Crossplane - Detailed Explanation

Crossplane, a project under the Cloud Native Computing Foundation, emerges as a transformative framework in the multi-cloud era. It extends Kubernetes, offering an open-source control plane that unifies cloud infrastructure management across diverse environments. This Kubernetes-native platform enables declarative configuration and promotes portability and scalability, addressing the complexities of multi-cloud strategies. As organizations face the challenges of vendor lock-in and infrastructure management, Crossplane provides the building blocks for customized, efficient solutions. Its vibrant community and adaptability make it a cornerstone for modern, agile, cloud-native application development and infrastructure management.

What is Crossplane?

Crossplane is an open source Kubernetes-native control plane that extends the capabilities of Kubernetes for managing cloud infrastructure and services. It provides a declarative approach to infrastructure management, allowing users to define and configure infrastructure resources as code, similar to how Kubernetes manages containerized applications. Here are some key points about Crossplane:

• Cloud Agnostic Infrastructure Management: Crossplane enables users to manage cloud resources across different cloud providers and on-premises environments, providing a unified and consistent approach to provisioning and managing infrastructure resources.
• Kubernetes Native Experience: Crossplane is built on top of Kubernetes and extends its capabilities, leveraging familiar Kubernetes tools and APIs for managing cloud infrastructure resources.
• Customizable Resource Definitions: Crossplane allows users to define their own resource classes, which are custom resource definitions (CRDs) that represent infrastructure resources such as databases, storage volumes, and virtual machines. It Allows users to configure and tailor Crossplane's behavior to their specific requirements.
• Infrastructure as Code (IaC) approach: Crossplane treats infrastructure resources as code, allowing users to define and version infrastructure configurations using popular code repositories such as Git. This enables infrastructure to be managed, versioned, and audited in a similar manner as application code.
• Ecosystem of Providers: Crossplane has a growing ecosystem of providers that offer support for various cloud providers, including AWS, Azure, GCP, and many others. This allows users to leverage existing provider integrations or develop their own custom providers for specific infrastructure resources.
• Community Driven Project: Crossplane is an open-source project with an active and growing community of contributors and users. It is backed by the Cloud Native Computing Foundation (CNCF), which ensures its sustainability and promotes its adoption in the cloud-native ecosystem.
• Scalable and Portable: Crossplane helps organizations achieve greater scalability and portability in their cloud infrastructure, making it ideal for modern cloud-native application development and multi-cloud deployments.

Who Uses Crossplane?

Crossplane is used by a wide range of organizations and individuals who want to extend Kubernetes to manage cloud infrastructure and services across multiple cloud providers and on-premises environments. Some common use cases and types of users who benefit from Crossplane include:

• Cloud Service Providers: Cloud service providers who offer managed Kubernetes services can use Crossplane to provide a consistent and unified way for their customers to provision and manage cloud resources across their different cloud offerings.
• Enterprises with Multi Cloud Strategy: Organizations with a multi-cloud strategy that leverage multiple cloud providers, such as AWS, Azure, GCP, and others, can use Crossplane as a single control plane to manage and provision cloud resources across different cloud providers in a consistent and unified manner.
• DevOps Teams: DevOps teams that leverage Kubernetes for application deployment and management and need a unified way to provision and manage cloud resources across multiple cloud providers. For example, a DevOps team might use Crossplane to define infrastructure-as-code (IaC) templates as Kubernetes "kind" resources, which can be version-controlled and used to provision and manage cloud resources across different cloud providers consistently.
• Application Developers: Application developers who build and deploy cloud-native applications on Kubernetes and need to provision and manage cloud resources as part of their application deployments. For example, an application developer might use Crossplane to define and deploy application-specific infrastructure resources, such as databases or caching services, using Kubernetes manifests.
• Cloud Architects and Infrastructure Engineers: Cloud architects who design and implement cloud infrastructure solutions for organizations and need a flexible and extensible platform for provisioning and managing cloud resources in a Kubernetes-native way. For example, a cloud architect might use Crossplane to define and manage infrastructure policies, templates, and configurations as Kubernetes "kind" resources, providing a unified and consistent approach to provisioning and managing cloud resources.
• Open Source Communities: Open-source communities that develop and contribute to cloud infrastructure management solutions can use Crossplane to extend Kubernetes and provide a Kubernetes-native way of managing cloud resources across different cloud providers.

What is A Control Plane, and Why do We Need a “universal” One?

A Control Plane in the context of cloud computing refers to the centralized management and control layer that oversees and orchestrates the provisioning, configuration, monitoring, and management of cloud resources. It acts as a "brain" that makes decisions and coordinates actions across the cloud infrastructure.

A "universal" control plane is a control plane that provides a consistent and unified interface for managing cloud resources across different cloud providers, as well as on-premises environments. It aims to abstract the complexities and differences of various cloud providers and presents a single, unified control plane for managing resources, regardless of the underlying cloud infrastructure.

