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Spring Cloud Vault Config provides client-side support for externalized configuration in a distributed system. With HashiCorp’s Vault you have a central place to manage external secret properties for applications across all environments. Vault can manage static and dynamic secrets such as username/password for remote applications/resources and provide credentials for external services such as MySQL, PostgreSQL, Apache Cassandra, MongoDB, Consul, AWS and more.

Quick Start

Prerequisites

To get started with Vault and this guide you need a *NIX-like operating systems that provides:

  • wget, openssl and unzip

  • at least Java 8 and a properly configured JAVA_HOME environment variable

This guide explains Vault setup from a Spring Cloud Vault perspective for integration testing. You can find a getting started guide directly on the Vault project site: https://learn.hashicorp.com/vault

Install Vault

$ wget https://releases.hashicorp.com/vault/${vault_version}/vault_${vault_version}_${platform}.zip
$ unzip vault_${vault_version}_${platform}.zip
These steps can be achieved by downloading and running install_vault.sh.

Create SSL certificates for Vault

Next, you’r required to generate a set of certificates:

  • Root CA

  • Vault Certificate (decrypted key work/ca/private/localhost.decrypted.key.pem and certificate work/ca/certs/localhost.cert.pem)

Make sure to import the Root Certificate into a Java-compliant truststore.

The easiest way to achieve this is by using OpenSSL.

create_certificates.sh creates certificates in work/ca and a JKS truststore work/keystore.jks. If you want to run Spring Cloud Vault using this quickstart guide you need to configure the truststore the spring.cloud.vault.ssl.trust-store property to file:work/keystore.jks.

Start Vault server

Next create a config file along the lines of:

backend "inmem" {
}

listener "tcp" {
  address = "0.0.0.0:8200"
  tls_cert_file = "work/ca/certs/localhost.cert.pem"
  tls_key_file = "work/ca/private/localhost.decrypted.key.pem"
}

disable_mlock = true
You can find an example config file at vault.conf. 
$ vault server -config=vault.conf

Vault is started listening on 0.0.0.0:8200 using the inmem storage and https. Vault is sealed and not initialized when starting up.

If you want to run tests, leave Vault uninitialized. The tests will initialize Vault and create a root token 00000000-0000-0000-0000-000000000000.

If you want to use Vault for your application or give it a try then you need to initialize it first.

$ export VAULT_ADDR="https://localhost:8200"
$ export VAULT_SKIP_VERIFY=true # Don't do this for production
$ vault init

You should see something like:

Key 1: 7149c6a2e16b8833f6eb1e76df03e47f6113a3288b3093faf5033d44f0e70fe701
Key 2: 901c534c7988c18c20435a85213c683bdcf0efcd82e38e2893779f152978c18c02
Key 3: 03ff3948575b1165a20c20ee7c3e6edf04f4cdbe0e82dbff5be49c63f98bc03a03
Key 4: 216ae5cc3ddaf93ceb8e1d15bb9fc3176653f5b738f5f3d1ee00cd7dccbe926e04
Key 5: b2898fc8130929d569c1677ee69dc5f3be57d7c4b494a6062693ce0b1c4d93d805
Initial Root Token: 19aefa97-cccc-bbbb-aaaa-225940e63d76

Vault initialized with 5 keys and a key threshold of 3. Please
securely distribute the above keys. When the Vault is re-sealed,
restarted, or stopped, you must provide at least 3 of these keys
to unseal it again.

Vault does not store the master key. Without at least 3 keys,
your Vault will remain permanently sealed.

Vault will initialize and return a set of unsealing keys and the root token. Pick 3 keys and unseal Vault. Store the Vault token in the VAULT_TOKEN environment variable.

$ vault unseal (Key 1)
$ vault unseal (Key 2)
$ vault unseal (Key 3)
$ export VAULT_TOKEN=(Root token)
# Required to run Spring Cloud Vault tests after manual initialization
$ vault token-create -id="00000000-0000-0000-0000-000000000000" -policy="root"

Spring Cloud Vault accesses different resources. By default, the secret backend is enabled which accesses secret config settings via JSON endpoints.

The HTTP service has resources in the form:

/secret/{application}/{profile}
/secret/{application}
/secret/{defaultContext}/{profile}
/secret/{defaultContext}

where the "application" is injected as the spring.application.name in the SpringApplication (i.e. what is normally "application" in a regular Spring Boot app), "profile" is an active profile (or comma-separated list of properties). Properties retrieved from Vault will be used "as-is" without further prefixing of the property names.

Client Side Usage

To use these features in an application, just build it as a Spring Boot application that depends on spring-cloud-vault-config (e.g. see the test cases). Example Maven configuration:

Example 1. pom.xml
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.0.RELEASE</version>
    <relativePath /> <!-- lookup parent from repository -->
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-vault-config</artifactId>
        <version>3.0.0-SNAPSHOT</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

<!-- repositories also needed for snapshots and milestones -->

Then you can create a standard Spring Boot application, like this simple HTTP server:

@SpringBootApplication
@RestController
public class Application {

    @RequestMapping("/")
    public String home() {
        return "Hello World!";
    }

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

When it runs it will pick up the external configuration from the default local Vault server on port 8200 if it is running. To modify the startup behavior you can change the location of the Vault server using bootstrap.properties (like application.properties but for the bootstrap phase of an application context), e.g.

Example 2. bootstrap.yml
spring.cloud.vault:
    host: localhost
    port: 8200
    scheme: https
    uri: https://localhost:8200
    connection-timeout: 5000
    read-timeout: 15000
    config:
        order: -10

  • host sets the hostname of the Vault host. The host name will be used for SSL certificate validation

  • port sets the Vault port

  • scheme setting the scheme to http will use plain HTTP. Supported schemes are http and https.

