README ¶
control-plane
This repository contains a Go-based implementation of an API server that implements the discovery service APIs defined in data-plane-api.
Scope
Due to the variety of platforms out there, there is no single control plane implementation that can satisfy everyone's needs. Hence this code base does not attempt to be a full scale control plane for a fleet of Envoy proxies. Instead, it provides infrastructure that is shared by multiple different control plane implementations. The components provided by this library are:
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API Server: A generic gRPC based API server that implements xDS APIs as defined in the data-plane-api. The API server is responsible for pushing configuration updates to Envoys. Consumers should be able to import this go library and use the API server as is, in production deployments.
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Configuration Cache: The library will cache Envoy configurations in memory in an attempt to provide fast response to consumer Envoys. It is the responsibility of the consumer of this library to populate the cache as well as invalidate it when necessary. The cache will be keyed based on a pre-defined hash function whose keys are based on the Node information.
At this moment, this repository will not tackle translating platform specific representation of resources (e.g., services, instances of services, etc.) into Envoy-style configuration. Based on usage and feedback, we might decided to revisit this aspect at a later point in time.
Requirements
- Go 1.16+
Quick start
It's recommended to run the tests with make docker_tests
as it executes the tests
in the same environment as CI. This makes sure to produce a consistent set of generated files.
-
Build and run tests:
make docker_tests
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Take a look at the example server.
XDS API versioning
The Envoy xDS APIs follow a well defined versioning scheme.
Deprecated
V2
control-plane code has been removed and will no longer be supported. For previous conversations on support for various xDS versions, see here:
Note: It is recommended to use a previous SHA if there is still a need for V2
.
Resource caching
Because Envoy clients are assumed to be ephemeral, and thus, can come and go away arbitrarily, the server relies on a configuration cache to minimize the client load on the server. There are several caches available in this repository:
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Simple
cache is a snapshot-based cache that maintains a consistent view of the configuration for each group of proxies. It supports running as an ADS server or as regular dis-aggregated xDS servers. In ADS mode, the cache can hold responses until the complete set of referenced resources is requested (e.g. the entire set of RDS as referenced by LDS). Holding the response enables an atomic update of xDS collections. -
Linear
is an eventually consistent cache for a single type URL collection. The cache maintains a single linear version history and a version vector for the resources in the cache. For each request, it compares the request version against latest versions for the requested resources, and responds with any updated resources. This cache assumes the resources are entirely opaque. -
Mux
cache is a simple cache combinator. It allows mixing multiple caches for different type URLs, e.g use a simple cache for LDS/RDS/CDS and a linear cache for EDS.
Usage
The example server demonstrates how to integrate the go-control-plane with your code.
Directories ¶
Path | Synopsis |
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contrib
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envoy
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internal
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pkg
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cache/v3
Package cache defines a configuration cache for the server.
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Package cache defines a configuration cache for the server. |
conversion
Package conversion contains shared utility functions for converting xDS resources.
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Package conversion contains shared utility functions for converting xDS resources. |
log
Package log provides a logging interface for use in this library.
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Package log provides a logging interface for use in this library. |
server/rest/v3
Package rest provides an implementation of REST-JSON part of XDS server
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Package rest provides an implementation of REST-JSON part of XDS server |
server/sotw/v3
Package sotw provides an implementation of GRPC SoTW (State of The World) part of XDS server
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Package sotw provides an implementation of GRPC SoTW (State of The World) part of XDS server |
server/v3
Package server provides an implementation of a streaming xDS server.
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Package server provides an implementation of a streaming xDS server. |
test
Package test contains test utilities
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Package test contains test utilities |
test/main
Package main contains the test driver for testing xDS manually.
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Package main contains the test driver for testing xDS manually. |
test/resource/v3
Package resource creates test xDS resources
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Package resource creates test xDS resources |
test/v3
Package test contains test utilities
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Package test contains test utilities |
wellknown
Package wellknown contains common names for filters, listeners, etc.
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Package wellknown contains common names for filters, listeners, etc. |