Global Mesh Options

Port on which Envoy should listen for incoming connections from other services. Default port is 15001.

Port on which Envoy should listen for HTTP PROXY requests if set.

Connection timeout used by Envoy. (MUST BE >=1ms) Default timeout is 10s.

Automatic protocol detection uses a set of heuristics to determine whether the connection is using TLS or not (on the server side), as well as the application protocol being used (e.g., http vs tcp). These heuristics rely on the client sending the first bits of data. For server first protocols like MySQL, MongoDB, etc. Envoy will timeout on the protocol detection after the specified period, defaulting to non mTLS plain TCP traffic. Set this field to tweak the period that Envoy will wait for the client to send the first bits of data. (MUST BE >=1ms or 0s to disable). Default detection timeout is 5s.

If set then set SO_KEEPALIVE on the socket to enable TCP Keepalives.

Class of ingress resources to be processed by Istio ingress controller. This corresponds to the value of kubernetes.io/ingress.class annotation.

Name of the Kubernetes service used for the istio ingress controller. If no ingress controller is specified, the default value istio-ingressgateway is used.

Defines whether to use Istio ingress controller for annotated or all ingress resources. Default mode is STRICT.

Defines which gateway deployment to use as the Ingress controller. This field corresponds to the Gateway.selector field, and will be set as istio: INGRESS_SELECTOR. By default, ingressgateway is used, which will select the default IngressGateway as it has the istio: ingressgateway labels. It is recommended that this is the same value as ingress_service.

Flag to control generation of trace spans and request IDs. Requires a trace span collector defined in the proxy configuration.

File address for the proxy access log (e.g. /dev/stdout). Empty value disables access logging.

Format for the proxy access log Empty value results in proxy’s default access log format

Encoding for the proxy access log (TEXT or JSON). Default value is TEXT.

This flag enables Envoy’s gRPC Access Log Service. See Access Log Service for details about Envoy’s gRPC Access Log Service API. Default value is false.

This flag disables Envoy Listener logs. See Listener Access Log Istio Enables Envoy’s listener access logs on “NoRoute” response flag. Default value is false.

Default proxy config used by the proxy injection mechanism operating in the mesh (e.g. Kubernetes admission controller) In case of Kubernetes, the proxy config is applied once during the injection process, and remain constant for the duration of the pod. The rest of the mesh config can be changed at runtime and config gets distributed dynamically.

Set the default behavior of the sidecar for handling outbound traffic from the application. If your application uses one or more external services that are not known apriori, setting the policy to ALLOW_ANY will cause the sidecars to route any unknown traffic originating from the application to its requested destination. Users are strongly encouraged to use ServiceEntries to explicitly declare any external dependencies, instead of using ALLOW_ANY, so that traffic to these services can be monitored. Can be overridden at a Sidecar level by setting the OutboundTrafficPolicy in the Sidecar API. Default mode is ALLOW_ANY which means outbound traffic to unknown destinations will be allowed.

ConfigSource describes a source of configuration data for networking rules, and other Istio configuration artifacts. Multiple data sources can be configured for a single control plane.

This flag is used to enable mutual TLS automatically for service to service communication within the mesh, default true. If set to true, and a given service does not have a corresponding DestinationRule configured, or its DestinationRule does not have ClientTLSSettings specified, Istio configures client side TLS configuration appropriately. More specifically, If the upstream authentication policy is in STRICT mode, use Istio provisioned certificate for mutual TLS to connect to upstream. If upstream service is in plain text mode, use plain text. If the upstream authentication policy is in PERMISSIVE mode, Istio configures clients to use mutual TLS when server sides are capable of accepting mutual TLS traffic. If service DestinationRule exists and has ClientTLSSettings specified, that is always used instead.

The trust domain corresponds to the trust root of a system. Refer to SPIFFE-ID

The trust domain aliases represent the aliases of trust_domain. For example, if we have

trustDomain: td1
trustDomainAliases: ["td2", "td3"]

Any service with the identity td1/ns/foo/sa/a-service-account, td2/ns/foo/sa/a-service-account, or td3/ns/foo/sa/a-service-account will be treated the same in the Istio mesh.

The default value for the ServiceEntry.export_to field and services imported through container registry integrations, e.g. this applies to Kubernetes Service resources. The value is a list of namespace names and reserved namespace aliases. The allowed namespace aliases are:

* - All Namespaces
. - Current Namespace
~ - No Namespace

If not set the system will use “*” as the default value which implies that services are exported to all namespaces.

