Containerized Microservices: All You Need to Know

Containerized microservices are one of the latest software development trends that are expected to grow considerably in the near future.

The popularity of these microservices lies in the fact that they are a cost-effective alternative to virtual machines. They also benefit software developers by giving them the opportunity to create and deploy applications in more faster and secure ways.

With that being said, we will discuss containerized microservices in the following blog post and explain why and how they can be beneficial.

What are Microservices?

Microservices refer to an architectural style for developing software applications in which the application is decomposed into smaller and self-contained services.

These services have well-defined interfaces (APIs) that allow them to communicate with each other. Each service is also developed and managed by a dedicated team.

The main goal of microservices architectures is to enhance the scalability and development speed of applications. This will contribute to faster innovation and quicker delivery of new features.

By breaking down the application into smaller services, individual services can be updated, deployed, and scaled independently based on specific functionalities.

Read More: API Integration Patterns: All You Need to Know

What is Containerization?

Containerization is a software deployment method where an application’s code is packaged alongside all necessary files and libraries. Based on this approach, the application can run on various infrastructures.

Traditionally, a particular application required specific versions for different operating systems which often resulted in deployment complexities.

Containerization takes care of this issue by creating a single, self-contained unit – called a container – that functions across diverse devices and operating systems.

Benefits of Containerization

The practice of containerization provides numerous advantages for software development teams. Below we will discuss 6 main benefits.

Portability

By encapsulating an application into a container, it becomes an independent executable package which is detached from the underlying operating system.

This independence makes sure that the application is not bound to the host OS, enhancing its portability and enabling it to operate reliably and evenly on any platform or cloud service.

In addition, the consolidation techniques used by developers help eliminate potential discrepancies, such as integration issues, that can hinder the application’s performance.

Speed

Containers are often described as lightweight because they use the host machine’s operating system kernel and avoid unnecessary load. This characteristic contributes to greater server productivity and lowers both server and licensing expenses.

Also, it accelerates the initiation process as there is no operating system to launch. With a Docker container, it is possible to establish a primary version of an application (known as an image) and deploy it swiftly as needed.

The containerized setting provides considerable adaptability for the rapid creation of numerous new instances of containerized applications.

Efficiency

In containerized settings, the software uses the host’s operating system kernel, which allows for the sharing of application layers among different containers.

Containers are also inherently more compact than virtual machines, meaning that they need less time to start up.

This efficiency enables the operation of a greater number of containers on the same computational resources that would typically support a single virtual machine.

As a result, this leads to improved server productivity and a reduction in related server and licensing expenditures.

Read more: FastAPI: The Modern Python Framework For Web Developers

Security

By segregating applications into containers, containerization safeguards them from the potential impact of harmful code on other apps in containers or the host system itself.

Security permissions can also be set to automatically restrict access to any undesired elements attempting to infiltrate other containers or to control communication between them.

Moreover, isolating applications allows developers to distribute new functionalities without compromising security.

For example, when collaborating with an external development team, necessary resources can be shared without exposing sensitive information within your own network.

Ease of Management

Container orchestration platforms enable the automation of deployment, management, and scaling of containerized applications and services.

Such platforms simplify management processes, including the deployment of new application versions, the scaling of containerized applications, and the provision of monitoring, logging, and debugging capabilities.

Developer-Friendly

The appeal of containers to developers lies in their ability to maintain a consistent environment for both development and production, which is often a challenge in web application development.

A development team might develop an application on a Windows laptop, only to come across issues when attempting to run it on a Mac workstation.

Containerization makes sure that the image developed locally by your team is identical to the one deployed in production.

This consistency, along with a well-structured workflow, reduces the instances where an application operates correctly in one setting but encounters problems in another.

Furthermore, the process of building containers is particularly effective when integrated into CI/CD pipelines. These advantages altogether will contribute to the productivity and efficiency of your development team.

Benefits of Containerized Microservices

It is clear that container technology provides many benefits like speed and efficiency for microservices. Below, we will take a look at several advantages that deploying microservices within containers offers.

Improved Performance and Reduced Footprint

Compared to virtual machines, containers boast faster startup times (typically seconds versus minutes). This feature aligns well with the agile nature of microservices and allows for smoother deployment and scaling.

