The transit secrets engine handles cryptographic functions on data in-transit, mainly to encrypt data from applications while still storing that encrypted data in some primary data store. Vault doesn’t store the data sent to the secrets engine, it can also be viewed as “cryptography as a service” or “encryption as a service”. For details about transit encryption, see the official documentation.


Enable Transit secrets engine 🔗︎

To enable and test the Transit secrets engine, complete the following steps.

  1. Enable the Transit secrets engine:

    vault secrets enable transit
  2. Create a named encryption key:

    vault write -f transit/keys/my-key
  3. Encrypt data with encryption key:

    vault write transit/encrypt/my-key plaintext=$(base64 <<< "my secret data")
  4. After completing the previous steps, the webhook will mutate pods that have at least one environment variable with a value which is encrypted by Vault. For example (in the last line of the example):

    apiVersion: apps/v1
    kind: Deployment
      name: vault-test
      replicas: 1
   "https://vault:8200" # optional, the address of the Vault service, default values is https://vault:8200
   "default" # optional, the default value is the name of the ServiceAccount the Pod runs in, in case of Secrets and ConfigMaps it is "default"
   "false" # optional, skip TLS verification of the Vault server certificate
   "vault-tls" # optinal, the name of the Secret where the Vault CA cert is, if not defined it is not mounted
   "false" # optional, if true, a Vault Agent will be started to do Vault authentication, by default not needed and vault-env will do Kubernetes Service Account based Vault authentication
   "kubernetes" # optional, the Kubernetes Auth mount path in Vault the default value is "kubernetes"
   "my-key" # required if encrypted data was found; transit key id that created before
          serviceAccountName: default
          - name: alpine
            image: alpine
            command: ["sh", "-c", "echo $AWS_SECRET_ACCESS_KEY && echo going to sleep... && sleep 10000"]
            - name: AWS_SECRET_ACCESS_KEY
              # Value based on encrypted key that stored in Vault, so value from this example
              # not the same as you can get after `encrypt`
              value: vault:v1:8SDd3WHDOjf7mq69CyCqYjBXAiQQAVZRkFM13ok481zoCmHnSeDX9vyf7w==