README

etcd

Go Report Card Coverage Build Status Travis Build Status Semaphore Godoc Releases LICENSE

Note: The master branch may be in an unstable or even broken state during development. Please use releases instead of the master branch in order to get stable binaries.

the etcd v2 documentation has moved

etcd Logo

etcd is a distributed reliable key-value store for the most critical data of a distributed system, with a focus on being:

  • Simple: well-defined, user-facing API (gRPC)
  • Secure: automatic TLS with optional client cert authentication
  • Fast: benchmarked 10,000 writes/sec
  • Reliable: properly distributed using Raft

etcd is written in Go and uses the Raft consensus algorithm to manage a highly-available replicated log.

etcd is used in production by many companies, and the development team stands behind it in critical deployment scenarios, where etcd is frequently teamed with applications such as Kubernetes, fleet, locksmith, vulcand, Doorman, and many others. Reliability is further ensured by rigorous testing.

See etcdctl for a simple command line client.

Community meetings

etcd contributors and maintainers have bi-weekly meetings at 11:00 AM (USA Pacific) on Tuesdays. There is an iCalendar format for the meetings here. Anyone is welcome to join via Zoom or audio-only: +1 669 900 6833. An initial agenda will be posted to the shared Google docs a day before each meeting, and everyone is welcome to suggest additional topics or other agendas.

Getting started

Getting etcd

The easiest way to get etcd is to use one of the pre-built release binaries which are available for OSX, Linux, Windows, rkt, and Docker. Instructions for using these binaries are on the GitHub releases page.

For those wanting to try the very latest version, build the latest version of etcd from the master branch. This first needs Go installed (version 1.9+ is required). All development occurs on master, including new features and bug fixes. Bug fixes are first targeted at master and subsequently ported to release branches, as described in the branch management guide.

Running etcd

First start a single-member cluster of etcd.

If etcd is installed using the pre-built release binaries, run it from the installation location as below:

/tmp/etcd-download-test/etcd

The etcd command can be simply run as such if it is moved to the system path as below:

mv /tmp/etcd-download-test/etcd /usr/locale/bin/

etcd

If etcd is build from the master branch, run it as below:

./bin/etcd

This will bring up etcd listening on port 2379 for client communication and on port 2380 for server-to-server communication.

Next, let's set a single key, and then retrieve it:

ETCDCTL_API=3 etcdctl put mykey "this is awesome"
ETCDCTL_API=3 etcdctl get mykey

That's it! etcd is now running and serving client requests. For more

etcd TCP ports

The official etcd ports are 2379 for client requests, and 2380 for peer communication.

Running a local etcd cluster

First install goreman, which manages Procfile-based applications.

Our Procfile script will set up a local example cluster. Start it with:

goreman start

This will bring up 3 etcd members infra1, infra2 and infra3 and etcd grpc-proxy, which runs locally and composes a cluster.

Every cluster member and proxy accepts key value reads and key value writes.

Running etcd on Kubernetes

To run an etcd cluster on Kubernetes, try etcd operator.

Next steps

Now it's time to dig into the full etcd API and other guides.

Contact

Contributing

See CONTRIBUTING for details on submitting patches and the contribution workflow.

Reporting bugs

See reporting bugs for details about reporting any issues.

License

etcd is under the Apache 2.0 license. See the LICENSE file for details.

Expand ▾ Collapse ▴

Documentation

Overview

Package main is a simple wrapper of the real etcd entrypoint package (located at github.com/coreos/etcd/etcdmain) to ensure that etcd is still "go getable"; e.g. `go get github.com/coreos/etcd` works as expected and builds a binary in $GOBIN/etcd

This package should NOT be extended or modified in any way; to modify the etcd binary, work in the `github.com/coreos/etcd/etcdmain` package.

