How to Use the Command 'dexter' for User Authentication with OpenID Connect (with examples)

Dexter is a powerful tool designed to facilitate the authentication of kubectl users via OpenID Connect (OIDC). With dexter, users can securely authenticate their Kubernetes clusters using OIDC providers, enhancing security and ease of use. Through simple command-line instructions, dexter manages the authentication process efficiently, ensuring that users can leverage their existing OIDC providers, such as Google, for secure access to their Kubernetes resources.

Use case 1: Create and Authenticate a User with Google OIDC

Code:

dexter auth -i client_id -s client_secret

Motivation:

In today’s digital environment, using robust and widely accepted identity providers, such as Google’s OpenID Connect (OIDC), is crucial for maintaining security and efficiency in Kubernetes environments. By using Google OIDC, administrators and developers can quickly authenticate users against a trusted provider, simplifying user management and enhancing security protocols. This use case is particularly beneficial for organizations already using Google Cloud services, as it allows for seamless integration and reduces the overhead of managing multiple identity providers.

Explanation:

• dexter: The command-line tool used for authenticating kubectl users with OpenID Connect.
• auth: This subcommand specifies that the action to be performed is user authentication.
• -i client_id: This argument represents the client ID provided by the OpenID Connect provider (e.g., Google). The client ID is an identifier for the client application (i.e., the application requesting authentication).
• -s client_secret: This argument is the client secret associated with the client ID. It is used as a password to authenticate the client application with the OpenID Connect provider.

Example Output:

Upon executing this command, you will be redirected to a browser to log in using your Google account. After successfully logging in, dexter will retrieve and store a token within the Kubernetes configuration file. The output may look like this:

Opening browser for authentication...
Authentication successful. Access token has been stored.

Use case 2: Override the Default Kube Configuration File Location

Code:

dexter auth -i client_id -s client_secret --kube-config sample/config

Motivation:

In situations where an organization needs to manage multiple Kubernetes environments or developers are working on different projects requiring separate Kubernetes configurations, the default kube configuration file may not be ideal. By specifying an alternate location for the kube-config file, users can customize their setup and easily switch between environments without overwriting existing configurations, facilitating greater flexibility and organization, especially in multi-cluster environments.

Explanation:

• dexter: The command-line tool used for authenticating kubectl users with OpenID Connect.
• auth: Specifies that the action to be performed is user authentication.
• -i client_id: Represents the client ID for the OpenID Connect provider, which is necessary for the authentication request.
• -s client_secret: The client secret associated with the client ID, used to authenticate the client application securely.
• --kube-config sample/config: An optional argument allowing the user to specify an alternate location for the Kubernetes configuration file. This is handy when managing multiple configurations across different clusters or environments.

Example Output:

After executing the command, you will be prompted to authenticate in a similar manner to the first use case. Upon successful authentication, the access token will be saved in the specified configuration file, and the output might read:

Opening browser for authentication...
Authentication successful. Access token has been saved in sample/config.

Conclusion:

Dexter offers a streamlined solution for Kubernetes authentication by integrating with OpenID Connect providers, such as Google. Whether you are authenticating a user using Google OIDC or managing multiple Kubernetes environments with separate configuration files, dexter ensures a secure and efficient authentication process. Its ease of use, coupled with detailed authorization handling, makes dexter an essential tool for Kubernetes administrators and developers alike.