---
layout: docs
page_title: Namespace and mount structure guide
description: >-
  Explains HashiCorp's recommended approach to structuring the Vault namespaces, and how namespaces impact on the endpoint paths.
---

# Namespace and mount structure guide

Namespaces are isolated environments that functionally create "Vaults within a
Vault." They have separate login paths, and support creating and managing data
isolated to their namespace. This functionality enables you to provide Vault as
a service to tenants.

![Conceptual diagram for namespace usages](/img/diagram_namespaces-for-org.png)

This guide provides recommended approach to structuring Vault namespaces and
mount paths, as well as some guidance around how to make decisions for
namespaces and paths structuring, given the organizational structure and use
cases.

### Why is this topic important?

Everything in Vault is path-based. Each path corresponds to an operation or
secret in Vault, and the Vault API endpoints map to these paths; therefore,
writing policies configures the permitted operations to specific secret paths.
For example, to grant access to manage tokens in the root namespace, the policy
path is `auth/token/*`. To manage tokens for the  _education_ namespace, the
fully-qualified path functionally becomes `education/auth/token/*`.

The following diagram demonstrates the API paths based on where the auth method
and secrets engines are enabled. 

![Namespaces and mount paths](/img/diagram_namespaces_paths.png)

You can isolate secrets using namespaces or mounts dedicated to each Vault
client. For example, you can create a namespace for each isolated tenant and
they are responsible for managing the resources under their namespace.
Alternatively, you can mount a dedicated secrets engine at a path dedicated to
each team within the organization. 

![Namespaces best practices](/img/diagram_namespaces_intro.png)

Depending on how you isolate the secrets, it determines who is responsible for
managing those secrets, and more importantly, policies related to those secrets.  


<Note>

The creation of namespaces should be performed by a user with a highly
privileged token such as `root` to set up isolated environments for each
organization, team, or application.

</Note>

## Deployment considerations

To plan and design the Vault namespaces, auth method paths and secrets engine
paths, you need to consider how to best structure Vault's logical objects for
your organization. 


<table>
  <thead>
    <tr>
      <th>Requirements</th>
      <th>What to consider</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Organizational structure</td>
      <td>
        <ul>
          <li>What is your organizational structure?</li>
          <li>What is the level of granularity across lines of businesses (LOBs), divisions, teams, services, apps that needs to be reflected in Vault's end-state design?</li>
        </ul>
      </td>
    </tr>
    <tr>
      <td>Self-service requirements</td>
      <td>
        <ul>
          <li>Given your organizational structure, what is the desired level of <strong>self-service</strong> required?</li>
          <li>How are Vault policies to be managed?</li>
          <li>Will teams need to directly manage policies for their own scope of responsibility?</li>
          <li>Or, will they be interacting with Vault via some abstraction layer where policies and patterns will be templatized? For example, configuration by code, Git flows, the Terraform Vault provider, custom onboarding layers, or some combination of these.</li>
        </ul>
      </td>
    </tr>
    <tr>
      <td>Audit requirements</td>
      <td>
        <ul>
          <li>What are the requirements around auditing usage of Vault within your organization?</li>
          <li>Is there a need to regularly certify access to secrets?</li>
          <li>Is there a need to review and/or decommission stale secrets or auth roles?</li>
          <li>Is there a need to determine chargeback amounts to internal customers?</li>
        </ul>
      </td>
    </tr>
    <tr>
      <td>Secrets engine requirements</td>
      <td>
        What types of secrets engines will you use (KV, database, AD, PKI, etc.)? <br /><br />
        For large organizations, each of these might require different structuring patterns. For example, with KV secrets engine, each team might have their own dedicated KV mount. However, for AD secrets engine, this is inherently a <em>shared</em> type of mount so you would manage access at a role level, rather than having multiple mounts that share the same connection configuration.
      </td>
    </tr>
  </tbody>
</table>


## Chroot namespace

<Note title="Vault version">

To use the chroot listener feature, you must run **Vault Enterprise 1.15** or
later.

</Note>

Vault clients (users, applications, etc.) must be aware of which namespace to
send requests, and set the target namespace using `-namespace` flag,
`X-Vault-Namespace` HTTP header, or `VAULT_NAMESPACE` environment variable. If
the target namespace is not properly set, the request will fail. This can be
cumbersome. 

To simplify, Vault operators can specify additional `listener` stanza in the
configuration file, and defines `chroot_namespace` to specify an alternate
top-level namespace.