  • uri configure the Vault endpoint with an URI. Takes precedence over host/port/scheme configuration

  • connection-timeout sets the connection timeout in milliseconds

  • read-timeout sets the read timeout in milliseconds

  • config.order sets the order for the property source

Enabling further integrations requires additional dependencies and configuration. Depending on how you have set up Vault you might need additional configuration like SSL and authentication.

If the application imports the spring-boot-starter-actuator project, the status of the vault server will be available via the /health endpoint.

The vault health indicator can be enabled or disabled through the property management.health.vault.enabled (default to true).

Authentication

Vault requires an authentication mechanism to authorize client requests.

Spring Cloud Vault supports multiple authentication mechanisms to authenticate applications with Vault.

For a quickstart, use the root token printed by the Vault initialization.

Example 3. bootstrap.yml
spring.cloud.vault:
    token: 19aefa97-cccc-bbbb-aaaa-225940e63d76
Consider carefully your security requirements. Static token authentication is fine if you want quickly get started with Vault, but a static token is not protected any further. Any disclosure to unintended parties allows Vault use with the associated token roles.

Authentication methods

Different organizations have different requirements for security and authentication. Vault reflects that need by shipping multiple authentication methods. Spring Cloud Vault supports token and AppId authentication.

Token authentication

Tokens are the core method for authentication within Vault. Token authentication requires a static token to be provided using the Bootstrap Application Context.

Token authentication is the default authentication method. If a token is disclosed an unintended party gains access to Vault and can access secrets for the intended client.
Example 4. bootstrap.yml
spring.cloud.vault:
    authentication: TOKEN
    token: 00000000-0000-0000-0000-000000000000

  • authentication setting this value to TOKEN selects the Token authentication method

  • token sets the static token to use

See also: Vault Documentation: Tokens

Vault Agent authentication

Vault ships a sidecar utility with Vault Agent since version 0.11.0. Vault Agent implements the functionality of Spring Vault’s SessionManager with its Auto-Auth feature. Applications can reuse cached session credentials by relying on Vault Agent running on localhost. Spring Vault can send requests without the X-Vault-Token header. Disable Spring Vault’s authentication infrastructure to disable client authentication and session management.

Example 5. bootstrap.yml
spring.cloud.vault:
    authentication: NONE

  • authentication setting this value to NONE disables ClientAuthentication and SessionManager.

See also: Vault Documentation: Agent

AppId authentication

Vault supports AppId authentication that consists of two hard to guess tokens. The AppId defaults to spring.application.name that is statically configured. The second token is the UserId which is a part determined by the application, usually related to the runtime environment. IP address, Mac address or a Docker container name are good examples. Spring Cloud Vault Config supports IP address, Mac address and static UserId’s (e.g. supplied via System properties). The IP and Mac address are represented as Hex-encoded SHA256 hash.

IP address-based UserId’s use the local host’s IP address.

Example 6. bootstrap.yml using SHA256 IP-Address UserId’s
spring.cloud.vault:
    authentication: APPID
    app-id:
        user-id: IP_ADDRESS

  • authentication setting this value to APPID selects the AppId authentication method

  • app-id-path sets the path of the AppId mount to use

  • user-id sets the UserId method. Possible values are IP_ADDRESS, MAC_ADDRESS or a class name implementing a custom AppIdUserIdMechanism

The corresponding command to generate the IP address UserId from a command line is:

$ echo -n 192.168.99.1 | sha256sum
Including the line break of echo leads to a different hash value so make sure to include the -n flag.

Mac address-based UserId’s obtain their network device from the localhost-bound device. The configuration also allows specifying a network-interface hint to pick the right device. The value of network-interface is optional and can be either an interface name or interface index (0-based).

Example 7. bootstrap.yml using SHA256 Mac-Address UserId’s
spring.cloud.vault:
    authentication: APPID
    app-id:
        user-id: MAC_ADDRESS
        network-interface: eth0

  • network-interface sets network interface to obtain the physical address

The corresponding command to generate the IP address UserId from a command line is:

$ echo -n 0AFEDE1234AC | sha256sum
The Mac address is specified uppercase and without colons. Including the line break of echo leads to a different hash value so make sure to include the -n flag.

Custom UserId

The UserId generation is an open mechanism. You can set spring.cloud.vault.app-id.user-id to any string and the configured value will be used as static UserId.

A more advanced approach lets you set spring.cloud.vault.app-id.user-id to a classname. This class must be on your classpath and must implement the org.springframework.cloud.vault.AppIdUserIdMechanism interface and the createUserId method. Spring Cloud Vault will obtain the UserId by calling createUserId each time it authenticates using AppId to obtain a token.

Example 8. bootstrap.yml
spring.cloud.vault:
    authentication: APPID
    app-id:
        user-id: com.examlple.MyUserIdMechanism
Example 9. MyUserIdMechanism.java
public class MyUserIdMechanism implements AppIdUserIdMechanism {

  @Override
  public String createUserId() {
    String userId = ...
    return userId;
  }
}

See also: Vault Documentation: Using the App ID auth backend

AppRole authentication

AppRole is intended for machine authentication, like the deprecated (since Vault 0.6.1) AppId authentication. AppRole authentication consists of two hard to guess (secret) tokens: RoleId and SecretId.

Spring Vault supports various AppRole scenarios (push/pull mode and wrapped).

