Migrating Cloud Apps from Heroku to Kubernetes

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At their core, containers are lightweight software components that bundle an application, its configuration, and its dependencies into a single image. The application can then run in an isolated environment on a traditional operating system, server or in a virtualized environment.

Containerization is quickly becoming the standard for managing app versions and DevOps in large production environments. And it’s easy to see why.

It offers portability between different platforms and clouds as well as easier scalability. In addition, containers are inherently more secure as they isolate applications from the host system and from each other. According to Datadog, half of the organizations running more than 1,000 hosts are already using containers.

A large number of companies are also using container orchestration tactics to manage and schedule the work of individual containers for applications based on microservices within multiple clusters. Due to the rapid evolution of the container orchestration market, several mature container platforms are available to developers.

Even though a Platform as a Service (PaaS) like Heroku offers a quick way of creating and deploying new apps, it doesn’t quite cut it due to a number of limitations – it isn’t cost-effective, gives poor performance, and comes with several platform limitations. This is why many developers are migrating cloud apps from Heroku to Kubernetes.

In this post, we’ll take a closer look at these two different container management platforms and share some useful tips about when you should use each one.

Heroku vs Kubernetes: Drilling Down into the Key Differences

When it comes to Heroku vs Kubernetes, there are plenty of reasons why developers choose to migrate to Kubernetes and don’t look back.

Heroku is PaaS that enables companies to build, deliver, monitor, and scale apps entirely in the cloud. Created in 2007 by James Lindenbaum, Adam Wiggins, and Orion Henry, Heroku initially only supported the Ruby programming language. It was acquired by Salesforce in 2010 for $212 million.

Heroku is a flexible and user-friendly platform that helps developers quickly get their apps to customers. It’s managed by Ruby specialists, although its services are hosted on Amazon’s EC2 cloud-computing platform. As an open-source solution, Heroku offers support for Linux OS and PostgreSQL database, providing greater flexibility to developers. Its middleware was built by in-house development using Erlang. Heroku’s environment is actively monitored and updated, helping deliver stable deployment platforms.

It’s a freemium solution, so Heroku is cost-effective for most users. However, it doesn’t come with all the computing tools offered by Amazon. Out of the box, it offers a variety of features, including a database, reverse proxy cache, email, server load balancing, resource allocation, syncing files and running tasks in the background.

Heroku uses the Delayed Job standard, which involves asynchronous execution of tasks by a group of job workers based on queued work. Developers can use Heroku’s background job execution interface to change the number of background workers assigned for jobs using a slider tool. In addition to this, it lets developers relegate slow processes as background tasks making it possible to offer additional features in their web apps.

One of the disadvantages of using Heroku is that it’s not meant to be used by big organizations. In fact, it’s aimed primarily at individual Ruby developers who are also system admins. Nonetheless, some big enterprises certainly use Heroku to meet their development needs. Moreover, Heroku isn’t ideal for uploading bulky files like high-resolution images and videos, considering that it’s a read-only file system. This means you’ll have to use Amazon S3 or another storage service to handle larger uploads.

On the flip side, Kubernetes, also open source, lets you automate deployment and management of containerized applications in distributed computer clusters. It helps system admins manage cluster resources on-prem and in the cloud. 

Kubernetes was launched in 2014 by Google to expand the container ecosystem. It’s a successor of Google’s in-house orchestration system, Borg.

Kubernetes offers deep integration in the cloud-native system as it’s supported by top cloud-service providers such as Google Compute Engine, AWS, IBM and Microsoft. These cloud hosting providers also offer managed Kubernetes services in the cloud. This way, companies using Kubernetes can access a mature orchestration platform while staying on par with competitors in terms of technological advances.

Kubernetes offers container orchestration and gives developers access to a number of interfaces, supporting tools, and services including monitoring, security, logging, machine learning and networking. All major networking solutions, application stacks and databases are constantly developing Helm charts i.e. pre-packaged apps deployable in Kubernetes. 

Moreover, the platform’s users can use customizable community-developed charts to start working with tools like WordPress and MySQL or perform machine learning tasks and data analytics. Kubernetes also offers support for stateful apps that require persistent, stable storage. It supports network storage, cloud storage, local persistent storage, and software-defined storage. In addition to this, you can attach your storage solution to your containers and reliably persist your app data.

Kubernetes gives developers access to a number of API resources and primitives for running any kind of app, including:

  • Daemons
  • Replicated apps
  • Microservices
  • Jobs and cron jobs
  • Application stacks and colocated apps
  • Stateful applications

It comes with the cloud controller manager that supports integration with popular cloud hosting providers. This has enabled developers to run various cloud control loops and cloud checks inside the K8s clusters. In addition to this, Kubernetes makes it easy to use cloud-specific resources such as Ingress controllers, cloud-based load balancers and cloud storage. 

One major drawback of using Kubernetes is that it’s not easy to use. The platform is more difficult to learn even for professional DevOps and developers. Teams will need to start by learning the basics of K8s concepts and primitives and work their way up towards advanced operations and development concepts. This journey requires a lot of time and effort to get to a productive place.

The entire cloud-native ecosystem requires you to develop skills in different subjects like cloud computing, networking, distributed applications, distributed logging, and services meshes. So, if you’re looking for a quick way to get comfortable with container orchestration, Kubernetes may not be the right solution for you.

Another disadvantage of using Kubernetes is that it’s difficult to install, configure, and manage. You have to configure and install multiple components individually to initialize the cluster.

By default, Kubernetes doesn’t offer a High Availability (HA) mode. If you want to create a fault-tolerant cluster, you’ll need to manually configure HA for your etcd clusters and master components like load balancers, apps, nodes and kube-apiserver.

If you manually install Kubernetes, you’ll need to configure security and perform a number of pre-installation and post-installation tasks like configuring HA of masters and apps, configuring multi-host networking, attaching storage, and enabling monitoring, auditing and logging.

Why Migrate From Heroku to Kubernetes

Heroku is great for small-scale projects such as hackathons, prototypes, and building MVPs. Moreover, you don’t need to worry about provisioning machines, networking, and scaling.

Heroku is the go-to solution for you if you’re just starting out and looking to deliver an MVP to your users. It’s simple and easy to use which enables you to focus on building great applications.

Kubernetes is essential for businesses that are scaling rapidly and need a mature container orchestration platform to meet their growing needs. It’s a great alternative to Heroku as it offers more flexibility in how your apps scale, is vendor-agnostic and lets you deploy on-prem or in the cloud.

When your app reaches a certain threshold, you’ll have to pay a premium for Heroku as the number of users and volume of traffic scales. It’s a useful option if you have dozens or hundreds of users but, beyond that, it can quickly become expensive. In other words, you can expect to spend tens (or hundreds) of thousands of dollars per year if you keep using Heroku.

Over time your app will require more complex infrastructure and Heroku won’t be able to meet your networking and container orchestration needs, especially when sub-applications and microservices are involved.

Heroku only scales based on request latency which is not ideal if you are looking for over-simplistic autoscaling. Kubernetes, however, works great if your app consists of independent sub-applications and microservices.

Conclusion

Heroku and Kubernetes are two different technologies that cater to completely separate markets, with different interfaces and functionalities, for container orchestration purposes.

To recap, Heroku is an open-source and flexible cloud platform that lets you create and deliver apps, making it ideal for small-scale projects. Kubernetes, on the other hand, is an open-source container orchestration platform that’s used by big companies that need more flexibility and scalability.

If you are looking for a feature-rich platform that offers growth and scalability, it might be time for you to consider switching from Heroku to Kubernetes.

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