Ansible vs. Kubernetes [Key Differences Explained]

If you are comparing Ansible and Kubernetes to decide which one to adopt, the honest answer is that most teams end up using both. They are often mentioned together, but they solve different problems. Ansible automates configuration across servers and infrastructure, whereas Kubernetes orchestrates containerized applications.

In this post, we compare Ansible and Kubernetes across architecture, configuration model, and use cases, and show how they work together in a real deployment.

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

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 — 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 lets you manage node inventory with handy operations such as grouping, filtering, and sorting.
5. Idempotency — Ansible modules are designed to be idempotent, so running the same playbook repeatedly produces the same result without making unnecessary changes, which keeps systems in a consistent, predictable state.

Ansible connects to nodes specified in the inventory over SSH and runs modules to perform various tasks, keeping the overall deployment state 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.

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 key features of Kubernetes are listed below.

1. Container orchestration — As mentioned earlier, Kubernetes automates the deployment, scaling, and management of containers, ensuring service availability and smooth fallbacks.
2. Self-healing — It has built-in self-healing capabilities that are critical when 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 DevOps, but they serve different purposes and offer distinct capabilities. 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 control plane node 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, especially in how it manages the deployment of applications —e specially microservices. 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.

Ansible and Kubernetes are not similar, as they address different problems. Ansible is a configuration management and automation tool that focuses on configuring systems and deploying applications. Kubernetes is a container orchestration platform that manages the deployment, scaling, and operation of containerized applications. While both help in application deployment, they operate at different levels of the infrastructure stack.

As for similarities, both Ansible and Kubernetes 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.

Feature	Ansible	Kubernetes
Purpose	Used to automate tasks for configuration management, infrastructure provisioning, and application deployment.	Used to orchestrate container deployments.
Architecture	Agentless. Uses SSH or WinRM. Requires respective ports to be open on all target systems.	Agent based. Implements control plane (master) – node architecture.
Language	Procedural and partly declarative. Written in YAML.	Declarative. Manifests are written in YAML or JSON.
Deployment sizes	Supports small and large deployments.	Designed for large-scale deployments, but can also manage smaller deployments if required.
Networking	Basic networking functionalities are available.	Advanced network configurations are possible. Service discovery, load balancing, and DNS-based routing are ideal for microservice-based architectures.
Deployment method	Push based. Configuration changes are pushed to the target servers.	The kubelet communicates with the control plane to obtain the current configurations and takes appropriate actions to reach the defined state.
Health checks	Basic health checks of the target systems.	Advanced health check mechanisms for containers and automatic restarts.

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 that often run many 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 the application level and introduce automation and procedural flexibility.

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 enables management of 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, while access to the cluster is configured through the kubeconfig file (by default ~/.kube/config). Ansible, known for its efficiency in configuration management, offers modules such as kubernetes.core.k8s and kubernetes.core.helm to define procedural playbooks for deploying applications.

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 packages on master and client nodes and 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.

Here is a minimal example of an Ansible playbook applying a Kubernetes Deployment with the kubernetes.core.k8s module:

- name: Deploy application to Kubernetes
  hosts: localhost
  tasks:
    - name: Apply the nginx deployment manifest
      kubernetes.core.k8s:
        state: present
        src: ./manifests/nginx-deployment.yaml

The same playbook can first configure the underlying nodes, then apply the manifest, so cluster setup and application rollout live in one automated workflow.

Ansible configures your servers. Kubernetes runs your workloads. Keeping the two in step usually means two toolchains, two sets of pipelines, and a stack of glue scripts holding it all together.

Spacelift manages both from one control plane. Create Stacks for your Ansible and Kubernetes work, then orchestrate them together so each tool does the job it does best, without the handoffs breaking.

It runs a GitOps workflow by default. Your Kubernetes Deployments stay in sync with their Stacks, and every pull request shows a preview of what will change before you merge. Policies give you the guardrails: automate your compliance checks and orchestrate workflows across Stacks, all as code.

The same control plane runs the rest of your infrastructure too. Manage Terraform, OpenTofu, Pulumi, CloudFormation, and Terragrunt alongside Ansible and Kubernetes, and combine their Stacks into workflows that cross tool boundaries. One place. One set of rules.

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 solve different problems. Use Ansible to configure servers, provision infrastructure, and deploy non-containerized applications. Use Kubernetes to orchestrate containerized applications at scale. 

In most production setups, you run both. Ansible prepares and configures the cluster nodes, and Kubernetes runs the workloads on top of them.