micro/config/source/etcd/etcd.go

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package etcd
import (
"context"
"fmt"
"net"
"time"
cetcd "github.com/coreos/etcd/clientv3"
"github.com/coreos/etcd/mvcc/mvccpb"
"github.com/micro/go-micro/config/source"
)
// Currently a single etcd reader
type etcd struct {
prefix string
stripPrefix string
opts source.Options
client *cetcd.Client
cerr error
}
var (
DefaultPrefix = "/micro/config/"
)
func (c *etcd) Read() (*source.ChangeSet, error) {
if c.cerr != nil {
return nil, c.cerr
}
rsp, err := c.client.Get(context.Background(), c.prefix, cetcd.WithPrefix())
if err != nil {
return nil, err
}
if rsp == nil || len(rsp.Kvs) == 0 {
return nil, fmt.Errorf("source not found: %s", c.prefix)
}
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kvs := make([]*mvccpb.KeyValue, 0, len(rsp.Kvs))
for _, v := range rsp.Kvs {
kvs = append(kvs, (*mvccpb.KeyValue)(v))
}
data := makeMap(c.opts.Encoder, kvs, c.stripPrefix)
b, err := c.opts.Encoder.Encode(data)
if err != nil {
return nil, fmt.Errorf("error reading source: %v", err)
}
cs := &source.ChangeSet{
Timestamp: time.Now(),
Source: c.String(),
Data: b,
Format: c.opts.Encoder.String(),
}
cs.Checksum = cs.Sum()
return cs, nil
}
func (c *etcd) String() string {
return "etcd"
}
func (c *etcd) Watch() (source.Watcher, error) {
if c.cerr != nil {
return nil, c.cerr
}
cs, err := c.Read()
if err != nil {
return nil, err
}
return newWatcher(c.prefix, c.stripPrefix, c.client.Watcher, cs, c.opts)
}
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func (c *etcd) Write(cs *source.ChangeSet) error {
return nil
}
func NewSource(opts ...source.Option) source.Source {
options := source.NewOptions(opts...)
var endpoints []string
// check if there are any addrs
addrs, ok := options.Context.Value(addressKey{}).([]string)
if ok {
for _, a := range addrs {
addr, port, err := net.SplitHostPort(a)
if ae, ok := err.(*net.AddrError); ok && ae.Err == "missing port in address" {
port = "2379"
addr = a
endpoints = append(endpoints, fmt.Sprintf("%s:%s", addr, port))
} else if err == nil {
endpoints = append(endpoints, fmt.Sprintf("%s:%s", addr, port))
}
}
}
if len(endpoints) == 0 {
endpoints = []string{"localhost:2379"}
}
// check dial timeout option
dialTimeout, ok := options.Context.Value(dialTimeoutKey{}).(time.Duration)
if !ok {
dialTimeout = 3 * time.Second // default dial timeout
}
config := cetcd.Config{
Endpoints: endpoints,
DialTimeout: dialTimeout,
}
u, ok := options.Context.Value(authKey{}).(*authCreds)
if ok {
config.Username = u.Username
config.Password = u.Password
}
// use default config
client, err := cetcd.New(config)
prefix := DefaultPrefix
sp := ""
f, ok := options.Context.Value(prefixKey{}).(string)
if ok {
prefix = f
}
if b, ok := options.Context.Value(stripPrefixKey{}).(bool); ok && b {
sp = prefix
}
return &etcd{
prefix: prefix,
stripPrefix: sp,
opts: options,
client: client,
cerr: err,
}
}