This tutorial builds on the Kubernetes Quickstart guide to describe how to set up OIDC Federation between a SPIRE Server and a Vault server. This will allow a SPIRE-identified workload to authenticate against a federated Vault server by presenting no more than its JWT-SVID. Using this technique the workload won't need to authenticate itself against the Vault server using another authentication method like AppRole or Username & Password.
In this tutorial you will learn how to:
- Deploy the OIDC Discovery Provider Service
- Create the required DNS A record to point to the OIDC Discovery document endpoint
- Set up a local Vault server to store secrets
- Configure a SPIRE Server OIDC provider as an authentication method for the Vault server
- Test access to secrets using a SPIRE-provided identity
Note the following required accounts, prerequisites, and limitations before starting this tutorial:
- You'll need access to the Kubernetes environment that you configured when going through Kubernetes Quickstart. The Kubernetes environment must be able to expose an Ingress to the public internet. Note: This is generally not possible for local Kubernetes environments such as Minikube.
- You'll need the ability to configure a DNS A record for the SPIRE OIDC Discovery document endpoint (see Part 2).
In the first part of this procedure, you will configure the SPIRE components in a Kubernetes deployment.
To get all of the files required for this tutorial, clone https://github.com/spiffe/spire-tutorials. The YAML files that describe the Kubernetes deployment are in the k8s/oidc-vault/k8s
directory.
The following strings in the YAML files must be substituted for values specific to your environment. Each location where you must make a change has been marked with TODO:
in the YAML files.
String | Description | Files to Change |
---|---|---|
MY_EMAIL_ADDRESS |
Replace with a valid email address to satisfy the terms of service for the Let's Encrypt certificate authority used in OIDC federation. No email will actually be sent to this address. Example value: user@example.org |
oidc-dp-configmap.yaml (1 appearance) |
MY_DISCOVERY_DOMAIN |
Replace with the domain that you will use in the A record for the OIDC Discovery Document endpoint. See Part 2 for details. Example value: oidc-discovery.example.org |
ingress.yaml (2 appearances), oidc-dp-configmap.yaml (1 appearance), server-configmap.yaml (1 appearance) |
MY_CLUSTER_NAME |
Replace with the name of the Kubernetes cluster where SPIRE will be deployed. Example value: gke_dev-prj_name-central1-c_vault-oidc-tutorial |
server-configmap.yaml (1 appearance) |
In the YAML files, instances of the example.org
trust domain are valid to use for this tutorial and do not need to be changed.
The SPIRE OIDC Discovery Provider provides a URL to the location of the Discovery Document specified by the OIDC protocol. The oidc-dp-configmap.yaml
file specifies the URL to the OIDC Discovery Provider.
Before running the command below, ensure that you have replaced the MY_DISCOVERY_DOMAIN
placeholder with the FQDN of the Discovery Provider as described in Replace Placeholder Strings in YAML Files.
Change to the directory k8s/oidc-vault/k8s
containing the YAML files that describe the Kubernetes deployment and use the following command to apply the updated server ConfigMap, the ConfigMap for the OIDC Discovery Provider, and deploy the updated spire-server
StatefulSet:
$ kubectl apply \
-f server-configmap.yaml \
-f oidc-dp-configmap.yaml \
-f server-statefulset.yaml
To verify that the spire-server
pod has spire-server
and spire-oidc
containers, run:
$ kubectl get pods -n spire -l app=spire-server -o \
jsonpath='{.items[*].spec.containers[*].name}{"\n"}'
This should output:
spire-server spire-oidc
Use the following command to set up a Service definition for the OIDC Discovery Provider and to configure an Ingress for that Service:
$ kubectl apply \
-f server-oidc-service.yaml \
-f ingress.yaml
As part of this tutorial, you will need to register a public DNS record that will resolve to the public IP address of your Kubernetes cluster. This will require you or an administrator to have registered a domain name (e.g. example.org
) with a domain name registrar, have configured its name server to point to a DNS service, and have the ability to create a new A record for the subdomain (e.g. oidc-discovery.example.org
) in that DNS service. If you don't have a registered domain name or access to a DNS service, services like Google Domains can help you set one up for a fee.
In this tutorial, the subdomain that you create will provide an endpoint to the Discovery Document specified by the OIDC protocol. The Vault server will query this endpoint as part of the authentication handshake between the Vault server and SPIRE.
