mTLS
Create a Secret containing a CA Certificate and pass the ID of the certificate to an mTLS plugin configuration.
Prerequisites
Kong Konnect
If you don’t have a Konnect account, you can get started quickly with our onboarding wizard.
- The following Konnect items are required to complete this tutorial:
- Personal access token (PAT): Create a new personal access token by opening the Konnect PAT page and selecting Generate Token.
-
Set the personal access token as an environment variable:
export KONNECT_TOKEN='YOUR KONNECT TOKEN'
Enable the Gateway API
-
Install the Gateway API CRDs before installing Kong Ingress Controller.
kubectl apply -f https://github.com/kubernetes-sigs/gateway-api/releases/download/v1.2.0/standard-install.yaml
-
Create a
Gateway
andGatewayClass
instance to use.
echo "
apiVersion: v1
kind: Namespace
metadata:
name: kong
---
apiVersion: gateway.networking.k8s.io/v1
kind: GatewayClass
metadata:
name: kong
annotations:
konghq.com/gatewayclass-unmanaged: 'true'
spec:
controllerName: konghq.com/kic-gateway-controller
---
apiVersion: gateway.networking.k8s.io/v1
kind: Gateway
metadata:
name: kong
spec:
gatewayClassName: kong
listeners:
- name: proxy
port: 80
protocol: HTTP
allowedRoutes:
namespaces:
from: All
" | kubectl apply -n kong -f -
Create a KIC Control Plane
Use the Konnect API to create a new CLUSTER_TYPE_K8S_INGRESS_CONTROLLER
Control Plane:
CONTROL_PLANE_DETAILS=$(curl -X POST "https://us.api.konghq.com/v2/control-planes" \
-H "Authorization: Bearer $KONNECT_TOKEN" \
--json '{
"name": "My KIC CP",
"cluster_type": "CLUSTER_TYPE_K8S_INGRESS_CONTROLLER"
}')
We’ll need the id
and telemetry_endpoint
for the values.yaml
file later. Save them as environment variables:
CONTROL_PLANE_ID=$(echo $CONTROL_PLANE_DETAILS | jq -r .id)
CONTROL_PLANE_TELEMETRY=$(echo $CONTROL_PLANE_DETAILS | jq -r '.config.telemetry_endpoint | sub("https://";"")')
Create mTLS certificates
Kong Ingress Controller talks to Konnect over a connected secured with TLS certificates.
Generate a new certificate using openssl
:
openssl req -new -x509 -nodes -newkey rsa:2048 -subj "/CN=kongdp/C=US" -keyout ./tls.key -out ./tls.crt
The certificate needs to be a single line string to send it to the Konnect API with curl. Use awk
to format the certificate:
export CERT=$(awk 'NF {sub(/\r/, ""); printf "%s\\n",$0;}' tls.crt);
Next, upload the certificate to Konnect:
curl -X POST "https://us.api.konghq.com/v2/control-planes/$CONTROL_PLANE_ID/dp-client-certificates" \
-H "Authorization: Bearer $KONNECT_TOKEN" \
--json '{
"cert": "'$CERT'"
}'
Finally, store the certificate in a Kubernetes secret so that Kong Ingress Controller can read it:
kubectl create namespace kong -o yaml --dry-run=client | kubectl apply -f -
kubectl create secret tls konnect-client-tls -n kong --cert=./tls.crt --key=./tls.key
Kong Ingress Controller running (attached to Konnect)
-
Add the Kong Helm charts:
helm repo add kong https://charts.konghq.com helm repo update
-
Create a
values.yaml
file:cat <<EOF > values.yaml controller: ingressController: image: tag: "3.4" env: feature_gates: "FillIDs=true" konnect: license: enabled: true enabled: true controlPlaneID: "$CONTROL_PLANE_ID" tlsClientCertSecretName: konnect-client-tls apiHostname: "us.kic.api.konghq.com" gateway: image: repository: kong/kong-gateway env: konnect_mode: 'on' vitals: "off" cluster_mtls: pki cluster_telemetry_endpoint: "$CONTROL_PLANE_TELEMETRY:443" cluster_telemetry_server_name: "$CONTROL_PLANE_TELEMETRY" cluster_cert: /etc/secrets/konnect-client-tls/tls.crt cluster_cert_key: /etc/secrets/konnect-client-tls/tls.key lua_ssl_trusted_certificate: system proxy_access_log: "off" dns_stale_ttl: "3600" secretVolumes: - konnect-client-tls EOF
-
Install Kong Ingress Controller using Helm:
helm install kong kong/ingress -n kong --create-namespace --values ./values.yaml
-
Set
$PROXY_IP
as an environment variable for future commands:export PROXY_IP=$(kubectl get svc --namespace kong kong-gateway-proxy -o jsonpath='{range .status.loadBalancer.ingress[0]}{@.ip}{@.hostname}{end}') echo $PROXY_IP
Kong Ingress Controller running (with an Enterprise license)
-
Add the Kong Helm charts:
helm repo add kong https://charts.konghq.com helm repo update
-
Create a file named
license.json
containing your Kong Gateway Enterprise license and store it in a Kubernetes secret:kubectl create namespace kong --dry-run=client -o yaml | kubectl apply -f - kubectl create secret generic kong-enterprise-license --from-file=license=./license.json -n kong
-
Create a
values.yaml
file:cat <<EOF > values.yaml gateway: image: repository: kong/kong-gateway env: LICENSE_DATA: valueFrom: secretKeyRef: name: kong-enterprise-license key: license EOF
-
Install Kong Ingress Controller using Helm:
helm install kong kong/ingress -n kong --create-namespace --values ./values.yaml
-
Set
$PROXY_IP
as an environment variable for future commands:export PROXY_IP=$(kubectl get svc --namespace kong kong-gateway-proxy -o jsonpath='{range .status.loadBalancer.ingress[0]}{@.ip}{@.hostname}{end}') echo $PROXY_IP
Required Kubernetes resources
This how-to requires some Kubernetes services to be available in your cluster. These services will be used by the resources created in this how-to.
