Merge pull request #275 from netixx/netixx/add-redis-locker

Add redis as a locker option

app/clustering.go

@@ -670,7 +670,7 @@ func (a *App) unassignTarget(ctx context.Context, name string, serviceID string)
 		}
 		rsp, err := client.Do(req)
 		if err != nil {
-			rsp.Body.Close()
+			// don't close the body here since Body will be nil
 			a.Logger.Printf("failed HTTP request: %v", err)
 			continue
 		}

app/metrics.go

@@ -69,7 +69,7 @@ func (a *App) startClusterMetrics() {
 			if err != nil {
 				a.Logger.Printf("failed to get leader key: %v", err)
 			}
-			if leader[leaderKey] == a.Config.InstanceName {
+			if leader[leaderKey] == a.Config.Clustering.InstanceName {
 				clusterIsLeader.Set(1)
 			} else {
 				clusterIsLeader.Set(0)
@@ -84,7 +84,7 @@ func (a *App) startClusterMetrics() {
 			}
 			numLockedNodes := 0
 			for _, v := range lockedNodes {
-				if v == a.Config.InstanceName {
+				if v == a.Config.Clustering.InstanceName {
 					numLockedNodes++
 				}
 			}

go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/fsnotify/fsnotify v1.6.0
 	github.com/fullstorydev/grpcurl v1.8.7
 	github.com/go-redis/redis/v8 v8.11.5
+	github.com/go-redsync/redsync/v4 v4.10.0
 	github.com/go-resty/resty/v2 v2.7.0
 	github.com/google/go-cmp v0.5.9
 	github.com/google/uuid v1.3.1
@@ -44,6 +45,7 @@ require (
 	github.com/prometheus/client_golang v1.16.0
 	github.com/prometheus/client_model v0.4.0
 	github.com/prometheus/prometheus v0.45.0
+	github.com/redis/go-redis/v9 v9.2.1
 	github.com/spf13/cobra v1.7.0
 	github.com/spf13/pflag v1.0.5
 	github.com/spf13/viper v1.15.0
@@ -88,6 +90,7 @@ require (
 	github.com/go-openapi/jsonpointer v0.19.6 // indirect
 	github.com/go-openapi/jsonreference v0.20.2 // indirect
 	github.com/go-openapi/swag v0.22.3 // indirect
+	github.com/gomodule/redigo v2.0.0+incompatible // indirect
 	github.com/google/gnostic v0.6.9 // indirect
 	github.com/google/gofuzz v1.2.0 // indirect
 	github.com/google/s2a-go v0.1.4 // indirect

