mirror of https://github.com/hashicorp/consul
366 lines
9.2 KiB
Markdown
366 lines
9.2 KiB
Markdown
---
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layout: docs
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page_title: 'Configuration Entry Kind: Service Splitter'
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description: >-
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The service-splitter config entry kind controls how to split incoming Connect
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requests across different subsets of a single service (like during staged
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canary rollouts), or perhaps across different services (like during a v2
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rewrite or other type of codebase migration).
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---
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# Service Splitter
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-> **v1.8.4+:** On Kubernetes, the `ServiceSplitter` custom resource is supported in Consul versions 1.8.4+.<br />
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**v1.6.0+:** On other platforms, this config entry is supported in Consul versions 1.6.0+.
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The `service-splitter` config entry kind (`ServiceSplitter` on Kubernetes) controls how to split incoming Connect
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requests across different subsets of a single service (like during staged
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canary rollouts), or perhaps across different services (like during a v2
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rewrite or other type of codebase migration).
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If no splitter config is defined for a service it is assumed 100% of traffic
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flows to a service with the same name and discovery continues on to the
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resolution stage.
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## Interaction with other Config Entries
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- Service splitter config entries are a component of [L7 Traffic
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Management](/docs/connect/l7-traffic).
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- Service splitter config entries are restricted to only services that define
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their protocol as http-based via a corresponding
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[`service-defaults`](/docs/connect/config-entries/service-defaults) config
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entry or globally via
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[`proxy-defaults`](/docs/connect/config-entries/proxy-defaults) .
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- Any split destination that specifies a different `Service` field and omits
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the `ServiceSubset` field is eligible for further splitting should a splitter
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be configured for that other service, otherwise resolution proceeds according
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to any configured
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[`service-resolver`](/docs/connect/config-entries/service-resolver).
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## UI
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Once a `service-splitter` is successfully entered, you can view it in the UI. Service routers, service splitters, and service resolvers can all be viewed by clicking on your service then switching to the _routing_ tab.
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![screenshot of service splitter in the UI](/img/l7-routing/Splitter.png)
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## Sample Config Entries
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### Two subsets of same service
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Split traffic between two subsets of the same service:
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<CodeTabs tabs={[ "HCL", "Kubernetes YAML", "JSON" ]}>
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```hcl
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Kind = "service-splitter"
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Name = "web"
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Splits = [
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{
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Weight = 90
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ServiceSubset = "v1"
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},
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{
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Weight = 10
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ServiceSubset = "v2"
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},
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]
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```
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```yaml
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apiVersion: consul.hashicorp.com/v1alpha1
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kind: ServiceSplitter
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metadata:
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name: web
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spec:
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splits:
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- weight: 90
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serviceSubset: v1
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- weight: 10
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serviceSubset: v2
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```
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```json
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{
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"Kind": "service-splitter",
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"Name": "web",
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"Splits": [
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{
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"Weight": 90,
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"ServiceSubset": "v1"
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},
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{
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"Weight": 10,
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"ServiceSubset": "v2"
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}
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]
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}
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```
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</CodeTabs>
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### Two different services
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Split traffic between two services:
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<CodeTabs tabs={[ "HCL", "Kubernetes YAML", "JSON" ]}>
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```hcl
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Kind = "service-splitter"
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Name = "web"
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Splits = [
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{
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Weight = 50
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# will default to service with same name as config entry ("web")
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},
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{
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Weight = 50
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Service = "web-rewrite"
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},
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]
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```
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```yaml
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apiVersion: consul.hashicorp.com/v1alpha1
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kind: ServiceSplitter
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metadata:
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name: web
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spec:
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splits:
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- weight: 50
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# will default to service with same name as config entry ("web")
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- weight: 50
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service: web-rewrite
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```
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```json
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{
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"Kind": "service-splitter",
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"Name": "web",
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"Splits": [
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{
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"Weight": 50
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},
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{
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"Weight": 50,
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"Service": "web-rewrite"
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}
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]
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}
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```
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</CodeTabs>
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### Set HTTP Headers
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Split traffic between two subsets with extra headers added so clients can tell
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which version:
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<CodeTabs tabs={[ "HCL", "Kubernetes YAML", "JSON" ]}>
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```hcl
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Kind = "service-splitter"
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Name = "web"
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Splits = [
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{
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Weight = 90
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ServiceSubset = "v1"
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ResponseHeaders {
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Set {
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"X-Web-Version": "v1"
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}
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}
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},
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{
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Weight = 10
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ServiceSubset = "v2"
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ResponseHeaders {
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Set {
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"X-Web-Version": "v2"
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}
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}
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},
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]
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```
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```yaml
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apiVersion: consul.hashicorp.com/v1alpha1
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kind: ServiceSplitter
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metadata:
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name: web
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spec:
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splits:
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- weight: 90
