go-etcd-service

command module
v0.0.0-...-458a3ee Latest Latest
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 Go to latest Published: Aug 14, 2018 License: MIT Imports: 12 Imported by: 0

README

go-etcd-service

Usage

A simple program to show how to integrate services.

Invocation
go-etcd-service

Demonstrate #1

In this demonstration, show how 2 separate etcd instances are "automatically" joined to a cluster.

Because etcd may already be running on your system as a service, stop the service. Example:

sudo systemctl stop etcd.service
Terminal #1

Create an embedded etcd agent.

Initialize environment.

export GOPATH="${HOME}/go"
export PATH="${PATH}:${GOPATH}/bin:/usr/local/go/bin"
export PROJECT_DIR="${GOPATH}/src/github.com/docktermj"
export REPOSITORY_DIR="${PROJECT_DIR}/go-etcd-service"
export ETCD_CLIENT_ENDPOINTS=http://localhost:2379
export ETCD_PEER_ENDPOINTS=http://localhost:2380

rm -rf ${REPOSITORY_DIR}/localhost:2380.etcd

If needed, clone the project.

mkdir -p ${PROJECT_DIR}
cd ${PROJECT_DIR}
git clone git@github.com:docktermj/go-etcd-service.git

Get prerequisistes.

cd ${REPOSITORY_DIR}
make dependencies

Fix bug.

rm  ${REPOSITORY_DIR}/vendor/github.com/coreos/etcd/client/keys.generated.go

Compile program.

cd ${REPOSITORY_DIR}
make

Run command to start etcd with client port of 2379 and peer port of 2380, which are defaults.

cd ${REPOSITORY_DIR}
go-etcd-service \
  --client-endpoints ${ETCD_CLIENT_ENDPOINTS} \
  --peer-endpoints ${ETCD_PEER_ENDPOINTS}
Terminal #2

Initialize environment.

export GOPATH="${HOME}/go"
export PATH="${PATH}:${GOPATH}/bin:/usr/local/go/bin"
export PROJECT_DIR="${GOPATH}/src/github.com/docktermj"
export REPOSITORY_DIR="${PROJECT_DIR}/go-etcd-service"
export ETCD_CLIENT_ENDPOINTS=http://localhost:17073
export ETCD_PEER_ENDPOINTS=http://localhost:17074
export ETCD_CLUSTER_CLIENT_ENDPOINTS=http://localhost:2379

rm -rf ${REPOSITORY_DIR}/localhost:17074.etcd

Run command to start etcd with client port of 17073 and peer port of 17074.

cd ${REPOSITORY_DIR}
go-etcd-service \
  --client-endpoints ${ETCD_CLIENT_ENDPOINTS} \
  --peer-endpoints ${ETCD_PEER_ENDPOINTS} \
  --cluster-client-endpoints ${ETCD_CLUSTER_CLIENT_ENDPOINTS}
Terminal #3

Initialize environment.

export GOPATH="${HOME}/go"
export PATH="${PATH}:${GOPATH}/bin:/usr/local/go/bin"
export PROJECT_DIR="${GOPATH}/src/github.com/docktermj"
export REPOSITORY_DIR="${PROJECT_DIR}/go-etcd-service"
export ETCD_CLIENT_ENDPOINTS=http://localhost:17075
export ETCD_PEER_ENDPOINTS=http://localhost:17076
export ETCD_CLUSTER_CLIENT_ENDPOINTS=http://localhost:2379

rm -rf ${REPOSITORY_DIR}/localhost:17076.etcd

Run command to start etcd with client port of 17075 and peer port of 17076.

cd ${REPOSITORY_DIR}
go-etcd-service \
  --client-endpoints ${ETCD_CLIENT_ENDPOINTS} \
  --peer-endpoints ${ETCD_PEER_ENDPOINTS} \
  --cluster-client-endpoints ${ETCD_CLUSTER_CLIENT_ENDPOINTS}
Terminal #4

