI tool.

For more information, see Deploy Your License.

Examining the license data on a Kong Gateway node

Retrieve license data using the Admin API’s /licenses endpoint, or through the Admin GUI in Kong Manager.

License expiration

Licenses expire at 00:00 on the date of expiration, relative to the time zone the machine is running in.

Kong Manager displays a banner with a license expiration warning starting at 15 days before expiration. Expiration warnings also appear in Kong Gateway logs.

After the license expires, Kong Gateway behaves as follows:

Kong Manager and its configuration are accessible and may be changed, however any Enterprise-specific features become read-only.
The Admin API allows OSS features to continue working and configured Kong Gateway Enterprise features to continue operating in read-only mode.
Proxy traffic, including traffic using Enterprise plugins, continues to be processed as if the license had not expired.
Other Enterprise features are not accessible.
There may be some Enterprise features that are still writable, but they may also change later, so do not rely on this behavior.

The behavior of the different deployment modes is as follows:

Traditional: Nodes will be able to restart/scale as needed.
Hybrid: Existing data planes or new data planes can accept config from a control plane with an expired license.
DB-less and KIC: New nodes cannot come up, restarts will break.

To upload a new license, see Deploy an Enterprise License.

License expiration logs

Kong Gateway logs the license expiration date on the following schedule:

90 days before: WARN log entry once a day
30 days before: ERR log entry once a day
At and after expiration: CRIT log entry once a day

Troubleshooting

When a valid license file is properly deployed, license file validation is a transparent operation; no additional output or logging data is written or provided. If an error occurs when attempting to validate the license, or the license data is not valid, an error message will be written to the console and logged to the Kong error log, followed by the process quitting. Below are possible error messages and troubleshooting steps to take:

license path environment variable not set: Neither the KONG_LICENSE_DATA nor the KONG_LICENSE_PATH environmental variables were defined, and no license file could be opened at the default license location (/etc/kong/license.json)
internal error: An internal error has occurred while attempting to validate the license. Such cases are extremely unlikely; contact Kong support to further troubleshoot.
error opening license file: The license file defined either in the default location, or using the KONG_LICENSE_PATH env variable, could not be opened. Check that the user executing the Nginx process (e.g., the user executing the Kong CLI utility) has permissions to read this file.
error reading license file: The license file defined either in the default location, or using the KONG_LICENSE_PATH env variable, could be opened, but an error occurred while reading. Confirm that the file is not corrupt, that there are no kernel error messages reported (e.g., out of memory conditions, etc). This is a generic error and is extremely unlikely to occur if the file could be opened.
could not decode license json: The license file data could not be decoded as valid JSON. Confirm that the file is not corrupt and has not been altered since you received it from Kong Inc. Try re-downloading and installing your license file from Kong Inc.; If you still receive this error after reinstallation, contact Kong support.
invalid license format: The license file data is missing one or more key/value pairs. Confirm that the file is not corrupt and has not been altered since you received it from Kong Inc. Try re-downloading and installing your license file from Kong Inc.; If you still receive this error after reinstallation, contact Kong support.
validation failed: The attempt to verify the payload of the license with the license’s signature failed. Confirm that the file is not corrupt and has not been altered since you received it from Kong Inc. Try re-downloading and installing your license file from Kong Inc.; If you still receive this error after reinstallation, contact Kong support.
license expired: The system time is past the license’s license_expiration_date.
invalid license expiration date: The data in the license_expiration_date field is incorrectly formatted. Try re-downloading and installing your license file from Kong Inc.; If you still receive this error after reinstallation, contact Kong support.

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