Now that the dev server is up and running, let's get straight to it and read and write our first secret.
One of the core features of Vault is the ability to read and write arbitrary secrets securely. On this page, we'll do this using the CLI, but there is also a complete HTTP API that can be used to programmatically do anything with Vault.
Secrets written to Vault are encrypted and then written to backend storage. For our dev server, backend storage is in-memory, but in production this would more likely be on disk or in Consul. Vault encrypts the value before it is ever handed to the storage driver. The backend storage mechanism never sees the unencrypted value and doesn't have the means necessary to decrypt it without Vault.
Writing a Secret
Let's start by writing a secret. This is done very simply with the
vault kv command, as shown below:
$ vault kv put secret/hello foo=world Key Value --- ----- created_time 2019-02-04T19:53:22.730733Z deletion_time n/a destroyed false version 1
This writes the pair
foo=world to the path
cover paths in more detail later, but for now it is important that the
path is prefixed with
secret/, otherwise this example won't work. The
secret/ prefix is where arbitrary secrets can be read and written.
You can even write multiple pieces of data, if you want:
$ vault kv put secret/hello foo=world excited=yes Key Value --- ----- created_time 2019-02-04T19:54:03.250328Z deletion_time n/a destroyed false version 2
vault kv put is a very powerful command. In addition to writing data
directly from the command-line, it can read values and key pairs from
STDIN as well as files. For more information, see the
Warning: The documentation uses the
key=value based entry
throughout, but it is more secure to use files if possible. Sending
data via the CLI is often logged in shell history. For real secrets,
please use files. See the link above about reading in from
STDIN for more information.
Getting a Secret
As you might expect, secrets can be gotten with
$ vault kv get secret/hello ====== Metadata ====== Key Value --- ----- created_time 2019-02-04T19:54:03.250328Z deletion_time n/a destroyed false version 2 ===== Data ===== Key Value --- ----- excited yes foo world
As you can see, the values we wrote are given back to us. Vault gets the data from storage and decrypts it.
The output format is purposefully whitespace separated to make it easy
to pipe into a tool like
This contains some extra information. Many secrets engines create leases for
secrets that allow time-limited access to other systems, and in those cases
lease_id would contain a lease identifier and
lease_duration would contain
the length of time for which the lease is valid, in seconds.
To print only the value of a given field:
$ vault kv get -field=excited secret/hello yes
Optional JSON output is very useful for scripts. For example below we use the
jq tool to extract the value of the
$ vault kv get -format=json secret/hello | jq -r .data.data.excited yes
Deleting a Secret
Now that we've learned how to read and write a secret, let's go ahead
and delete it. We can do this with
$ vault kv delete secret/hello Success! Data deleted (if it existed) at: secret/hello
In this section we learned how to use the powerful CRUD features of Vault to store arbitrary secrets. On its own this is already a useful but basic feature.