# Setup Multi User

Fleet uses Kubernetes RBAC where possible.

One addition on top of RBAC is the [`GitRepoRestriction`](./namespaces.md#restricting-gitrepos) resource, which can be used to control GitRepo resources in a namespace.

A multi-user fleet setup looks like this:

* tenants don't share namespaces, each tenant has one or more namespaces on the
  upstream cluster, where they can create GitRepo resources
* tenants can't deploy cluster wide resources and are limited to a set of
  namespaces on downstream clusters
* clusters are in a separate namespace

![Shared Clusters](/img/FleetSharedClusters.svg)

:::warning important information

The isolation of tenants is not complete and relies on Kubernetes RBAC to be
set up correctly. Without manual setup from an operator tenants can still
deploy cluster wide resources. Even with the available Fleet restrictions,
users are only restricted to namespaces, but namespaces don't provide much
isolation on their own. E.g. they can still consume as many resources as they
like.

However, the existing Fleet restrictions allow users to share clusters, and
deploy resources without conflicts.

:::

## Example User

This would create a user 'fleetuser', who can only manage GitRepo resources in the 'project1' namespace.

    kubectl create serviceaccount fleetuser
    kubectl create namespace project1
    kubectl create -n project1 role fleetuser --verb=get --verb=list --verb=create --verb=delete --resource=gitrepos.fleet.cattle.io
    kubectl create -n project1 rolebinding fleetuser --serviceaccount=default:fleetuser --role=fleetuser

If we want to give access to multiple namespaces, we can use a single cluster role with two role bindings:

    kubectl create clusterrole fleetuser --verb=get --verb=list --verb=create --verb=delete --resource=gitrepos.fleet.cattle.io
    kubectl create -n project1 rolebinding fleetuser --serviceaccount=default:fleetuser --clusterrole=fleetuser
    kubectl create -n project2 rolebinding fleetuser --serviceaccount=default:fleetuser --clusterrole=fleetuser

This makes sure, tenants can't interfere with GitRepo resources from other tenants, since they don't have access to their namespaces.

## Allow Access to Clusters

This assumes all GitRepos created by 'fleetuser' have the `team: one` label. Different labels could be used, to select different cluster namespaces.

In each of the user's namespaces, as an admin create a [`BundleNamespaceMapping`](./namespaces.md#cross-namespace-deployments).

    kind: BundleNamespaceMapping
    apiVersion: fleet.cattle.io/v1alpha1
    metadata:
      name: mapping
      namespace: project1

    # Bundles to match by label.
    # The labels are defined in the fleet.yaml # labels field or from the
    # GitRepo metadata.labels field
    bundleSelector:
      matchLabels:
        team: one
        # or target one repo
        #fleet.cattle.io/repo-name: simpleapp

    # Namespaces, containing clusters, to match by label
    namespaceSelector:
      matchLabels:
        kubernetes.io/metadata.name: fleet-default
        # the label is on the namespace
        #workspace: prod

The [`target` section](./gitrepo-targets.md) in the GitRepo resource can be used to deploy only to a subset of the matched clusters.

## Restricting Access to Downstream Clusters

Admins can further restrict tenants by creating a `GitRepoRestriction` in each of their namespaces.

    kind: GitRepoRestriction
    apiVersion: fleet.cattle.io/v1alpha1
    metadata:
      name: restriction
      namespace: project1

    allowedTargetNamespaces:
      - project1simpleapp

This will deny the creation of cluster wide resources, which may interfere with other tenants and limit the deployment to the 'project1simpleapp' namespace.

## An Example GitRepo Resource

A GitRepo resource created by a tenant, without admin access could look like this:

    kind: GitRepo
    apiVersion: fleet.cattle.io/v1alpha1
    metadata:
      name: simpleapp
      namespace: project1
      labels:
        team: one

    spec:
      repo: https://github.com/rancher/fleet-examples
      paths:
      - bundle-diffs

      targetNamespace: project1simpleapp

      # do not match the upstream/local cluster, won't work
      targets:
      - name: dev
        clusterSelector:
          matchLabels:
            env: dev

This includes the `team: one` label and and the required `targetNamespace`.

Together with the previous `BundleNamespaceMapping` it would target all clusters with a `env: dev` label in the 'fleet-default' namespace.

:::note

`BundleNamespaceMappings` do not work with local clusters, so make sure not to target them.

:::