Quarkus - Working with HashiCorp Vault

HashiCorp Vault is a multi-purpose tool aiming at protecting sensitive data, such ascredentials, certificates, access tokens, encryption keys, …​ In the context of Quarkus,it is being used for 3 primary use cases:

• mounting a map of properties stored into theVault kv secret engine as an Eclipse MicroProfile config source

• fetch credentials from Vault when configuring an Agroal datasource

• access the Vault kv secret engine programmatically

Under the hood, the Quarkus Vault extension takes care of authentication when negotiating a client Vault token plusany transparent token or lease renewals according to ttl and max-ttl.

Prerequisites

To complete this guide, you need:

• roughly 20 minutes

• an IDE

• JDK 1.8+ installed with JAVA_HOME configured appropriately

• Apache Maven 3.5.3+

• Docker installed

Starting Vault

Let’s start Vault in development mode:

docker run --rm --cap-add=IPC_LOCK -e VAULT_ADDR=http://localhost:8200 -p 8200:8200 -d --name=dev-vault vault:1.2.2

You can check that vault is running with:

docker logs dev-vault

You should see:

==> Vault server configuration:
             Api Address: http://0.0.0.0:8200
                     Cgo: disabled
         Cluster Address: https://0.0.0.0:8201
              Listener 1: tcp (addr: "0.0.0.0:8200", cluster address: "0.0.0.0:8201", max_request_duration: "1m30s", max_request_size: "33554432", tls: "disabled")
               Log Level: info
                   Mlock: supported: true, enabled: false
                 Storage: inmem
                 Version: Vault v1.2.2
WARNING! dev mode is enabled! In this mode, Vault runs entirely in-memory
and starts unsealed with a single unseal key. The root token is already
authenticated to the CLI, so you can immediately begin using Vault.
You may need to set the following environment variable:
    $ export VAULT_ADDR='http://0.0.0.0:8200'
The unseal key and root token are displayed below in case you want to
seal/unseal the Vault or re-authenticate.
Unseal Key: 0lZ2/vzpa92pH8gersSn2h9b5tmzd4m5sqIdMC/4PDs=
Root Token: s.5VUS8pte13RqekCB2fmMT3u2
Development mode should NOT be used in production installations!
==> Vault server started! Log data will stream in below:

In development mode, Vault gets configured with several options that makes it convenient:

• Vault is already initialized with one key share (whereas in normal mode this has to be done explicitly and thenumber of key shares is 5 by default)

• the unseal key and the root token are displayed in the logs (please write down the root token, we will need itin the following step)

• Vault is unsealed

• in-memory storage

• TLS is disabled

• a kv secret engine v2 is mounted at secret/

In the following step, we are going to add a userpass authentication that we will use from the Quarkus application,to access a secret stored in the kv secret engine.

First open a shell inside the vault container:

docker exec -it dev-vault sh

Set the VAULT_TOKEN with the value that was printed in the logs:

export VAULT_TOKEN=s.5VUS8pte13RqekCB2fmMT3u2

You can check Vault’s status using the CLI command vault status:

Key             Value
---             -----
Seal Type       shamir
Initialized     true
Sealed          false
Total Shares    1
Threshold       1
Version         1.2.2
Cluster Name    vault-cluster-b07e80d8
Cluster ID      55bd74b6-eaaf-3862-f7ce-3473ab86c57f
HA Enabled      false

For simplicity reasons, we are going to use a kv secret engine version 1 (which is the default) mounted at pathsecret instead of the pre-configured kv version 2 available in dev mode. So let’s disable the current kv engine,and recreate a new one:

# this will disable the current kv version 2 secret engine mounted at path 'secret'
vault secrets disable secret
# this will enable a new kv engine version 1 at path 'secret'
vault secrets enable -path=secret kv

Now let’s add a secret configuration for our application:

vault kv put secret/myapps/vault-quickstart/config a-private-key=123456

We have defined a path secret/myapps/vault-quickstart in Vault that we need to give access to from the Quarkus application.

Create a policy that gives read access to secret/myapps/vault-quickstart and subpaths:

cat <<EOF | vault policy write vault-quickstart-policy -
path "secret/myapps/vault-quickstart/*" {
  capabilities = ["read"]
}
EOF

And finally, let’s enable the userpass auth secret engine, and create user bob with access to the vault-quickstart-policy:

vault auth enable userpass
vault write auth/userpass/users/bob password=sinclair policies=vault-quickstart-policy

To check that the configuration is correct, try logging in:

vault login -method=userpass username=bob password=sinclair

You should see:

Success! You are now authenticated. The token information displayed below
is already stored in the token helper. You do NOT need to run "vault login"
again. Future Vault requests will automatically use this token.
Key                    Value
---                    -----
token                  s.s93BVzJPzBiIGuYJHBTkG8Uw
token_accessor         OKNipTAgxWbxsrjixASNiwdY
token_duration         768h
token_renewable        true
token_policies         ["default" "vault-quickstart-policy"]
identity_policies      []
policies               ["default" "vault-quickstart-policy"]
token_meta_username    bob

Now set VAULT_TOKEN to the token above (instead of the root token), and try reading the vault-quickstart secret config:

export VAULT_TOKEN=s.s93BVzJPzBiIGuYJHBTkG8Uw
vault kv get secret/myapps/vault-quickstart/config

You should see:

======== Data ========
Key              Value
---              -----
a-private-key    123456

Create a quarkus application with a secret configuration

mvn io.quarkus:quarkus-maven-plugin:1.0.0.CR1:create \
    -DprojectGroupId=org.acme \
    -DprojectArtifactId=vault-quickstart \
    -DclassName="org.acme.quickstart.GreetingResource" \
    -Dpath="/hello" \
    -Dextensions="vault,hibernate-orm,jdbc-postgresql"
cd vault-quickstart

Configure access to vault from the application.properties:

# vault url
quarkus.vault.url=http://localhost:8200
# vault authentication
quarkus.vault.authentication.userpass.username=bob
quarkus.vault.authentication.userpass.password=sinclair
# path within the kv secret engine where is located the vault-quickstart secret configuration
quarkus.vault.secret-config-kv-path=myapps/vault-quickstart/config

This should mount whatever keys are stored in secret/myapps/vault-quickstart as MicroProfile config properties.