All namespaces is a reasonable default for implementations that don’t need to restrict access or visibility of services across namespace boundaries. If that requirement is present it is generally good practice to make the default Current namespace so that services are only visible within their own namespaces by default. Operators can then expand the visibility of services to other namespaces as needed. Use of No Namespace is expected to be rare but can have utility for deployments where dependency management needs to be precise even within the scope of a single namespace.

For further discussion see the reference documentation for ServiceEntry, Sidecar, and Gateway.

The default value for the VirtualService.export_to field. Has the same syntax as default_service_export_to.

If not set the system will use “*” as the default value which implies that virtual services are exported to all namespaces

The default value for the DestinationRule.export_to field. Has the same syntax as default_service_export_to.

If not set the system will use “*” as the default value which implies that destination rules are exported to all namespaces

The namespace to treat as the administrative root namespace for Istio configuration. When processing a leaf namespace Istio will search for declarations in that namespace first and if none are found it will search in the root namespace. Any matching declaration found in the root namespace is processed as if it were declared in the leaf namespace.

The precise semantics of this processing are documented on each resource type.

Locality based load balancing distribution or failover settings.

Configures DNS refresh rate for Envoy clusters of type STRICT_DNS Default refresh rate is 5s.

Specify if http1.1 connections should be upgraded to http2 by default. if sidecar is installed on all pods in the mesh, then this should be set to UPGRADE. If one or more services or namespaces do not have sidecar(s), then this should be set to DO_NOT_UPGRADE. It can be enabled by destination using the destinationRule.trafficPolicy.connectionPool.http.h2UpgradePolicy override.

Name to be used while emitting statistics for inbound clusters. The same pattern is used while computing stat prefix for network filters like TCP and Redis. By default, Istio emits statistics with the pattern inbound|<port>|<port-name>|<service-FQDN>. For example inbound|7443|grpc-reviews|reviews.prod.svc.cluster.local. This can be used to override that pattern.

A Pattern can be composed of various pre-defined variables. The following variables are supported.

• %SERVICE% - Will be substituted with name of the service.
• %SERVICE_FQDN% - Will be substituted with FQDN of the service.
• %SERVICE_PORT% - Will be substituted with port of the service.
• %SERVICE_PORT_NAME% - Will be substituted with port name of the service.

Following are some examples of supported patterns for reviews:

• %SERVICE_FQDN%_%SERVICE_PORT% will use reviews.prod.svc.cluster.local_7443 as the stats name.
• %SERVICE% will use reviews.prod as the stats name.

Name to be used while emitting statistics for outbound clusters. The same pattern is used while computing stat prefix for network filters like TCP and Redis. By default, Istio emits statistics with the pattern outbound|<port>|<subsetname>|<service-FQDN>. For example outbound|8080|v2|reviews.prod.svc.cluster.local. This can be used to override that pattern.

A Pattern can be composed of various pre-defined variables. The following variables are supported.

• %SERVICE% - Will be substituted with name of the service.
• %SERVICE_FQDN% - Will be substituted with FQDN of the service.
• %SERVICE_PORT% - Will be substituted with port of the service.
• %SERVICE_PORT_NAME% - Will be substituted with port name of the service.
• %SUBSET_NAME% - Will be substituted with subset.

Following are some examples of supported patterns for reviews:

• %SERVICE_FQDN%_%SERVICE_PORT% will use reviews.prod.svc.cluster.local_7443 as the stats name.
• %SERVICE% will use reviews.prod as the stats name.

Configure the provision of certificates.

Set configuration for Thrift protocol

If enabled, Istio agent will merge metrics exposed by the application with metrics from Envoy and Istio agent. The sidecar injection will replace prometheus.io annotations present on the pod and redirect them towards Istio agent, which will then merge metrics of from the application with Istio metrics. This relies on the annotations prometheus.io/scrape, prometheus.io/port, and prometheus.io/path annotations. If you are running a separately managed Envoy with an Istio sidecar, this may cause issues, as the metrics will collide. In this case, it is recommended to disable aggregation on that deployment with the prometheus.istio.io/merge-metrics: "false" annotation. If not specified, this will be enabled by default.

VerifyCertificateAtClient sets the mesh global default for peer certificate validation at the client-side proxy when SIMPLE TLS or MUTUAL TLS (non ISTIO_MUTUAL) origination modes are used. This setting can be overridden at the host level via DestinationRule API. By default, VerifyCertificateAtClient is true.

CaCertificates: If set, proxy verifies CA signature based on given CaCertificates. If unset, and VerifyCertificateAtClient is true, proxy uses default System CA bundle. If unset and VerifyCertificateAtClient is false, proxy will not verify the CA.

