SPIRE
SPIRE is a production-ready implementation of the SPIFFE specification that performs node and workload attestation in order to securely issue cryptographic identities to workloads running in heterogeneous environments. SPIRE can be configured as a source of cryptographic identities for Istio workloads through an integration with Envoy’s SDS API. Istio can detect the existence of a UNIX Domain Socket that implements the Envoy SDS API on a defined socket path, allowing Envoy to communicate and fetch identities directly from it.
This integration with SPIRE provides flexible attestation options not available with the default Istio identity management while harnessing Istio’s powerful service management. For example, SPIRE’s plugin architecture enables diverse workload attestation options beyond the Kubernetes namespace and service account attestation offered by Istio. SPIRE’s node attestation extends attestation to the physical or virtual hardware on which workloads run.
For a quick demo of how this SPIRE integration with Istio works, see Integrating SPIRE as a CA through Envoy’s SDS API.
The integration is compatible with Istio upgrades.
Install SPIRE
Option 1: Quick start
Istio provides a basic sample installation to quickly get SPIRE up and running:
$ kubectl apply -f @samples/security/spire/spire-quickstart.yaml@
This will deploy SPIRE into your cluster, along with two additional components: the SPIFFE CSI Driver — used to share the SPIRE Agent’s UNIX Domain Socket with the other pods throughout the node — and the SPIRE Controller Manager, a facilitator that performs workload registration and establishes federation relationships within Kubernetes. See Install Istio to configure Istio and integrate with the SPIFFE CSI Driver.
Option 2: Configure a custom SPIRE installation
See the SPIRE’s Quick start for Kubernetes guide to get started deploying SPIRE into your Kubernetes environment. See SPIRE CA Integration Prerequisites for more information on configuring SPIRE to integrate with Istio deployments.
SPIRE CA Integration Prerequisites
To integrate your SPIRE deployment with Istio, configure SPIRE:
Access the SPIRE Agent reference and configure the SPIRE Agent socket path to match the Envoy SDS defined socket path.
socket_path = "/run/secrets/workload-spiffe-uds/socket"
Share the SPIRE Agent socket with the pods within the node by deploying the SPIFFE CSI Driver. The
-workload-api-socket-dir
argument to the driver should be the mount location of the socket’s directory.
See Install Istio to configure Istio to integrate with the SPIFFE CSI Driver.
Install Istio
Option 1: Configuration for Workload Registration with the SPIRE Controller Manager
By deploying SPIRE Controller Manager along with a SPIRE Server, new entries can be automatically registered for each new pod that matches the selector defined in a ClusterSPIFFEID custom resource.
A ClusterSPIFFEID must be applied prior to installing Istio in order for the Ingress-gateway to obtain its certificates. Additionally, the Ingress-gateway pod must be configured to match the selector defined in the ClusterSPIFFEID. If a registration entry for the Ingress Gateway workload was not automatically created during install, the workload would not reach a Ready
state and installation would fail.
Create example ClusterSPIFFEID:
$ kubectl apply -f - <<EOF apiVersion: spire.spiffe.io/v1alpha1 kind: ClusterSPIFFEID metadata: name: example spec: spiffeIDTemplate: "spiffe://{{ .TrustDomain }}/ns/{{ .PodMeta.Namespace }}/sa/{{ .PodSpec.ServiceAccountName }}" podSelector: matchLabels: spiffe.io/spire-managed-identity: "true" EOF
The example ClusterSPIFFEID enables automatic workload registration for all workloads with the
spiffe.io/spire-managed-identity: "true"
label. For pods with this label, the values specified in thespiffeIDTemplate
will be extracted to form the SPIFFE ID.Create the Istio configuration with custom patches for the Ingress-gateway and istio-proxy. The Ingress Gateway component includes the
spiffe.io/spire-managed-identity: "true"
