This topic describes the requirements for installing an application with the Replicated app manager on an existing cluster.
In addition to the requirements listed on this page, you must also meet the general system requirements as well as any additional requirements from your software vendor. For more information about the system requirements, see General System Requirements.
To install an application on an existing cluster with Replicated, the cluster must meet the following requirements:
Kubernetes version compatibility: The version of Kubernetes running on the cluster must be compatible with the version of KOTS that you use to install the application. KOTS is an open source project maintained by Replicated. The Replicated app manager is based on the KOTS project. This compatibility requirement does not include any specific and additional requirements defined by the software vendor for the application.
For more information about the versions of Kubernetes that are compatible with each version of KOTS, see Kubernetes Version Compatibility in General System Requirements.
Storage class: The cluster must have an existing storage class available. For more information, see Storage Classes in the Kubernetes documentation.
Role-based access control (RBAC): Replicated requires the following RBAC permissions on the cluster:
- An existing namespace and an RBAC binding that permits the user of the kubectl command-line tool to create workloads, ClusterRoles, and ClusterRoleBindings.
- cluster-admin permissions to create namespaces and assign RBAC roles across the cluster.
requireMinimalRBACPrivileges property is set to
true in the Application custom resource manifest, or if the
supportMinimalRBACPrivileges property is set to
true in the Application custom resource manifest and the
--use-minimal-rbac flag is passed to the
kots install command, the app manager does not require the ability to create ClusterRoles and ClusterRoleBindings and uses a namespace-scoped Role and RoleBinding instead. For more information about the Application custom resource, see Application in Custom resources.
Note: Root access on nodes or workstations is not required to install an application on an existing cluster.