Integration with Vault is also possible using JWKS. This method does not require a DNS entry but does require that Vault be deployed inside the Kubernetes deployment, unlike the method described in this tutorial. As such, these instructions don't describe how to integrate with Vault using the JWKS method, but you can find more information on the Vault documentation site.
Run the following command to retrieve the external IP address of the spire-oidc
service. The spire-oidc
Discovery Provider service must provide an external IP address for Vault to access the OIDC Discovery document provided by spire-oidc
.
$ kubectl get service -n spire spire-oidc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
spire-oidc LoadBalancer 10.12.0.18 34.82.139.13 443:30198/TCP 108s
Using your preferred DNS tool, put the MY_DISCOVERY_DOMAIN
domain and the spire-oidc
external IP address in a new DNS A record. The A record should take the following form:
MY_DISCOVERY_DOMAIN A <EXTERNAL-IP for spire-oidc service>
For example:
oidc-discovery.example.org A 34.82.139.13
Note: Do not use the oidc-discovery.example.org
domain or IP address shown above.
As with any change to DNS, it will take minutes or hours for the new A record to propagate to DNS servers. This tutorial will not work until the A record is propagated. Negative DNS query results will be cached, causing headaches. So, to be safe, wait an hour or so to test the DNS change after creating the A record.
-
Use
nslookup
to display the DNS information for the domain you configured in the A record:$ nslookup oidc-discovery.example.org Server: 203.0.113.0 Address: 203.0.113.0#53 Non-authoritative answer: Name: oidc-discovery.example.org Address: 93.184.216.34
The
Address:
field at the bottom should correspond to the IP address in the A record. -
In your browser, navigate to
https://MY_DISCOVERY_DOMAIN/.well-known/openid-configuration
. You should see JSON output similar to the following:{ "issuer": "https://oidc-discovery.example.org", "jwks_uri": "https://oidc-discovery.example.org/keys", "authorization_endpoint": "", "response_types_supported": [ "id_token" ], "subject_types_supported": [], "id_token_signing_alg_values_supported": [ "RS256", "ES256", "ES384" ] }
After configuring an A Record for the OIDC Discovery document endpoint, continue with configuring the Vault server.
Ensure that HashiCorp Vault is installed on your local computer and that the location of the vault
executable is in your system PATH
. Verify that Vault is installed by typing vault version
in a terminal window. The output indicates the Vault version if it is installed, or a command not found error otherwise, in which case you need to install Vault. Packages are available for some Linux flavors, MacOS (via Homebrew), and Windows (via Chocolatey). Alternatively, you can download a precompiled binary for your operating system. For complete installation instructions, see Install Vault or Getting Started - Install Vault.
Use a new Vault installation for this tutorial. An existing Vault installation may have configuration settings that conflict with this tutorial.
First, let's review the config file we will be using for our local Vault server.
Open up a terminal window and ensure your current path is ./k8s/oidc-vault
inside of the directory where you have cloned the spire-tutorials
repository.
In ./vault/config.hcl
we define that the Vault server will listen on our local interface 127.0.0.1 at port 8200. We'll disable TLS for simplicity (don't do this on a production environment) and set a default file
backend:
listener "tcp" {
address = "127.0.0.1:8200",
tls_disable = 1
}
storage "file" {
path = "vault-storage"
}
-
Let's spin up the Vault server using our config file:
$ vault server -config ./vault/config.hcl
-
Check that your Vault server has started correctly and has no errors. It is typical to see some warning messages. The following message indicates that the Vault server has started:
==> Vault server started! Log data will stream in below:
Before authenticating and using our Vault server we need to initialize and unseal it.
-
Set the
VAULT_ADDR
environment variable. This tells the Vault CLI where it needs to talk to:$ export VAULT_ADDR=http://127.0.0.1:8200
-
Initialize Vault:
$ vault operator init
This outputs something like this:
... Unseal Key 1: VI0/4yK8H/tHC625aDYaf62+Jmo5qqlizn5bVmsbY0j0 Unseal Key 2: UINTf0oPzpiMIhOU3CNzFpo6Pkun36hGKPlcbQUkl1qT Unseal Key 3: SYO0yTfCn5IkoQ5f/JzE98yQI8Nfiv51gjXZMamyjXn/ Unseal Key 4: 90vXLQJqba32VpBxYr4jB9gRVu6gRC/uWt812oF44zzP Unseal Key 5: 2eBBVUC63DOPqNKn4WPoxci4VOfchA7tOr3LTqHtS5FC Initial Root Token: s.PFuCtYgzjh6mRAfAVjfsGv3O ...