label.$ cat <<EOF > ./istio.yaml apiVersion: install.istio.io/v1alpha1 kind: IstioOperator metadata: namespace: istio-system spec: profile: default meshConfig: trustDomain: example.org values: global: # This is used to customize the sidecar template sidecarInjectorWebhook: templates: spire: | spec: containers: - name: istio-proxy volumeMounts: - name: workload-socket mountPath: /run/secrets/workload-spiffe-uds readOnly: true volumes: - name: workload-socket csi: driver: "csi.spiffe.io" readOnly: true components: ingressGateways: - name: istio-ingressgateway enabled: true label: istio: ingressgateway spiffe.io/spire-managed-identity: "true" k8s: overlays: - apiVersion: apps/v1 kind: Deployment name: istio-ingressgateway patches: - path: spec.template.spec.volumes.[name:workload-socket] value: name: workload-socket csi: driver: "csi.spiffe.io" readOnly: true - path: spec.template.spec.containers.[name:istio-proxy].volumeMounts.[name:workload-socket] value: name: workload-socket mountPath: "/run/secrets/workload-spiffe-uds" readOnly: true - path: spec.template.spec.initContainers value: - name: wait-for-spire-socket image: busybox:1.28 volumeMounts: - name: workload-socket mountPath: /run/secrets/workload-spiffe-uds readOnly: true env: - name: CHECK_FILE value: /run/secrets/workload-spiffe-uds/socket command: - sh - "-c" - |- echo "$(date -Iseconds)" Waiting for: ${CHECK_FILE} while [[ ! -e ${CHECK_FILE} ]] ; do echo "$(date -Iseconds)" File does not exist: ${CHECK_FILE} sleep 15 done ls -l ${CHECK_FILE} EOF
Apply the configuration:
$ istioctl install --skip-confirmation -f ./istio.yaml
Check Ingress-gateway pod state:
$ kubectl get pods -n istio-system NAME READY STATUS RESTARTS AGE istio-ingressgateway-5b45864fd4-lgrxs 1/1 Running 0 17s istiod-989f54d9c-sg7sn 1/1 Running 0 23s
The Ingress-gateway pod is
Ready
since the corresponding registration entry is automatically created for it on the SPIRE Server. Envoy is able to fetch cryptographic identities from SPIRE.
Note that SPIRE Controller Manager
is used in the quick start section.
Option 2: Configuration for Manual Workload Registration with SPIRE
After deploying SPIRE into your environment, and verifying that all deployments are in
Ready
state, configure Istio with custom patches for the Ingress-gateway as well as for istio-proxy.Create Istio configuration:
$ cat <<EOF > ./istio.yaml apiVersion: install.istio.io/v1alpha1 kind: IstioOperator metadata: namespace: istio-system spec: profile: default meshConfig: trustDomain: example.org values: global: # This is used to customize the sidecar template sidecarInjectorWebhook: templates: spire: | spec: containers: - name: istio-proxy volumeMounts: - name: workload-socket mountPath: /run/secrets/workload-spiffe-uds readOnly: true volumes: - name: workload-socket csi: driver: "csi.spiffe.io" readOnly: true components: ingressGateways: - name: istio-ingressgateway enabled: true label: istio: ingressgateway k8s: overlays: - apiVersion: apps/v1 kind: Deployment name: istio-ingressgateway patches: - path: spec.template.spec.volumes.[name:workload-socket] value: name: workload-socket csi: driver: "csi.spiffe.io" readOnly: true - path: spec.template.spec.containers.[name:istio-proxy].volumeMounts.[name:workload-socket] value: name: workload-socket mountPath: "/run/secrets/workload-spiffe-uds" readOnly: true - path: spec.template.spec.initContainers value: - name: wait-for-spire-socket image: busybox:1.28 volumeMounts: - name: workload-socket mountPath: /run/secrets/workload-spiffe-uds readOnly: true env: - name: CHECK_FILE value: /run/secrets/workload-spiffe-uds/socket command: - sh - "-c" - |- echo "$(date -Iseconds)" Waiting for: ${CHECK_FILE} while [[ ! -e ${CHECK_FILE} ]] ; do echo "$(date -Iseconds)" File does not exist: ${CHECK_FILE} sleep 15 done ls -l ${CHECK_FILE} EOF
Apply the configuration:
$ istioctl install --skip-confirmation -f ./istio.yaml
Check Ingress-gateway pod state:
$ kubectl get pods -n istio-system NAME READY STATUS RESTARTS AGE istio-ingressgateway-5b45864fd4-lgrxs 0/1 Running 0 20s istiod-989f54d9c-sg7sn 1/1 Running 0 25s
The Ingress-gateway pod and data plane containers will only reach
Ready
if a corresponding registration entry is created for them on the SPIRE Server. Then, Envoy will be able to fetch cryptographic identities from SPIRE. See Register workloads to register entries for services in your mesh.
