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.

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