Take note of the Unseal Keys and the Initial Root Token.
-
Now we need to unseal our Vault. We use 3 of our 5 Unseal Keys (whichever you want) and the Initial Root Token from the previous step. When we run the command we are prompted for one of our Unseal Keys.
We need to repeat this process three times with three different keys:
$ vault operator unseal Unseal Key (will be hidden): <PASTE ONE OF YOUR KEYS HERE> Key Value --- ----- Seal Type shamir Initialized true Sealed true # <- this means that Vault is still sealed Total Shares 5 Threshold 3 Unseal Progress 1/3 # <- this is how many keys you have entered Unseal Nonce e1bf3fa2-0058-5703-e2dc-a5c45c1b7f9a Version 1.3.4 HA Enabled false
Note that here we see a key
Sealed
that tells us that Vault has not been unsealed yet, and a keyUnseal Progress
that says how many correct Unseal Keys we have entered.Once we entered three different correct keys we have successfully unsealed Vault and the key
Sealed
changes tofalse
.Sealed false
Using our root access via the CLI (by storing the Initial Root Token in a VAULT_TOKEN
environment variable) we are going to enable the kv
(key-value) secrets engine and store a secret that we are going to retrieve later using our SPIRE-enabled login.
-
Given that you may be in a different terminal window, let's set the
VAULT_ADDR
again, and theVAULT_TOKEN
with the Initial Root Token:$ export VAULT_ADDR=http://127.0.0.1:8200 $ export VAULT_TOKEN="s.PFuCtYgzjh6mRAfAVjfsGv3O" # <- here use the Initial Root Token from the previous section
-
Enable the
kv
(key-value) secrets engine on thesecret/
path:$ vault secrets enable -path=secret kv
-
Put a secret in the new path. This is what we are going to retrieve using our SPIRE-enabled identity. Since we've specified a key-value Vault secret engine, we'll store a key-value pair in Vault:
$ vault kv put secret/my-super-secret test=123
In this section, we'll configure the Vault server to federate with our SPIRE Server that is running on a Kubernetes cluster.
-
Enable the JWT authentication method:
$ vault auth enable jwt
-
Set up our OIDC Discovery URL, using the DNS A Record we defined in a previous section:
$ vault write auth/jwt/config oidc_discovery_url=https://oidc-discovery.example.org default_role=“dev”
-
Define a policy
my-dev-policy
that will be assigned to adev
role that we'll create in the next step.Ensure your current path is
./k8s/oidc-vault
inside of the directory where you have cloned thespire-tutorials
repository. In vault-policy.hcl we define a policy with read capabilities for the path/secret/my-super-secret
:path "secret/my-super-secret" { capabilities = ["read"] }
then load the policy into Vault:
$ vault policy write my-dev-policy ./vault/vault-policy.hcl
-
Create a role
dev
, binding the subject and audience that will be in the JWT, and configuring thesub
claim that will be used to identify the user. Also set up a 24 hour TTL for testing purposes and a policymy-dev-policy
that will be assigned to the tokens:$ vault write auth/jwt/role/dev role_type=jwt user_claim=sub bound_audiences=TESTING bound_subject=spiffe://example.org/ns/default/sa/default token_ttl=24h token_policies=my-dev-policy
Now we are going to get an access token to use with Vault. We'll use a sample client workload to get an identity using the SPIRE Federation feature.
