mirror of https://github.com/hashicorp/consul
47 lines
2.7 KiB
Markdown
47 lines
2.7 KiB
Markdown
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# V2 Service Mesh Architecture
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In Consul 1.16 and 1.17 releases, Consul's service mesh has been rewritten to use the controller architecture and the
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resource APIs.
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At a high level, the service mesh consists of resources and controllers living in three groups: `catalog`, `mesh`,
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and `auth`.
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The controllers in each groups are responsible for producing an output that may then be used by other controllers.
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-> **Note:** This diagram is valid as of Consul 1.17. It may change in the future releases.
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## Catalog controllers
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Catalog controllers are responsible for reconciling resources in the `catalog` API group.
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1. **FailoverPolicy** controller validates `FailoverPolicy` resource has valid service references and updating the
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status the `FailoverPolicy` resource with the result.
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2. **WorkloadHealth** controller takes in workloads and any relevant health statuses and updates the status of a
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workload with the combined health status.
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3. **NodeHealth** controller takes in nodes and any relevant health statuses and updates the status of a node with the
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combined health status.
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4. **ServiceEndpoints** controller generates a `ServiceEndpoints` object that is name-aligned with a service and
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contains workload addresses and ports that constitute a service.
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## Mesh Controllers
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1. **ProxyConfiguration** controller generates a `ComputedProxyConfiguration` resource that is name-aligned with a
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workload. `ComputedProxyConfiguration` contains all merged `ProxyConfiguration` resources that apply to a specific
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workload.
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2. **Routes** controller generates a `ComputedRoutes` resource that is name-aligned with a service. It contains merged
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configuration from all xRoutes objects as well as `FailoverPolicy` and `DestinationPolicy`.
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3. **ExplicitDestinations** controller generates a `ComputedExplicitDestinations` resource that is name-aligned with a
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workload. It contains merged `Destinations` resources that apply to a specific workload.
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4. **SidecarProxy** controller takes in the results of the previous three controllers as well as some user-provided
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resources and generates `ProxyStateTemplate` resource which serves as the representation of Envoy configuration for
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sidecar proxies.
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5. **XDSController** takes in `ProxyStateTemplate` resources, fills in missing endpoints references as well as
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certificates and CA roots and sends them over to another component that sends this information over to Envoy.
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## Auth Controllers
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1. **TrafficPermissions** controller generates `ComputedTrafficPermissions` resource that is name-aligned
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with `WorkloadIdentity`. This computed resource contains all traffic permissions that apply to a specific workload
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identity.
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