A Comparison of CI/CD Tools on Kubernetes

Sammanfattning: Kubernetes is a fast emerging technological platform for developing and operating modern IT applications. The capacity to deploy new apps and change old ones at a faster rate with less chance of error is one of the key value proposition of the Kubernetes platform. A continuous integration and continuous deployment (CI/CD) pipeline is a crucial component of the technology. Such pipelines compile all updated code and do specific tests and may then automatically deploy the produced code artifacts to a running system. There is a thriving ecosystem of CI/CD tools. Tools can also be divided into two types: integrated and standalone. Integrated tools will be utilized for both pipeline phases, CI and CD. The standalone tools will be used just for one of the processes, which needs the usage of two independent programs to build up the pipeline. Some tools predate Kubernetes and may be converted to operate on Kubernetes, while others are new and designed specifically for usage with Kubernetes clusters. CD systems are classified as push-style (artifacts from outside the cluster are pushed into the cluster) or pull-style (CD tool running inside the cluster pulling built artifacts into the cluster). Pull- and push-style pipelines will have an impact on how cluster credentials are managed and if they ever need to leave the cluster. This thesis investigates the deployment time, fault tolerance, and access security of pipelines. Using a simple microservices application, a testing setup is created to measure the metrics of the pipelines. Drone, Argo Workflows, ArgoCD, and GoCD are the tools compared in this study. These tools are coupled to form various pipelines. The pipeline using Kubernetes-specific tools, Argo Workflows and ArgoCD, is the fastest, the pipeline with GoCD is somewhat slower, and the Drone pipeline is the slowest. The pipeline that used Argo Workflows and ArgoCD could also withstand failures. Theother pipelines that used Drone and GoCD were unable to recover and timed out. Pull pipelines handles the Kubernetes access differently to push pipelines as the Kubernetes cluster credentials does not have to leave the cluster, whereas push pipelines needs the cluster credentials in the external environment where the CD tool is running.