RoleId and optionally SecretId must be provided by configuration, Spring Vault will not look up these or create a custom SecretId.

Example 10. bootstrap.yml with AppRole authentication properties
spring.cloud.vault:
    authentication: APPROLE
    app-role:
        role-id: bde2076b-cccb-3cf0-d57e-bca7b1e83a52

The following scenarios are supported along the required configuration details:

Table 1. Configuration

Method

RoleId

SecretId

RoleName

Token

Provided RoleId/SecretId

Provided

Provided

Provided RoleId without SecretId

Provided

Provided RoleId, Pull SecretId

Provided

Provided

Provided

Provided

Pull RoleId, provided SecretId

Provided

Provided

Provided

Full Pull Mode

Provided

Provided

Wrapped

Provided

Wrapped RoleId, provided SecretId

Provided

Provided

Provided RoleId, wrapped SecretId

Provided

Provided
Table 2. Pull/Push/Wrapped Matrix

RoleId

SecretId

Supported

Provided

Provided

✅

Provided

Pull

✅

Provided

Wrapped

✅

Provided

Absent

✅

Pull

Provided

✅

Pull

Pull

✅

Pull

Wrapped

❌

Pull

Absent

❌

Wrapped

Provided

✅

Wrapped

Pull

❌

Wrapped

Wrapped

✅

Wrapped

Absent

❌
You can use still all combinations of push/pull/wrapped modes by providing a configured AppRoleAuthentication bean within the bootstrap context. Spring Cloud Vault cannot derive all possible AppRole combinations from the configuration properties.
AppRole authentication is limited to simple pull mode using reactive infrastructure. Full pull mode is not yet supported. Using Spring Cloud Vault with the Spring WebFlux stack enables Vault’s reactive auto-configuration which can be disabled by setting spring.cloud.vault.reactive.enabled=false.
Example 11. bootstrap.yml with all AppRole authentication properties
spring.cloud.vault:
    authentication: APPROLE
    app-role:
        role-id: bde2076b-cccb-3cf0-d57e-bca7b1e83a52
        secret-id: 1696536f-1976-73b1-b241-0b4213908d39
        role: my-role
        app-role-path: approle

  • role-id sets the RoleId.

  • secret-id sets the SecretId. SecretId can be omitted if AppRole is configured without requiring SecretId (See bind_secret_id).

  • role: sets the AppRole name for pull mode.

  • app-role-path sets the path of the approle authentication mount to use.

See also: Vault Documentation: Using the AppRole auth backend

AWS-EC2 authentication

The aws-ec2 auth backend provides a secure introduction mechanism for AWS EC2 instances, allowing automated retrieval of a Vault token. Unlike most Vault authentication backends, this backend does not require first-deploying, or provisioning security-sensitive credentials (tokens, username/password, client certificates, etc.). Instead, it treats AWS as a Trusted Third Party and uses the cryptographically signed dynamic metadata information that uniquely represents each EC2 instance.

Example 12. bootstrap.yml using AWS-EC2 Authentication
spring.cloud.vault:
    authentication: AWS_EC2

AWS-EC2 authentication enables nonce by default to follow the Trust On First Use (TOFU) principle. Any unintended party that gains access to the PKCS#7 identity metadata can authenticate against Vault.

During the first login, Spring Cloud Vault generates a nonce that is stored in the auth backend aside the instance Id. Re-authentication requires the same nonce to be sent. Any other party does not have the nonce and can raise an alert in Vault for further investigation.

The nonce is kept in memory and is lost during application restart. You can configure a static nonce with spring.cloud.vault.aws-ec2.nonce.

AWS-EC2 authentication roles are optional and default to the AMI. You can configure the authentication role by setting the spring.cloud.vault.aws-ec2.role property.

Example 13. bootstrap.yml with configured role
spring.cloud.vault:
    authentication: AWS_EC2
    aws-ec2:
        role: application-server
Example 14. bootstrap.yml with all AWS EC2 authentication properties
spring.cloud.vault:
    authentication: AWS_EC2
    aws-ec2:
        role: application-server
        aws-ec2-path: aws-ec2
        identity-document: http://...
        nonce: my-static-nonce

  • authentication setting this value to AWS_EC2 selects the AWS EC2 authentication method

  • role sets the name of the role against which the login is being attempted.

  • aws-ec2-path sets the path of the AWS EC2 mount to use

  • identity-document sets URL of the PKCS#7 AWS EC2 identity document

  • nonce used for AWS-EC2 authentication. An empty nonce defaults to nonce generation

See also: Vault Documentation: Using the aws auth backend

AWS-IAM authentication

The aws backend provides a secure authentication mechanism for AWS IAM roles, allowing the automatic authentication with vault based on the current IAM role of the running application. Unlike most Vault authentication backends, this backend does not require first-deploying, or provisioning security-sensitive credentials (tokens, username/password, client certificates, etc.). Instead, it treats AWS as a Trusted Third Party and uses the 4 pieces of information signed by the caller with their IAM credentials to verify that the caller is indeed using that IAM role.

The current IAM role the application is running in is automatically calculated. If you are running your application on AWS ECS then the application will use the IAM role assigned to the ECS task of the running container. If you are running your application naked on top of an EC2 instance then the IAM role used will be the one assigned to the EC2 instance.

When using the AWS-IAM authentication you must create a role in Vault and assign it to your IAM role. An empty role defaults to the friendly name the current IAM role.

