feat: automatically generated instanceId (#174)

README.md

@@ -35,6 +35,7 @@ go get github.com/Unleash/unleash-client-go
 The easiest way to get started with Unleash is to initialize it early in your application code:
 
 **Asynchronous initialization example:**
+
 ```go
 import (
 	"github.com/Unleash/unleash-client-go/v4"
@@ -70,6 +71,10 @@ func init() {
 }
 ```
 
+#### instanceId
+
+Starting from version 5.0.0, `instanceId` is automatically generated and can no longer be set manually.
+
 #### Preloading feature toggles
 
 If you'd like to prebake your application with feature toggles (maybe you're working without persistent storage, so Unleash's backup isn't available), you can replace the defaultStorage implementation with a BootstrapStorage. This allows you to pass in a reader to where data in the format of `/api/client/features` can be found.
@@ -273,8 +278,6 @@ you can add the following to your apps `go.mod`:
     replace github.com/Unleash/unleash-client-go/v4 => ../unleash-client-go/
 ```
 
-
-
 ## Steps to release
 
 - Update the clientVersion in `client.go`

client.go

@@ -7,6 +7,8 @@ import (
 	"strings"
 	"time"
 
+	"github.com/google/uuid"
+
 	"github.com/Unleash/unleash-client-go/v4/api"
 	"github.com/Unleash/unleash-client-go/v4/context"
 	"github.com/Unleash/unleash-client-go/v4/internal/constraints"
@@ -159,9 +161,7 @@ func NewClient(options ...ConfigOption) (*Client, error) {
 		return nil, fmt.Errorf("unleash client appName missing")
 	}
 
-	if uc.options.instanceId == "" {
-		uc.options.instanceId = generateInstanceId()
-	}
+	uc.options.instanceId = uuid.New().String()
 
 	uc.repository = newRepository(
 		repositoryOptions{

client_test.go

@@ -30,7 +30,6 @@ func TestClientWithoutListener(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 	)
 	assert.Nil(err, "client should not return an error")
 
@@ -46,7 +45,6 @@ func TestClient_WithFallbackFunc(t *testing.T) {
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	gock.New(mockerServer).
@@ -65,7 +63,6 @@ func TestClient_WithFallbackFunc(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -90,7 +87,6 @@ func TestClient_WithResolver(t *testing.T) {
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	gock.New(mockerServer).
@@ -109,7 +105,6 @@ func TestClient_WithResolver(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -198,7 +193,6 @@ func TestClient_ListFeatures(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -232,7 +226,6 @@ func TestClientWithProjectName(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithProjectName(projectName),
 		WithListener(mockListener),
 	)
@@ -265,7 +258,6 @@ func TestClientWithoutProjectName(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -342,7 +334,6 @@ func TestClientWithVariantContext(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -381,7 +372,6 @@ func TestClient_WithSegment(t *testing.T) {
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	feature := "feature-segment"
@@ -430,7 +420,6 @@ func TestClient_WithSegment(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -466,7 +455,6 @@ func TestClient_WithNonExistingSegment(t *testing.T) {
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	feature := "feature-segment-non-existing"
@@ -508,7 +496,6 @@ func TestClient_WithNonExistingSegment(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -545,7 +532,6 @@ func TestClient_WithMultipleSegments(t *testing.T) {
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	feature := "feature-segment-multiple"
@@ -612,7 +598,6 @@ func TestClient_WithMultipleSegments(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -648,7 +633,6 @@ func TestClient_VariantShouldRespectConstraint(t *testing.T) {
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	feature := "feature-segment-multiple"
@@ -727,7 +711,6 @@ func TestClient_VariantShouldRespectConstraint(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -767,7 +750,6 @@ func TestClient_VariantShouldFailWhenSegmentConstraintsDontMatch(t *testing.T) {