Source Files

Directories

Path Synopsis
alarm Package alarm manages health status alarms in etcd.
auth Package auth provides client role authentication for accessing keys in etcd.
auth/authpb
client Package client provides bindings for the etcd APIs.
client/integration Package integration implements tests built upon embedded etcd, focusing on the correctness of the etcd v2 client.
clientv3 Package clientv3 implements the official Go etcd client for v3.
clientv3/balancer Package balancer implements client balancer.
clientv3/balancer/connectivity Package connectivity implements client connectivity operations.
clientv3/balancer/picker Package picker defines/implements client balancer picker policy.
clientv3/balancer/resolver/endpoint Package endpoint resolves etcd entpoints using grpc targets of the form 'endpoint://<id>/<endpoint>'.
clientv3/clientv3util Package clientv3util contains utility functions derived from clientv3.
clientv3/concurrency Package concurrency implements concurrency operations on top of etcd such as distributed locks, barriers, and elections.
clientv3/credentials Package credentials implements gRPC credential interface with etcd specific logic.
clientv3/integration Package integration implements tests built upon embedded etcd, and focuses on correctness of etcd client.
clientv3/leasing Package leasing serves linearizable reads from a local cache by acquiring exclusive write access to keys through a client-side leasing protocol.
clientv3/mirror Package mirror implements etcd mirroring operations.
clientv3/namespace Package namespace is a clientv3 wrapper that translates all keys to begin with a given prefix.
clientv3/naming Package naming provides an etcd-backed gRPC resolver for discovering gRPC services.
clientv3/ordering Package ordering is a clientv3 wrapper that caches response header revisions to detect ordering violations from stale responses.
clientv3/snapshot Package snapshot implements utilities around etcd snapshot.
clientv3/yaml Package yaml handles yaml-formatted clientv3 configuration data.
compactor Package compactor implements automated policies for compacting etcd's mvcc storage.
contrib/raftexample raftexample is a simple KV store using the raft and rafthttp libraries.
contrib/recipes Package recipe contains experimental client-side distributed synchronization primitives.
contrib/systemd/etcd2-backup-coreos
discovery Package discovery provides an implementation of the cluster discovery that is used by etcd.
embed Package embed provides bindings for embedding an etcd server in a program.
error Package error describes errors in etcd project.
etcdctl etcdctl is a command line application that controls etcd.
etcdctl/ctlv2 Package ctlv2 contains the main entry point for the etcdctl for v2 API.
etcdctl/ctlv2/command Package command is a set of libraries for etcdctl commands.
etcdctl/ctlv3 Package ctlv3 contains the main entry point for the etcdctl for v3 API.
etcdctl/ctlv3/command Package command is a set of libraries for etcd v3 commands.
etcdmain Package etcdmain contains the main entry point for the etcd binary.
etcdserver Package etcdserver defines how etcd servers interact and store their states.
etcdserver/api Package api manages the capabilities and features that are exposed to clients by the etcd cluster.
etcdserver/api/etcdhttp Package etcdhttp implements HTTP transportation layer for etcdserver.
etcdserver/api/v2http Package v2http provides etcd client and server implementations.
etcdserver/api/v2http/httptypes Package httptypes defines how etcd's HTTP API entities are serialized to and deserialized from JSON.
etcdserver/api/v2v3 Package v2v3 provides a ServerV2 implementation backed by clientv3.Client.
etcdserver/api/v3client Package v3client provides clientv3 interfaces from an etcdserver.
etcdserver/api/v3election Package v3election provides a v3 election service from an etcdserver.
etcdserver/api/v3election/v3electionpb
etcdserver/api/v3election/v3electionpb/gw Package v3electionpb is a reverse proxy.
etcdserver/api/v3lock Package v3lock provides a v3 locking service from an etcdserver.
etcdserver/api/v3lock/v3lockpb
etcdserver/api/v3lock/v3lockpb/gw Package v3lockpb is a reverse proxy.
etcdserver/api/v3rpc Package v3rpc implements etcd v3 RPC system based on gRPC.
etcdserver/api/v3rpc/rpctypes Package rpctypes has types and values shared by the etcd server and client for v3 RPC interaction.
etcdserver/auth Package auth implements etcd authentication.
etcdserver/etcdserverpb
etcdserver/etcdserverpb/gw Package etcdserverpb is a reverse proxy.
etcdserver/membership Package membership describes individual etcd members and clusters of members.
etcdserver/stats Package stats defines a standard interface for etcd cluster statistics.
functional/agent Package agent implements functional-tester agent server.
functional/cmd/etcd-agent etcd-agent is a program that runs functional-tester agent.