Enhanced Security

Another benefit of containerization is improved security for microservices by isolating each service within its own container. This isolation is argued to reduce the attack surface and thus creates a smaller potential target for attacks.

Moreover, a security vulnerability discovered in one container is less likely to compromise other containers due to the isolation provided.

In contrast, deploying microservices directly on a host operating system or virtual machine will offer less security in comparison with the containerized deployments.

Simplified Development Process

The use of containerized microservices simplifies the development process for developers.

Given that microservices are compact and independent units, developers can focus on discrete tasks without being entangled in the broader application’s complexities.

What’s more, containerization offers the flexibility to code each service in the most appropriate programming language for its unique requirements.

Consistency in Development and Testing

The isolation of microservices in containers leads to a more consistent development and testing environment for automated microservice applications or code segments.

With fewer variables to manage, the likelihood of encountering issues during critical phases such as development, testing, and deployment will be reduced.

Scalability

Unlike the older method of virtual machine development, containerization improves scalability. It permits the stacking of multiple containers on a single server and even within the same OS environment. This will in turn facilitate sustained expansion when necessary.

Service Discovery

Service discovery is an important aspect of SOA-based architectures. Hosting microservices in containers simplifies their localization and intercommunication.

On the other hand, deploying microservices on virtual machines can result in diverse networking configurations across hosts which will complicate the creation of a network architecture that ensures dependable service discovery.

Challenges of Containerized Microservices

While it is true that containerization provides many advantages for microservices, it also comes with certain implementation challenges.

Additional Complexity For Teams

The introduction of containers brings an additional abstraction layer, which can make management, monitoring, and debugging processes more complicated.

The abstract characteristics of containers often pose challenges for developers, particularly when integrating microservices within a large-scale application.

Furthermore, the dynamic nature of containers, which frequently start up and shut down in response to workload changes, is very likely to complicate deployment, management, and monitoring tasks even more.

Also, the use of multiple programming languages for microservices introduces yet another layer of complexity that cannot be overlooked.

Read More: What is an API Development? The Things You Should Know

Learning Curve

They need to have a good grasp of container orchestration tools such as Docker and Kubernetes. It is also essential that your servers are configured to support various container runtimes, along with the requisite network and storage capabilities.

One possible way to lower the learning curve associated with containerized microservices is to employ managed container solutions like AWS’s ECS or EKS.

Service Discovery and Load Balancing

As the number of microservices goes up, the necessity for effective service discovery methods to identify and interact with each service becomes more critical.

Another important point to take into account is load balancing, which guarantees the even distribution of incoming network traffic among various instances of a microservice.

The problem is that it is quite challenging to establish strong service discovery and load balancing in containerized settings.

Incompatibility with Legacy Systems

Although microservices are beneficial in application development, they might not be suitable for every scenario, particularly with certain legacy applications.

This incompatibility can introduce further complexities when attempting to integrate microservices within containerized infrastructures.

Monitoring and Observability

Large-scale deployments of microservices within containers require robust monitoring and observability practices to guarantee system health and efficient troubleshooting.

However, the sheer volume of logs, metrics, and traces generated by these environments is very difficult to manage without appropriate tools and strategies.

Security and Access Control

Containerized microservices introduce new security considerations. Securing containerized environments from potential vulnerabilities, providing secure communication between services, managing access controls, and safeguarding data privacy are all critical aspects to take into consideration.

Implementing appropriate security measures, such as authentication, authorization, and encryption, is essential to mitigate these risks.

Key Components and Tools of Containerized Microservices

There are a number of essential tools that you need to use for building and managing microservices. Below we have a look at some of the most popular ones.

Docker

Docker emerged in 2013 as an open-source solution for large-scale containerization. It simplified access and use of existing Linux container functionalities such as groups and namespaces.

Docker’s influence has been such that it has become widely associated with container technology and containerized microservices in general.

Following Docker’s release, innovative enterprises adopted the platform to establish containerized runtime environments. This adoption facilitated initiatives in cloud migration, digital transformation, and the development of microservices architectures.

By replacing virtual machines with containers, Docker-based containerization offered the potential for immediate reductions in cloud computing overhead costs for these enterprises.

Kubernetes

Kubernetes is another widely-used containerization tool which is a freely available platform created to orchestrate containers.

It provides developers with the tools needed to oversee and maintain applications that are container-based within live production settings.