Example 15. bootstrap.yml with required AWS-IAM Authentication properties
spring.cloud.vault:
    authentication: AWS_IAM
Example 16. bootstrap.yml with all AWS-IAM Authentication properties
spring.cloud.vault:
    authentication: AWS_IAM
    aws-iam:
        role: my-dev-role
        aws-path: aws
        server-id: some.server.name
        endpoint-uri: https://sts.eu-central-1.amazonaws.com

  • role sets the name of the role against which the login is being attempted. This should be bound to your IAM role. If one is not supplied then the friendly name of the current IAM user will be used as the vault role.

  • aws-path sets the path of the AWS mount to use

  • server-id sets the value to use for the X-Vault-AWS-IAM-Server-ID header preventing certain types of replay attacks.

  • endpoint-uri sets the value to use for the AWS STS API used for the iam_request_url parameter.

AWS-IAM requires the AWS Java SDK dependency (com.amazonaws:aws-java-sdk-core) as the authentication implementation uses AWS SDK types for credentials and request signing.

See also: Vault Documentation: Using the aws auth backend

Azure MSI authentication

The azure auth backend provides a secure introduction mechanism for Azure VM instances, allowing automated retrieval of a Vault token. Unlike most Vault authentication backends, this backend does not require first-deploying, or provisioning security-sensitive credentials (tokens, username/password, client certificates, etc.). Instead, it treats Azure as a Trusted Third Party and uses the managed service identity and instance metadata information that can be bound to a VM instance.

Example 17. bootstrap.yml with required Azure Authentication properties
spring.cloud.vault:
    authentication: AZURE_MSI
    azure-msi:
        role: my-dev-role
Example 18. bootstrap.yml with all Azure Authentication properties
spring.cloud.vault:
    authentication: AZURE_MSI
    azure-msi:
        role: my-dev-role
        azure-path: azure

  • role sets the name of the role against which the login is being attempted.

  • azure-path sets the path of the Azure mount to use

Azure MSI authentication fetches environmental details about the virtual machine (subscription Id, resource group, VM name) from the instance metadata service.

See also: Vault Documentation: Using the azure auth backend

TLS certificate authentication

The cert auth backend allows authentication using SSL/TLS client certificates that are either signed by a CA or self-signed.

To enable cert authentication you need to:

  1. Use SSL, see Vault Client SSL configuration

  2. Configure a Java Keystore that contains the client certificate and the private key

  3. Set the spring.cloud.vault.authentication to CERT

Example 19. bootstrap.yml
spring.cloud.vault:
    authentication: CERT
    ssl:
        key-store: classpath:keystore.jks
        key-store-password: changeit
        cert-auth-path: cert

See also: Vault Documentation: Using the Cert auth backend

Cubbyhole authentication

Cubbyhole authentication uses Vault primitives to provide a secured authentication workflow. Cubbyhole authentication uses tokens as primary login method. An ephemeral token is used to obtain a second, login VaultToken from Vault’s Cubbyhole secret backend. The login token is usually longer-lived and used to interact with Vault. The login token will be retrieved from a wrapped response stored at /cubbyhole/response.

Creating a wrapped token

Response Wrapping for token creation requires Vault 0.6.0 or higher.
Example 20. Creating and storing tokens
$ vault token-create -wrap-ttl="10m"
Key                            Value
---                            -----
wrapping_token:                397ccb93-ff6c-b17b-9389-380b01ca2645
wrapping_token_ttl:            0h10m0s
wrapping_token_creation_time:  2016-09-18 20:29:48.652957077 +0200 CEST
wrapped_accessor:              46b6aebb-187f-932a-26d7-4f3d86a68319
Example 21. bootstrap.yml
spring.cloud.vault:
    authentication: CUBBYHOLE
    token: 397ccb93-ff6c-b17b-9389-380b01ca2645

See also:

GCP-GCE authentication

The gcp auth backend allows Vault login by using existing GCP (Google Cloud Platform) IAM and GCE credentials.

GCP GCE (Google Compute Engine) authentication creates a signature in the form of a JSON Web Token (JWT) for a service account. A JWT for a Compute Engine instance is obtained from the GCE metadata service using Instance identification. This API creates a JSON Web Token that can be used to confirm the instance identity.

Unlike most Vault authentication backends, this backend does not require first-deploying, or provisioning security-sensitive credentials (tokens, username/password, client certificates, etc.). Instead, it treats GCP as a Trusted Third Party and uses the cryptographically signed dynamic metadata information that uniquely represents each GCP service account.

Example 22. bootstrap.yml with required GCP-GCE Authentication properties
spring.cloud.vault:
    authentication: GCP_GCE
    gcp-gce:
        role: my-dev-role
Example 23. bootstrap.yml with all GCP-GCE Authentication properties
spring.cloud.vault:
    authentication: GCP_GCE
    gcp-gce:
        gcp-path: gcp
        role: my-dev-role
        service-account: [email protected]

  • role sets the name of the role against which the login is being attempted.

  • gcp-path sets the path of the GCP mount to use

  • service-account allows overriding the service account Id to a specific value. Defaults to the default service account.

See also:

GCP-IAM authentication

The gcp auth backend allows Vault login by using existing GCP (Google Cloud Platform) IAM and GCE credentials.

GCP IAM authentication creates a signature in the form of a JSON Web Token (JWT) for a service account. A JWT for a service account is obtained by calling GCP IAM’s projects.serviceAccounts.signJwt API. The caller authenticates against GCP IAM and proves thereby its identity. This Vault backend treats GCP as a Trusted Third Party.

