micro-config-consul/consul.go

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package consul
import (
"context"
"fmt"
"reflect"
"github.com/hashicorp/consul/api"
"github.com/imdario/mergo"
"github.com/unistack-org/micro/v3/config"
"github.com/unistack-org/micro/v3/util/jitter"
rutil "github.com/unistack-org/micro/v3/util/reflect"
)
var (
DefaultStructTag = "consul"
)
type consulConfig struct {
opts config.Options
cli *api.Client
path string
}
func (c *consulConfig) Options() config.Options {
return c.opts
}
func (c *consulConfig) Init(opts ...config.Option) error {
for _, o := range opts {
o(&c.opts)
}
if c.opts.Codec == nil {
return config.ErrCodecMissing
}
cfg := api.DefaultConfigWithLogger(&consulLogger{logger: c.opts.Logger})
path := ""
if c.opts.Context != nil {
if v, ok := c.opts.Context.Value(configKey{}).(*api.Config); ok {
cfg.Address = v.Address
cfg.Scheme = v.Scheme
cfg.Datacenter = v.Datacenter
cfg.Transport = v.Transport
cfg.HttpClient = v.HttpClient
cfg.HttpAuth = v.HttpAuth
cfg.WaitTime = v.WaitTime
cfg.Token = v.Token
cfg.TokenFile = v.TokenFile
cfg.Namespace = v.Namespace
cfg.TLSConfig = v.TLSConfig
}
if v, ok := c.opts.Context.Value(addrKey{}).(string); ok {
cfg.Address = v
}
if v, ok := c.opts.Context.Value(tokenKey{}).(string); ok {
cfg.Token = v
}
if v, ok := c.opts.Context.Value(pathKey{}).(string); ok {
path = v
}
/*
if v, ok := c.opts.Context.Value(tlsConfigKey{}).(*tls.Config); ok {
cfg.TLSConfig = *v
}
*/
}
cli, err := api.NewClient(cfg)
if err != nil && !c.opts.AllowFail {
return err
}
c.cli = cli
c.path = path
return nil
}
func (c *consulConfig) Load(ctx context.Context, opts ...config.LoadOption) error {
for _, fn := range c.opts.BeforeLoad {
if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
}
pair, _, err := c.cli.KV().Get(c.path, nil)
if err != nil && !c.opts.AllowFail {
return fmt.Errorf("consul path %s load error: %v", c.path, err)
} else if pair == nil && !c.opts.AllowFail {
return fmt.Errorf("consul path %s not found", c.path)
}
if err == nil && pair != nil {
options := config.NewLoadOptions(opts...)
mopts := []func(*mergo.Config){mergo.WithTypeCheck}
if options.Override {
mopts = append(mopts, mergo.WithOverride)
}
if options.Append {
mopts = append(mopts, mergo.WithAppendSlice)
}
dst := c.opts.Struct
if options.Struct != nil {
dst = options.Struct
}
src, err := rutil.Zero(dst)
if err == nil {
err = c.opts.Codec.Unmarshal(pair.Value, src)
if err == nil {
err = mergo.Merge(dst, src, mopts...)
}
}
if err != nil && !c.opts.AllowFail {
return err
}
}
for _, fn := range c.opts.AfterLoad {
if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
}
return nil
}
func (c *consulConfig) Save(ctx context.Context, opts ...config.SaveOption) error {
for _, fn := range c.opts.BeforeSave {
if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
}
buf, err := c.opts.Codec.Marshal(c.opts.Struct)
if err == nil {
_, err = c.cli.KV().Put(&api.KVPair{Key: c.path, Value: buf}, nil)
}
if err != nil && !c.opts.AllowFail {
return fmt.Errorf("consul path %s save error: %v", c.path, err)
}
for _, fn := range c.opts.AfterSave {
if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
}
return nil
}
func (c *consulConfig) String() string {
return "consul"
}
func (c *consulConfig) Name() string {
return c.opts.Name
}
func (c *consulConfig) Watch(ctx context.Context, opts ...config.WatchOption) (config.Watcher, error) {
w := &consulWatcher{
cli: c.cli,
path: c.path,
opts: c.opts,
wopts: config.NewWatchOptions(opts...),
done: make(chan struct{}),
vchan: make(chan map[string]interface{}),
echan: make(chan error),
}
go w.run()
return w, nil
}
type consulWatcher struct {
cli *api.Client
path string
opts config.Options
wopts config.WatchOptions
done chan struct{}
vchan chan map[string]interface{}
echan chan error
}
func (w *consulWatcher) run() {
ticker := jitter.NewTicker(w.wopts.MinInterval, w.wopts.MaxInterval)
defer ticker.Stop()
src := w.opts.Struct
if w.wopts.Struct != nil {
src = w.wopts.Struct
}
for {
select {
case <-w.done:
return
case <-ticker.C:
dst, err := rutil.Zero(src)
if err != nil {
w.echan <- err
return
}
pair, _, err := w.cli.KV().Get(w.path, nil)
if err != nil {
w.echan <- err
return
}
if pair == nil {
w.echan <- fmt.Errorf("consul path %s not found", w.path)
return
}
err = w.opts.Codec.Unmarshal(pair.Value, dst)
if err != nil {
w.echan <- err
return
}
srcmp, err := rutil.StructFieldsMap(src)
if err != nil {
w.echan <- err
return
}
dstmp, err := rutil.StructFieldsMap(dst)
if err != nil {
w.echan <- err
return
}
for sk, sv := range srcmp {
if reflect.DeepEqual(dstmp[sk], sv) {
delete(dstmp, sk)
}
}
w.vchan <- dstmp
src = dst
}
}
}
func (w *consulWatcher) Next() (map[string]interface{}, error) {
select {
case <-w.done:
break
case err := <-w.echan:
return nil, err
case v, ok := <-w.vchan:
if !ok {
break
}
return v, nil
}
return nil, config.ErrWatcherStopped
}
func (w *consulWatcher) Stop() error {
close(w.done)
return nil
}
func NewConfig(opts ...config.Option) config.Config {
options := config.NewOptions(opts...)
if len(options.StructTag) == 0 {
options.StructTag = DefaultStructTag
}
return &consulConfig{opts: options}
}