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	feature := "feature-segment-multiple"
@@ -846,7 +828,6 @@ func TestClient_VariantShouldFailWhenSegmentConstraintsDontMatch(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -949,7 +930,6 @@ func TestClient_ShouldFavorStrategyVariantOverFeatureVariant(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -1049,7 +1029,6 @@ func TestClient_ShouldReturnOldVariantForNonMatchingStrategyVariant(t *testing.T
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -1075,7 +1054,6 @@ func TestClient_VariantFromEnabledFeatureWithNoVariants(t *testing.T) {
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	feature := "feature-no-variants"
@@ -1112,7 +1090,6 @@ func TestClient_VariantFromEnabledFeatureWithNoVariants(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(mockListener),
 	)
 
@@ -1152,7 +1129,6 @@ func TestGetVariantWithFallbackVariantWhenFeatureDisabled(t *testing.T) {
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	feature := "feature-disabled"
@@ -1183,7 +1159,6 @@ func TestGetVariantWithFallbackVariantWhenFeatureDisabled(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(&NoopListener{}),
 	)
 
@@ -1220,7 +1195,6 @@ func TestGetVariantWithFallbackVariantWhenFeatureEnabledButNoVariants(t *testing
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	feature := "feature-no-variants"
@@ -1251,7 +1225,6 @@ func TestGetVariantWithFallbackVariantWhenFeatureEnabledButNoVariants(t *testing
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(&NoopListener{}),
 	)
 
@@ -1292,7 +1265,6 @@ func TestGetVariantWithFallbackVariantWhenFeatureDoesntExist(t *testing.T) {
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	feature := "feature-no-variants"
@@ -1309,7 +1281,6 @@ func TestGetVariantWithFallbackVariantWhenFeatureDoesntExist(t *testing.T) {
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(&NoopListener{}),
 	)
 
@@ -1346,7 +1317,6 @@ func TestGetVariant_FallbackVariantFeatureEnabledSettingIsLeftUnchanged(t *testi
 	gock.New(mockerServer).
 		Post("/client/register").
 		MatchHeader("UNLEASH-APPNAME", mockAppName).
-		MatchHeader("UNLEASH-INSTANCEID", mockInstanceId).
 		Reply(200)
 
 	enabledFeatureNoVariants := "enabled-feature"
@@ -1391,7 +1361,6 @@ func TestGetVariant_FallbackVariantFeatureEnabledSettingIsLeftUnchanged(t *testi
 	client, err := NewClient(
 		WithUrl(mockerServer),
 		WithAppName(mockAppName),
-		WithInstanceId(mockInstanceId),
 		WithListener(&NoopListener{}),
 	)
 

config.go

@@ -54,14 +54,6 @@ func WithEnvironment(env string) ConfigOption {
 	}
 }
 
-// WithInstanceId specifies the instance identifier of the current instance. If not provided,
-// one will be generated based on various parameters such as current user and hostname.
-func WithInstanceId(instanceId string) ConfigOption {
-	return func(o *configOption) {
-		o.instanceId = instanceId
-	}
-}
-
 // WithUrl specifies the url of the unleash server the user is connecting to.
 func WithUrl(url string) ConfigOption {
 	return func(o *configOption) {

go.mod

@@ -3,6 +3,7 @@ module github.com/Unleash/unleash-client-go/v4
 require (
 	github.com/Masterminds/semver/v3 v3.1.1
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/google/uuid v1.6.0
 	github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/stretchr/objx v0.1.1 // indirect

go.sum

@@ -2,6 +2,8 @@ github.com/Masterminds/semver/v3 v3.1.1 h1:hLg3sBzpNErnxhQtUy/mmLR2I9foDujNK030I
 github.com/Masterminds/semver/v3 v3.1.1/go.mod h1:VPu/7SZ7ePZ3QOrcuXROw5FAcLl4a0cBrbBpGY/8hQs=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32 h1:W6apQkHrMkS0Muv8G/TipAy/FJl/rCYT0+EuS8+Z0z4=
 github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32/go.mod h1:9wM+0iRr9ahx58uYLpLIr5fm8diHn0JbqRycJi6w0Ms=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=