One of the best features of Kubernetes is its automated deployment. These features give developers the chance to streamline application management by automating various tasks within containerized environments.

This includes automatic scaling of resources (CPU, memory) based on application usage, along with automatic updates when necessary.

Kubernetes also enables the collective management of microservices housed in containers, known as a cluster.

Within such a cluster, Kubernetes can fine-tune the distribution of resources like CPU and memory to match the unique requirements of each service within containers.

Moreover, it has the capability to shift containers between various virtual hosts in response to the varying demands of their workloads.

OpenShift

Another useful containerization tool that you need to consider is Red Hat’s OpenShift. It is a hybrid cloud platform that incorporates Kubernetes functionality.

Designed for enterprise use, it runs on the Linux operating system and offers both CaaS (Container-as-a-Service) and PaaS (Platform-as-a-Service) models.

OpenShift is known for its user-friendly interface that allows developers to quickly start working on applications. Also, it streamlines workflows by enabling developers to easily create databases, frameworks, and other services needed for their applications.

One more useful feature of OpenShift is that it provides access to a marketplace with certified applications from Red Hat for various functionalities such as billing, support, and governance.

Nomad

Nomad is a software platform that is created to orchestrate containers. Similar to Kubernetes in function, Nomad provides broader support by managing both containerized and non-containerized applications.

Nomad also integrates seamlessly with other HashiCorp tools such as Consul, Vault, and Terraform. This integration allows for a more comprehensive approach to infrastructure management.

Additionally, providing a unified workflow for developers to manage applications regardless of containerization, Nomad offers flexibility across macOS, Windows, and Linux environments.

Read More: What is API Modernization? Benefits and Phases

Best Practices For Using Containerized Microservices

When it comes to using containerized microservices, there are several best practices that you need to follow.

API Gateway for Managing Microservice Requests

An API gateway functions as a central point where all client requests enter the system. It routes these requests to the appropriate microservices.

It simplifies client interaction with the architecture, enforces secure access control, and can offer additional features such as rate limiting, caching, and request transformation.

Moreover, by separating clients from individual services, the API gateway promotes a more manageable, scalable, and secure microservices architecture.

This centralized approach helps manage complexity and lowers the number of client-service interactions.

Distributed Tracing in Microservices

Distributed tracing is a powerful tool for monitoring and troubleshooting containerized microservices. It tracks a request’s journey across different services and displays the flow of transactions and service interactions.

This valuable information helps developers identify bottlenecks, pinpoint errors, and understand how services depend on each other. To make use of distributed tracing, integration with tools like Jaeger, Zipkin, or OpenTelemetry is required.

These tools collect, analyze, and visualize trace data, helping developers address problems and optimize microservice performance.

Smaller Container Images

There are advantages to using minimal base images for containers. These images are smaller because they contain fewer components. This reduces the potential attack surface and thus leads to better security.

What’s more, smaller images start faster and use resources more efficiently, which can enhance container scalability and overall performance.

However, using minimal base images requires careful management of dependencies. This is necessary since it helps maintain application functionality while achieving security and performance improvements.

Security

Generally speaking, containerized microservices are more secure than traditional VM-based monolithic applications due to their reduced attack surface.

Nonetheless, these microservices frequently need to interact with back-end resources. Operating containers in privileged mode gives them unrestricted access to the host’s root functions, potentially risking exposure of the kernel and other critical system elements.

As a result, establishing robust IAM protocols, security groups, effective network policies, and precise security context settings is essential.

It is also crucially important to use auditing tools that assess whether container setups comply with security standards and to use image scanners that automatically identify potential security risks.

Storage For Microservices

Since container data is typically lost when the container instance shuts down, you need a plan for external storage for your microservice architecture.

Many container orchestration tools offer integrated data storage solutions, so you should evaluate the features and functionalities of these solutions to select the best orchestration tool for your organization’s specific storage needs.

Final Words

Although they add some development complexity, containerization remains a prevalent method for deploying functional microservices.

Its adoption is widespread across various industries and many organizations are embracing cloud-native containerization for their applications.

If your organization heavily relies on virtualization for security and web application separation, containerization will offer significant benefits.

To maximize the potential of this established yet evolving strategy, you need to encourage your developers to explore both commercial and open-source tools that can streamline containerized microservice development.