Let’s verify that by adding a new endpoint in GreetingResource:

@Path("/hello")
public class GreetingResource {
    @ConfigProperty(name = "a-private-key")
    String privateKey;
    ...
    @GET
    @Path("/private-key")
    @Produces(MediaType.TEXT_PLAIN)
    public String privateKey() {
        return privateKey;
    }
}

Now compile the application and run it:

./mvnw clean install
java -jar target/vault-quickstart-1.0-SNAPSHOT-runner.jar

Finally test the new endpoint:

curl http://localhost:8080/hello/private-key

You should see:

123456

Fetching credentials from Vault with Hibernate ORM

Start a PostgreSQL database:

docker run --ulimit memlock=-1:-1 -it --rm=true --memory-swappiness=0 --name postgres-quarkus-hibernate -e POSTGRES_USER=sarah -e POSTGRES_PASSWORD=connor -e POSTGRES_DB=mydatabase -p 5432:5432 postgres:10.5

Create a simple service:

@ApplicationScoped
public class SantaClausService {
    @Inject
    EntityManager em;
    @Transactional
    public List<Gift> getGifts() {
        return (List<Gift>) em.createQuery("select g from Gift g").getResultList();
    }
}

With its Gift entity:

@Entity
public class Gift {
    private Long id;
    private String name;
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator="giftSeq")
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

Finally, add a new endpoint in GreetingResource:

@Inject
SantaClausService santaClausService;
@GET
@Path("/gift-count")
@Produces(MediaType.TEXT_PLAIN)
public int geGiftCount() {
    return santaClausService.getGifts().size();
}

Create a new path in Vault where the database password will be added:

# set the root token again
export VAULT_TOKEN={root-token}
vault kv put secret/myapps/vault-quickstart/db password=connor

Since we allowed read access on secret/myapps/vault-quickstart/ subpaths in the policy, there is nothing elsewe have to do to allow the application to read it.

When fetching credentials from Vault that are intended to be used by the Agroal connection pool, we needfirst to create a named Vault credentials provider in the application.properties:

quarkus.vault.credentials-provider.mydatabase.kv-path=myapps/vault-quickstart/db

This defines a credentials provider mydatabase that will fetch the password from key passwordat path myapps/vault-quickstart/db.

The credentials provider can now be used in the datasource configuration, in place of the passwordproperty:

# configure your datasource
quarkus.datasource.url = jdbc:postgresql://localhost:5432/mydatabase
quarkus.datasource.driver = org.postgresql.Driver
quarkus.datasource.username = sarah
#quarkus.datasource.password = connor
quarkus.datasource.credentials-provider = mydatabase
# drop and create the database at startup (use `update` to only update the schema)
quarkus.hibernate-orm.database.generation=drop-and-create

Restart the application after rebuilding it, and test it with the new endpoint:

curl http://localhost:8080/hello/gift-count

You should see:

0

Programmatic access to the KV secret engine

Sometimes secrets are retrieved from an arbitrary path that is known only at runtime through an applicationspecific property, or a method argument for instance.In that case it is possible to inject a Quarkus VaultKVSecretEngine, and retrieve secrets programmatically.

For instance, in GreetingResource, add:

@Inject
VaultKVSecretEngine kvSecretEngine;
...
@GET
@Path("/secrets/{vault-path}")
@Produces(MediaType.TEXT_PLAIN)
public String getSecrets(@PathParam("vault-path") String vaultPath) {
    return kvSecretEngine.readSecret("myapps/vault-quickstart/" + vaultPath).toString();
}

Restart the application after rebuilding it, and test it with the new endpoint:

curl http://localhost:8080/hello/secrets/db

You should see:

{password=connor}

TLS

In production mode, TLS should be activated between the Quarkus application and Vault to prevent man-in-the-middle attacks.

There are several ways to configure the Quarkus application:

• through the standard javax.net.ssl.trustStore system property, which should refer to a JKS truststore containingthe trusted certificates

• using property quarkus.vault.tls.ca-cert, which should refer to a pem encoded file.

If quarkus.vault.tls.ca-cert is not set and the Quarkus application is using the Kubernetes authentication,TLS will be active and use the CA certificate bundle located in /var/run/secrets/kubernetes.io/serviceaccount/ca.crt.If you want to disable this behavior (for instance when using a trust store), you need to set it explicitly using:quarkus.vault.tls.use-kubernetes-ca-cert=false.

The last relevant property is quarkus.vault.tls.skip-verify, which allows to communicate with Vault using TLS,but without checking the certificate authenticity. This may be convenient in development, but is stronglydiscouraged in production as it is not more secure than talking to Vault in plain HTTP.

Conclusion

As a general matter, you should consider reading the extensive Vault documentationand apply best practices.

The features exposed today through the Vault extension covers only a small fraction of what the product is capable of.Still, it addresses already some of the most common microservices scenarii (e.g. sensitive configuration and databasecredentials), which goes a long way towards creating secured applications.

Configuration Reference

Configuration property fixed at build time - ️ Configuration property overridable at runtime