Setup vmgateway - Multi-Tenant Access with Grafana & OIDC

Using Grafana with vmgateway is a great way to provide multi-tenant access to your metrics. vmgateway provides a way to authenticate users using JWT tokens issued by an external identity provider. Those tokens can include information about the user and the tenant they belong to, which can be used to restrict access to metrics to only those that belong to the tenant.

Prerequisites #

Identity service that can issue JWT tokens
Grafana
VictoriaMetrics single-node or cluster version
vmgateway
An active license key. You can obtain a trial license key here.

Configure identity service #

The identity service must be able to issue JWT tokens with the following vm_access claim:

{
  "vm_access": {
    "tenant_id": {
      "account_id": 0,
      "project_id": 0
    }
  }
}

See details about all supported options in the vmgateway documentation.

Configuration example for Keycloak #

Keycloak is an open source identity service that can be used to issue JWT tokens.

Log in with admin credentials to your Keycloak instance
Go to Clients -> Create.
Use OpenID Connect as Client Type.
Specify grafana as Client ID.
Click Next.
Enable Client authentication.
Enable Authorization.
Click Next.
Add Grafana URL as Root URL. For example, http://localhost:3000/.
Click Save.
Go to Clients -> grafana -> Credentials.
Copy the value of Client secret. It will be used later in Grafana configuration.
Go to Clients -> grafana -> Client scopes.
Click at grafana-dedicated -> Add mapper -> By configuration -> User attribute.
Configure the mapper as follows
- Name as vm_access.
- Token Claim Name as vm_access.
- User Attribute as vm_access.
- Claim JSON Type as JSON. Enable Add to ID token and Add to access token.
Click Save.
Go to Users -> select user to configure claims -> Attributes.
Specify vm_access as Key.
For the purpose of this example, we will use 2 users:
- for the first user we will specify {"tenant_id" : {"account_id": 0, "project_id": 0 },"extra_labels":{ "team": "admin" }} as Value.
- for the second user we will specify {"tenant_id" : {"account_id": 0, "project_id": 1 },"extra_labels":{ "team": "dev" }} as Value.
  Click Save.

Configure grafana #

To forward JWT tokens Grafana must be configured to use OpenID Connect authentication as follows:

[auth.generic_oauth]
enabled = true
allow_sign_up = true
name = keycloak
client_id = {CLIENT_ID_FROM_IDENTITY_PROVIDER}
client_secret = {SECRET_FROM_IDENTITY_PROVIDER}
scopes = openid profile email
auth_url = http://localhost:3001/realms/{KEYCLOAK_REALM}/protocol/openid-connect/auth
token_url = http://localhost:3001/realms/{KEYCLOAK_REALM}/protocol/openid-connect/token
api_url = http://localhost:3001/realms/{KEYCLOAK_REALM}/protocol/openid-connect/userinfo

After restarting Grafana with the new config you should be able to log in using your identity provider.

Start vmgateway #

Multi-tenant access for VictoriaMetrics cluster #

Now starting vmgateway with enabled authentication is as simple as adding the -enable.auth=true flag. In order to enable multi-tenant access, you must also specify the -clusterMode=true flag.

./bin/vmgateway \
    -licenseFile=./vm-license.key
    -enable.auth=true \
    -clusterMode=true \
    -write.url=http://localhost:8480 \
    -read.url=http://localhost:8481

With this configuration vmgateway will use the vm_access claim from the JWT token to restrict access to metrics. For example, if the JWT token contains the following vm_access claim:

{
  "vm_access": {
    "tenant_id": {
      "account_id": 0,
      "project_id": 0
    }
  }
}

Note: in case project_id is not specified, default value 0 is used.

Then vmgateway will proxy request to an endpoint with the following path:

http://localhost:8480/select/0:0/

This allows to restrict access to specific tenants without having to create separate datasources in Grafana, or manually managing access at another proxy level.

Multi-tenant access for single-node VictoriaMetrics #

In order to use multi-tenant access with single-node VictoriaMetrics, you can use token claims such as extra_labels or extra_filters filled dynamically by using Identity Provider’s user information. vmgateway uses those claims and enhanced Prometheus querying API to provide additional filtering capabilities.

