Pavel Rykov
July 31, 2023 ・ Code
Migrate NodeJS GraphQL app to Kubernetes
GraphQL and NodeJS are two popular technologies used for writing and powering modern web applications. GraphQL is a modern query language that allows developers to interact with databases in an efficient, reliable, and secure way. With GraphQL, developers are able to structure their data and query it in a way that is most meaningful to their application. It also allows developers to keep the data up-to-date and easily maintainable.
NodeJS is an open-source server-side runtime based on Google's V8 JavaScript Engine that enables developers to create dynamic web applications on the server-side. It is designed for building fast and scalable network applications. With NodeJS, developers can create performant, real-time applications such as web apps, microservices, and APIs. NodeJS can be used in conjunction with GraphQL to create a powerful and efficient application that can satisfy the needs of modern businesses.
Overview of Migrating an App to Kubernetes
Kubernetes is an open source platform for managing containerized applications across multiple clusters. This system allows developers and IT operations teams to manage applications and infrastructures more efficiently and effectively. Kubernetes is a highly effective way of deploying, managing and scaling applications, and is becoming increasingly popular for companies of all sizes.
In this overview, we’ll discuss the process of migrating an existing application to the Kubernetes platform. To start, we’ll break down the process into four steps:
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Assess: This step is critical to the entire process and involves assessing the existing application and the associated services to determine if they are suitable for migrating to Kubernetes. This step ensures that the application and services require the migration, and if they do, then the resources, resource dependencies and current configuration that will be needed for the migration.
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Plan: Once the assessment process has been completed, the planning stage begins. This step involves planning for, and validating the resources and environment needed for the migration, as well as the job dependencies, security models, and configuration processes that will be required.
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Prepare: This step involves preparing the existing application services for the migration. This may involve some code refactoring, updating any external services that the application relies on, and testing the application in its current state.
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Deploy: The final step of the process is deploying the application to the Kubernetes platform. This involves creating a deployment plan and configuring and managing the deployment of the application. Once the migration is complete, the application can be monitored and any performance or other issues that arise can be addressed.
These are the steps needed to migrate an existing application to the Kubernetes platform. By following this process, companies can leverage the powerful features of Kubernetes to help them manage, scale and maintain their applications and infrastructures more efficiently.
Configuring a Kubernetes Cluster
The first step to configuring a Kubernetes cluster for a NodeJS GraphQL application is to create a Kubernetes cluster. This can be achieved using several methods, such as using the Google Cloud Platform or by using a cloud provider like Amazon Web Services. Once the cluster is created, the NodeJS GraphQL application can be deployed using the Kubernetes command-line tools or Helm.
After the application is deployed, it must be configured to use the correct resources, such as memory, CPU and networking. This can be achieved by creating Kubernetes namespaces and setting resource limits or by using Kubernetes horizontal or vertical scaling settings.
Once the application is configured, it must be secured. This can be done using the Kubernetes Networkpolicy, which is a powerful security model used to limit access to the underlying resources. In addition, Kubernetes annotations can be used to provide additional granularity in controlling access to the resources.
Finally, the application must be monitored to ensure that it is running correctly. Kubernetes provides several services to monitor the health of the application and the cluster, such as the Kubernetes Metrics API and the Kubernetes Events API. In addition, a logging solution, such as the Elastic Stack, can be used to provide detailed logging information in order to better debug and monitor the application.
Preparing NodeJS GraphQL application
We'll discuss setting up Dockerfiles, container images, and deploying simple NodeJS GraphQL applications, using both console and script-based commands. In order to begin using Docker and consequently Kubernetes, you need to install Docker Desktop. Using the link provided, download it onto your device and install it configuring it correctly. To ensure successful installation of the application, type 'docker version' into the terminal to get the output. Having Docker installed guarantees running of Kubernetes Pods.
A Dockerfile enables us to package an application, including all its dependencies, into a single image that can easily be deployed to a cluster. In our example, we'll use a Dockerfile to package a simple NodeJS GraphQL application. Here's one example of a Dockerfile we could use:
# Get Node.js
FROM node:14
# Create the application folder
WORKDIR /app
# Copy package.json
COPY package*.json ./
# Install dependencies
RUN npm install
# Copy application files
COPY . .
