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Discover Instances

servicediscovery_discover_instances R Documentation

Discovers registered instances for a specified namespace and service

Description

Discovers registered instances for a specified namespace and service. You can use discover_instances to discover instances for any type of namespace. discover_instances returns a randomized list of instances allowing customers to distribute traffic evenly across instances. For public and private DNS namespaces, you can also use DNS queries to discover instances.

Usage

servicediscovery_discover_instances(NamespaceName, ServiceName,
  MaxResults, QueryParameters, OptionalParameters, HealthStatus)

Arguments

NamespaceName

[required] The HttpName name of the namespace. It's found in the HttpProperties member of the Properties member of the namespace. In most cases, Name and HttpName match. However, if you reuse Name for namespace creation, a generated hash is added to HttpName to distinguish the two.

ServiceName

[required] The name of the service that you specified when you registered the instance.

MaxResults

The maximum number of instances that you want Cloud Map to return in the response to a discover_instances request. If you don't specify a value for MaxResults, Cloud Map returns up to 100 instances.

QueryParameters

Filters to scope the results based on custom attributes for the instance (for example, ⁠{version=v1, az=1a}⁠). Only instances that match all the specified key-value pairs are returned.

OptionalParameters

Opportunistic filters to scope the results based on custom attributes. If there are instances that match both the filters specified in both the QueryParameters parameter and this parameter, all of these instances are returned. Otherwise, the filters are ignored, and only instances that match the filters that are specified in the QueryParameters parameter are returned.

HealthStatus

The health status of the instances that you want to discover. This parameter is ignored for services that don't have a health check configured, and all instances are returned.

HEALTHY

Returns healthy instances.

UNHEALTHY

Returns unhealthy instances.

ALL

Returns all instances.

HEALTHY_OR_ELSE_ALL

Returns healthy instances, unless none are reporting a healthy state. In that case, return all instances. This is also called failing open.

Value

A list with the following syntax: 

list(
  Instances = list(
    list(
      InstanceId = "string",
      NamespaceName = "string",
      ServiceName = "string",
      HealthStatus = "HEALTHY"|"UNHEALTHY"|"UNKNOWN",
      Attributes = list(
        "string"
      )
    )
  ),
  InstancesRevision = 123
)

Request syntax

svc$discover_instances(
  NamespaceName = "string",
  ServiceName = "string",
  MaxResults = 123,
  QueryParameters = list(
    "string"
  ),
  OptionalParameters = list(
    "string"
  ),
  HealthStatus = "HEALTHY"|"UNHEALTHY"|"ALL"|"HEALTHY_OR_ELSE_ALL"
)

Examples

## Not run: 
# Example: Discover registered instances
svc$discover_instances(
  HealthStatus = "ALL",
  MaxResults = 10L,
  NamespaceName = "example.com",
  ServiceName = "myservice"
)

## End(Not run)