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Indicates whether connections to this port should be secured using TLS. The value of this field determines how TLS is enforced.
clientCertificate
string
REQUIRED if mode is MUTUAL. The path to the file holding the client-side TLS certificate to use. Should be empty if mode is ISTIO_MUTUAL.
privateKey
string
REQUIRED if mode is MUTUAL. The path to the file holding the client's private key. Should be empty if mode is ISTIO_MUTUAL.
caCertificates
string
OPTIONAL: The path to the file containing certificate authority certificates to use in verifying a presented server certificate. If omitted, the proxy will not verify the server's certificate. Should be empty if mode is ISTIO_MUTUAL.
credentialName
string
The name of the secret that holds the TLS certs for the client including the CA certificates. Secret must exist in the same namespace with the proxy using the certificates. The secret (of type generic)should contain the following keys and values: key: <privateKey>, cert: <clientCert>, cacert: <CACertificate>. Here CACertificate is used to verify the server certificate. Secret of type tls for client certificates along with ca.crt key for CA certificates is also supported. Only one of client certificates and CA certificate or credentialName can be specified. NOTE: This field is currently applicable only at gateways. Sidecars will continue to use the certificate paths.
subjectAltNames
[]string
repeated
A list of alternate names to verify the subject identity in the certificate. If specified, the proxy will verify that the server certificate's subject alt name matches one of the specified values. If specified, this list overrides the value of subject_alt_names from the ServiceEntry.
sni
string
SNI string to present to the server during TLS handshake.
InsecureSkipVerify specifies whether the proxy should skip verifying the CA signature and SAN for the server certificate corresponding to the host. This flag should only be set if global CA signature verifcation is enabled, VerifyCertAtClient environmental variable is set to true, but no verification is desired for a specific host. If enabled with or without VerifyCertAtClient enabled, verification of the CA signature and SAN will be skipped. InsecureSkipVerify is false by default. VerifyCertAtClient is false by default in Istio version 1.9 but will be true by default in a later version where, going forward, it will be enabled by default.
The idle timeout for upstream connection pool connections. The idle timeout is defined as the period in which there are no active requests. If not set, the default is 1 hour. When the idle timeout is reached, the connection will be closed. If the connection is an HTTP/2 connection a drain sequence will occur prior to closing the connection. Note that request based timeouts mean that HTTP/2 PINGs will not keep the connection alive. Applies to both HTTP1.1 and HTTP2 connections.
Specify if http1.1 connection should be upgraded to http2 for the associated destination.
useClientProtocol
bool
If set to true, client protocol will be preserved while initiating connection to backend. Note that when this is set to true, h2_upgrade_policy will be ineffective i.e. the client connections will not be upgraded to http2.
ConnectionPoolSettings.TCPSettings
Field
Type
Label
Description
maxConnections
int32
Maximum number of HTTP1 /TCP connections to a destination host. Default 2^32-1.
If set then set SO_KEEPALIVE on the socket to enable TCP Keepalives.
ConnectionPoolSettings.TCPSettings.TcpKeepalive
Field
Type
Label
Description
probes
uint32
Maximum number of keepalive probes to send without response before deciding the connection is dead. Default is to use the OS level configuration (unless overridden, Linux defaults to 9.)
The time duration a connection needs to be idle before keep-alive probes start being sent. Default is to use the OS level configuration (unless overridden, Linux defaults to 7200s (ie 2 hours.)
The time duration between keep-alive probes. Default is to use the OS level configuration (unless overridden, Linux defaults to 75s.)
DestinationRule
Field
Type
Label
Description
host
string
The name of a service from the service registry. Service names are looked up from the platform's service registry (e.g., Kubernetes services, Consul services, etc.) and from the hosts declared by ServiceEntries. Rules defined for services that do not exist in the service registry will be ignored. Note for Kubernetes users: When short names are used (e.g. “reviews” instead of “reviews.default.svc.cluster.local”), Istio will interpret the short name based on the namespace of the rule, not the service. A rule in the “default” namespace containing a host “reviews” will be interpreted as “reviews.default.svc.cluster.local”, irrespective of the actual namespace associated with the reviews service. _To avoid potential misconfigurations, it is recommended to always use fully qualified domain names over short names._ Note that the host field applies to both HTTP and TCP services.
One or more named sets that represent individual versions of a service. Traffic policies can be overridden at subset level.
exportTo
[]string
repeated
A list of namespaces to which this destination rule is exported. The resolution of a destination rule to apply to a service occurs in the context of a hierarchy of namespaces. Exporting a destination rule allows it to be included in the resolution hierarchy for services in other namespaces. This feature provides a mechanism for service owners and mesh administrators to control the visibility of destination rules across namespace boundaries. If no namespaces are specified then the destination rule is exported to all namespaces by default. The value “.” is reserved and defines an export to the same namespace that the destination rule is declared in. Similarly, the value “*” is reserved and defines an export to all namespaces.