functional/cmd/etcd-proxy etcd-proxy is a proxy layer that simulates various network conditions.
functional/cmd/etcd-runner etcd-runner is a program for testing etcd clientv3 features against a fault injected cluster.
functional/cmd/etcd-tester etcd-tester is a program that runs functional-tester client.
functional/rpcpb Package rpcpb is a generated protocol buffer package.
functional/runner Package runner implements individual etcd-runner commands for the etcd-runner utility.
functional/tester Package tester implements functional-tester tester server.
integration Package integration implements tests built upon embedded etcd, and focus on etcd correctness.
lease Package lease provides an interface and implementation for time-limited leases over arbitrary resources.
lease/leasehttp Package leasehttp serves lease renewals made through HTTP requests.
lease/leasepb
mvcc Package mvcc defines etcd's stable MVCC storage.
mvcc/backend Package backend defines a standard interface for etcd's backend MVCC storage.
mvcc/mvccpb
pkg/adt Package adt implements useful abstract data types.
pkg/contention Package contention provides facilities for detecting system contention.
pkg/cors Package cors handles cross-origin HTTP requests (CORS).
pkg/cpuutil Package cpuutil provides facilities for detecting cpu-specific features.
pkg/crc Package crc provides utility function for cyclic redundancy check algorithms.
pkg/debugutil Package debugutil includes utility functions for debugging.
pkg/expect Package expect implements a small expect-style interface
pkg/fileutil Package fileutil implements utility functions related to files and paths.
pkg/flags Package flags implements command-line flag parsing.
pkg/httputil Package httputil provides HTTP utility functions.
pkg/idutil Package idutil implements utility functions for generating unique, randomized ids.
pkg/ioutil Package ioutil implements I/O utility functions.
pkg/logutil Package logutil includes utilities to facilitate logging.
pkg/mock/mockserver Package mockserver provides mock implementations for etcdserver's server interface.
pkg/mock/mockstorage Package mockstorage provides mock implementations for etcdserver's storage interface.
pkg/mock/mockstore Package mockstore provides mock structures for the etcd store package.
pkg/mock/mockwait Package mockwait provides mock implementations for pkg/wait.
pkg/netutil Package netutil implements network-related utility functions.
pkg/osutil Package osutil implements operating system-related utility functions.
pkg/pathutil Package pathutil implements utility functions for handling slash-separated paths.
pkg/pbutil Package pbutil defines interfaces for handling Protocol Buffer objects.
pkg/proxy Package proxy implements proxy servers for network fault testing.
pkg/report Package report generates human-readable benchmark reports.
pkg/runtime Package runtime implements utility functions for runtime systems.
pkg/schedule Package schedule provides mechanisms and policies for scheduling units of work.
pkg/srv Package srv looks up DNS SRV records.
pkg/stringutil Package stringutil exports string utility functions.
pkg/systemd Package systemd provides utility functions for systemd.
pkg/testutil Package testutil provides test utility functions.
pkg/tlsutil Package tlsutil provides utility functions for handling TLS.
pkg/transport Package transport implements various HTTP transport utilities based on Go net package.
pkg/types Package types declares various data types and implements type-checking functions.
pkg/wait Package wait provides utility functions for polling, listening using Go channel.
proxy/grpcproxy Package grpcproxy is an OSI level 7 proxy for etcd v3 API requests.
proxy/grpcproxy/adapter Package adapter provides gRPC adapters between client and server gRPC interfaces without needing to go through a gRPC connection.
proxy/grpcproxy/cache Package cache exports functionality for efficiently caching and mapping `RangeRequest`s to corresponding `RangeResponse`s.
proxy/httpproxy Package httpproxy implements etcd httpproxy.
proxy/tcpproxy Package tcpproxy is an OSI level 4 proxy for routing etcd clients to etcd servers.
raft Package raft sends and receives messages in the Protocol Buffer format defined in the raftpb package.
raft/raftpb
raft/rafttest Package rafttest provides functional tests for etcd's raft implementation.
rafthttp Package rafthttp implements HTTP transportation layer for etcd/raft pkg.
snap Package snap stores raft nodes' states with snapshots.
snap/snappb
snapshot Package snapshot implements utilities around etcd snapshot.
store Package store defines etcd's in-memory key/value store.
tests/e2e
version Package version implements etcd version parsing and contains latest version information.
wal Package wal provides an implementation of a write ahead log that is used by etcd.
wal/walpb