The Istio configuration shares the spiffe-csi-driver
with the Ingress Gateway and the sidecars that are going to be injected on workload pods,
granting them access to the SPIRE Agent’s UNIX Domain Socket.
This configuration also adds an initContainer to the gateway that will wait for SPIRE to create the UNIX Domain Socket before starting the istio-proxy. If the SPIRE agent is not ready or has not been properly configured with the same socket path, the Ingress Gateway initContainer will wait forever.
Register workloads
This section describes the options available for registering workloads in a SPIRE Server.
Option 1: Registration using the SPIRE Controller Manager
New entries will be automatically registered for each new pod that matches the selector defined in a ClusterSPIFFEID custom resource. See Configuration for Workload Registration with the SPIRE Controller Manager for the example ClusterSPIFFEID configuration.
Deploy an example workload:
$ istioctl kube-inject --filename @samples/security/spire/sleep-spire.yaml@ | kubectl apply -f -
In addition to needing
spiffe.io/spire-managed-identity
label, the workload will need the SPIFFE CSI Driver volume to access the SPIRE Agent socket. To accomplish this, you can leverage thespire
pod annotation template from the Install Istio section or add the CSI volume to the deployment spec of your workload. Both of these alternatives are highlighted on the example snippet below:apiVersion: apps/v1 kind: Deployment metadata: name: sleep spec: replicas: 1 selector: matchLabels: app: sleep template: metadata: labels: app: sleep spiffe.io/spire-managed-identity: "true" # Injects custom sidecar template annotations: inject.istio.io/templates: "sidecar,spire" spec: terminationGracePeriodSeconds: 0 serviceAccountName: sleep containers: - name: sleep image: curlimages/curl command: ["/bin/sleep", "3650d"] imagePullPolicy: IfNotPresent volumeMounts: - name: tmp mountPath: /tmp securityContext: runAsUser: 1000 volumes: - name: tmp emptyDir: {} # CSI volume - name: workload-socket csi: driver: "csi.spiffe.io" readOnly: true
See Verifying that identities were created for workloads to check issued identities.
Note that SPIRE Controller Manager
is used in the quick start section.
Option 2: Manual Registration
To improve workload attestation security robustness, SPIRE is able to verify against a group of selector values based on different parameters. Skip these steps if you installed SPIRE
by following the quick start since it uses automatic registration.
Generate an entry for an Ingress Gateway with a set of selectors such as the pod name and pod UID:
$ INGRESS_POD=$(kubectl get pod -l istio=ingressgateway -n istio-system -o jsonpath="{.items[0].metadata.name}") $ INGRESS_POD_UID=$(kubectl get pods -n istio-system "$INGRESS_POD" -o jsonpath='{.metadata.uid}')
Get the spire-server pod:
$ SPIRE_SERVER_POD=$(kubectl get pod -l app=spire-server -n spire -o jsonpath="{.items[0].metadata.name}")
Register an entry for the SPIRE Agent running on the node:
$ kubectl exec -n spire "$SPIRE_SERVER_POD" -- \ /opt/spire/bin/spire-server entry create \ -spiffeID spiffe://example.org/ns/spire/sa/spire-agent \ -selector k8s_psat:cluster:demo-cluster \ -selector k8s_psat:agent_ns:spire \ -selector k8s_psat:agent_sa:spire-agent \ -node -socketPath /run/spire/sockets/server.sock Entry ID : d38c88d0-7d7a-4957-933c-361a0a3b039c SPIFFE ID : spiffe://example.org/ns/spire/sa/spire-agent Parent ID : spiffe://example.org/spire/server Revision : 0 TTL : default Selector : k8s_psat:agent_ns:spire Selector : k8s_psat:agent_sa:spire-agent Selector : k8s_psat:cluster:demo-cluster
Register an entry for the Ingress-gateway pod:
$ kubectl exec -n spire "$SPIRE_SERVER_POD" -- \ /opt/spire/bin/spire-server entry create \ -spiffeID spiffe://example.org/ns/istio-system/sa/istio-ingressgateway-service-account \ -parentID spiffe://example.org/ns/spire/sa/spire-agent \ -selector k8s:sa:istio-ingressgateway-service-account \ -selector k8s:ns:istio-system \ -selector k8s:pod-uid:"$INGRESS_POD_UID" \ -dns "$INGRESS_POD" \ -dns istio-ingressgateway.istio-system.svc \ -socketPath /run/spire/sockets/server.sock Entry ID : 6f2fe370-5261-4361-ac36-10aae8d91ff7 SPIFFE ID : spiffe://example.org/ns/istio-system/sa/istio-ingressgateway-service-account Parent ID : spiffe://example.org/ns/spire/sa/spire-agent Revision : 0 TTL : default Selector : k8s:ns:istio-system Selector : k8s:pod-uid:63c2bbf5-a8b1-4b1f-ad64-f62ad2a69807 Selector : k8s:sa:istio-ingressgateway-service-account DNS name : istio-ingressgateway.istio-system.svc DNS name : istio-ingressgateway-5b45864fd4-lgrxs
Deploy an example workload:
$ istioctl kube-inject --filename @samples/security/spire/sleep-spire.yaml@ | kubectl apply -f -
Note that the workload will need the SPIFFE CSI Driver volume to access the SPIRE Agent socket. To accomplish this, you can leverage the
spire
pod annotation template from the Install Istio section or add the CSI volume to the deployment spec of your workload. Both of these alternatives are highlighted on the example snippet below:apiVersion: apps/v1 kind: Deployment metadata: name: sleep spec: replicas: 1 selector: matchLabels: app: sleep template: metadata: labels: app: sleep # Injects custom sidecar template annotations: inject.istio.io/templates: "sidecar,spire" spec: terminationGracePeriodSeconds: 0 serviceAccountName: sleep containers: - name: sleep image: curlimages/curl command: ["/bin/sleep", "3650d"] imagePullPolicy: IfNotPresent volumeMounts: - name: tmp mountPath: /tmp securityContext: runAsUser: 1000 volumes: - name: tmp emptyDir: {} # CSI volume - name: workload-socket csi: driver: "csi.spiffe.io" readOnly: true
Get pod information:
$ SLEEP_POD=$(kubectl get pod -l app=sleep -o jsonpath="{.items[0].metadata.name}") $ SLEEP_POD_UID=$(kubectl get pods "$SLEEP_POD" -o jsonpath='{.metadata.uid}')
Register the workload:
$ kubectl exec -n spire "$SPIRE_SERVER_POD" -- \ /opt/spire/bin/spire-server entry create \ -spiffeID spiffe://example.org/ns/default/sa/sleep \ -parentID spiffe://example.org/ns/spire/sa/spire-agent \ -selector k8s:ns:default \ -selector k8s:pod-uid:"$SLEEP_POD_UID" \ -dns "$SLEEP_POD" \ -socketPath /run/spire/sockets/server.sock
See the SPIRE help on Registering workloads to learn how to create new entries for workloads and get them attested using multiple selectors to strengthen attestation criteria.
Verifying that identities were created for workloads
Use the following command to confirm that identities were created for the workloads:
$ kubectl exec -t "$SPIRE_SERVER_POD" -n spire -c spire-server -- ./bin/spire-server entry show
Found 2 entries
Entry ID : c8dfccdc-9762-4762-80d3-5434e5388ae7
SPIFFE ID : spiffe://example.org/ns/istio-system/sa/istio-ingressgateway-service-account
Parent ID : spiffe://example.org/spire/agent/k8s_psat/demo-cluster/bea19580-ae04-4679-a22e-472e18ca4687
Revision : 0
X509-SVID TTL : default
JWT-SVID TTL : default
Selector : k8s:pod-uid:88b71387-4641-4d9c-9a89-989c88f7509d
Entry ID : af7b53dc-4cc9-40d3-aaeb-08abbddd8e54
SPIFFE ID : spiffe://example.org/ns/default/sa/sleep
Parent ID : spiffe://example.org/spire/agent/k8s_psat/demo-cluster/bea19580-ae04-4679-a22e-472e18ca4687
Revision : 0
X509-SVID TTL : default
JWT-SVID TTL : default
Selector : k8s:pod-uid:ee490447-e502-46bd-8532-5a746b0871d6
Check the Ingress-gateway pod state:
$ kubectl get pods -n istio-system
NAME READY STATUS RESTARTS AGE
istio-ingressgateway-5b45864fd4-lgrxs 1/1 Running 0 60s
istiod-989f54d9c-sg7sn 1/1 Running 0 45s
After registering an entry for the Ingress-gateway pod, Envoy receives the identity issued by SPIRE and uses it for all TLS and mTLS communications.