go.sum

@@ -236,6 +236,10 @@ github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+Ce
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kBD4zp0CCIs=
+github.com/bsm/ginkgo/v2 v2.12.0 h1:Ny8MWAHyOepLGlLKYmXG4IEkioBysk6GpaRTLC8zwWs=
+github.com/bsm/ginkgo/v2 v2.12.0/go.mod h1:SwYbGRRDovPVboqFv0tPTcG1sN61LM1Z4ARdbAV9g4c=
+github.com/bsm/gomega v1.27.10 h1:yeMWxP2pV2fG3FgAODIY8EiRE3dy0aeFYt4l7wh6yKA=
+github.com/bsm/gomega v1.27.10/go.mod h1:JyEr/xRbxbtgWNi8tIEVPUYZ5Dzef52k01W3YH0H+O0=
 github.com/bufbuild/protocompile v0.5.1 h1:mixz5lJX4Hiz4FpqFREJHIXLfaLBntfaJv1h+/jS+Qg=
 github.com/bufbuild/protocompile v0.5.1/go.mod h1:G5iLmavmF4NsYtpZFvE3B/zFch2GIY8+wjsYLR/lc40=
 github.com/buger/jsonparser v1.1.1/go.mod h1:6RYKKt7H4d4+iWqouImQ9R2FZql3VbhNgx27UK13J/0=
@@ -407,8 +411,14 @@ github.com/go-playground/locales v0.13.0/go.mod h1:taPMhCMXrRLJO55olJkUXHZBHCxTM
 github.com/go-playground/universal-translator v0.17.0/go.mod h1:UkSxE5sNxxRwHyU+Scu5vgOQjsIJAF8j9muTVoKLVtA=
 github.com/go-playground/validator/v10 v10.2.0/go.mod h1:uOYAAleCW8F/7oMFd6aG0GOhaH6EGOAJShg8Id5JGkI=
 github.com/go-playground/validator/v10 v10.4.1/go.mod h1:nlOn6nFhuKACm19sB/8EGNn9GlaMV7XkbRSipzJ0Ii4=
+github.com/go-redis/redis v6.15.9+incompatible h1:K0pv1D7EQUjfyoMql+r/jZqCLizCGKFlFgcHWWmHQjg=
+github.com/go-redis/redis v6.15.9+incompatible/go.mod h1:NAIEuMOZ/fxfXJIrKDQDz8wamY7mA7PouImQ2Jvg6kA=
+github.com/go-redis/redis/v7 v7.4.0 h1:7obg6wUoj05T0EpY0o8B59S9w5yeMWql7sw2kwNW1x4=
+github.com/go-redis/redis/v7 v7.4.0/go.mod h1:JDNMw23GTyLNC4GZu9njt15ctBQVn7xjRfnwdHj/Dcg=
 github.com/go-redis/redis/v8 v8.11.5 h1:AcZZR7igkdvfVmQTPnu9WE37LRrO/YrBH5zWyjDC0oI=
 github.com/go-redis/redis/v8 v8.11.5/go.mod h1:gREzHqY1hg6oD9ngVRbLStwAWKhA0FEgq8Jd4h5lpwo=
+github.com/go-redsync/redsync/v4 v4.10.0 h1:hTeAak4C73mNBQSTq6KCKDFaiIlfC+z5yTTl8fCJuBs=
+github.com/go-redsync/redsync/v4 v4.10.0/go.mod h1:ZfayzutkgeBmEmBlUR3j+rF6kN44UUGtEdfzhBFZTPc=
 github.com/go-resty/resty/v2 v2.7.0 h1:me+K9p3uhSmXtrBZ4k9jcEAfJmuC8IivWHwaLZwPrFY=
 github.com/go-resty/resty/v2 v2.7.0/go.mod h1:9PWDzw47qPphMRFfhsyk0NnSgvluHcljSMVIq3w7q0I=
 github.com/go-sql-driver/mysql v1.6.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
@@ -470,6 +480,8 @@ github.com/golang/snappy v0.0.3/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEW
 github.com/golang/snappy v0.0.4 h1:yAGX7huGHXlcLOEtBnF4w7FQwA26wojNCwOYAEhLjQM=
 github.com/golang/snappy v0.0.4/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/golangci/lint-1 v0.0.0-20181222135242-d2cdd8c08219/go.mod h1:/X8TswGSh1pIozq4ZwCfxS0WA5JGXguxk94ar/4c87Y=
+github.com/gomodule/redigo v2.0.0+incompatible h1:K/R+8tc58AaqLkqG2Ol3Qk+DR/TlNuhuh457pBFPtt0=
+github.com/gomodule/redigo v2.0.0+incompatible/go.mod h1:B4C85qUVwatsJoIUNIfCRsp7qO0iAmpGFZ4EELWSbC4=
 github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/btree v1.0.1 h1:gK4Kx5IaGY9CD5sPJ36FHiBJ6ZXl0kilRiiCj+jdYp4=
@@ -1011,6 +1023,10 @@ github.com/prometheus/prometheus v0.45.0/go.mod h1:jC5hyO8ItJBnDWGecbEucMyXjzxGv
 github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
 github.com/rcrowley/go-metrics v0.0.0-20201227073835-cf1acfcdf475 h1:N/ElC8H3+5XpJzTSTfLsJV/mx9Q9g7kxmchpfZyxgzM=
 github.com/rcrowley/go-metrics v0.0.0-20201227073835-cf1acfcdf475/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
+github.com/redis/go-redis/v9 v9.2.1 h1:WlYJg71ODF0dVspZZCpYmoF1+U1Jjk9Rwd7pq6QmlCg=
+github.com/redis/go-redis/v9 v9.2.1/go.mod h1:hdY0cQFCN4fnSYT6TkisLufl/4W5UIXyv0b/CLO2V2M=
+github.com/redis/rueidis v1.0.19 h1:s65oWtotzlIFN8eMPhyYwxlwLR1lUdhza2KtWprKYSo=
+github.com/redis/rueidis v1.0.19/go.mod h1:8B+r5wdnjwK3lTFml5VtxjzGOQAC+5UmujoD12pDrEo=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.4.4 h1:8TfxU8dW6PdqD27gjM8MVNuicgxIjxpm4K7x4jp8sis=
 github.com/rivo/uniseg v0.4.4/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
@@ -1083,6 +1099,8 @@ github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o
 github.com/stretchr/testify v1.8.3/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/stvp/tempredis v0.0.0-20181119212430-b82af8480203 h1:QVqDTf3h2WHt08YuiTGPZLls0Wq99X9bWd0Q5ZSBesM=
+github.com/stvp/tempredis v0.0.0-20181119212430-b82af8480203/go.mod h1:oqN97ltKNihBbwlX8dLpwxCl3+HnXKV/R0e+sRLd9C8=
 github.com/subosito/gotenv v1.4.2 h1:X1TuBLAMDFbaTAChgCBLu3DU3UPyELpnF2jjJ2cz/S8=
 github.com/subosito/gotenv v1.4.2/go.mod h1:ayKnFf/c6rvx/2iiLrJUk1e6plDbT3edrFNGqEflhK0=
 github.com/tv42/httpunix v0.0.0-20150427012821-b75d8614f926/go.mod h1:9ESjWnEqriFuLhtthL60Sar/7RFoluCcXsuvEwTV5KM=

