Istio 1.25.0 Change Notes

Deprecation Notices

These notices describe functionality that will be removed in a future release according to Istio’s deprecation policy. Please consider upgrading your environment to remove the deprecated functionality.

• Deprecated use of ISTIO_META_DNS_AUTO_ALLOCATE in proxyMetadata in favor of a newer version of DNS auto-allocation. New users of Istio IP auto-allocation should adopt the new status based controller. Existing users may continue to use the older implementation. (Issue #53596)

• Deprecated traffic.sidecar.istio.io/kubevirtInterfaces, in favor of istio.io/reroute-virtual-interfaces. (Issue #49829)

Traffic Management

• Promoted the cni.ambient.dnsCapture value to default to true. This enables the DNS proxying for workloads in ambient mesh by default, improving security, performance, and enabling a number of features. This can be disabled explicitly or with compatibilityVersion=1.24. Note: only new pods will have DNS enabled. To enable for existing pods, pods must be manually restarted, or the iptables reconciliation feature must be enabled with --set cni.ambient.reconcileIptablesOnStartup=true.

• Promoted the PILOT_ENABLE_IP_AUTOALLOCATE value to default to true. This enables the new iteration of IP auto-allocation, fixing long-standing issues around allocation instability, ambient support, and increased visibility. ServiceEntry objects without spec.address set will now see a new field, status.addresses, automatically set. Note: these will not be used unless proxies are configured to do DNS proxying, which remains off-by-default.

• Updated the PILOT_SEND_UNHEALTHY_ENDPOINTS feature (which is off by default) to not include terminating endpoints. This ensures a service is not considered unhealthy during scale down or rollout events.

• Updated DNS proxying algorithm to randomly select which upstream to forward DNS requests to. (Issue #53414)

• Added new istiod environment variable PILOT_DNS_JITTER_DURATION that sets jitter for periodic DNS resolution. See dns_jitter in https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/cluster.proto. (Issue #52877)

• Added ObservedGeneration to ambient status conditions. This field will show the generation of the object that was observed by the controller when the condition was generated. (Issue #53331)

• Added Istiod environment variable PILOT_DNS_CARES_UDP_MAX_QUERIES that controls the udp_max_queries field of Envoy’s default Cares DNS resolver. This value defaults to 100 when unset. For more information, see Envoy documentation (Issue #53577)

• Added support for reconciling in-pod iptables rules of existing ambient pods from the previous version on istio-cni upgrade. Feature can be toggled with --set cni.ambient.reconcileIptablesOnStartup=true, and will be enabled by default in future releases. (Issue #1360)

• Added istio.io/reroute-virtual-interfaces annotation, a comma separated list of virtual interfaces whose inbound traffic will be unconditionally treated as outbound. This allows workloads using virtual networking (KubeVirt, VMs, docker-in-docker, etc) to function correctly with both sidecar and ambient mesh traffic capture.

• Added support for attaching policy defaults for istio-waypoint by targeting the GatewayClass. (Issue #54696)

• Added ambient.istio.io/dns-capture annotation, which may be unset, or set to true or false. When specified on a Pod enrolled in ambient mesh, controls whether DNS traffic (TCP and UDP on port 53) will be captured and proxied in ambient. This pod-level annotation, if present on a pod, will override the global istio-cni AMBIENT_DNS_CAPTURE setting, which as of 1.25 defaults to true. Note: setting this to false will break some Istio features, such as ServiceEntries and egress waypoints, but may be desirable for workloads that interact poorly with DNS proxies. (Issue #49829)

• Added support for configuring the istio.io/ingress-use-waypoint label at the namespace level.

• Added support to preserve the original case of HTTP/1.x headers. (Issue #53680)

• Added support for the Service.spec.trafficDistribution field and networking.istio.io/traffic-distribution annotation, allowing a simpler mechanism to make traffic prefer geographically close endpoints. Note: this feature previously existed only for ztunnel, but is now supported across all data planes.

• Fixed a bug with mixed cased Hosts in Gateway and TLS redirect which resulted in stale RDS. (Issue #49638)

• Fixed an issue where an HTTPRoute in a VirtualService with a matcher specifying sourceLabels would be applied to a waypoint. (Issue #51565)

• Fixed an issue where if a WASM image fetch fails, an allow all RBAC filter is used. Now if failStrategy is set to FAIL_CLOSE, a DENY-ALL RBAC filter will be used. (Issue #53279), (Issue #23624)

• Fixed waypoint proxy to respect trust domain.

