Enabling multi-provider service composition among different kubernetes clusters

The digital landscape has witnessed a shift towards cloud-based computing, making cloud computing an integral part of the modern era. This transition has led to increased demand for managing computational resources in the cloud. Kubernetes has emerged as a game-changer in meeting this demand. By breaking applications into microservices, Kubernetes ensures high availability and accessibility across multiple replicas, decoupling applications from specific infrastructures and enabling workload distribution across hosts. The Liqo project, an open-source initiative from Politecnico di Torino, complements Kubernetes by connecting disparate cloud systems. It allows the aggregation and movement of resources across various cloud environments, facilitating resource and application sharing. With Liqo, multiple Kubernetes clusters can participate, enabling an application hosted on one cluster to be utilized by another. This innovative approach enables different Kubernetes clusters to incorporate services offered by independent providers into their ecosystems. This is particularly useful in cluster federation scenarios where entities operate independently but need to utilize third-party services while maintaining control over their data. The objective of the present work is to establish a functional model for offering, purchasing, and deploying services across multiple Kubernetes clusters. The OpenService Broker API specifications provide a similar solution, but their application is limited to single-cluster, single-user scenarios. To overcome these limitations, a custom catalog software was developed, enhancing and customizing the OpenService Broker API specifications. This catalog software operates as a web server, extending the REST APIs with additional endpoints for managing service purchasing and Liqo peering with specific clusters. To ensure a secure environment, the OpenID Connect protocol was integrated, enabling a multi-user scenario within the same catalog. Additionally, an automated mechanism was incorporated to link purchased and deployed services to microservices. This streamlined approach empowers users to maximize the potential of their cloud-based operations.