Initialize environment.

export GOPATH="${HOME}/go"
export PATH="${PATH}:${GOPATH}/bin:/usr/local/go/bin"
export ETCDCTL_API=3
export ETCD_CLIENT_ENDPOINT_1=http://localhost:2379
export ETCD_PEER_ENDPOINT_1=http://localhost:2380
export ETCD_CLIENT_ENDPOINT_2=http://localhost:17073
export ETCD_PEER_ENDPOINT_2=http://localhost:17074
export ETCD_CLIENT_ENDPOINT_3=http://localhost:17075
export ETCD_PEER_ENDPOINT_3=http://localhost:17076

View member lists from all etcd nodes.

$ etcdctl --endpoint ${ETCD_CLIENT_ENDPOINT_1} member list
d567bb5c5a585dd: name=localhost:17074 peerURLs=http://localhost:17074 clientURLs=http://localhost:17073
8e646f365e5c4a9c: name=localhost:17076 peerURLs=http://localhost:17076 clientURLs=http://localhost:17075
8e9e05c52164694d: name=localhost:2380 peerURLs=http://localhost:2380 clientURLs=http://localhost:2379

$ etcdctl --endpoint ${ETCD_CLIENT_ENDPOINT_2} member list
d567bb5c5a585dd: name=localhost:17074 peerURLs=http://localhost:17074 clientURLs=http://localhost:17073
8e646f365e5c4a9c: name=localhost:17076 peerURLs=http://localhost:17076 clientURLs=http://localhost:17075
8e9e05c52164694d: name=localhost:2380 peerURLs=http://localhost:2380 clientURLs=http://localhost:2379

$ etcdctl --endpoint ${ETCD_CLIENT_ENDPOINT_3} member list
d567bb5c5a585dd: name=localhost:17074 peerURLs=http://localhost:17074 clientURLs=http://localhost:17073
8e646f365e5c4a9c: name=localhost:17076 peerURLs=http://localhost:17076 clientURLs=http://localhost:17075
8e9e05c52164694d: name=localhost:2380 peerURLs=http://localhost:2380 clientURLs=http://localhost:2379

Set a key/value pair on one etcd node and retrieve from another etcd node.

$ curl -X PUT --data value="Hello world" ${ETCD_CLIENT_ENDPOINT_1}/v2/keys/message | jq
{
  "action": "set",
  "node": {
    "key": "/message",
    "value": "Hello world",
    "modifiedIndex": 8,
    "createdIndex": 8
  }
}

$ curl -X GET ${ETCD_CLIENT_ENDPOINT_1}/v2/keys/message | jq
{
  "action": "get",
  "node": {
    "key": "/message",
    "value": "Hello world",
    "modifiedIndex": 8,
    "createdIndex": 8
  }
}

$ etcdctl --endpoint ${ETCD_CLIENT_ENDPOINT_1} get /message
Hello world

$ etcdctl --endpoint ${ETCD_CLIENT_ENDPOINT_2} get /message
Hello world

$ etcdctl --endpoint ${ETCD_CLIENT_ENDPOINT_3} get /message
Hello world

Get version.

$ curl -X GET ${ETCD_CLIENT_ENDPOINT_1}/version | jq
{
  "etcdserver": "3.2.12",
  "etcdcluster": "3.2.0"
}

Get health.

$ curl -X GET ${ETCD_CLIENT_ENDPOINT_1}/health | jq
{
  "health": true
}

Find the leader.

$ curl -X GET ${ETCD_CLIENT_ENDPOINT_1}/v2/stats/leader | jq
{
  "leader": "8e9e05c52164694d",
  "followers": {
    "2ae66c8b60ad88da": {
      "latency": {
        "current": 0.002674,
        "average": 0.006149571428571429,
        "standardDeviation": 0.0036228481241437995,
        "minimum": 0.002674,
        "maximum": 0.012785
      },
      "counts": {
        "fail": 0,
        "success": 7
      }
    }
  }
}

Am I the leader?