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serviceSubset: v1
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responseHeaders:
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set:
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x-web-version: v1
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- weight: 10
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serviceSubset: v2
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responseHeaders:
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set:
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x-web-version: v2
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```
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```json
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{
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"Kind": "service-splitter",
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"Name": "web",
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"Splits": [
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{
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"Weight": 90,
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"ServiceSubset": "v1",
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"ResponseHeaders": {
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"Set": {
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"X-Web-Version": "v1"
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}
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}
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},
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{
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"Weight": 10,
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"ServiceSubset": "v2",
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"ResponseHeaders": {
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"Set": {
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"X-Web-Version": "v2"
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}
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}
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}
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]
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}
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```
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</CodeTabs>
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## Available Fields
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<ConfigEntryReference
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keys={[
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{
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name: 'apiVersion',
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description: 'Must be set to `consul.hashicorp.com/v1alpha1`',
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hcl: false,
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},
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{
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name: 'Kind',
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description: {
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hcl: 'Must be set to `service-splitter`',
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yaml: 'Must be set to `ServiceSplitter`',
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},
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},
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{
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name: 'Name',
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description: 'Set to the name of the service being configured.',
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type: 'string: <required>',
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yaml: false,
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},
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{
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name: 'Namespace',
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type: `string: "default"`,
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enterprise: true,
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description:
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'Specifies the namespace to which the configuration entry will apply.',
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yaml: false,
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},
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{
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name: 'Partition',
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type: `string: "default"`,
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enterprise: true,
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description:
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'Specifies the admin partition to which the configuration entry will apply.',
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yaml: false,
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},
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{
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name: 'Meta',
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type: 'map<string|string>: nil',
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description:
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'Specifies arbitrary KV metadata pairs. Added in Consul 1.8.4.',
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yaml: false,
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},
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{
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name: 'metadata',
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children: [
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{
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name: 'name',
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description: 'Set to the name of the service being configured.',
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},
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{
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name: 'namespace',
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description:
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'If running Consul Open Source, the namespace is ignored (see [Kubernetes Namespaces in Consul OSS](/docs/k8s/crds#consul-oss)). If running Consul Enterprise see [Kubernetes Namespaces in Consul Enterprise](/docs/k8s/crds#consul-enterprise) for more details.',
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},
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],
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hcl: false,
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},
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{
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name: 'Splits',
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type: 'array<ServiceSplit>',
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description:
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'Defines how much traffic to send to which set of service instances during a traffic split. The sum of weights across all splits must add up to 100.',
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children: [
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{
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name: 'weight',
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type: 'float32: 0',
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description:
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'A value between 0 and 100 reflecting what portion of traffic should be directed to this split. The smallest representable eight is 1/10000 or .01%',
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},
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{
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name: 'Service',
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type: 'string: ""',
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description: 'The service to resolve instead of the default.',
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},
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{
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name: 'ServiceSubset',
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type: 'string: ""',
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description: {
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hcl:
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"A named subset of the given service to resolve instead of one defined as that service's `DefaultSubset`. If empty the default subset is used.",
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yaml:
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"A named subset of the given service to resolve instead of one defined as that service's `defaultSubset`. If empty the default subset is used.",
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},
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},
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{
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name: 'Namespace',
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enterprise: true,
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type: 'string: ""',
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description:
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'The namespace to resolve the service from instead of the current namespace. If empty, the current namespace is used.',
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},
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{
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name: 'Partition',
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enterprise: true,
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type: 'string: ""',
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description:
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'The admin partition to resolve the service from instead of the current partition. If empty, the current partition is used.',
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},
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{
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name: 'RequestHeaders',
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type: 'HTTPHeaderModifiers: <optional>',
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description: `A set of [HTTP-specific header modification rules](/docs/connect/config-entries/service-router#httpheadermodifiers)
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that will be applied to requests routed to this split.
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This cannot be used with a \`tcp\` listener.`,
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},
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{
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name: 'ResponseHeaders',
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type: 'HTTPHeaderModifiers: <optional>',
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description: `A set of [HTTP-specific header modification rules](/docs/connect/config-entries/service-router#httpheadermodifiers)
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that will be applied to responses from this split.
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This cannot be used with a \`tcp\` listener.`,
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},
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],
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},
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]}
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/>
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## ACLs
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Configuration entries may be protected by [ACLs](/docs/security/acl).
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Reading a `service-splitter` config entry requires `service:read` on the resource.
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Creating, updating, or deleting a `service-splitter` config entry requires
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`service:write` on the resource and `service:read` on any other service referenced by
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name in these fields:
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- [`Splits[].Service`](#service)
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