Locality load balancer settings, this will override mesh wide settings in entirety, meaning no merging would be performed between this object and the object one in MeshConfig
Hash based on the source IP address. This is applicable for both TCP and HTTP connections.
httpQueryParameterName
string
Hash based on a specific HTTP query parameter.
minimumRingSize
uint64
The minimum number of virtual nodes to use for the hash ring. Defaults to 1024. Larger ring sizes result in more granular load distributions. If the number of hosts in the load balancing pool is larger than the ring size, each host will be assigned a single virtual node.
Optional: only one of distribute, failover or failoverPriority can be set. Explicitly specify loadbalancing weight across different zones and geographical locations. Refer to Locality weighted load balancing If empty, the locality weight is set according to the endpoints number within it.
Optional: only one of distribute, failover or failoverPriority can be set. Explicitly specify the region traffic will land on when endpoints in local region becomes unhealthy. Should be used together with OutlierDetection to detect unhealthy endpoints. Note: if no OutlierDetection specified, this will not take effect.
failoverPriority
[]string
repeated
failoverPriority is an ordered list of labels used to sort endpoints to do priority based load balancing. This is to support traffic failover across different groups of endpoints. Suppose there are total N labels specified: 1. Endpoints matching all N labels with the client proxy have priority P(0) i.e. the highest priority. 2. Endpoints matching the first N-1 labels with the client proxy have priority P(1) i.e. second highest priority. 3. By extension of this logic, endpoints matching only the first label with the client proxy has priority P(N-1) i.e. second lowest priority. 4. All the other endpoints have priority P(N) i.e. lowest priority. Note: For a label to be considered for match, the previous labels must match, i.e. nth label would be considered matched only if first n-1 labels match. It can be any label specified on both client and server workloads. The following labels which have special semantic meaning are also supported: - topology.istio.io/network is used to match the network metadata of an endpoint, which can be specified by pod/namespace label topology.istio.io/network, sidecar env ISTIO_META_NETWORK or MeshNetworks. - topology.istio.io/cluster is used to match the clusterID of an endpoint, which can be specified by pod label topology.istio.io/cluster or pod env ISTIO_META_CLUSTER_ID. - topology.kubernetes.io/region is used to match the region metadata of an endpoint, which maps to Kubernetes node label topology.kubernetes.io/region or the deprecated label failure-domain.beta.kubernetes.io/region. - topology.kubernetes.io/zone is used to match the zone metadata of an endpoint, which maps to Kubernetes node label topology.kubernetes.io/zone or the deprecated label failure-domain.beta.kubernetes.io/zone. - topology.istio.io/subzone is used to match the subzone metadata of an endpoint, which maps to Istio node label topology.istio.io/subzone. The below topology config indicates the following priority levels: yaml failoverPriority: - "topology.istio.io/network" - "topology.kubernetes.io/region" - "topology.kubernetes.io/zone" - "topology.istio.io/subzone" 1. endpoints match same [network, region, zone, subzone] label with the client proxy have the highest priority. 2. endpoints have same [network, region, zone] label but different [subzone] label with the client proxy have the second highest priority. 3. endpoints have same [network, region] label but different [zone] label with the client proxy have the third highest priority. 4. endpoints have same [network] but different [region] labels with the client proxy have the fourth highest priority. 5. all the other endpoints have the same lowest priority. Optional: only one of distribute, failover or failoverPriority can be set. And it should be used together with OutlierDetection to detect unhealthy endpoints, otherwise has no effect.
enable locality load balancing, this is DestinationRule-level and will override mesh wide settings in entirety. e.g. true means that turn on locality load balancing for this DestinationRule no matter what mesh wide settings is.
LocalityLoadBalancerSetting.Distribute
Field
Type
Label
Description
from
string
Originating locality, ‘/’ separated, e.g. ‘region/zone/sub_zone’.
Map of upstream localities to traffic distribution weights. The sum of all weights should be 100. Any locality not present will receive no traffic.
LocalityLoadBalancerSetting.Distribute.ToEntry
Field
Type
Label
Description
key
string
value
uint32
LocalityLoadBalancerSetting.Failover
Field
Type
Label
Description
from
string
Originating region.
to
string
Destination region the traffic will fail over to when endpoints in the ‘from’ region becomes unhealthy.
