Ansible vs. Kubernetes [Key Differences Explained]

Ansible and Kubernetes are the industry standards for automation in infrastructure and software development. Ansible, an open-source tool developed by Red Hat, simplifies the configuration and management of complex systems across various platforms, from servers to cloud services. Kubernetes, developed by Google, is a container orchestration tool that automates the deployment, scaling, and management of containerized applications, ensuring high availability and scalability.

Given their widespread use, understanding the strengths and weaknesses of both tools is crucial for making informed decisions. In this blog post, we’ll compare Ansible vs Kubernetes, exploring their features, advantages, and limitations, as well as how to use them effectively together.

What we will cover:

1. What is Ansible?
2. What is Kubernetes?
3. Differences between Ansible and Kubernetes
4. Ansible and Kubernetes similarities
5. Ansible vs. Kubernetes: Table comparison
6. Using Ansible and Kubernetes together

Software development, release management, and deployment are collectively known as configuration management. Ansible is designed to address the complex configuration management required by organizations and teams. It streamlines IT operations, helps with repetitive tasks, and can improve the efficiency of otherwise time-consuming and error-prone processes.

Ansible features

The key features of Ansible listed below provide insights into how this optimization is achieved.

1. Agentless architecture — Ansible does not require agents to be installed on the target nodes under its management, resulting in ease of deployment and management of infrastructure.
2. Playbooks — Ansible uses playbooks, which are YAML files that define the tasks and actions to be performed on the nodes. Playbooks are easy to write and can be reused across multiple environments.
3. Modules — Modules are a collection of specific tasks, such as installing software, configuring networks, managing users, etc. Ansible provides a wide range of modules that can be used to perform these tasks.
4. Inventory management — Ansible allows you to manage the inventory of nodes with handy operations like grouping, filtering, and sorting.
5. Role-Based Access Control (RBAC) — Ansible provides RBAC, which allows you to define different roles for various users and limit their access to specific resources.

Ansible connects with nodes specified in the inventory over SSH and performs various tasks defined in the modules to keep the overall state of deployment intact. It is flexible, so any process can be simplified, automated, and managed efficiently.

If you would like to know more about Ansible, follow our Ansible tutorial, where we dive deep into the details of installing and setting up the Ansible control node and demonstrate how Playbooks are used with Ansible.

Software application containerization has become a key aspect of modern software development and deployment and a standard across the industry. Containerization of application components offers various benefits, like a consistent runtime environment, platform independence, and potential for scaling. Kubernetes is an open-source platform designed to automate the deployment, scaling, and management of containerized applications. It is also known as a container orchestration platform.

Kubernetes features

Some of the key features of Kubernetes are mentioned below.

1. Container orchestration — As mentioned earlier, Kubernetes allows you to automate the deployment, scaling, and management of containers, ensuring service availability and smooth fallback capabilities.
2. Self-healing — It has built-in self-healing capabilities, which are critical in cases where containers fail or become unresponsive. Kubernetes automatically restarts or replaces the running container instances.
3. Scalability — In Kubernetes, we can define the scaling policies either horizontally or vertically. Horizontal scaling simply means adding more instances of the container, while vertical scaling involves allocating more resources to the same container.
4. High availability — Kubernetes ensures high availability by automatically distributing your applications across multiple nodes in the cluster.
5. Security — Security is built into Kubernetes and implemented using network policies, secrets management, and RBAC.
6. Extensibility — Kubernetes is highly extensible, allowing you to integrate it with a wide range of third-party tools and services. This is why many cloud platform providers have introduced a dedicated service to host Kubernetes clusters and, therefore, containerized workloads.

These features make Kubernetes a great choice for automating the deployment, management, and scaling of containerized applications. See our Kubernetes architecture overview for a detailed explanation of what Kubernetes is composed of. 

Ansible and Kubernetes are both powerful tools in the DevOps field, but they serve different purposes and offer distinct functionalities. Ansible’s simplicity and agentless architecture make it ideal for automating tasks across multiple platforms, supported by its extensive library of modules. On the other hand, Kubernetes excels in managing containerized applications with powerful features for scaling, self-healing, and load balancing.

1. Configuration management vs. container orchestration

Ansible is primarily a configuration management and automation tool designed for setting up and maintaining IT infrastructure. It uses declarative YAML files to define the desired state of the infrastructure and then executes tasks on remote hosts to achieve that state. It is useful for infrastructure management tasks like configuring the network, keeping software installations up-to-date, and ensuring consistency across multiple nodes.

Kubernetes, on the other hand, is a container orchestration platform that automates the deployment, scaling, and lifecycle management of containerized applications.  It provides the environment needed to run and manage containers, ensuring efficient resource utilization and high availability. Kubernetes handles tasks such as scheduling containers on appropriate nodes, load balancing, service discovery, and automating scaling based on resource demands.

2. Agentless vs. agent-based architecture

Ansible uses an agentless architecture, meaning it doesn’t require any software installation on the target hosts. Instead, it leverages SSH or WinRM (depending on the target machine’s OS) to connect to remote machines and execute tasks. This approach simplifies the deployment and updating of runtime environments and software components while minimizing human errors. However, its reliance on SSH/WinRM could pose a security challenge for organizations.