IAM credentials can be obtained from either the runtime environment , specifically the GOOGLE_APPLICATION_CREDENTIALS environment variable, the Google Compute metadata service, or supplied externally as e.g. JSON or base64 encoded. JSON is the preferred form as it carries the project id and service account identifier required for calling projects.serviceAccounts.signJwt.

Example 24. bootstrap.yml with required GCP-IAM Authentication properties
spring.cloud.vault:
    authentication: GCP_IAM
    gcp-iam:
        role: my-dev-role
Example 25. bootstrap.yml with all GCP-IAM Authentication properties
spring.cloud.vault:
    authentication: GCP_IAM
    gcp-iam:
        credentials:
            location: classpath:credentials.json
            encoded-key: e+KApn0=
        gcp-path: gcp
        jwt-validity: 15m
        project-id: my-project-id
        role: my-dev-role
        service-account-id: [email protected]

  • role sets the name of the role against which the login is being attempted.

  • credentials.location path to the credentials resource that contains Google credentials in JSON format.

  • credentials.encoded-key the base64 encoded contents of an OAuth2 account private key in the JSON format.

  • gcp-path sets the path of the GCP mount to use

  • jwt-validity configures the JWT token validity. Defaults to 15 minutes.

  • project-id allows overriding the project Id to a specific value. Defaults to the project Id from the obtained credential.

  • service-account allows overriding the service account Id to a specific value. Defaults to the service account from the obtained credential.

GCP IAM authentication requires the Google Cloud Java SDK dependency (com.google.apis:google-api-services-iam and com.google.auth:google-auth-library-oauth2-http) as the authentication implementation uses Google APIs for credentials and JWT signing.

Google credentials require an OAuth 2 token maintaining the token lifecycle. All API is synchronous therefore, GcpIamAuthentication does not support AuthenticationSteps which is required for reactive usage.

See also:

Kubernetes authentication

Kubernetes authentication mechanism (since Vault 0.8.3) allows to authenticate with Vault using a Kubernetes Service Account Token. The authentication is role based and the role is bound to a service account name and a namespace.

A file containing a JWT token for a pod’s service account is automatically mounted at /var/run/secrets/kubernetes.io/serviceaccount/token.

Example 26. bootstrap.yml with all Kubernetes authentication properties
spring.cloud.vault:
    authentication: KUBERNETES
    kubernetes:
        role: my-dev-role
        kubernetes-path: kubernetes
        service-account-token-file: /var/run/secrets/kubernetes.io/serviceaccount/token

  • role sets the Role.

  • kubernetes-path sets the path of the Kubernetes mount to use.

  • service-account-token-file sets the location of the file containing the Kubernetes Service Account Token. Defaults to /var/run/secrets/kubernetes.io/serviceaccount/token.

See also:

Pivotal CloudFoundry authentication

The pcf auth backend provides a secure introduction mechanism for applications running within Pivotal’s CloudFoundry instances allowing automated retrieval of a Vault token. Unlike most Vault authentication backends, this backend does not require first-deploying, or provisioning security-sensitive credentials (tokens, username/password, client certificates, etc.) as identity provisioning is handled by PCF itself. Instead, it treats PCF as a Trusted Third Party and uses the managed instance identity.

Example 27. bootstrap.yml with required PCF Authentication properties
spring.cloud.vault:
    authentication: PCF
    pcf:
        role: my-dev-role
Example 28. bootstrap.yml with all PCF Authentication properties
spring.cloud.vault:
    authentication: PCF
    pcf:
        role: my-dev-role
        pcf-path: path
        instance-certificate: /etc/cf-instance-credentials/instance.crt
        instance-key: /etc/cf-instance-credentials/instance.key

  • role sets the name of the role against which the login is being attempted.

  • pcf-path sets the path of the PCF mount to use.

  • instance-certificate sets the path to the PCF instance identity certificate. Defaults to ${CF_INSTANCE_CERT} env variable.

  • instance-key sets the path to the PCF instance identity key. Defaults to ${CF_INSTANCE_KEY} env variable.

PCF authentication requires BouncyCastle (bcpkix-jdk15on) to be on the classpath for RSA PSS signing.

See also: Vault Documentation: Using the pcf auth backend

Secret Backends

Key-Value Backend

Spring Cloud Vault supports both Key-Value secret backends, the versioned (v2) and unversioned (v1). The key-value backend allows storage of arbitrary values as key-value store. A single context can store one or many key-value tuples. Contexts can be organized hierarchically. Spring Cloud Vault determines itself whether a secret is using versioning and maps the path to its appropriate URL. Spring Cloud Vault allows using the Application name and a default context name (application) in combination with active profiles.

/secret/{application}/{profile}
/secret/{application}
/secret/{default-context}/{profile}
/secret/{default-context}

The application name is determined by the properties:

  • spring.cloud.vault.kv.application-name

  • spring.cloud.vault.application-name

  • spring.application.name

The profiles are determined by the properties:

  • spring.cloud.vault.kv.profiles

  • spring.profiles.active

Secrets can be obtained from other contexts within the key-value backend by adding their paths to the application name, separated by commas. For example, given the application name usefulapp,mysql1,projectx/aws, each of these folders will be used:

  • /secret/usefulapp

  • /secret/mysql1

  • /secret/projectx/aws

Spring Cloud Vault adds all active profiles to the list of possible context paths. No active profiles will skip accessing contexts with a profile name.

Properties are exposed like they are stored (i.e. without additional prefixes).