SubjectAltNames: If set, proxy verifies subject alt names are present in the SAN. If unset, and VerifyCertificateAtClient is true, proxy uses host in destination rule to verify the SANs. If unset, and VerifyCertificateAtClient is false, proxy does not verify SANs.

For SAN, client-side proxy will exact match host in DestinationRule as well as one level wildcard if the specified host in DestinationRule doesn’t contain a wildcard. For example, if the host in DestinationRule is x.y.com, client-side proxy will match either x.y.com or *.y.com for the SAN in the presented server certificate. For wildcard host name in DestinationRule, client-side proxy will do a suffix match. For example, if host is *.x.y.com, client-side proxy will verify the presented server certificate SAN matches `.x.y.com suffix.

Address of the server implementing the Istio Mesh Configuration protocol (MCP). Can be IP address or a fully qualified DNS name. Use fs:/// to specify a file-based backend with absolute path to the directory.

Use the tls_settings to specify the tls mode to use. If the MCP server uses Istio mutual TLS and shares the root CA with Pilot, specify the TLS mode as ISTIO_MUTUAL.

Describes the source of configuration, if nothing is specified default is MCP

Name of the secret the certificate and its key will be stored into. If it is empty, it will not be stored into a secret. Instead, the certificate and its key will be stored into a hard-coded directory.

The DNS names for the certificate. A certificate may contain multiple DNS names.

Specify thrift rate limit service URL. If pilot has thrift protocol support enabled, this will enable the rate limit service for destinations that have matching rate limit configurations.

Specify thrift rate limit service timeout, in milliseconds. Default is 50ms

REQUIRED. Address of the CA server implementing the Istio CA gRPC API. Can be IP address or a fully qualified DNS name with port Eg: custom-ca.default.svc.cluster.local:8932, 192.168.23.2:9000

Use the tlssettings to specify the tls mode to use. Regarding tlssettings: - DISABLE MODE is legitimate for the case Istiod is making the request via an Envoy sidecar. DISABLE MODE can also be used for testing - TLS MUTUAL MODE be on by default. If the CA certificates (cert bundle to verify the CA server’s certificate) is omitted, Istiod will use the system root certs to verify the CA server’s certificate.

timeout for forward CSR requests from Istiod to External CA Default: 10s

Use istiod_side to specify CA Server integrate to Istiod side or Agent side Default: true

If true, specifies that the client and service endpoints must reside in the same cluster. By default, in multi-cluster deployments, the Istio control plane assumes all service endpoints to be reachable from any client in any of the clusters which are part of the mesh. This configuration option limits the set of service endpoints visible to a client to be cluster scoped.

There are some common scenarios when this can be useful:

• A service (or group of services) is inherently local to the cluster and has local storage for that cluster. For example, the kube-system namespace (e.g. the Kube API Server).
• A mesh administrator wants to slowly migrate services to Istio. They might start by first having services cluster-local and then slowly transition them to mesh-wide. They could do this service-by-service (e.g. mysvc.myns.svc.cluster.local) or as a group (e.g. *.myns.svc.cluster.local).

By default, Istio will consider all services in the kube-system namespace to be cluster-local, unless explicitly overridden here.

Use the tls_settings to specify the tls mode to use. If the remote tracing service uses Istio mutual TLS and shares the root CA with Pilot, specify the TLS mode as ISTIO_MUTUAL.

True if SDS is enabled.

Path of k8s service account JWT path.

Path to the generated configuration file directory. Proxy agent generates the actual configuration and stores it in this directory.

Path to the proxy binary

Service cluster defines the name for the service_cluster that is shared by all Envoy instances. This setting corresponds to --service-cluster flag in Envoy. In a typical Envoy deployment, the service-cluster flag is used to identify the caller, for source-based routing scenarios.

Since Istio does not assign a local service/service version to each Envoy instance, the name is same for all of them. However, the source/caller’s identity (e.g., IP address) is encoded in the --service-node flag when launching Envoy. When the RDS service receives API calls from Envoy, it uses the value of the service-node flag to compute routes that are relative to the service instances located at that IP address.

The time in seconds that Envoy will drain connections during a hot restart. MUST be >=1s (e.g., 1s/1m/1h) Default drain duration is 45s.

The time in seconds that Envoy will wait before shutting down the parent process during a hot restart. MUST be >=1s (e.g., 1s/1m/1h). MUST BE greater than drain_duration parameter. Default shutdown duration is 60s.

Address of the discovery service exposing xDS with mTLS connection. The inject configuration may override this value.

IP Address and Port of a statsd UDP listener (e.g. 10.75.241.127:9125).

