hashicorp/vault

Vault

Vault is a tool for securely accessing secrets. A secret is anything that you want to tightly control access to, such as API keys, passwords, certificates, and more. Vault provides a unified interface to any secret, while providing tight access control and recording a detailed audit log. For more information, please see:

• Vault documentation
• https://github.com/hashicorp/vault

Using the Container

We chose Alpine as a lightweight base with a reasonably small surface area for security concerns, but with enough functionality for development and interactive debugging.

Vault always runs under https://github.com/Yelp/dumb-init, which handles reaping zombie processes and forwards signals on to all processes running in the container. This binary is built by HashiCorp and signed with our GPG key, so you can verify the signed package used to build a given base image.

Running the Vault container with no arguments will give you a Vault server in development mode. The provided entry point script will also look for Vault subcommands and run vault with that subcommand. For example, you can execute docker run vault status and it will run the vault status command inside the container. The entry point also adds some special configuration options as detailed in the sections below when running the server subcommand. Any other command gets exec-ed inside the container under dumb-init.

The container exposes two optional VOLUMEs:

• /vault/logs, to use for writing persistent audit logs. By default nothing is written here; the file audit backend must be enabled with a path under this directory.
• /vault/file, to use for writing persistent storage data when using thefile data storage plugin. By default nothing is written here (a dev server uses an in-memory data store); the file data storage backend must be enabled in Vault's configuration before the container is started.

The container has a Vault configuration directory set up at /vault/config and the server will load any HCL or JSON configuration files placed here by binding a volume or by composing a new image and adding files. Alternatively, configuration can be added by passing the configuration JSON via environment variable VAULT_LOCAL_CONFIG.

Memory Locking and 'setcap'

The container will attempt to lock memory to prevent sensitive values from being swapped to disk and as a result must have --cap-add=IPC_LOCK provided to docker run. Since the Vault binary runs as a non-root user, setcap is used to give the binary the ability to lock memory. With some Docker storage plugins in some distributions this call will not work correctly; it seems to fail most often with AUFS. The memory locking behavior can be disabled by setting the SKIP_SETCAP environment variable to any non-empty value.

Running Vault for Development

console
$ docker run --cap-add=IPC_LOCK -d --name=dev-vault hashicorp/vault

This runs a completely in-memory Vault server, which is useful for development but should not be used in production.

When running in development mode, two additional options can be set via environment variables:

• VAULT_DEV_ROOT_TOKEN_ID: This sets the ID of the initial generated root token to the given value
• VAULT_DEV_LISTEN_ADDRESS: This sets the IP:port of the development server listener (defaults to 0.0.0.0:8200)

As an example:

console
$ docker run --cap-add=IPC_LOCK -e 'VAULT_DEV_ROOT_TOKEN_ID=myroot' -e 'VAULT_DEV_LISTEN_ADDRESS=0.0.0.0:1234' hashicorp/vault

Running Vault in Server Mode for Development

console
$ docker run --cap-add=IPC_LOCK -e 'VAULT_LOCAL_CONFIG={"storage": {"file": {"path": "/vault/file"}}, "listener": [{"tcp": { "address": "0.0.0.0:8200", "tls_disable": true}}], "default_lease_ttl": "168h", "max_lease_ttl": "720h", "ui": true}' -p 8200:8200 hashicorp/vault server

This runs a Vault server with TLS disabled, the file storage backend at path /vault/file and a default secret lease duration of one week and a maximum of 30 days. Disabling TLS and using the file storage backend are not recommended for production use.

Note the --cap-add=IPC_LOCK: this is required in order for Vault to lock memory, which prevents it from being swapped to disk. This is highly recommended. In a non-development environment, if you do not wish to use this functionality, you must add "disable_mlock: true" to the configuration information.

At startup, the server will read configuration HCL and JSON files from /vault/config (any information passed into VAULT_LOCAL_CONFIG is written into local.json in this directory and read as part of reading the directory for configuration files). Please see Vault's configuration documentation for a full list of options.

We suggest volume mounting a directory into the Docker image in order to give both the configuration and TLS certificates to Vault. You can accomplish this with:

console
$ docker run --volume config/:/vault/config.d ...

For more scalability and reliability, we suggest running containerized Vault in an orchestration environment like k8s or OpenShift.

Since 0.6.3 this container also supports the VAULT_REDIRECT_INTERFACE and VAULT_CLUSTER_INTERFACE environment variables. If set, the IP addresses used for the redirect and cluster addresses in Vault's configuration will be the address of the named interface inside the container (e.g. eth0).

License

View https://raw.githubusercontent.com/hashicorp/vault/main/LICENSE for the software contained in this image.