Spring Cloud Vault adds the data/ context between the mount path and the actual context path depending on whether the mount uses the versioned key-value backend. 
spring.cloud.vault:
    kv:
        enabled: true
        backend: secret
        profile-separator: '/'
        default-context: application
        application-name: my-app
        profiles: local, cloud

  • enabled setting this value to false disables the secret backend config usage

  • backend sets the path of the secret mount to use

  • default-context sets the context name used by all applications

  • application-name overrides the application name for use in the key-value backend

  • profiles overrides the active profiles for use in the key-value backend

  • profile-separator separates the profile name from the context in property sources with profiles

The key-value secret backend can be operated in versioned (v2) and non-versioned (v1) modes.

See also:

Consul

Spring Cloud Vault can obtain credentials for HashiCorp Consul. The Consul integration requires the spring-cloud-vault-config-consul dependency.

Example 29. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-consul</artifactId>
        <version>3.0.0-SNAPSHOT</version>
    </dependency>
</dependencies>

The integration can be enabled by setting spring.cloud.vault.consul.enabled=true (default false) and providing the role name with spring.cloud.vault.consul.role=….

The obtained token is stored in spring.cloud.consul.token so using Spring Cloud Consul can pick up the generated credentials without further configuration. You can configure the property name by setting spring.cloud.vault.consul.token-property.

spring.cloud.vault:
    consul:
        enabled: true
        role: readonly
        backend: consul
        token-property: spring.cloud.consul.token

  • enabled setting this value to true enables the Consul backend config usage

  • role sets the role name of the Consul role definition

  • backend sets the path of the Consul mount to use

  • token-property sets the property name in which the Consul ACL token is stored

See also: Vault Documentation: Setting up Consul with Vault

RabbitMQ

Spring Cloud Vault can obtain credentials for RabbitMQ.

The RabbitMQ integration requires the spring-cloud-vault-config-rabbitmq dependency.

Example 30. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-rabbitmq</artifactId>
        <version>3.0.0-SNAPSHOT</version>
    </dependency>
</dependencies>

The integration can be enabled by setting spring.cloud.vault.rabbitmq.enabled=true (default false) and providing the role name with spring.cloud.vault.rabbitmq.role=….

Username and password are stored in spring.rabbitmq.username and spring.rabbitmq.password so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.rabbitmq.username-property and spring.cloud.vault.rabbitmq.password-property.

spring.cloud.vault:
    rabbitmq:
        enabled: true
        role: readonly
        backend: rabbitmq
        username-property: spring.rabbitmq.username
        password-property: spring.rabbitmq.password

  • enabled setting this value to true enables the RabbitMQ backend config usage

  • role sets the role name of the RabbitMQ role definition

  • backend sets the path of the RabbitMQ mount to use

  • username-property sets the property name in which the RabbitMQ username is stored

  • password-property sets the property name in which the RabbitMQ password is stored

See also: Vault Documentation: Setting up RabbitMQ with Vault

AWS

Spring Cloud Vault can obtain credentials for AWS.

The AWS integration requires the spring-cloud-vault-config-aws dependency.

Example 31. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-aws</artifactId>
        <version>3.0.0-SNAPSHOT</version>
    </dependency>
</dependencies>

The integration can be enabled by setting spring.cloud.vault.aws=true (default false) and providing the role name with spring.cloud.vault.aws.role=….

The access key and secret key are stored in cloud.aws.credentials.accessKey and cloud.aws.credentials.secretKey so using Spring Cloud AWS will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.aws.access-key-property and spring.cloud.vault.aws.secret-key-property.

spring.cloud.vault:
    aws:
        enabled: true
        role: readonly
        backend: aws
        access-key-property: cloud.aws.credentials.accessKey
        secret-key-property: cloud.aws.credentials.secretKey

  • enabled setting this value to true enables the AWS backend config usage

  • role sets the role name of the AWS role definition

  • backend sets the path of the AWS mount to use

  • access-key-property sets the property name in which the AWS access key is stored

  • secret-key-property sets the property name in which the AWS secret key is stored

See also: Vault Documentation: Setting up AWS with Vault

Database backends

Vault supports several database secret backends to generate database credentials dynamically based on configured roles. This means services that need to access a database no longer need to configure credentials: they can request them from Vault, and use Vault’s leasing mechanism to more easily roll keys.

Spring Cloud Vault integrates with these backends:

Using a database secret backend requires to enable the backend in the configuration and the spring-cloud-vault-config-databases dependency.

Vault ships since 0.7.1 with a dedicated database secret backend that allows database integration via plugins. You can use that specific backend by using the generic database backend. Make sure to specify the appropriate backend path, e.g. spring.cloud.vault.mysql.role.backend=database.

Example 32. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-databases</artifactId>
        <version>3.0.0-SNAPSHOT</version>
    </dependency>
</dependencies>
Enabling multiple JDBC-compliant databases will generate credentials and store them by default in the same property keys hence property names for JDBC secrets need to be configured separately.

Database

Spring Cloud Vault can obtain credentials for any database listed at https://www.vaultproject.io/api/secret/databases/index.html. The integration can be enabled by setting spring.cloud.vault.database.enabled=true (default false) and providing the role name with spring.cloud.vault.database.role=….

While the database backend is a generic one, spring.cloud.vault.database specifically targets JDBC databases. Username and password are available from spring.datasource.username and spring.datasource.password properties so using Spring Boot will pick up the generated credentials for your DataSource without further configuration. You can configure the property names by setting spring.cloud.vault.database.username-property and spring.cloud.vault.database.password-property.

spring.cloud.vault:
    database:
        enabled: true
        role: readonly
        backend: database
        username-property: spring.datasource.username
        password-property: spring.datasource.password

  • enabled setting this value to true enables the Database backend config usage

  • role sets the role name of the Database role definition

  • backend sets the path of the Database mount to use

  • username-property sets the property name in which the Database username is stored

  • password-property sets the property name in which the Database password is stored

See also: Vault Documentation: Database Secrets backend

Spring Cloud Vault does not support getting new credentials and configuring your DataSource with them when the maximum lease time has been reached. That is, if max_ttl of the Database role in Vault is set to 24h that means that 24 hours after your application has started it can no longer authenticate with the database.

