Nomad Secret Backend

Name: Nomad

Nomad is a simple, flexible scheduler and workload orchestrator. The Nomad secret backend for Vault generates Nomad ACL tokens dynamically based on pre-existing Nomad ACL policies.

This page will show a quick start for this backend. For detailed documentation on every path, use vault path-help after mounting the backend.

Quick Start

The first step to using the vault backend is to mount it. Unlike the generic backend, the nomad backend is not mounted by default.

$ vault secrets enable nomad
Successfully mounted 'nomad' at 'nomad'!

Optionally, we can configure the lease settings for credentials generated by Vault. This is done by writing to the config/lease key:

$ vault write nomad/config/lease ttl=3600 max_ttl=86400
Success! Data written to: nomad/config/lease

For a quick start, you can use the SecretID token provided by the Nomad ACL bootstrap process, although this is discouraged for production deployments.

$ nomad acl bootstrap
Accessor ID  = 95a0ee55-eaa6-2c0a-a900-ed94c156754e
Secret ID    = c25b6ca0-ea4e-000f-807a-fd03fcab6e3c
Name         = Bootstrap Token
Type         = management
Global       = true
Policies     = n/a
Create Time  = 2017-09-20 19:40:36.527512364 +0000 UTC
Create Index = 7
Modify Index = 7

The suggested pattern is to generate a token specifically for Vault, following the Nomad ACL guide

Next, we must configure Vault to know how to contact Nomad. This is done by writing the access information:

$ vault write nomad/config/access \
    address=http://127.0.0.1:4646 \
    token=adf4238a-882b-9ddc-4a9d-5b6758e4159e
Success! Data written to: nomad/config/access

In this case, we've configured Vault to connect to Nomad on the default port with the loopback address. We've also provided an ACL token to use with the token parameter. Vault must have a management type token so that it can create and revoke ACL tokens.

The next step is to configure a role. A role is a logical name that maps to a set of policy names used to generate those credentials. For example, let's create a "monitoring" role that maps to a "readonly" policy:

$ vault write nomad/role/monitoring policies=readonly
Success! Data written to: nomad/role/monitoring

The backend expects either a single or a comma separated list of policy names.

To generate a new Nomad ACL token, we simply read from that role:

$ vault read nomad/creds/monitoring
Key              Value
---              -----
lease_id         nomad/creds/monitoring/78ec3ef3-c806-1022-4aa8-1dbae39c760c
lease_duration   768h0m0s
lease_renewable  true
accessor_id      a715994d-f5fd-1194-73df-ae9dad616307
secret_id        b31fb56c-0936-5428-8c5f-ed010431aba9

Here we can see that Vault has generated a new Nomad ACL token for us. We can test this token out, by reading it in Nomad (by it's accessor):

$ nomad acl token info a715994d-f5fd-1194-73df-ae9dad616307
Accessor ID  = a715994d-f5fd-1194-73df-ae9dad616307
Secret ID    = b31fb56c-0936-5428-8c5f-ed010431aba9
Name         = Vault example root 1505945527022465593
Type         = client
Global       = false
Policies     = [readonly]
Create Time  = 2017-09-20 22:12:07.023455379 +0000 UTC
Create Index = 138
Modify Index = 138

Learn

Refer to Generate Nomad Tokens with HashiCorp Vault for a step-by-step tutorial.

API

The Nomad secret backend has a full HTTP API. Please see the Nomad secret backend API for more details.