kubectl apply -f https://developer.konghq.com/manifests/kic/echo-service.yaml -n kong
This how-to also requires 1 pre-configured route:
About mTLS
Mutual TLS (mTLS) is a way to secure connectivity using certificates. Kong Gateway can look for a certificate in incoming requests and reject the request if the public key presented does not match the private key stored in Kong Gateway.
Generate a CA certificate
To use the mtls-auth
plugin you need a CA certificate. If you don’t have one, generate a new certificate using openssl
:
openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -sha256 -days 365 -nodes \
-subj "/C=US/ST=California/L=San Francisco/O=Kong/OU=Org/CN=www.example.com"
Add the Certificate to Kong Gateway
CA Certificates in Kong Gateway are provisioned by creating a Secret
or ConfigMap
resource in Kubernetes.
Resources holding CA certificates must have the following properties:
- The
konghq.com/ca-cert: "true"
label applied - A
cert
orca.crt
data property which contains a valid CA certificate in PEM format - A
kubernetes.io/ingress.class
annotation whose value matches the value of the controller’s--ingress-class
argument. By default, that value iskong
. - An
id
data property which contains a random UUID
Each CA Certificate that you create needs a unique ID. Any random UUID should suffice here, and it doesn’t have a security implication. You can use uuidgen (Linux, macOS) or New-Guid (Windows) to generate an ID.
CERT_ID=$(uuidgen | tr "[:upper:]" "[:lower:]")
kubectl create secret -n kong generic my-ca-cert --from-literal=id=$CERT_ID --from-file=cert=./cert.pem
kubectl label secret -n kong my-ca-cert 'konghq.com/ca-cert=true'
kubectl annotate secret -n kong my-ca-cert 'kubernetes.io/ingress.class=kong'
Configure the mtls-auth plugin
The mtls-auth plugin requires a CA Certificate ID that will be used to validate the Certificate in the incoming request. In this example we disable revocation checks, but you should enable checks in a production setting.
echo "
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
name: mtls-auth
namespace: kong
annotations:
kubernetes.io/ingress.class: kong
config:
ca_certificates:
- '$CERT_ID'
skip_consumer_lookup: true
revocation_check_mode: SKIP
plugin: mtls-auth
" | kubectl apply -f -
Next, apply the KongPlugin
resource by annotating the service
resource:
kubectl annotate -n kong service echo konghq.com/plugins=mtls-auth
Validate your configuration
At this point, Kong Gateway will reject requests that do not contain a client certificate.
-
Send a request to check Kong Gateway prompts for a client certificate:
curl "$PROXY_IP/echo"
You should see the following response:
No required TLS certificate was sent
curl "$PROXY_IP/echo"
You should see the following response:
No required TLS certificate was sent
As you can see, Kong Gateway is restricting the request because it doesn’t have the necessary authentication information.
Two things to note here:
-
-k
is used because Kong Gateway is set up to serve a self-signed certificate by default. For full mutual authentication in production use cases, you must configure Kong Gateway to serve a Certificate that is signed by a trusted CA. - For some deployments
$PROXY_IP
might contain a port that points tohttp
port of Kong Gateway. In others, it might contain a DNS name instead of an IP address. If needed, update the command to send anhttps
request to thehttps
port of Kong Gateway or the load balancer in front of it.
-
-
Use the key and Certificate to authenticate against Kong Gateway and use the Service:
curl -k --key key.pem --cert cert.pem "https://$PROXY_IP/echo"
curl -k --key key.pem --cert cert.pem "https://$PROXY_IP/echo"
The results should look like this:
HTTP/2 200 content-type: text/plain; charset=UTF-8 server: echoserver x-kong-upstream-latency: 1 x-kong-proxy-latency: 1 via: kong/x.y.z
Cleanup
Delete created Kubernetes resources
kubectl delete -n kong -f https://developer.konghq.com/manifests/kic/echo-service.yaml
Uninstall KIC from your cluster
helm uninstall kong -n kong