Apache Cassandra

The cassandra backend has been deprecated in Vault 0.7.1 and it is recommended to use the database backend and mount it as cassandra.

Spring Cloud Vault can obtain credentials for Apache Cassandra. The integration can be enabled by setting spring.cloud.vault.cassandra.enabled=true (default false) and providing the role name with spring.cloud.vault.cassandra.role=….

Username and password are available from spring.data.cassandra.username and spring.data.cassandra.password properties so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.cassandra.username-property and spring.cloud.vault.cassandra.password-property.

spring.cloud.vault:
    cassandra:
        enabled: true
        role: readonly
        backend: cassandra
        username-property: spring.data.cassandra.username
        password-property: spring.data.cassandra.password

  • enabled setting this value to true enables the Cassandra backend config usage

  • role sets the role name of the Cassandra role definition

  • backend sets the path of the Cassandra mount to use

  • username-property sets the property name in which the Cassandra username is stored

  • password-property sets the property name in which the Cassandra password is stored

See also: Vault Documentation: Setting up Apache Cassandra with Vault

Elasticsearch

Spring Cloud Vault can obtain since version 3.0 credentials for Elasticsearch. The integration can be enabled by setting spring.cloud.vault.elasticsearch.enabled=true (default false) and providing the role name with spring.cloud.vault.elasticsearch.role=….

Username and password are available from spring.elasticsearch.rest.username and spring.elasticsearch.rest.password properties so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.elasticsearch.username-property and spring.cloud.vault.elasticsearch.password-property.

spring.cloud.vault:
    elasticsearch:
        enabled: true
        role: readonly
        backend: mongodb
        username-property: spring.elasticsearch.rest.username
        password-property: spring.elasticsearch.rest.password

  • enabled setting this value to true enables the Elasticsearch database backend config usage

  • role sets the role name of the Elasticsearch role definition

  • backend sets the path of the Elasticsearch mount to use

  • username-property sets the property name in which the Elasticsearch username is stored

  • password-property sets the property name in which the Elasticsearch password is stored

See also: Vault Documentation: Setting up Elasticsearch with Vault

MongoDB

The mongodb backend has been deprecated in Vault 0.7.1 and it is recommended to use the database backend and mount it as mongodb.

Spring Cloud Vault can obtain credentials for MongoDB. The integration can be enabled by setting spring.cloud.vault.mongodb.enabled=true (default false) and providing the role name with spring.cloud.vault.mongodb.role=….

Username and password are stored in spring.data.mongodb.username and spring.data.mongodb.password so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.mongodb.username-property and spring.cloud.vault.mongodb.password-property.

spring.cloud.vault:
    mongodb:
        enabled: true
        role: readonly
        backend: mongodb
        username-property: spring.data.mongodb.username
        password-property: spring.data.mongodb.password

  • enabled setting this value to true enables the MongodB backend config usage

  • role sets the role name of the MongoDB role definition

  • backend sets the path of the MongoDB mount to use

  • username-property sets the property name in which the MongoDB username is stored

  • password-property sets the property name in which the MongoDB password is stored

See also: Vault Documentation: Setting up MongoDB with Vault

MySQL

The mysql backend has been deprecated in Vault 0.7.1 and it is recommended to use the database backend and mount it as mysql. Configuration for spring.cloud.vault.mysql will be removed in a future version.

Spring Cloud Vault can obtain credentials for MySQL. The integration can be enabled by setting spring.cloud.vault.mysql.enabled=true (default false) and providing the role name with spring.cloud.vault.mysql.role=….

Username and password are available from spring.datasource.username and spring.datasource.password properties so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.mysql.username-property and spring.cloud.vault.mysql.password-property.

spring.cloud.vault:
    mysql:
        enabled: true
        role: readonly
        backend: mysql
        username-property: spring.datasource.username
        password-property: spring.datasource.password

  • enabled setting this value to true enables the MySQL backend config usage

  • role sets the role name of the MySQL role definition

  • backend sets the path of the MySQL mount to use

  • username-property sets the property name in which the MySQL username is stored

  • password-property sets the property name in which the MySQL password is stored

See also: Vault Documentation: Setting up MySQL with Vault

PostgreSQL

The postgresql backend has been deprecated in Vault 0.7.1 and it is recommended to use the database backend and mount it as postgresql. Configuration for spring.cloud.vault.postgresql will be removed in a future version.

Spring Cloud Vault can obtain credentials for PostgreSQL. The integration can be enabled by setting spring.cloud.vault.postgresql.enabled=true (default false) and providing the role name with spring.cloud.vault.postgresql.role=….

Username and password are available from spring.datasource.username and spring.datasource.password properties so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.postgresql.username-property and spring.cloud.vault.postgresql.password-property.

spring.cloud.vault:
    postgresql:
        enabled: true
        role: readonly
        backend: postgresql
        username-property: spring.datasource.username
        password-property: spring.datasource.password

  • enabled setting this value to true enables the PostgreSQL backend config usage

  • role sets the role name of the PostgreSQL role definition

  • backend sets the path of the PostgreSQL mount to use

  • username-property sets the property name in which the PostgreSQL username is stored

  • password-property sets the property name in which the PostgreSQL password is stored

See also: Vault Documentation: Setting up PostgreSQL with Vault

Configure PropertySourceLocator behavior

Spring Cloud Vault uses property-based configuration to create PropertySources for key-value and discovered secret backends.

