Overview

Simple compose file that prepares a vault server that can be use to auto-unseal other vaults

Usage

Just clone the repo, cd into the folder and run:

docker compose build

docker compose up -d

# Wait a few seconds

docker compose logs -f initializer

Now depending on the use case you need to grab the cert and token shown in the output and use them accordingly. Some examples

1. Locally for validation purposes

export VAULT_ADDR=https://127.0.0.1:8201
export VAULT_CACERT=/tmp/vault/certs/cert.pem
export VAULT_TOKEN=s.b4b90sp0PNd4rssXvbFFK08j  #This was taken from the output of the initializer

vault write transit/encrypt/defaultautounseal plaintext=$(base64 <<< "my secret data")

2. To initialize another vault running in the host

Add the below seal section to your vault config:

seal "transit" {
  address            = "https://127.0.0.1:8201"
  disable_renewal    = "false"
  key_name           = "defaultautounseal"
  mount_path         = "transit/"
  tls_ca_cert        = "/tmp/vault/certs/cert.pem"
  tls_skip_verify    = "false"
  
}

More Details

This is what happens behind the scenes:

1. Spin up a container vaulttransit with vault
   • Creates self signed cert and enables TLS
   • Exposes 8201 port
   • mounts /tmp/vault/certs folder from host to store certs
2. Spin a container called initializer that will initialize and prepare vault to be used by other vault servers to auto-unseal.
   • Initializes vault with just 1 key share
   • Token and Unseal Key are saved to: /vault/certs/token and /vault/certs/key respectively
   • Enables transit engine (default mount path transit/)
   • Creates transit key: defaultautounseal
   • Creates a policy that can only encrypt and decrypt data using the ge key above
   • Creates a token with the policy
   • Prints the content of the Cert to stdout (you can check it with docker logs initializer)
   • Prints the token to stdout (you can check it with docker logs initializer)
   • saves the generated tokens into file /vault/transit_tokens inside the container

How to get details required to connect to this server

The VAULT_ADDR can be:

1. From the host:

• https://127.0.0.1:8201
• https://localhost:8201

2. From another container on the same network:

• https://vaulttransit:8200

Then, the cert and token can be retrieved with any of these options:

Option 1: Self signed cert can be found under /tmp/vault/certs on the host or from the output of the container named initializer

Option 2: Self signed cert and token can be found by looking at the output of the initializer container docker logs initializer