Kubernetes requires a kubelet to be installed on each node in the cluster. Although the kubelet has a minimal resource footprint, its presence classifies Kubernetes as having an agent-based architecture. The kubelet communicates with the Kubernetes master to send vital information about the containers running on its node, enabling proper management.

3. Procedural vs. declarative configuration

In most cases, Ansible follows a procedural approach. The tasks defined in Ansible Playbooks are executed in a specific order, as laid out in the Playbook. These Playbooks are written procedurally, detailing each step required to achieve a desired state. This approach is intuitive for developers and administrators, allowing them to modify the process later as new requirements arise. However, Ansible also supports a declarative approach through its modules. These modules handle the necessary steps internally to accomplish a task, relieving the user from the cognitive burden of specifying each detail.

On the other hand, Kubernetes takes a declarative approach. With YAML manifests, you define the desired state of a Kubernetes environment, and Kubernetes automatically ensures that state is achieved. The developer only needs to create these manifests for the application and provide them to Kubernetes, which simplifies the management of complex applications.

4. Configuration vs. application management

Ansible primarily focuses on configuring runtime environments across multiple target servers. It can also provision infrastructure components such as servers, networks, and storage. It is used to automate tasks that support software development, delivery, and deployment. With Ansible, we can manage a wide range of servers, whether hosted in private data centers or by cloud providers, ensuring consistent deployment of application components.

Kubernetes is more application-centric, specifically in managing how applications—especially microservices—are deployed. Kubernetes does not handle the provisioning of node clusters; rather, each node must be added to the Kubernetes management system. Once integrated, Kubernetes determines how many instances of a particular microservice should be deployed on each node within the cluster. It provides features like service discovery, load balancing, and automatic scaling, making it a comprehensive tool for container orchestration.

As far as similarities are concerned, Ansible and Kubernetes are open-source, designed to automate IT operations, and highly flexible. Both tools can operate across various cloud environments, including public, private, and hybrid clouds. Neither requires extensive programming knowledge to use effectively. Basic knowledge of systems administration and scripting is sufficient for both. 

However, despite high-level similarities, their core functions differ, providing potential solutions for complex use cases. 

The table below summarizes the comparison between Ansible and Kubernetes.

You can run Kubernetes independently, i.e., without the help of any deployment tools. Deployments in Kubernetes environments can be managed using kubectl command-line tools and a bunch of YAML manifest files that define the final state of the containers to be run on the K8s cluster.

However, it makes sense to use Kubernetes for large applications, which tend to have a huge number of container instances. Manually deploying or upgrading them can become a daunting task. Package managers like Helm charts and Argo are widely used for this sole purpose. These package managers bundle all the manifest files at an application level and introduce automation and flexibility in terms of procedural approach.

Using package managers is highly recommended to realize a robust Kubernetes deployment strategy. However, with Ansible, this strategy can be further strengthened as it also offers to manage the underlying cluster infrastructure and configurations required by Kubernetes. It also helps roll out deployments on Kubernetes environments. The diagram below provides a high-level overview of how the infrastructure components (nodes and clusters) are provisioned and configured for Kubernetes deployment.

Ansible can certainly be used with package managers, but it doesn’t necessarily require them. Kubernetes deployments and rollouts rely on manifests or a bundle of manifests and configurations found in the ‘./kube/config’ files. Ansible, known for its efficiency in configuration management, offers modules like kubernetes.core.k8s and kubernetes.core.helm to define procedural playbooks for executing deployments.

Configuring a Kubernetes cluster is inherently complex, particularly when the cluster spans multiple data centers or cloud providers. Automating this process is crucial. Ansible is particularly well-suited for this task, as it allows you to automate the installation of various packages on the master server and client nodes and to establish communication between them. This forms the foundation of an Ansible Playbook.

Once the Playbooks are defined, the entire deployment process—from setting up the infrastructure to deploying application containers on Kubernetes clusters in the desired configuration—can be fully automated. This approach offers a robust solution for any deployment strategy.

Spacelift supports both Ansible and Kubernetes and enables users to create stacks based on them. Leveraging Spacelift, you can build CI/CD pipelines to combine them and get the best of each tool.

It brings with it a GitOps flow, so, for example, your Kubernetes Deployments are synced with your Kubernetes Stacks, and pull requests show you a preview of what they’re planning to change. It also has an extensive selection of policies, which lets you automate compliance checks and build complex multi-stack workflows.

Another great advantage of using Spacelift is that you can manage more infrastructure tools like OpenTofu, Terraform, Pulumi, and AWS CloudFormation from the same place and combine their Stacks with building workflows across tools.

If you want to learn more about Spacelift, create a free account today or book a demo with one of our engineers.

Ansible and Kubernetes are DevOps tools that offer a streamlined and efficient approach to infrastructure automation and configuration management. They provide a robust deployment strategy for all business services that depend on Kubernetes workloads. Ansible includes features like RBAC automation of operational tasks, and consistency. Additionally, it provides modules for managing Kubernetes deployments, further automating container orchestration, which can significantly accelerate time-to-market.