Port on which Envoy should listen for administrative commands. Default port is 15000.

AuthenticationPolicy defines how the proxy is authenticated when it connects to the control plane. Default is set to MUTUAL_TLS.

File path of custom proxy configuration, currently used by proxies in front of Mixer and Pilot.

Maximum length of name field in Envoy’s metrics. The length of the name field is determined by the length of a name field in a service and the set of labels that comprise a particular version of the service. The default value is set to 189 characters. Envoy’s internal metrics take up 67 characters, for a total of 256 character name per metric. Increase the value of this field if you find that the metrics from Envoys are truncated.

The number of worker threads to run. If unset, this will be automatically determined based on CPU requests/limits. If set to 0, all cores on the machine will be used. Default is 2 worker threads.

Path to the proxy bootstrap template file

The mode used to redirect inbound traffic to Envoy.

Tracing configuration to be used by the proxy.

Secret Discovery Service(SDS) configuration to be used by the proxy.

Address of the service to which access logs from Envoys should be sent. (e.g. accesslog-service:15000). See Access Log Service for details about Envoy’s gRPC Access Log Service API.

Address of the Envoy Metrics Service implementation (e.g. metrics-service:15000). See Metric Service for details about Envoy’s Metrics Service API.

Port on which the agent should listen for administrative commands such as readiness probe. Default is set to port 15020.

An additional list of tags to extract from the in-proxy Istio telemetry. These extra tags can be added by configuring the telemetry extension. Each additional tag needs to be present in this list. Extra tags emitted by the telemetry extensions must be listed here so that they can be processed and exposed as Prometheus metrics.

The amount of time allowed for connections to complete on proxy shutdown. On receiving SIGTERM or SIGINT, istio-agent tells the active Envoy to start draining, preventing any new connections and allowing existing connections to complete. It then sleeps for the termination_drain_duration and then kills any remaining active Envoy processes. If not set, a default of 5s will be applied.

The unique identifier for the service mesh All control planes running in the same service mesh should specify the same mesh ID. Mesh ID is used to label telemetry reports for cases where telemetry from multiple meshes is mixed together.

VM Health Checking readiness probe. This health check config exactly mirrors the kubernetes readiness probe configuration both in schema and logic. Only one health check method of 3 can be set at a time.

Proxy stats matcher defines configuration for reporting custom Envoy stats. To reduce memory and CPU overhead from Envoy stats system, Istio proxies by default create and expose only a subset of Envoy stats. This option is to control creation of additional Envoy stats with prefix, suffix, and regex expressions match on the name of the stats. This replaces the stats inclusion annotations (sidecar.istio.io/statsInclusionPrefixes, sidecar.istio.io/statsInclusionRegexps, and sidecar.istio.io/statsInclusionSuffixes). For example, to enable stats for circuit breaker, retry, and upstream connections, you can specify stats matcher as follow:

proxyStatsMatcher:
  inclusionRegexps:
    - .*circuit_breakers.*
  inclusionPrefixes:
    - upstream_rq_retry
    - upstream_cx

Note including more Envoy stats might increase number of time series collected by prometheus significantly. Care needs to be taken on Prometheus resource provision and configuration to reduce cardinality.

Address of a remove service used for various purposes (access log receiver, metrics receiver, etc.). Can be IP address or a fully qualified DNS name.

Use the tls_settings to specify the tls mode to use. If the remote service uses Istio mutual TLS and shares the root CA with Pilot, specify the TLS mode as ISTIO_MUTUAL.

If set then set SO_KEEPALIVE on the socket to enable TCP Keepalives.

Address of the Zipkin service (e.g. zipkin:9411).

Address of the Lightstep Satellite pool.

The Lightstep access token.

Address of the Datadog Agent.

gRPC address for the OpenCensus agent (e.g. dns://authority/host:port or unix:path). See gRPC naming docs for details.

Specifies the set of context propagation headers used for distributed tracing. Default is ["W3C_TRACE_CONTEXT"]. If multiple values are specified, the proxy will attempt to read each header for each request and will write all headers.

Proxy stats name prefix matcher for inclusion.

Proxy stats name suffix matcher for inclusion.

Proxy stats name regexps matcher for inclusion.

The list of endpoints in the network (obtained through the constituent service registries or from CIDR ranges). All endpoints in the network are directly accessible to one another.

Set of gateways associated with the network.

The set of networks inside this mesh. Each network should have a unique name and information about how to infer the endpoints in the network as well as the gateways associated with the network.

The port associated with the gateway.

The locality associated with an explicitly specified gateway (i.e. ip)