**Example:** 

<CodeBlockConfig filename="vault-config.hcl" highlight="17-25">

```hcl
ui            = true
cluster_addr  = "https://127.0.0.1:8201"
api_addr      = "https://127.0.0.1:8200"
disable_mlock = true

storage "raft" {
  path = "/path/to/raft/data"
  node_id = "raft_node_1"
}

listener "tcp" {
  address       = "127.0.0.1:8200"
  tls_cert_file = "/path/to/full-chain.pem"
  tls_key_file  = "/path/to/private-key.pem"
}

listener "tcp" {
   address          = "127.0.0.1:8300"
   chroot_namespace = "usa-hq"
   tls_cert_file = "/path/to/full-chain.pem"
   tls_key_file  = "/path/to/private-key.pem"
   telemetry {
      unauthenticated_metrics_access = true
  }
}

telemetry {
  statsite_address = "127.0.0.1:8125"
  disable_hostname = true
}
```

</CodeBlockConfig>

The `chroot_namespace` specifies an alternate top-level namespace for the
listener, `https//127.0.0.1:8300`.

**Example request:**

```shell-session
$ curl --header "X-Vault-Namespace: team_1" \
   --header "X-Vault-Token: $VAULT_TOKEN" \
   --request POST \
   --data '{"type": "kv-v2"}' \
   https://127.0.0.1:8300/v1/sys/mounts/team-secret
```

The request operates on the `usa-hq/team_1` namespace since the top-level
namespace is set to `usa-hq` for the listener address, `127.0.0.1:8300`.

The top-level namespace for `https://127.0.0.1:8200` is `root`. 


## General guidance

The following principles should be used to guide an appropriate namespace or
mount path structure.

- [Use namespaces sparingly](#use-namespaces-sparingly)
- [Leverage Vault identities](#leverage-vault-identities)
- [Understand Vault's mount points](#understand-vault-s-mount-points)
- [Granularity of paths](#granularity-of-paths)
- [Standardized onboarding process](#standardized-onboarding-process)

### Use namespaces sparingly

The primary purpose of namespaces is to delineate administrative boundaries.
The main determining factor for **encapsulating an organizational unit** into
its own namespace is the need for that unit to be able to directly manage
policies. However, many organizations may find their deployment requirements are
more nuanced, especially if they want to enable "self-service" for their
consumers of Vault.

When setting up Vault to be self-service, you should first ask what does
"self-service" actually mean to your organization.

- Will teams be managing Vault directly?
- Will there be an onboarding process/layer that teams interact with?

When possible, HashiCorp recommends providing the self-service capability by
implementing an onboarding layer rather than directly through Vault. The
onboarding layer can enforce a standard naming convention, secrets path
structure, and templated policies. In this case, the administrative boundary
is at the onboarding layer and not at the organizational unit level. As such,
this use case should not require a separate namespace for the team.

![Namespaces best practices](/img/diagram_namespaces_bp.png)

However, these teams may roll up to a specific platform team or LOB for which
the policy structuring, authentication methods, and secrets use cases are common
across all teams within that LOB. Here, it makes sense that the higher-level
organizational unit has its own namespace.

Additionally, in many cases, most of the desired level of isolation can be
enforced via ACL policies.

The entire list of namespaces must fit into a single storage entry in Vault, and
each namespace creates at least two secrets engines which also require storage
space. Namespace planning should include a review of the maximum number of
namespaces allowed by the storage entry size.

### Leverage Vault identities

It's also critical to understand identity in order to make use of [Vault ACL
templates](/vault/docs/concepts/policies#templated-policies),
which can ease policy management.

Vault provides an internal layer of identity management that can be used to map
entities to multiple auth methods as well as provide grouping capabilities. This
allows for more robust policy assignment options.

<Tip>

Visit the [identity alias name
table](/vault/docs/secrets/identity#mount-bound-aliases) documentation page to
learn about constructing templated ACL policies.

</Tip>

The entity aliases, based on specific information available from the auth
method, maps to identity entities that you create. You can use the default names
and associated metadata that are created for aliases and entities as part of
policy templates and deciding on naming conventions for secrets paths/roles.
This allows you to avoid having hard-coded policies for use cases that follow a
certain pattern broadly.

You can define identity groups to associate entities that should have
permissions in common, and reference those groups in policy templates as much as
you can entities and aliases. These groups may also be created automatically for
you, depending on the auth methods used.

