The recommended and most robust method for installing the Instana host agent on Kubernetes is by using the Instana Agent Operator. The Operator is a Kubernetes-native application that automates the deployment and lifecycle management of the agent. It simplifies installation, configuration, and updates by managing the agent DaemonSet across all schedulable nodes in the cluster. This approach aligns with best practices for managing applications on Kubernetes, providing a declarative and automated way to ensure the agent is always running and correctly configured.

A. Homebrew: This is a package manager for macOS and Linux, designed for installing software on a single workstation, not for deploying agents across a Kubernetes cluster.

B. Binary: While the agent is a binary, this is not a valid installation method for Kubernetes. A direct binary installation is impractical for managing deployments on a multi-node, dynamic cluster.

D. RPM: This is a package management system for Red Hat-based Linux distributions. It is used for single-host installations and is not the standard method for deploying applications on Kubernetes.

1. IBM Instana Observability Documentation: "Installing the Instana agent on Kubernetes". This official documentation explicitly lists the Operator as the recommended installation method. It states, "The recommended way to install the Instana agent on Kubernetes is by using the Instana Agent Operator." The page details the steps for deploying the agent using the Operator, Helm Chart, or a YAML file (DaemonSet), with the Operator being the primary recommendation.

Source: IBM Documentation, Instana Observability, "Installing the Instana agent on Kubernetes".

2. IBM Instana Observability Documentation: "Host agent installation". This page provides an overview of installation methods for various platforms. For Kubernetes, it directs users to the specific Kubernetes installation guide, which prioritizes the Operator method. The sections for other operating systems like Linux detail the use of package managers (like RPM and DEB), clearly distinguishing them from the Kubernetes approach.

Source: IBM Documentation, Instana Observability, "Host agent installation".