# Expose ports
EXPOSE 3000
# Start the app
CMD ["node", "index.js"]
Our next step is to write the NodeJS GraphQL application that we wish to deploy and package using the Dockerfile. This is a simple application, designed to listen on port 3000 and accept requests on a /graphql path:
const express = require('express');
const { ApolloServer } = require('apollo-server-express');
const typeDefs = require('./server/schema');
const resolvers = require('./server/resolvers')
// Setup express
const app = express();
// Setup GraphQL server
const apolloServer = new ApolloServer({ typeDefs, resolvers });
// Use `/graphql` URL path
apolloServer.applyMiddleware({ app, path: '/graphql' });
app.listen(3000);
console.log(`GraphQL server running on port 3000`);
Finally, we need to package up the application and the Dockerfile, into a single container image. To do this, we use the docker build
command, pointing to the location of the Dockerfile.
docker build -t nodejs-graphql-application:v1 ./
Once the image has been built, we can easily deploy it to a Kubernetes Cluster. We do this using the kubectl
command line tool. Here's an example command for deploying a single replica of our application to a Kubernetes cluster:
kubectl run nodejs-graphql-application --image=nodejs-graphql-application:v1 --replicas=1
By following these steps, we can prepare NodeJS GraphQL applications for deploying to Kubernetes clusters. We can package our applications into container images, using Dockerfiles and the command line docker build
command, and easily deploy our applications to Kubernetes clusters, using the command line kubectl
command.
Updating the application in Kubernetes
Updating the GraphQL NodeJS application in Kubernetes can be a simple process. The first step is to check the version of your application in the Kubernetes cluster. This can be done by running the command kubectl get pods -n <namespace>
. This command will list all the pods in your cluster along with the version of each pod.
If the version of your application is not the desired version, the next step is to update the application by running the command kubectl set image deployment/<name> <name>=<image>:<tag> -n <namespace>
. This will update the desired version of the application in the Kubernetes cluster. After the application is updated, you can then check the current version of the application by running the same command as in the beginning.
Best Practices to deploy applications in Kubernetes
Deploying Node.js and GraphQL applications in Kubernetes is becoming increasingly popular and easy. Here are some best practices to secure and optimize your application deployments.
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Make sure Resource requests and limits are set. Kubernetes offers several options to scale your deployment. When you create the pod templates for your application, you should include Resource requests and limits. The resource requests help Kubernetes schedule the appropriate CPU and memory for each container. The resource limits help protect the other containers running on the nodes.
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Maintain Pod Readiness. In Kubernetes, Pod Readiness is an indicator that the container in the pod is up and ready. You should be monitoring the Pod Readiness using the Kubernetes API and setting alerts when the Pod Readiness is low.
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Use Autoscalers to Scale your Deployments. Autoscalers are used to automatically scale your deployments based on the metrics you set. For example, you can set a Metric autoscaler to scale the number of replicas based on the CPU utilization of the pods.
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Continuous Integration and Delivery (CI/CD) for Deployments. CI/CD is essential to ensure consistent deployments of your applications in Kubernetes. You should set up a CI/CD workflow to build and test the images for your containers and deploy them in Kubernetes.
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Use Kubernetes namespaces and TLS certificates. Namespaces in Kubernetes provide an extra layer of security and control to your deployments. You should also create and manage TLS certificates to ensure your application is secure.
The above are some best practices for deploying Node.js and GraphQL applications in Kubernetes. Following best practices, setting the right resource requests and limits, using autoscalers, and CI/CD will help ensure that your application is deployed optimally in Kubernetes. In conclusion, if you are planning to migrate to Kubernetes, following the right best practices will help you make the most out of your Kubernetes deployments.
Summary and Conclusion
In this article, we have described the process of migrating a NodeJS GraphQL application from a single server instance to a Kubernetes cluster in a very detailed manner. We discussed the need for migrating the application and the important steps such as configuring the Kubernetes cluster, preparing the NodeJS GraphQL application, and updating the application in Kubernetes for performing the migration. We then discussed some best practices to follow when deploying applications using Kubernetes. In conclusion, we can say that migrating applications to Kubernetes can be a straightforward process that can offer better scalability and performance to the applications.
Overall, migrating from a traditional platform to Kubernetes can be a daunting task but if done properly, it can save your business significant time and money and provide you with a secure environment for running applications. Moreover, this process can be greatly simplified if your business has access to the right resources. Ivinco team provides managed solutions and services, such as turn-key environments, deployments to managed clusters, and secure features like network policies. With our expertise and years of experience in Kubernetes, our team can make sure your NodeJS GraphQL application is securely deployed and running efficiently and reliably in Kubernetes.
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