For example, the following claims can be used to restrict user access to specific metrics:

{
  "vm_access": {
    "extra_labels": {
      "team": "dev"
    },
    "extra_filters": ["{env=~\"aws|gcp\",cluster!=\"production\"}"]
  }
}

This will add the following query args to the proxied request:

extra_labels=team=dev
extra_filters={env=~"aws|gcp",cluster!="production"}

With this configuration VictoriaMetrics will add the following filters to every query: {team="dev", env=~"aws|gcp", cluster!="production"}. So when user will try to query vm_http_requests_total query will be transformed to vm_http_requests_total{team="dev", env=~"aws|gcp", cluster!="production"}.

Token signature verification #

It is also possible to enable JWT token signature verification at vmgateway. To do this by using OpenID Connect discovery endpoint you need to specify the -auth.oidcDiscoveryEndpoints flag. For example:

./bin/vmgateway \
    -licenseFile=./vm-license.key
    -enable.auth=true \
    -clusterMode=true \
    -write.url=http://localhost:8480 \
    -read.url=http://localhost:8481
    -auth.oidcDiscoveryEndpoints=http://localhost:3001/realms/master/.well-known/openid-configuration

Now vmgateway will print the following message on startup:

2023-03-13T14:45:31.552Z        info    VictoriaMetrics/app/vmgateway/main.go:154  using 2 keys for JWT token signature verification

That means that vmgateway has successfully fetched the public keys from the OpenID Connect discovery endpoint.

It is also possible to provide the public keys directly via the -auth.publicKeys flag. See the vmgateway documentation for details.

Use Grafana to query metrics #

Create a new Prometheus datasource in Grafana with the following URL http://<vmgateway>:8431. URL should point to the vmgateway instance.

In the “Type and version” section it is recommended to set the type to “Prometheus” and the version to at least “2.24.x”:

This allows Grafana to use a more efficient API to get label values.

You can also use VictoriaMetrics Grafana datasource plugin. See installation instructions here.

Enable Forward OAuth identity flag.

Now you can use Grafana to query metrics from the specified tenant. Users with vm_access claim will be able to query metrics from the specified tenant.

Test multi-tenant access #

For the test purpose we will setup the following services as docker-compose manifest:

Grafana
Keycloak
vmagent to generate test metrics
VictoriaMetrics cluster
vmgateway configured to work in cluster mode
VictoriaMetrics single node
vmgateway configured to work in single node mode

version: '3'

services:
  keycloak:
    image: quay.io/keycloak/keycloak:21.0
    command:
      - start-dev
    ports:
      - 3001:8080
    environment:
      KEYCLOAK_ADMIN: admin
      KEYCLOAK_ADMIN_PASSWORD: change_me

  grafana:
    image: grafana/grafana:10.4.2
    network_mode: host
    volumes:
      - ./grafana.ini:/etc/grafana/grafana.ini
      - grafana_data:/var/lib/grafana/

  vmsingle:
    image: victoriametrics/victoria-metrics:v1.106.1
    command:
      - -httpListenAddr=0.0.0.0:8429

  vmstorage:
    image: victoriametrics/vmstorage:v1.106.1-cluster

  vminsert:
    image: victoriametrics/vminsert:v1.106.1-cluster
    command:
      - -storageNode=vmstorage:8400
      - -httpListenAddr=0.0.0.0:8480

  vmselect:
    image: victoriametrics/vmselect:v1.106.1-cluster
    command:
      - -storageNode=vmstorage:8401
      - -httpListenAddr=0.0.0.0:8481

  vmagent:
    image: victoriametrics/vmagent:v1.106.1
    volumes:
      - ./scrape.yaml:/etc/vmagent/config.yaml
    command:
      - -promscrape.config=/etc/vmagent/config.yaml
      - -remoteWrite.url=http://vminsert:8480/insert/0/prometheus/api/v1/write
      - -remoteWrite.url=http://vmsingle:8429/api/v1/write

  vmgateway-cluster:
    image: victoriametrics/vmgateway:v1.106.1-enterprise
    ports:
      - 8431:8431
    volumes:
      - ./vm-license.key:/opt/vm-license.key
    command:
      - -licenseFile=/opt/vm-license.key
      - -license.forceOffline=true
      - -enable.auth=true
      - -clusterMode=true
      - -write.url=http://vminsert:8480
      - -read.url=http://vmselect:8481
      - -httpListenAddr=0.0.0.0:8431
      - -auth.oidcDiscoveryEndpoints=http://keycloak:8080/realms/master/.well-known/openid-configuration

  vmgateway-single:
    image: victoriametrics/vmgateway:v1.106.1-enterprise
    ports:
      - 8432:8431
    volumes:
      - ./vm-license.key:/opt/vm-license.key
    command:
      - -licenseFile=/opt/vm-license.key
      - -enable.auth=true
      - -write.url=http://vmsingle:8429
      - -read.url=http://vmsingle:8429
      - -httpListenAddr=0.0.0.0:8431
      - -auth.oidcDiscoveryEndpoints=http://keycloak:8080/realms/master/.well-known/openid-configuration

volumes:
  grafana_data:

For the test purpose vmagent will be configured to scrape metrics from the following targets(scrape.yaml contents):

scrape_configs:
  - job_name: stat
    metric_relabel_configs:
      - if: "{instance =~ 'vmgateway.*'}"
        action: replace
        target_label: team
        replacement: admin
      - if: "{instance =~ 'localhost.*'}"
        action: replace
        target_label: team
        replacement: dev
    static_configs:
      - targets:
          - localhost:8429
          - vmgateway-single:8431
          - vmgateway-cluster:8431

Relabeling rules will add the team label to the scraped metrics in order to test multi-tenant access. Metrics from localhost will be labeled with team=dev and metrics from vmgateway will be labeled with team=admin.

vmagent will write data into VictoriaMetrics single-node and cluster(with tenant 0:0).

Grafana datasources configuration will be the following:

Let’s login as user with team=dev labels limitation set via claims.

Using vmgateway-cluster results into No data response as proxied request will go to tenant 0:1. Since vmagent is only configured to write to 0:0 No data is an expected response.

Switching to vmgateway-single does have data. Note that it is limited to metrics with team=dev label.

Now lets login as user with team=admin.

Both cluster and single node datasources now return metrics for team=admin.

Using oAuth for remote write with vmagent #

vmagent can be configured to use oAuth for remote write. This is in order to add authentication to the write requests.

In order to create a client for vmagent to use, follow the steps below:

Log in with admin credentials to your Keycloak instance
Go to Clients -> Create.
Use OpenID Connect as Client Type.
Specify vmagent as Client ID.
Click Next.
Enable Client authentication.
Enable Authorization.
Click Next.
Leave URLs section empty as vmagent will not use any. Click Save.
Go to Clients -> vmagent -> Credentials.
Copy the value of Client secret. It will be used later in vmagent configuration.
Go to Clients -> vmagent -> Client scopes.
Click at vmagent-dedicated -> Add mapper -> By configuration -> User attribute.
Configure the mapper as follows
- Name as vm_access.
- Token Claim Name as vm_access.
- User Attribute as vm_access.
- Claim JSON Type as JSON. Enable Add to ID token and Add to access token.
Click Save.
Go to Service account roles -> click on service-account-vmagent.
Go to Attributes tab and add an attribute. Specify vm_access as Key.
Specify {"tenant_id" : {"account_id": 0, "project_id": 0 }} as a value.
Click Save.

Once iDP configuration is done, vmagent configuration needs to be updated to use oAuth for remote write:

  vmagent:
    image: victoriametrics/vmagent:v1.106.1
    volumes:
      - ./scrape.yaml:/etc/vmagent/config.yaml
      - ./vmagent-client-secret:/etc/vmagent/oauth2-client-secret
    command:
      - -promscrape.config=/etc/vmagent/config.yaml
      - -remoteWrite.url=http://vmgateway-cluster:8431/api/v1/write
      - -remoteWrite.url=http://vmgateway-single:8431/api/v1/write
      - -remoteWrite.oauth2.clientID={CLIENT_ID}
      - -remoteWrite.oauth2.clientSecretFile=/etc/vmagent/oauth2-client-secret
      - -remoteWrite.oauth2.tokenUrl=http://keycloak:8080/realms/master/protocol/openid-connect/token
      - -remoteWrite.oauth2.scopes=openid

It is required to replace {CLIENT_ID} with the client ID and provide the client secret in vmagent-client-secret file. Note that vmagent will use the same token for both single-node and cluster vmgateway. vmgateway running in cluster mode will use tenant information from the token to route the request to the correct tenant. vmgateway running in single-node mode will just verify token validity.

Setup vmgateway - Multi-Tenant Access with Grafana & OIDC #