lourenco/mgmt
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

etcd: Rewrite embed etcd implementation

Browse Source 
This is a giant cleanup of the etcd code. The earlier version was
written when I was less experienced with golang.

This is still not perfect, and does contain some races, but at least
it's a decent base to start from. The automatic elastic clustering
should be considered an experimental feature. If you need a more
battle-tested cluster, then you should manage etcd manually and point
mgmt at your existing cluster.
This commit is contained in:
James Shubin
2018-05-05 17:35:08 -04:00
parent fb275d9537
commit a5842a41b2
56 changed files with 5459 additions and 2654 deletions
Download Patch File Download Diff File Expand all files Collapse all files

107
etcd/world.go
View File

@@ -18,19 +18,27 @@
package etcd
import (
"context"
"fmt"
"net/url"
"strings"
"github.com/purpleidea/mgmt/engine"
"github.com/purpleidea/mgmt/etcd/chooser"
"github.com/purpleidea/mgmt/etcd/client"
"github.com/purpleidea/mgmt/etcd/client/resources"
"github.com/purpleidea/mgmt/etcd/client/str"
"github.com/purpleidea/mgmt/etcd/client/strmap"
etcdfs "github.com/purpleidea/mgmt/etcd/fs"
"github.com/purpleidea/mgmt/etcd/interfaces"
"github.com/purpleidea/mgmt/etcd/scheduler"
"github.com/purpleidea/mgmt/util"
)
// World is an etcd backed implementation of the World interface.
type World struct {
Hostname string // uuid for the consumer of these
EmbdEtcd *EmbdEtcd
Client interfaces.Client
MetadataPrefix string // expected metadata prefix
StoragePrefix string // storage prefix for etcdfs storage
StandaloneFs engine.Fs // store an fs here for local usage
@@ -40,72 +48,113 @@ type World struct {
// ResWatch returns a channel which spits out events on possible exported
// resource changes.
func (obj *World) ResWatch() chan error {
return WatchResources(obj.EmbdEtcd)
func (obj *World) ResWatch(ctx context.Context) (chan error, error) {
return resources.WatchResources(ctx, obj.Client)
}
// ResExport exports a list of resources under our hostname namespace.
// Subsequent calls replace the previously set collection atomically.
func (obj *World) ResExport(resourceList []engine.Res) error {
return SetResources(obj.EmbdEtcd, obj.Hostname, resourceList)
func (obj *World) ResExport(ctx context.Context, resourceList []engine.Res) error {
return resources.SetResources(ctx, obj.Client, obj.Hostname, resourceList)
}
// ResCollect gets the collection of exported resources which match the filter.
// It does this atomically so that a call always returns a complete collection.
func (obj *World) ResCollect(hostnameFilter, kindFilter []string) ([]engine.Res, error) {
func (obj *World) ResCollect(ctx context.Context, hostnameFilter, kindFilter []string) ([]engine.Res, error) {
// XXX: should we be restricted to retrieving resources that were
// exported with a tag that allows or restricts our hostname? We could
// enforce that here if the underlying API supported it... Add this?
return GetResources(obj.EmbdEtcd, hostnameFilter, kindFilter)
return resources.GetResources(ctx, obj.Client, hostnameFilter, kindFilter)
}
// IdealClusterSizeWatch returns a stream of errors anytime the cluster-wide
// dynamic cluster size setpoint changes.
func (obj *World) IdealClusterSizeWatch(ctx context.Context) (chan error, error) {
c := client.NewClientFromSimple(obj.Client, ChooserPath)
if err := c.Init(); err != nil {
return nil, err
}
util.WgFromCtx(ctx).Add(1)
go func() {
util.WgFromCtx(ctx).Done()
// This must get closed *after* because it will not finish until
// the Watcher returns, because it contains a wg.Wait() in it...
defer c.Close() // ignore error
select {
case <-ctx.Done():
}
}()
return c.Watcher(ctx, chooser.IdealDynamicSizePath)
}
// IdealClusterSizeGet gets the cluster-wide dynamic cluster size setpoint.
func (obj *World) IdealClusterSizeGet(ctx context.Context) (uint16, error) {
c := client.NewClientFromSimple(obj.Client, ChooserPath)
if err := c.Init(); err != nil {
return 0, err
}
defer c.Close() // ignore error
return chooser.DynamicSizeGet(ctx, c) // use client with added namespace
}
// IdealClusterSizeSet sets the cluster-wide dynamic cluster size setpoint.