-
First, let's get the client pod name we created in the Kubernetes Getting Started Guide:
$ kubectl get pods
output:
NAME READY STATUS RESTARTS AGE client-7c94755d97-mq8dl 1/1 Running 1 10d
-
Get the JWT-SVID that identifies our client workload:
kubectl exec client-7c94755d97-mq8dl -- /opt/spire/bin/spire-agent api fetch jwt \ -audience TESTING \ -socketPath /run/spire/sockets/agent.sock
-
Copy the JWT from the response into your clipboard. You'll find the JWT under
token(spiffe://example.org/ns/default/sa/default)
. It looks something like this:eyJhbGciOiJSUzI1NiIsImtpZCI6IjQ0c0R2cW9kRHRUUmVqR1pTMmZ4c2RUdTNuc3FmTzl6IiwidHlwIjoiSldUIn0.eyJhdWQiOlsiVEVTVElORyJdLCJleHAiOjE1ODgwOTIyODgsImlhdCI6MTU4ODA5MTk4OCwiaXNzIjoiaHR0cHM6Ly9zcGlyZS12YXVsdC1vaWRjLnNraXRhbGVlLm9yZyIsInN1YiI6InNwaWZmZTovL2V4YW1wbGUub3JnL25zL2RlZmF1bHQvc2EvZGVmYXVsdCJ9.Me8U9qE6yyd5mezSiMcPgwoJm2ihQZXTL-0ClAJyssg9yhCx1D4Gea3_n4pFjp86RfLiUSsGzyjBL4r0FRA6_0grJFnLdret2ynni6zZyYw6s0k38vsJIZ4rZNfY09IanQ1Ak_GW1yHVOtzRqd3vr8GgrtXzHzsWfl5YgzhWozJUYVIj1eN91aftJ-Iuvo2KYcxu1QgrIhP8Ec_6m2Kg06oRsKCb0a6C4J78wW-lXd5orDvrO2wAksmUjBwtxFA6EggtVVSKE85EG7gUgPT1xU7B2rggXC1RKUgxXqpFWHk-7qbFdk7enurxsSSGqvVSIW7KK0sYTcw5GeKze0iggQ
-
Create a file somewhere in your home directory called
payload.json
that contains the line below. Paste your JWT from the previous step in the location indicated, omitting the angle brackets:{"role": "dev","jwt": "<PASTE_YOUR_JWT_TOKEN_HERE>"}
-
Authenticate against the Vault server REST API using the payload:
$ curl --request POST --data @/path/to/payload.json http://localhost:8200/v1/auth/jwt/login
-
Under
auth
, grab yourclient_token
from the response (for example, save it in your clipboard). This is how we are going to identify ourselves against the Vault REST API. In the output, notice themy-dev-policy
that we specified in Vault before. This will allow us to read our secret.{ "request_id": "78bc2546-8e3f-900e-ac32-ae590870ea67", "lease_id": "", "renewable": false, "lease_duration": 0, "data": null, "wrap_info": null, "warnings": null, "auth": { "client_token": "s.lQ3KIYjUnFwCJkUnOKKF8kxn", # <- your token "accessor": "ZdVaNVQDcOL15FNSjyWogwiX", "policies": [ "default", "my-dev-policy" # <- the role policy we created ], "token_policies": [ "default", "my-dev-policy" ], "metadata": { "role": "dev" }, "lease_duration": 86400, "renewable": true, "entity_id": "5e467f7c-7270-6e2d-2929-e76b9d2b5b32", "token_type": "service", "orphan": true } }
Let's test our new client token and try to get the secret we created before.
-
Get the secret using our
client_token
from the previous step:$ curl \ -H "X-Vault-Token: <PASTE_YOUR_client_token_HERE>" \ http://127.0.0.1:8200/v1/secret/my-super-secret
The
curl
command queries the Vault server REST API usingclient_token
to authenticate. The Vault server REST API returns the following JSON output, which includes the secret key-value pair that we stored in Vault earlier:{ "request_id": "1a10d3f7-e3b4-2c05-48c5-94a04f3758bc", "lease_id": "", "renewable": false, "lease_duration": 2764800, "data": { "test": "123" # <- here's our secret key-value pair }, "wrap_info": null, "warnings": null, "auth": null }
When you are finished running this tutorial, you can use the following commands to remove the SPIRE setup for Vault OIDC Authentication.
Keep in mind that these commands will also remove the setup that you configured in the Kubernetes Quickstart.
-
Delete the workload container:
$ kubectl delete deployment client
-
Delete all deployments and configurations for the SPIRE Agent, Server, and namespace:
$ kubectl delete namespace spire
-
Delete the ClusterRole and ClusterRoleBinding settings:
$ kubectl delete clusterrole spire-server-trust-role spire-agent-cluster-role $ kubectl delete clusterrolebinding spire-server-trust-role-binding spire-agent-cluster-role-binding
You may also need to remove configuration elements from your cloud-based Kubernetes environment.
Delete the policy and JWT config that you configured for this tutorial.
$ vault policy delete my-dev-policy
$ vault auth disable jwt
Remove the A record that you configured for the SPIRE OIDC Discovery document endpoint.