What is a secrets engine?
Secrets engines are Vault components which store, generate or encrypt secrets. In Your First Secrets tutorial, you used key/value v2 secrets engine to store data. Some secrets engines like the key/value secrets engine simply store and read data. Other secrets engines connect to other services and generate dynamic credentials on demand. Other secrets engines provide encryption as a service.
There are a number of secrets engines available. You can think of them as a plugin. Enable the secrets engine that meets your security needs.
Secrets Management has a tutorial for different secrets engines. But first, complete this tutorial to learn the basic commands.
In the Your First Secrets
tutorial, we used the
-mount=secret flag with our
kv commands. The
key/value v2 secrets engine was enabled and ready to receive requests at
secret/ by default because we had started our Vault server in
-mount flag syntax (e.g.
vault kv get -mount=secret foo) from
the previous tutorial is recommended
when using the KV v2 secrets engine, but in this tutorial, we'll be using the
KV v1 secrets engine and the path prefix syntax instead (e.g.
vault kv get secret/foo)
just to quickly demonstrate some concepts universal to all secrets engines.
Try the following command which will result an error:
$ vault kv put foo/bar a=b Error making API request. URL: GET http://localhost:8200/v1/sys/internal/ui/mounts/foo/bar Code: 403. Errors: * preflight capability check returned 403, ... grant access to path "foo/bar/"
The path prefix (or alternatively the
-mount flag for
vault kv commands)
tells Vault which secrets engine to which it should route traffic. When a
request comes to Vault, it matches the initial path part using a longest
prefix match and then passes the request to the corresponding secrets engine
enabled at that path. Vault presents these secrets engines similar to a
There is no secrets engine mounted at
foo, so the above command returned an error.
This tutorial discusses secrets engines and the operations they support. This information is important to both operators who will configure Vault and users who will interact with Vault.
Enable a secrets engine
To get started, enable a new KV secrets engine at the path
kv. Each path is
completely isolated and cannot talk to other paths. For example, a KV secrets
engine enabled at
foo has no ability to communicate with a KV secrets engine
$ vault secrets enable -path=kv kv Success! Enabled the kv secrets engine at: kv/
The path where the secrets engine is enabled defaults to the name of the secrets engine. Thus, the following command is equivalent to executing the above command.
$ vault secrets enable kv
Executing this command will throw the
path is already in use at kv/ error.
To verify our success and get more information about the secrets engine, use the
vault secrets list command:
$ vault secrets list Path Type Accessor Description ---- ---- -------- ----------- cubbyhole/ cubbyhole cubbyhole_78189996 per-token private secret storage identity/ identity identity_ac07951e identity store kv/ kv kv_15087625 n/a secret/ kv kv_4b990c45 key/value secret storage sys/ system system_adff0898 system endpoints used for control, policy and debugging
This shows there are 5 enabled secrets engines on this Vault server. You can see
the type of the secrets engine, the corresponding path, and an optional
description (or "n/a" if none was given). Running the above command with the
-detailed flag can show you the version of the KV secrets engine and more.
sys/ path corresponds to the system backend. These paths interact with
Vault's core system and are not required for beginners.
Take a few moments to read and write some data to the new
kv secrets engine
kv/. Here are a few ideas to get started.
To create secrets, use the
kv put command.
$ vault kv put kv/hello target=world Success! Data written to: kv/hello
To read the secrets stored in the
kv/hello path, use the
kv get command.
$ vault kv get kv/hello ===== Data ===== Key Value --- ----- target world
Create secrets at the
$ vault kv put kv/my-secret value="s3c(eT" Success! Data written to: kv/my-secret
Read the secrets at
$ vault kv get kv/my-secret ==== Data ==== Key Value --- ----- value s3c(eT
Delete the secrets at
$ vault kv delete kv/my-secret Success! Data deleted (if it existed) at: kv/my-secret
List existing keys at the
$ vault kv list kv/ Keys ---- hello
Disable a secrets engine
When a secrets engine is no longer needed, it can be disabled. When a secrets engine is disabled, all secrets are revoked and the corresponding Vault data and configuration is removed.
$ vault secrets disable kv/ Success! Disabled the secrets engine (if it existed) at: kv/
Note that this command takes a PATH to the secrets engine as an argument, not the TYPE of the secrets engine.
Any requests to route data to the original path would result in an error, but another secrets engine could now be enabled at that path.
Vault behaves similarly to a virtual filesystem. The read/write/delete/list operations are forwarded to the corresponding secrets engine, and the secrets engine decides how to react to those operations.
This abstraction is incredibly powerful. It enables Vault to interface directly with physical systems, databases, HSMs, etc. But in addition to these physical systems, Vault can interact with more unique environments like AWS IAM, dynamic SQL user creation, etc. all while using the same read/write interface.
You learned the basics of the
vault secrets command. This is important
knowledge to move forward and explore other secrets engines.