$ curl -X GET ${ETCD_CLIENT_ENDPOINT_1}/v2/stats/self | jq
{
  "name": "localhost:2380",
  "id": "8e9e05c52164694d",
  "state": "StateLeader",
  "startTime": "2017-12-29T14:44:06.201700523-05:00",
  "leaderInfo": {
    "leader": "8e9e05c52164694d",
    "uptime": "15m11.554077768s",
    "startTime": "2017-12-29T14:44:07.102218352-05:00"
  },
  "recvAppendRequestCnt": 0,
  "sendAppendRequestCnt": 7
}

$ curl -X GET ${ETCD_CLIENT_ENDPOINT_2}/v2/stats/self | jq
{
  "name": "localhost:17074",
  "id": "2ae66c8b60ad88da",
  "state": "StateFollower",
  "startTime": "2017-12-29T14:49:56.394369884-05:00",
  "leaderInfo": {
    "leader": "8e9e05c52164694d",
    "uptime": "9m46.2818071s",
    "startTime": "2017-12-29T14:49:57.127177766-05:00"
  },
  "recvAppendRequestCnt": 7,
  "sendAppendRequestCnt": 0
}
Untested

Join clusters

$ curl -X GET http://localhost:${ETCD_CLIENT_PORT}/v2/members | jq

{
  "members": [
    {
      "id": "8e9e05c52164694d",
      "name": "go-2379",
      "peerURLs": [
        "http://localhost:2380"
      ],
      "clientURLs": [
        "http://localhost:2379"
      ]
    }
  ]
}

$ export DATA='{
  "peerUrls": [
    "http://localhost:'${ETCD_PEER_PORT2}'"
  ],
  "clientUrls": [
    "http://localhost:'${ETCD_CLIENT_PORT2}'"
  ]
}'

$ curl -X POST \
    --header "Content-Type: application/json" \
    --data "${DATA}" \
    http://localhost:${ETCD_CLIENT_PORT}/v2/members | jq

{
  "id": "703691f5941046d6",
  "name": "",
  "peerURLs": [
    "http://localhost:17074"
  ],
  "clientURLs": []
}

$ curl -X GET http://localhost:${ETCD_CLIENT_PORT}/v2/members | jq

{
  "members": [
    {
      "id": "4c28a520d0e9a9d6",
      "name": "",
      "peerURLs": [
        "http://localhost:17073"
      ],
      "clientURLs": []
    },
    {
      "id": "8e9e05c52164694d",
      "name": "go-2379",
      "peerURLs": [
        "http://localhost:2380"
      ],
      "clientURLs": [
        "http://localhost:2379"
      ]
    }
  ]
}

Demonstrate #2

Terminal #1
export GOPATH="${HOME}/go"
export PATH="${PATH}:${GOPATH}/bin:/usr/local/go/bin"
export PROJECT_DIR="${GOPATH}/src/github.com/docktermj"
export REPOSITORY_DIR="${PROJECT_DIR}/go-etcd-service"
export ETCD_CLIENT_ENDPOINT_1=http://localhost:2379
export ETCD_PEER_ENDPOINT_1=http://localhost:2380
rm -rf ${REPOSITORY_DIR}/localhost:2380.etcd

cd ${REPOSITORY_DIR}
go-etcd-service \
  --client-endpoints ${ETCD_CLIENT_ENDPOINT_1} \
  --peer-endpoints ${ETCD_PEER_ENDPOINT_1}
Terminal #2
export GOPATH="${HOME}/go"
export PATH="${PATH}:${GOPATH}/bin:/usr/local/go/bin"
export PROJECT_DIR="${GOPATH}/src/github.com/docktermj"
export REPOSITORY_DIR="${PROJECT_DIR}/go-etcd-service"
export ETCD_CLIENT_ENDPOINT_2=http://localhost:17073
export ETCD_PEER_ENDPOINT_2=http://localhost:17074
rm -rf ${REPOSITORY_DIR}/localhost:17074.etcd