• Fixed an issue where merging Duration in an EnvoyFilter could lead to all listeners associated attributes unexpectedly being modified because all listeners shared the same pointer type (listener_filters_timeout).

• Fixed an issue where errors were being raised during cleanup of iptables rules that were conditional.

• Fixed a configuration issue so that DNS traffic (UDP and TCP) is now affected by traffic annotations like traffic.sidecar.istio.io/excludeOutboundIPRanges and traffic.sidecar.istio.io/excludeOutboundPorts. Before, UDP/DNS traffic would uniquely ignore these traffic annotations, even if a DNS port was specified, because of the rule structure. The behavior change actually happened in the 1.23 release series, but was left out of the release notes for 1.23. (Issue #53949)

• Fixed an issue where istiod did not handle RequestAuthentication correctly for cross-namespace waypoint proxies. (Issue #54051)

• Fixed an issue that caused patches to a managed gateway/waypoint deployment to fail during upgrade to 1.24. (Issue #54145)

• Fixed an issue where non-default revisions controlling gateways lacked istio.io/rev labels. (Issue #54280)

• Fixed the wording of the status message when L7 rules are present in an AuthorizationPolicy which is bound to ztunnel to be more clear. (Issue #54334)

• Fixed a bug where request mirror filter incorrectly computed the percentage. (Issue #54357)

• Fixed an issue where using a tag in the istio.io/rev label on a gateway causes the gateway to be improperly programmed and to lack status. (Issue #54458)

• Fixed an issue where out-of-order ztunnel disconnects could put istio-cni in a state where it believes it has no connections. (Issue #54544), (Issue #53843)

• Fixed excessive iptables info-level log entries for rule checks and deletions. Detailed logging can be re-enabled by switching to debug-level logs, if necessary. (Issue #54644)

• Fixed an issue that caused ExternalName services to fail to resolve when using ambient mode and DNS proxying.

• Fixed an issue causing configuration to be rejected when there is a partial overlap between IP addresses across multiple services. For example, a Service with [IP-A] and one with [IP-B, IP-A]. (Issue #52847)

• Fixed an issue causing VirtualService header name validation to reject valid header names.

• Fixed an issue when upgrading waypoint proxies from Istio 1.23.x to Istio 1.24.x. (Issue #53883)

Security

• Added the DAC_OVERRIDE capability to the istio-cni-node DaemonSet. This fixes issues when running in environments where certain files are owned by non-root users. Note: prior to Istio 1.24, the istio-cni-node ran as privileged. Istio 1.24 removed this, but removed some required privileges which are now added back. Relatively to Istio 1.23, istio-cni-node still has fewer privileges than it does with this change.

• Added unconfined AppArmor annotation to the istio-cni-node DaemonSet to avoid conflicts with AppArmor profiles which block certain privileged pod capabilities. Previously, AppArmor (when enabled) was bypassed for the istio-cni-node DaemonSet since privileged was set to true in the SecurityContext. This change ensures that the AppArmor profile is set to unconfined for the istio-cni-node DaemonSet.

• Fixed an issue where ambient PeerAuthentication policies were overly strict. (Issue #53884)

• Fixed a possible race conditions in JWK resolution cache for JWT policies that, when triggered, would cause cache misses & failures to update signing keys when rotated. (Issue #52121)

• Fixed a bug in ambient (only) where multiple STRICT port-level mTLS rules in a PeerAuthentication policy would effectively result in a permissive policy due to incorrect evaluation logic (AND vs. OR). (Issue #54146)

• Fixed an issue where ingress gateways did not use WDS discovery to retrieve metadata for ambient destinations.

Telemetry

• Added support for additional label exchange for telemetry in sidecar mode. (Issue #54000)

• Added a new service.istio.io/workload-name label that can be added to a Pod or WorkloadEntry to override the “workload name” reported in telemetry.

• Added a fallback to use the WorkloadGroup name as the “workload name” (as reported in telemetry) for WorkloadEntrys created by a WorkloadGroup.

• Fixed $(HOST_IP) interpolation causes istio-proxy failures when Datadog tracing enabled on IPv6 clusters. (Issue #54267)

• Fixed an issue where access log order instability caused connection draining. (Issue #54672)

• Fixed an issue where many panels in the Grafana dashboards showed No data if Prometheus had a scrape interval configured to be larger than 15s. (Background information and usage)

• Removed OpenCensus support.