func (obj *World) IdealClusterSizeSet(ctx context.Context, size uint16) (bool, error) {
c := client.NewClientFromSimple(obj.Client, ChooserPath)
if err := c.Init(); err != nil {
return false, err
}
defer c.Close() // ignore error
return chooser.DynamicSizeSet(ctx, c, size)
}
// StrWatch returns a channel which spits out events on possible string changes.
func (obj *World) StrWatch(namespace string) chan error {
return WatchStr(obj.EmbdEtcd, namespace)
func (obj *World) StrWatch(ctx context.Context, namespace string) (chan error, error) {
return str.WatchStr(ctx, obj.Client, namespace)
}
// StrIsNotExist returns whether the error from StrGet is a key missing error.
func (obj *World) StrIsNotExist(err error) bool {
return err == ErrNotExist
return err == interfaces.ErrNotExist
}
// StrGet returns the value for the the given namespace.
func (obj *World) StrGet(namespace string) (string, error) {
return GetStr(obj.EmbdEtcd, namespace)
func (obj *World) StrGet(ctx context.Context, namespace string) (string, error) {
return str.GetStr(ctx, obj.Client, namespace)
}
// StrSet sets the namespace value to a particular string.
func (obj *World) StrSet(namespace, value string) error {
return SetStr(obj.EmbdEtcd, namespace, &value)
func (obj *World) StrSet(ctx context.Context, namespace, value string) error {
return str.SetStr(ctx, obj.Client, namespace, &value)
}
// StrDel deletes the value in a particular namespace.
func (obj *World) StrDel(namespace string) error {
return SetStr(obj.EmbdEtcd, namespace, nil)
func (obj *World) StrDel(ctx context.Context, namespace string) error {
return str.SetStr(ctx, obj.Client, namespace, nil)
}
// StrMapWatch returns a channel which spits out events on possible string changes.
func (obj *World) StrMapWatch(namespace string) chan error {
return WatchStrMap(obj.EmbdEtcd, namespace)
func (obj *World) StrMapWatch(ctx context.Context, namespace string) (chan error, error) {
return strmap.WatchStrMap(ctx, obj.Client, namespace)
}
// StrMapGet returns a map of hostnames to values in the given namespace.
func (obj *World) StrMapGet(namespace string) (map[string]string, error) {
return GetStrMap(obj.EmbdEtcd, []string{}, namespace)
func (obj *World) StrMapGet(ctx context.Context, namespace string) (map[string]string, error) {
return strmap.GetStrMap(ctx, obj.Client, []string{}, namespace)
}
// StrMapSet sets the namespace value to a particular string under the identity
// of its own hostname.
func (obj *World) StrMapSet(namespace, value string) error {
return SetStrMap(obj.EmbdEtcd, obj.Hostname, namespace, &value)
func (obj *World) StrMapSet(ctx context.Context, namespace, value string) error {
return strmap.SetStrMap(ctx, obj.Client, obj.Hostname, namespace, &value)
}
// StrMapDel deletes the value in a particular namespace.
func (obj *World) StrMapDel(namespace string) error {
return SetStrMap(obj.EmbdEtcd, obj.Hostname, namespace, nil)
func (obj *World) StrMapDel(ctx context.Context, namespace string) error {
return strmap.SetStrMap(ctx, obj.Client, obj.Hostname, namespace, nil)
}
// Scheduler returns a scheduling result of hosts in a particular namespace.
// XXX: Add a context.Context here
func (obj *World) Scheduler(namespace string, opts ...scheduler.Option) (*scheduler.Result, error) {
modifiedOpts := []scheduler.Option{}
for _, o := range opts {
@@ -115,7 +164,8 @@ func (obj *World) Scheduler(namespace string, opts ...scheduler.Option) (*schedu
modifiedOpts = append(modifiedOpts, scheduler.Debug(obj.Debug))
modifiedOpts = append(modifiedOpts, scheduler.Logf(obj.Logf))
return scheduler.Schedule(obj.EmbdEtcd.GetClient(), fmt.Sprintf("%s/scheduler/%s", NS, namespace), obj.Hostname, modifiedOpts...)
path := fmt.Sprintf(schedulerPathFmt, namespace)
return scheduler.Schedule(obj.Client.GetClient(), path, obj.Hostname, modifiedOpts...)
}
// Fs returns a distributed file system from a unique URI. For single host
@@ -144,9 +194,14 @@ func (obj *World) Fs(uri string) (engine.Fs, error) {
}
etcdFs := &etcdfs.Fs{
Client: obj.EmbdEtcd.GetClient(),
Client: obj.Client, // TODO: do we need to add a namespace?
Metadata: u.Path,
DataPrefix: obj.StoragePrefix,
Debug: obj.Debug,
Logf: func(format string, v ...interface{}) {
obj.Logf("fs: "+format, v...)
},
}
return etcdFs, nil
}