**ACL policy template example:**

<CodeBlockConfig lineNumbers>

```hcl 
path "kvv1-{{identity.entity.metadata.team_name}}/*" {
   capabilities = [ "create", "read", "update", "delete", "list" ]
}

path "transit/encrypt/{{identity.entity.aliases.auth_approle_b2560218.name}}" {
   capabilities = [ "update" ]
}
```

</CodeBlockConfig>

Those templated values get resolved dynamically based on the requester's entity
token metadata. 

At line 1, the `{{identity.entity.metadata.team_name}}` value retrieves the
`team_name` value set on the entity's metadata. Similarly, the
`{{identity.entity.aliases.auth_approle_b2560218.name}}` value at line 5 returns
the Role ID of the requesting client. This enables your policies to be less
static.

<Note>

 The number of identity entities is how Vault determines the number
of active clients for reporting and licensing purposes. Refer to the [Client
Count](/vault/docs/concepts/client-count) documentation for
more detail. 

</Note>

<Tip>

If you are not familiar with templated policies, read the [ACL Policy Path
Templating](/vault/tutorials/policies/policy-templating) tutorial.

</Tip>

### Understand Vault's mount points

Auth methods and secrets engines can be categorized into two types:

1. **Dedicated:** Auth methods and secrets engines that can be managed and
mapped directly to a specific organizational unit. For example, the team that
manages `app-1` can utilize their own AppRole and/or KV mounts without the
ability to impact other teams' mounts.

1. **Shared:** An organization level resources such as Kubernetes auth method
and the Active Directory (AD) secrets engine that are **shared** and managed at
the company level; therefore, mounted at the company-level namespace.

It's important to understand [Vault's sizing
restrictions](/vault/docs/internals/limits) for mounts. All
secrets engine and auth method mount points must each fit within a single storage
entry. For Consul, the storage limit is 512KB. For Integrated Storage the limit
is 1MB. 

Each JSON object describing a mount uses ~500 bytes, but in compressed form
it's ~75 bytes. Since auth mounts, secrets engine mount points, local-only auth
methods, and local-only secrets engine mounts are stored separately the limit
applies to each independently. 

By default, each namespace is created with a token auth mount (`/auth/`), an
identity mount (`/identity/`), and system mount (`/sys/`). This means that each
namespace requires three different mounts and then you will add your custom
mounts. Multiply that by 1,000s means that your mount tables will grow
exponentially.

### Granularity of paths 

When thinking about Vault's logical structure, you want to find the right
balance of granularity between the various mounts needed and the roles defined
within the mounts. 

Sharing mounts between teams has benefits and risk. It is up to you to find the
right balance of granularity between the various mounts needed and the roles
defined within the mounts. Below are a couple use cases with their benefits and
risks. 

You create a single KV mount with a sub-path for every team within the same
mount.  

- **Benefit:** reduces potential of hitting mount table limits.  
- **Risk:** the KV mount is accidentally deleted causing all users of that secret 
engine to be
impacted.

You create a unique mount per LOB.  

- **Benefit:** can provide sub-paths for different teams and limit the 
blast-radius  of an errant change to a single mount.  
- **Risk:** unique KV mounts per team becomes inefficient from a mount
management perspective.

![Compare a single mount vs. multiple mounts](/img/diagram_namespaces_kv-paths.png)

### Standardized onboarding process

When deploying Vault at scale, it is critical to Vault adoption to consider the
consumer experience. Specifically, it's important to reduce the level of
friction of consuming Vault. While it maybe quick to drop Vault into an
environment and interact with it directly, it's important to deliberately map
out how consumers will onboard to Vault and consume the service.

One of the pillars behind the Tao of Hashicorp is automation through
codification. Many HashiCorp users are using Terraform for managing
infrastructure on-prem and in the cloud. Terraform can also be used to [codify
Vault](/vault/tutorials/operations/codify-mgmt-enterprise)
configuration tasks such as creation of namespaces, policies, and mounts. This
allows Vault operators to increase their productivity, move quicker, promote
repeatable processes, and reduce human error.

## Tutorials

To learn more, review the following tutorials:

- [Secure multi-tenancy with namespaces](/vault/tutorials/enterprise/namespaces)
- [Vault recommended patterns](/vault/tutorials/recommended-patterns)
- [Vault standard operating procedures](/vault/tutorials/standard-procedures)