cd ${REPOSITORY_DIR}
go-etcd-service \
  --client-endpoints ${ETCD_CLIENT_ENDPOINT_2} \
  --peer-endpoints ${ETCD_PEER_ENDPOINT_2}
Terminal #3
export GOPATH="${HOME}/go"
export PATH="${PATH}:${GOPATH}/bin:/usr/local/go/bin"
export PROJECT_DIR="${GOPATH}/src/github.com/docktermj"
export REPOSITORY_DIR="${PROJECT_DIR}/go-etcd-service"
export ETCD_CLIENT_ENDPOINT_3=http://localhost:17075
export ETCD_PEER_ENDPOINT_3=http://localhost:17076
rm -rf ${REPOSITORY_DIR}/localhost:17076.etcd

cd ${REPOSITORY_DIR}
go-etcd-service \
  --client-endpoints ${ETCD_CLIENT_ENDPOINT_3} \
  --peer-endpoints ${ETCD_PEER_ENDPOINT_3}
Terminal #4

Initialize environment.

export GOPATH="${HOME}/go"
export PATH="${PATH}:${GOPATH}/bin:/usr/local/go/bin"
export PROJECT_DIR="${GOPATH}/src/github.com/docktermj"
export REPOSITORY_DIR="${PROJECT_DIR}/etcd-service"

export ETCDCTL_API=3
export ETCD_CLIENT_ENDPOINT_1=http://localhost:2379
export ETCD_PEER_ENDPOINT_1=http://localhost:2380
export ETCD_CLIENT_ENDPOINT_2=http://localhost:17073
export ETCD_PEER_ENDPOINT_2=http://localhost:17074
export ETCD_CLIENT_ENDPOINT_3=http://localhost:17075
export ETCD_PEER_ENDPOINT_3=http://localhost:17076

Development

Dependencies
Set environment variables
export GOPATH="${HOME}/go"
export PATH="${PATH}:${GOPATH}/bin:/usr/local/go/bin"
export PROJECT_DIR="${GOPATH}/src/github.com/docktermj"
export REPOSITORY_DIR="${PROJECT_DIR}/go-etcd-service"
Download project
mkdir -p ${PROJECT_DIR}
cd ${PROJECT_DIR}
git clone git@github.com:docktermj/go-etcd-service.git
Download dependencies
cd ${REPOSITORY_DIR}
make dependencies

Fix bug.

rm  ${REPOSITORY_DIR}/vendor/github.com/coreos/etcd/client/keys.generated.go
Build
Local build
cd ${REPOSITORY_DIR}
make

The results will be in the ${GOPATH}/bin directory.

Docker build

Create rpm and deb installation packages.

cd ${REPOSITORY_DIR}
make build

The results will be in the ${REPOSITORY_DIR}/target directory.

Test
cd ${REPOSITORY_DIR}
make test-local
Cleanup
cd ${REPOSITORY_DIR}
make clean
APIs

Get Swagger / Open API

wget https://coreos.com/etcd/docs/3.2.11/dev-guide/apispec/swagger/rpc.swagger.json
  1. Visit swagger.io editor
    1. File > Import File > {Choose downloaded rpc.swagger.json}
References
  1. https://coreos.com/etcd/docs/3.2.11/index.html
    1. https://godoc.org/github.com/coreos/etcd/embed
  2. Curl API
  3. etcd Swagger / Open API
    1. In editor
  4. Client options:
    1. etcd/clientv3
      1. Go Doc
    2. http requests / curl calls
      1. v2
      2. cluster management
      3. examples

Documentation

The Go Gopher

There is no documentation for this package.

Source Files

View all Source files

Directories

Path Synopsis
common
help
runner
service
etcd

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