lockers/all/all.go

@@ -11,4 +11,5 @@ package all
 import (
 	_ "github.com/openconfig/gnmic/lockers/consul_locker"
 	_ "github.com/openconfig/gnmic/lockers/k8s_locker"
+	_ "github.com/openconfig/gnmic/lockers/redis_locker"
 )

lockers/locker.go

@@ -17,27 +17,44 @@ import (
 	"github.com/mitchellh/mapstructure"
 )
 
-var (
-	ErrCanceled = errors.New("canceled")
-)
+var ErrCanceled = errors.New("canceled")
 
 type Locker interface {
+	// Init initialises the locker data, with the given configuration read from flags/files.
 	Init(context.Context, map[string]interface{}, ...Option) error
+	// Stop is called when the locker instance is called. It should unlock all aquired locks.
+	Stop() error
+	SetLogger(*log.Logger)
+
+	// This is the Target locking logic.
 
+	// Lock acquires a lock on given key.
 	Lock(context.Context, string, []byte) (bool, error)
+	// KeepLock maintains the lock on the target.
 	KeepLock(context.Context, string) (chan struct{}, chan error)
+	// IsLocked replys if the target given as string is currently locked or not.
 	IsLocked(context.Context, string) (bool, error)
+	// Unlock unlocks the target log.
 	Unlock(context.Context, string) error
 
+	// This is the instance registration logic.
+
+	// Register registers this instance in the registry. It must also maintain the registration (called in a goroutine from the main). ServiceRegistration.ID contains the ID of the service to register.
 	Register(context.Context, *ServiceRegistration) error
+	// Deregister removes this instance from the registry. This looks like it's not called.
 	Deregister(string) error
 
-	List(context.Context, string) (map[string]string, error)
+	// GetServices must return the gnmic instances.
 	GetServices(ctx context.Context, serviceName string, tags []string) ([]*Service, error)
+	// WatchServices must push all existing discovered gnmic instances
+	// into the provided channel.
 	WatchServices(ctx context.Context, serviceName string, tags []string, ch chan<- []*Service, dur time.Duration) error
 
-	Stop() error
-	SetLogger(*log.Logger)
+	// Mixed registration/target lock functions
+
+	// List returns all locks that start with prefix string,
+	// indexed by the lock name. Could be target locks or leader lock. It must return a map of matching keys to instance name.
+	List(ctx context.Context, prefix string) (map[string]string, error)
 }
 
 type Initializer func() Locker
@@ -55,6 +72,7 @@ func WithLogger(logger *log.Logger) Option {
 var LockerTypes = []string{
 	"consul",
 	"k8s",
+	"redis",
 }
 
 func Register(name string, initFn Initializer) {