starting Hashicorp vault in server mode under docker container

Running Hashicorp vault in development mode is really easy, but starting the vault in server mode under a docker container may have some changes described in this article.

There are several simple steps, which is hard to get in one place, to run a Hashicorp vault in server mode (under docker):

  1. Prepare the directories to map in the docker. The data in the directories will be safe and won’t be deleted if the container is deleted.
  2. Prepare an initial base configuration to start the server. Without it, the server won’t startup. Even it is really simple.
  3. Start the Hashicorp vault process in a docker container.
  4. Initiliza the vault. During this step, the server will generate the database backend storage (files or in-memory or cloud backends) and 5 unseal keys and an administrative root token will be generated. To manage the vault an administrative user is required.
  5. Unseal the vault. Unencrypt the database backend to use the service with at least three commands and three different unseal keys generated during the initialization step.
  6. Login with the administrative user and enable vault engine to store values (or generate tokens, passwords, and so on). The example here enables the secret engine to store key:value backend. Check out the secrets engines – https://www.vaultproject.io/docs/secrets

STEP 1) Summary of the mapped directories in the docker

Three directories are preserved:

  • /vault/config – contains configuration files in HCL or JSON format.
  • /vault/data – the place, where the encrypted database files will be kept only if a similar storage engine is used like “file” or “raft” storages. More information here – https://www.vaultproject.io/docs/configuration/storage
  • /vault/log – writing persistent audit logs. This feature should be enabled explicitly in the configuration.

The base directory used is /srv/vault/. And the three direcotries are created as follow and will be mapped in the docker container:

mkdir -p /srv/vault/config /srv/vault/data /srv/vault/log

The server’s directory /srv/vault/config will be mapped in docker’s directory /vault/config and the other two, too.

STEP 2) Initial base configuration

The initial configuration file is placed in /vault/config/config.hcl and is using HCL format – https://github.com/hashicorp/hcl. The initial configuration is minimal:

storage "raft" {
  path    = "/vault/data"
  node_id = "node1"
}

listener "tcp" {
  address     = "127.0.0.1:8200"
  tls_disable = 1
}

disable_mlock = true

api_addr = "http://127.0.0.1:8200"
cluster_addr = "https://127.0.0.1:8201"
ui = true

Place the file in /srv/vault/config/config.hcl

STEP 3) Start the Hashicorp vault server in docker

Mapping the three directories.

root@srv ~ # docker run --cap-add=IPC_LOCK -v /srv/vault/config:/vault/config -v /srv/vault/data:/vault/data -v /srv/vault/logs:/vault/logs --name=srv-vault vault server
==> Vault server configuration:

             Api Address: http://127.0.0.1:8200
                     Cgo: disabled
         Cluster Address: https://127.0.0.1:8201
              Go Version: go1.14.7
              Listener 1: tcp (addr: "127.0.0.1:8200", cluster address: "127.0.0.1:8201", max_request_duration: "1m30s", max_request_size: "33554432", tls: "disabled")
               Log Level: info
                   Mlock: supported: true, enabled: false
           Recovery Mode: false
                 Storage: raft (HA available)
                 Version: Vault v1.5.3
             Version Sha: 9fcd81405feb320390b9d71e15a691c3bc1daeef

==> Vault server started! Log data will stream in below:

Keep on reading!