Deploying a Node.js API to Kubernetes involves several steps, including creating a Docker image of your application, creating a Kubernetes deployment, and creating a Kubernetes service. Here is a general overview of the process:

1. Create a Dockerfile for your application: This file specifies how to build a Docker image of your application. It should include instructions for installing any dependencies, copying your application code, and specifying the command to run your application.Note: the above process is a general overview of the process and it may vary depending on the complexity of your application and the environment you have, and it’s highly recommended to use a CI/CD pipeline to automate this process.

   Here is an example of a simple Dockerfile for a Node.js API:

   FROM node:14
   
   # Set the working directory
   WORKDIR /usr/src/app
   
   # Copy package.json and package-lock.json
   COPY package*.json ./
   
   # Install dependencies
   RUN npm install
   
   # Copy the rest of the application files
   COPY . .
   
   # Expose the port the application runs on
   EXPOSE 3000
   
   # Start the application
   CMD ["npm", "start"]

   This Dockerfile uses the official Node.js 14 image as the base image. It sets the working directory to /usr/src/app, which is where the application files will be stored. Then it copies the package.json and package-lock.json files and runs npm install to install the dependencies. After that, it copies the rest of the application files to the container. Finally, it exposes port 3000, which is the port that the application runs on, and starts the application using the npm start command.

   You can adapt this Dockerfile according to your needs, for example, if you are using TypeScript you need to add a step to compile your code. Also, you can use a specific version of Node.js or any other package manager other than npm.

   It is important to note that this Dockerfile is for simple applications and for more complex applications that may have multiple services, or use a specific version of Node.js, or have specific environment variables you will need to add more instructions to the Dockerfile.

2. Build the Docker image: Use the docker build command to build an image of your application based on the Dockerfile. This image can then be used to create a container on a Kubernetes cluster.
3. Push the Docker image to a container registry: Push the image to a container registry such as Docker Hub or Google Container Registry, so that it can be easily accessed by Kubernetes.
4. Create a Kubernetes deployment: A deployment is a set of replicas of your application. It ensures that the desired number of replicas of your application is running at all times.
5. Create a Kubernetes service: A service is a way to expose your application to the outside world. It provides a stable IP address and DNS name for your application.
6. Use kubectl command to deploy the containerized application on a Kubernetes cluster: Use the kubectl apply command to create the deployment and service objects in your cluster.
7. Monitor and scale your application: Use Kubernetes tools to monitor the health of your application and scale it up or down as needed.