Installation

• Improved Both platform and profile Helm values overrides now equivalently support global or local override forms, e.g.

  • --set global.platform=foo
  • --set global.profile=bar
  • --set platform=foo
  • --set profile=bar

• Improved the ztunnel Helm chart to set resource names to .Release.Name instead of being hard-coded to ztunnel.

• Added new messages to the WaypointBound condition to represent a service binding to a waypoint proxy for ingress.

• Added an issue where istioctl install not working on Windows.

• Added a pod dnsPolicy of ClusterFirstWithHostNet to istio-cni when it runs with hostNetwork=true (i.e. ambient mode).

• Added GKE platform profile for ambient mode. When installing on GKE, use --set global.platform=gke (Helm) or --set values.global.platform=gke (istioctl) to apply GKE-specific value overrides. This replaces the previous GKE auto detection based on K8S version used in the istio-cni chart.

• Added support for Envoy config parameter to skip deprecated logs, with the default set to true. Setting the ENVOY_SKIP_DEPRECATED_LOGS environment variable to false will enable deprecated logs.

• Added ambient dataplane exclusion labels to Istio-shipped gateways by default, to avoid out-of-the-box confusing behavior if installing gateways outside of istio-system. (Issue #54824)

• Fixed an issue where ipset entry creation would fail on certain kinds of Docker-based Kubernetes nodes. (Issue #53512)

• Fixed Helm render to properly apply annotations on pilot serviceAccount. (Issue #51289)

• Fixed a issue where includeInboundPorts: "" not working when istio-cni is enabled. (Issue #54288)

• Fixed an issue where the CNI installation left temporary files when a container was repeatedly killed during the binary copy, which could have filled the storage space. (Issue #54311)

• Fixed an issue in the gateway chart where --set platform worked but --set global.platform did not.

• Fixed an issue where gateway injection template did not respect the kubectl.kubernetes.io/default-logs-container and kubectl.kubernetes.io/default-container annotations.

• Fixed an issue causing the istio-iptables command to fail when a non-built-in table is present in the system.

• Fixed an issue preventing the PodDisruptionBudget maxUnavailable field from being customizable. (Issue #54087)

• Fixed an issue where injection configuration errors were being silenced (i.e. logged and not returned) when the sidecar injector was unable to process the sidecar config. This change will now propagate the error to the user instead of continuing to process a faulty config. (Issue #53357)

istioctl

• Improved the output of istioctl proxy-config secret to display trust bundles provided by Spire.

• Added alias -r for --revision flags in istioctl analyze.

• Added support for AuthorizationPolicies with CUSTOM action in the istioct x authz check command.

• Added support for the --network parameter to the istioctl experimental workload group create command. (Issue #54022)

• Added the ability to safely restart/upgrade the system-node-critical istio-cni node agent DaemonSet in-place. This works by preventing new pods from starting on the node while istio-cni is being restarted or upgraded. This feature is enabled by default and can be disabled by setting the environment variable AMBIENT_DISABLE_SAFE_UPGRADE=true in istio-cni. (Issue #49009)

• Added changes for rootca-compare command to handle the case when pod has multiple root CA. (Issue #54545)

• Added support for istioctl waypoint delete to delete specified revision waypoints.

• Added support for the analyzer to report negative status conditions on select Istio and Kubernetes Gateway API resources. (Issue #55055)

• Improved the performance of istioctl proxy-config secret and istioctl proxy-config. (Issue #53931)

• Fixed an issue in the rootca-compare command to handle the case when a pod has multiple root CAs. (Issue #54545)

• Fixed an issue where istioctl install deadlocks if multiple ingress gateways are specified in the IstioOperator file. (Issue #53875)

• Fixed an issue where istioctl waypoint delete --all would delete all gateway resources, even non-waypoints. (Issue #54056)

• Fixed the istioctl experimental injector list command to not print redundant namespaces for injector webhooks.

• Fixed istioctl analyze reporting IST0145 errors when using the same host with different ports and multiple gateways. (Issue #54643)

• Fixed an issue where istioctl --as implicitly set --as-group="" when --as is used without --as-group.

• Removed --recursive flags and set recursion to true for istioctl analyze.

• Removed the experimental flag --xds-via-agents from the istioctl proxy-status command.