Discovered backends provide VaultSecretBackendDescriptor beans to describe the configuration state to use secret backend as PropertySource. A SecretBackendMetadataFactory is required to create a SecretBackendMetadata object which contains path, name and property transformation configuration.

SecretBackendMetadata is used to back a particular PropertySource.

You can register an arbitrary number of beans implementing VaultConfigurer for customization. Default key-value and discovered backend registration is disabled if Spring Cloud Vault discovers at least one VaultConfigurer bean. You can however enable default registration with SecretBackendConfigurer.registerDefaultKeyValueSecretBackends() and SecretBackendConfigurer.registerDefaultDiscoveredSecretBackends().

public class CustomizationBean implements VaultConfigurer {

    @Override
    public void addSecretBackends(SecretBackendConfigurer configurer) {

        configurer.add("secret/my-application");

        configurer.registerDefaultKeyValueSecretBackends(false);
        configurer.registerDefaultDiscoveredSecretBackends(true);
    }
}
All customization is required to happen in the bootstrap context. Add your configuration classes to META-INF/spring.factories at org.springframework.cloud.bootstrap.BootstrapConfiguration in your application.

Service Registry Configuration

You can use a DiscoveryClient (such as from Spring Cloud Consul) to locate a Vault server by setting spring.cloud.vault.discovery.enabled=true (default false). The net result of that is that your apps need a bootstrap.yml (or an environment variable) with the appropriate discovery configuration. The benefit is that the Vault can change its co-ordinates, as long as the discovery service is a fixed point. The default service id is vault but you can change that on the client with spring.cloud.vault.discovery.serviceId.

The discovery client implementations all support some kind of metadata map (e.g. for Eureka we have eureka.instance.metadataMap). Some additional properties of the service may need to be configured in its service registration metadata so that clients can connect correctly. Service registries that do not provide details about transport layer security need to provide a scheme metadata entry to be set either to https or http. If no scheme is configured and the service is not exposed as secure service, then configuration defaults to spring.cloud.vault.scheme which is https when it’s not set.

spring.cloud.vault.discovery:
    enabled: true
    service-id: my-vault-service

Vault Client Fail Fast

In some cases, it may be desirable to fail startup of a service if it cannot connect to the Vault Server. If this is the desired behavior, set the bootstrap configuration property spring.cloud.vault.fail-fast=true and the client will halt with an Exception.

spring.cloud.vault:
    fail-fast: true

Vault Enterprise Namespace Support

Vault Enterprise allows using namespaces to isolate multiple Vaults on a single Vault server. Configuring a namespace by setting spring.cloud.vault.namespace=… enables the namespace header X-Vault-Namespace on every outgoing HTTP request when using the Vault RestTemplate or WebClient.

Please note that this feature is not supported by Vault Community edition and has no effect on Vault operations.

spring.cloud.vault:
    namespace: my-namespace

See also: Vault Enterprise: Namespaces

Vault Client SSL configuration

SSL can be configured declaratively by setting various properties. You can set either javax.net.ssl.trustStore to configure JVM-wide SSL settings or spring.cloud.vault.ssl.trust-store to set SSL settings only for Spring Cloud Vault Config.

spring.cloud.vault:
    ssl:
        trust-store: classpath:keystore.jks
        trust-store-password: changeit

  • trust-store sets the resource for the trust-store. SSL-secured Vault communication will validate the Vault SSL certificate with the specified trust-store.

  • trust-store-password sets the trust-store password

Please note that configuring spring.cloud.vault.ssl.* can be only applied when either Apache Http Components or the OkHttp client is on your class-path.

Lease lifecycle management (renewal and revocation)

With every secret, Vault creates a lease: metadata containing information such as a time duration, renewability, and more.

Vault promises that the data will be valid for the given duration, or Time To Live (TTL). Once the lease is expired, Vault can revoke the data, and the consumer of the secret can no longer be certain that it is valid.

Spring Cloud Vault maintains a lease lifecycle beyond the creation of login tokens and secrets. That said, login tokens and secrets associated with a lease are scheduled for renewal just before the lease expires until terminal expiry. Application shutdown revokes obtained login tokens and renewable leases.

Secret service and database backends (such as MongoDB or MySQL) usually generate a renewable lease so generated credentials will be disabled on application shutdown.

Static tokens are not renewed or revoked.

Lease renewal and revocation is enabled by default and can be disabled by setting spring.cloud.vault.config.lifecycle.enabled to false. This is not recommended as leases can expire and Spring Cloud Vault cannot longer access Vault or services using generated credentials and valid credentials remain active after application shutdown.

spring.cloud.vault:
    config.lifecycle:
    	enabled: true
    	min-renewal: 10s
    	expiry-threshold: 1m
    	lease-endpoints: Legacy

  • enabled controls whether leases associated with secrets are considered to be renewed and expired secrets are rotated. Enabled by default.

  • min-renewal sets the duration that is at least required before renewing a lease. This setting prevents renewals from happening too often.

  • expiry-threshold sets the expiry threshold. A lease is renewed the configured period of time before it expires.

  • lease-endpoints sets the endpoints for renew and revoke. Legacy for vault versions before 0.8 and SysLeases for later.

See also: Vault Documentation: Lease, Renew, and Revoke