140 lines
6.3 KiB
Markdown
140 lines
6.3 KiB
Markdown
---
|
|
layout: "vault"
|
|
page_title: "Provider: Vault"
|
|
sidebar_current: "docs-vault-index"
|
|
description: |-
|
|
The Vault provider allows Terraform to read from, write to, and configure Hashicorp Vault
|
|
---
|
|
|
|
# Vault Provider
|
|
|
|
The Vault provider allows Terraform to read from, write to, and configure
|
|
[Hashicorp Vault](https://vaultproject.io/).
|
|
|
|
~> **Important** Interacting with Vault from Terraform causes an secrets
|
|
that you read and write to be persisted in both Terraform's state file
|
|
*and* in any generated plan files. For any Terraform module that reads or
|
|
writes Vault secrets, these files should be treated as sensitive and
|
|
protected accordingly.
|
|
|
|
This provider serves two pretty-distinct use-cases, which each have their
|
|
own security trade-offs and caveats that are covered in the sections that
|
|
follow. Consider these carefully before using this provider within your
|
|
Terraform configuration.
|
|
|
|
## Configuring and Populating Vault
|
|
|
|
Terraform can be used by the Vault adminstrators to configure Vault and
|
|
populate it with secrets. In this case, the state and any plans associated
|
|
with the configuration must be stored and communicated with care, since they
|
|
will contain in cleartext any values that were written into Vault.
|
|
|
|
Currently Terraform has no mechanism to redact or protect secrets
|
|
that are provided via configuration, so teams choosing to use Terraform
|
|
for populating Vault secrets should pay careful attention to the notes
|
|
on each resource's documentation page about how any secrets are persisted
|
|
to the state and consider carefully whether such usage is compatible with
|
|
their security policies.
|
|
|
|
Except as otherwise noted, the resources that write secrets into Vault are
|
|
designed such that they require only the *create* and *update* capabilities
|
|
on the relevant resources, so that distinct tokens can be used for reading
|
|
vs. writing and thus limit the exposure of a compromised token.
|
|
|
|
## Using Vault credentials in Terraform configuration
|
|
|
|
Most Terraform providers require credentials to interact with a third-party
|
|
service that they wrap. This provider allows such credentials to be obtained
|
|
from Vault, which means that operators or systems running Terraform need
|
|
only access to a suitably-privileged Vault token in order to temporarily
|
|
lease the credentials for other providers.
|
|
|
|
Currently Terraform has no mechanism to redact or protect secrets that
|
|
are returned via data sources, so secrets read via this provider will be
|
|
persisted into the Terraform state, into any plan files, and in some cases
|
|
in the console output produced while planning and applying. These artifacts
|
|
must therefore all be protected accordingly.
|
|
|
|
To reduce the exposure of such secrets, the provider requests a Vault token
|
|
with a relatively-short TTL (20 minutes, by default) which in turn means
|
|
that where possible Vault will revoke any issued credentials after that
|
|
time, but in particular it is unable to retract any static secrets such as
|
|
those stored in Vault's "generic" secret backend.
|
|
|
|
The requested token TTL can be controlled by the `max_lease_ttl_seconds`
|
|
provider argument described below. It is important to consider that Terraform
|
|
reads from data sources during the `plan` phase and writes the result into
|
|
the plan. Thus a subsequent `apply` will likely fail if it is run after the
|
|
intermediate token has expired, due to the revocation of the secrets that
|
|
are stored in the plan.
|
|
|
|
Except as otherwise noted, the resources that read secrets from Vault
|
|
are designed such that they require only the *read* capability on the relevant
|
|
resources.
|
|
|
|
## Provider Arguments
|
|
|
|
The provider configuration block accepts the following arguments.
|
|
In most cases it is recommended to set them via the indicated environment
|
|
variables in order to keep credential information out of the configuration.
|
|
|
|
* `address` - (Required) Origin URL of the Vault server. This is a URL
|
|
with a scheme, a hostname and a port but with no path. May be set
|
|
via the `VAULT_ADDR` environment variable.
|
|
|
|
* `token` - (Required) Vault token that will be used by Terraform to
|
|
authenticate. May be set via the `VAULT_TOKEN` environment variable.
|
|
Terraform will issue itself a new token that is a child of the one given,
|
|
with a short TTL to limit the exposure of any requested secrets.
|
|
|
|
* `ca_cert_file` - (Optional) Path to a file on local disk that will be
|
|
used to validate the certificate presented by the Vault server.
|
|
May be set via the `VAULT_CACERT` environment variable.
|
|
|
|
* `ca_cert_dir` - (Optional) Path to a directory on local disk that
|
|
contains one or more certificate files that will be used to validate
|
|
the certificate presented by the Vault server. May be set via the
|
|
`VAULT_CAPATH` environment variable.
|
|
|
|
* `client_auth` - (Optional) A configuration block, described below, that
|
|
provides credentials used by Terraform to authenticate with the Vault
|
|
server. At present there is little reason to set this, because Terraform
|
|
does not support the TLS certificate authentication mechanism.
|
|
|
|
* `skip_tls_verify` - (Optional) Set this to `true` to disable verification
|
|
of the Vault server's TLS certificate. This is strongly discouraged except
|
|
in prototype or development environments, since it exposes the possibility
|
|
that Terraform can be tricked into writing secrets to a server controlled
|
|
by an intruder. May be set via the `VAULT_SKIP_VERIFY` environment variable.
|
|
|
|
* `max_lease_ttl_seconds` - (Optional) Used as the duration for the
|
|
intermediate Vault token Terraform issues itself, which in turn limits
|
|
the duration of secret leases issued by Vault. Defaults to 20 minutes
|
|
and may be set via the `TERRAFORM_VAULT_MAX_TTL` environment variable.
|
|
See the section above on *Using Vault credentials in Terraform configuration*
|
|
for the implications of this setting.
|
|
|
|
The `client_auth` configuration block accepts the following arguments:
|
|
|
|
* `cert_file` - (Required) Path to a file on local disk that contains the
|
|
PEM-encoded certificate to present to the server.
|
|
|
|
* `key_file` - (Required) Path to a file on local disk that contains the
|
|
PEM-encoded private key for which the authentication certificate was issued.
|
|
|
|
## Example Usage
|
|
|
|
```
|
|
provider "vault" {
|
|
# It is strongly recommended to configure this provider through the
|
|
# environment variables described below, so that each user can have
|
|
# separate credentials set in the environment.
|
|
address = "https://vault.example.net:8200"
|
|
}
|
|
|
|
data "vault_generic_secret" "example" {
|
|
path = "secret/foo"
|
|
}
|
|
```
|
|
|