Check that the workload identity was issued by SPIRE
Retrieve sleep’s SVID identity document using the istioctl proxy-config secret command:
$ istioctl proxy-config secret "$SLEEP_POD" -o json | jq -r \ '.dynamicActiveSecrets[0].secret.tlsCertificate.certificateChain.inlineBytes' | base64 --decode > chain.pem
Inspect the certificate and verify that SPIRE was the issuer:
$ openssl x509 -in chain.pem -text | grep SPIRE Subject: C = US, O = SPIRE, CN = sleep-5f4d47c948-njvpk
SPIFFE Federation
SPIRE Servers are able to authenticate SPIFFE identities originating from different trust domains. This is known as SPIFFE federation.
SPIRE Agent can be configured to push federated bundles to Envoy through the Envoy SDS API, allowing Envoy to use validation context to verify peer certificates and trust a workload from another trust domain. To enable Istio to federate SPIFFE identities through SPIRE integration, consult SPIRE Agent SDS configuration and set the following SDS configuration values for your SPIRE Agent configuration file.
Configuration | Description | Resource Name |
---|---|---|
default_svid_name | The TLS Certificate resource name to use for the default X509-SVID with Envoy SDS | default |
default_bundle_name | The Validation Context resource name to use for the default X.509 bundle with Envoy SDS | null |
default_all_bundles_name | The Validation Context resource name to use for all bundles (including federated) with Envoy SDS | ROOTCA |
This will allow Envoy to get federated bundles directly from SPIRE.
Create federated registration entries
If using the SPIRE Controller Manager, create federated entries for workloads by setting the
federatesWith
field of the ClusterSPIFFEID CR to the trust domains you want the pod to federate with:apiVersion: spire.spiffe.io/v1alpha1 kind: ClusterSPIFFEID metadata: name: federation spec: spiffeIDTemplate: "spiffe://{{ .TrustDomain }}/ns/{{ .PodMeta.Namespace }}/sa/{{ .PodSpec.ServiceAccountName }}" podSelector: matchLabels: spiffe.io/spire-managed-identity: "true" federatesWith: ["example.io", "example.ai"]
For manual registration see Create Registration Entries for Federation.
Cleanup SPIRE
If you installed SPIRE using the quick start SPIRE deployment provided by Istio, use the following commands to remove those Kubernetes resources:
$ kubectl delete CustomResourceDefinition clusterspiffeids.spire.spiffe.io
$ kubectl delete CustomResourceDefinition clusterfederatedtrustdomains.spire.spiffe.io
$ kubectl delete -n spire configmap spire-bundle
$ kubectl delete -n spire serviceaccount spire-agent
$ kubectl delete -n spire configmap spire-agent
$ kubectl delete -n spire daemonset spire-agent
$ kubectl delete csidriver csi.spiffe.io
$ kubectl delete ValidatingWebhookConfiguration spire-controller-manager-webhook
$ kubectl delete -n spire configmap spire-controller-manager-config
$ kubectl delete -n spire configmap spire-server
$ kubectl delete -n spire service spire-controller-manager-webhook-service
$ kubectl delete -n spire service spire-server-bundle-endpoint
$ kubectl delete -n spire service spire-server
$ kubectl delete -n spire serviceaccount spire-server
$ kubectl delete -n spire deployment spire-server
$ kubectl delete clusterrole spire-server-cluster-role spire-agent-cluster-role manager-role
$ kubectl delete clusterrolebinding spire-server-cluster-role-binding spire-agent-cluster-role-binding manager-role-binding
$ kubectl delete -n spire role spire-server-role leader-election-role
$ kubectl delete -n spire rolebinding spire-server-role-binding leader-election-role-binding
$ kubectl delete namespace spire
$ rm istio.yaml chain.pem