There are several reasons why a "universal" control plane is needed in cloud infrastructure management:

• Simplified Management: Managing cloud resources and services across multiple cloud providers and on-premises environments can be complex and challenging. A "universal" control plane like Crossplane provides a common and consistent interface to manage resources across different clouds, simplifying management tasks and reducing operational overhead.
• Consistent Operations: A "universal" control plane allows for consistent operations, policies, and configurations across different cloud providers or clusters. This helps to ensure that resources are provisioned and managed consistently, regardless of the underlying infrastructure, leading to better consistency and predictability in application deployments and operations.
• Portability and Interoperability: A "universal" control plane promotes portability and interoperability of applications and workloads across different cloud providers or Kubernetes clusters. It enables users to define and manage resources using a common interface, making it easier to move applications or workloads across different environments without significant modifications.
• Vendor Lock-in Mitigation: Cloud providers often have their own proprietary APIs and management tools, which can result in vendor lock-in. A "universal" control plane like Crossplane abstracts away the differences between cloud providers, allowing users to switch or use multiple cloud providers without being tied to any particular vendor's tools or APIs.
• Flexibility and Extensibility: A "universal" control plane provides flexibility and extensibility in managing different types of resources, allowing users to define custom resource types, policies, and configurations. This enables users to adapt the control plane to their specific requirements and extend its capabilities to manage new types of resources or integrate with existing tools and processes.
• Future Proofing: A "universal" control plane helps to future-proof cloud infrastructure management by providing a consistent interface and abstraction layer that can adapt to changes in the underlying infrastructure or technology landscape.

Why Does Crossplane Use The Kubernetes API?

Crossplane uses the Kubernetes API for managing cloud resources and services due to its familiarity, declarative and Kubernetes-native approach, extensibility through custom resources, ecosystem and tooling support, and interoperability across different Kubernetes distributions and cloud providers.

• Familiarity and Consistency: Crossplane leverages the syntax, conventions, and workflows of Kubernetes, which is widely adopted and familiar to many users in the Kubernetes community. This makes it easier for Kubernetes users to adopt and use Crossplane seamlessly.
• Declarative and Kubernetes-Native: Crossplane follows the declarative model of Kubernetes, allowing users to define the desired state of the system using YAML manifests. This aligns with the Kubernetes-native approach and enables users to manage cloud resources using familiar Kubernetes-style manifests.
• Extensibility and Custom Resources: Crossplane takes advantage of Kubernetes' custom resource definitions (CRDs) to provide extensibility and customization. This allows users to define their own custom resources for managing different cloud providers or services, extending Crossplane's capabilities and flexibility.
• Ecosystem and Tooling: Crossplane benefits from the extensive ecosystem of Kubernetes tools, libraries, and extensions. This includes kubectl for command-line management, Kubernetes operators for extending CRD functionality, and Kubernetes-native RBAC for access control, providing a robust and mature tooling ecosystem for Crossplane users.
• Interoperability: Crossplane's use of the Kubernetes API enables it to work across different Kubernetes distributions, cloud providers, and infrastructure environments. This ensures a consistent and interoperable approach to managing cloud resources and services, regardless of the underlying infrastructure.

Do I have to Use Kubernetes?

Crossplane is designed to be used in conjunction with Kubernetes, but it does not necessarily require the use of Kubernetes. While Crossplane leverages the Kubernetes API and follows the Kubernetes-native approach for managing cloud resources and services, it is possible to use Crossplane without Kubernetes in certain scenarios.

However, it's worth noting that Crossplane's core design and features are built around the Kubernetes ecosystem, and it is optimized for use with Kubernetes clusters. Using Crossplane with Kubernetes provides the full benefits of its declarative and Kubernetes-native approach, extensibility through custom resources, ecosystem and tooling support, and interoperability with different Kubernetes distributions and cloud providers.

So, while it is technically possible to use Crossplane without Kubernetes in certain scenarios through the XaaS mode, it is recommended to use Crossplane with Kubernetes to fully leverage its capabilities and take advantage of its integration with the Kubernetes ecosystem.

What are The Advantages of using Crossplane?

No Need to Write Code

Using Crossplane eliminates the need to write code for provisioning and managing cloud resources, allowing users to define their desired state using declarative YAML manifests. This simplifies the process and reduces the complexity of managing cloud resources, making it more accessible to non-developers and reducing the reliance on coding skills.

Developer-Friendly

Crossplane provides a developer-friendly approach for managing cloud resources, allowing developers to define infrastructure as code (IaC) using familiar Kubernetes-style YAML manifests. This allows for version control, automation, and collaboration using GitOps practices, making it easier for developers to manage infrastructure alongside their application code, improving productivity and development workflows.

Production-Ready

Crossplane is production-ready, meaning it is stable, reliable, and suitable for use in production environments. It has been widely adopted by organizations and has a mature ecosystem of providers, integrations, and community support. This ensures that Crossplane can be used with confidence to manage critical cloud resources in production environments, meeting the demands of enterprise-grade applications and workloads.

Drift Detection and Synchronisation

Crossplane offers drift detection and synchronization to automatically identify and correct discrepancies between desired and actual cloud resource states. This ensures consistent configuration, mitigates risks, and reduces operational overhead, enhancing the reliability and compliance of the managed infrastructure.

Satisfies Both InfraOps and AppOpps Needs

Crossplane caters to the needs of both infrastructure operations (InfraOps) and application operations (AppOps) teams. It provides a unified control plane for managing cloud resources, allowing both teams to collaborate, define infrastructure as code, and manage cloud resources in a Kubernetes-native manner, enhancing efficiency and coordination between teams.

Conclusion

• Crossplane is an open source Kubernetes-native control plane that provides a unified approach to manage cloud resources and infrastructure as code (IaC).
• Crossplane is used by DevOps teams, Cloud engineers, Cloud Providers and Infrastructure Operators, etc.
• A universal one is needed for consistent, unified management of diverse cloud resources and providers.
• Crossplane utilizes the Kubernetes API as a universal control plane to manage cloud resources, leveraging its mature ecosystem, extensibility, and developer-friendly approach.
• Using Kubernetes is not mandatory for Crossplane, but it leverages Kubernetes-style declarative YAML manifests for defining and managing cloud resources.
• Advantages of using crossplane are No Need to Write Code, Developer Friendly, Production Ready, Drift Detection and Synchronisation, Satisfies both Infra Ops and App Opps needs.