OutlierDetection
Field
Type
Label
Description
consecutiveErrors
int32
Number of errors before a host is ejected from the connection pool. Defaults to 5. When the upstream host is accessed over HTTP, a 502, 503, or 504 return code qualifies as an error. When the upstream host is accessed over an opaque TCP connection, connect timeouts and connection error/failure events qualify as an error. $hide_from_docs
splitExternalLocalOriginErrors
bool
Determines whether to distinguish local origin failures from external errors. If set to true consecutive_local_origin_failure is taken into account for outlier detection calculations. This should be used when you want to derive the outlier detection status based on the errors seen locally such as failure to connect, timeout while connecting etc. rather than the status code retuned by upstream service. This is especially useful when the upstream service explicitly returns a 5xx for some requests and you want to ignore those responses from upstream service while determining the outlier detection status of a host. Defaults to false.
The number of consecutive locally originated failures before ejection occurs. Defaults to 5. Parameter takes effect only when split_external_local_origin_errors is set to true.
Number of gateway errors before a host is ejected from the connection pool. When the upstream host is accessed over HTTP, a 502, 503, or 504 return code qualifies as a gateway error. When the upstream host is accessed over an opaque TCP connection, connect timeouts and connection error/failure events qualify as a gateway error. This feature is disabled by default or when set to the value 0. Note that consecutive_gateway_errors and consecutive_5xx_errors can be used separately or together. Because the errors counted by consecutive_gateway_errors are also included in consecutive_5xx_errors, if the value of consecutive_gateway_errors is greater than or equal to the value of consecutive_5xx_errors, consecutive_gateway_errors will have no effect.
Number of 5xx errors before a host is ejected from the connection pool. When the upstream host is accessed over an opaque TCP connection, connect timeouts, connection error/failure and request failure events qualify as a 5xx error. This feature defaults to 5 but can be disabled by setting the value to 0. Note that consecutive_gateway_errors and consecutive_5xx_errors can be used separately or together. Because the errors counted by consecutive_gateway_errors are also included in consecutive_5xx_errors, if the value of consecutive_gateway_errors is greater than or equal to the value of consecutive_5xx_errors, consecutive_gateway_errors will have no effect.
Minimum ejection duration. A host will remain ejected for a period equal to the product of minimum ejection duration and the number of times the host has been ejected. This technique allows the system to automatically increase the ejection period for unhealthy upstream servers. format: 1h/1m/1s/1ms. MUST BE >=1ms. Default is 30s.
maxEjectionPercent
int32
Maximum % of hosts in the load balancing pool for the upstream service that can be ejected. Defaults to 10%.
minHealthPercent
int32
Outlier detection will be enabled as long as the associated load balancing pool has at least min_health_percent hosts in healthy mode. When the percentage of healthy hosts in the load balancing pool drops below this threshold, outlier detection will be disabled and the proxy will load balance across all hosts in the pool (healthy and unhealthy). The threshold can be disabled by setting it to 0%. The default is 0% as it's not typically applicable in k8s environments with few pods per service.
Subset
Field
Type
Label
Description
name
string
Name of the subset. The service name and the subset name can be used for traffic splitting in a route rule.
Traffic policies that apply to this subset. Subsets inherit the traffic policies specified at the DestinationRule level. Settings specified at the subset level will override the corresponding settings specified at the DestinationRule level.
Traffic policies specific to individual ports. Note that port level settings will override the destination-level settings. Traffic settings specified at the destination-level will not be inherited when overridden by port-level settings, i.e. default values will be applied to fields omitted in port-level traffic policies.
TLS related settings for connections to the upstream service.
ClientTLSSettings.TLSmode
Name
Number
Description
DISABLE
0
Do not setup a TLS connection to the upstream endpoint.
SIMPLE
1
Originate a TLS connection to the upstream endpoint.
MUTUAL
2
Secure connections to the upstream using mutual TLS by presenting client certificates for authentication.
ISTIO_MUTUAL
3
Secure connections to the upstream using mutual TLS by presenting client certificates for authentication. Compared to Mutual mode, this mode uses certificates generated automatically by Istio for mTLS authentication. When this mode is used, all other fields in ClientTLSSettings should be empty.
Do not upgrade the connection to http2. This opt-out option overrides the default.
UPGRADE
2
Upgrade the connection to http2. This opt-in option overrides the default.
LoadBalancerSettings.SimpleLB
Name
Number
Description
ROUND_ROBIN
0
Round Robin policy. Default
LEAST_CONN
1
The least request load balancer uses an O(1) algorithm which selects two random healthy hosts and picks the host which has fewer active requests.
RANDOM
2
The random load balancer selects a random healthy host. The random load balancer generally performs better than round robin if no health checking policy is configured.
PASSTHROUGH
3
This option will forward the connection to the original IP address requested by the caller without doing any form of load balancing. This option must be used with care. It is meant for advanced use cases. Refer to Original Destination load balancer in Envoy for further details.
