feat!: start command flag refactor (#222)

Corresponding OFO changes
[here](open-feature/open-feature-operator#256)
<!-- Please use this template for your pull request. -->
<!-- Please use the sections that you need and delete other sections -->

## This PR
<!-- add the description of the PR here -->

- refactors the start command flags to remove `--sync-provider`
- multiple `--uri` flags can be passed indicating the use of different
existing `sync-provider` types, all of which will work
- uses a prefix on the uri to define the `sync-provider`; `http(s)://`
will be passed to the http sync, `file://` will be passed to the file
path sync and the Kubernetes sync uses the following pattern
`core.openfeature.dev/{namespace}/{name}`, this will also allow for the
Kubernetes sync to watch multiple `FeatureFlagConfigurations` from
different namespaces.
- adds deprecation warning when the `--sync-provider` flag is passed as
an argument

`./flagd start --uri file://etc/flagd/end-to-end.json --uri
core.openfeature.dev/test/end-to-end-2`

### Related Issues
<!-- add here the GitHub issue that this PR resolves if applicable -->

open-feature/open-feature-operator#251

### Notes
<!-- any additional notes for this PR -->

### Follow-up Tasks

### How to test
<!-- if applicable, add testing instructions under this section -->

Signed-off-by: James Milligan <james@omnant.co.uk>
Signed-off-by: James Milligan <75740990+james-milligan@users.noreply.github.com>
Co-authored-by: Todd Baert <toddbaert@gmail.com>

cmd/start.go

@@ -16,54 +16,55 @@ const (
 	portFlagName           = "port"
 	metricsPortFlagName    = "metrics-port"
 	socketPathFlagName     = "socket-path"
-	syncProviderFlagName   = "sync-provider"
 	providerArgsFlagName   = "sync-provider-args"
 	evaluatorFlagName      = "evaluator"
 	serverCertPathFlagName = "server-cert-path"
 	serverKeyPathFlagName  = "server-key-path"
 	uriFlagName            = "uri"
 	bearerTokenFlagName    = "bearer-token"
 	corsFlagName           = "cors-origin"
+	syncProviderFlagName   = "sync-provider"
 )
 
 func init() {
 	flags := startCmd.Flags()
 
 	// allows environment variables to use _ instead of -
-	viper.SetEnvKeyReplacer(strings.NewReplacer("-", "_")) // sync-provider becomes SYNC_PROVIDER
+	viper.SetEnvKeyReplacer(strings.NewReplacer("-", "_")) // sync-provider-args becomes SYNC_PROVIDER_ARGS
 	viper.SetEnvPrefix("FLAGD")                            // port becomes FLAGD_PORT
 	flags.Int32P(metricsPortFlagName, "m", 8014, "Port to serve metrics on")
 	flags.Int32P(portFlagName, "p", 8013, "Port to listen on")
 	flags.StringP(socketPathFlagName, "d", "", "Flagd socket path. "+
 		"With grpc the service will become available on this address. "+
 		"With http(s) the grpc-gateway proxy will use this address internally.")
-	flags.StringP(
-		syncProviderFlagName, "y", "filepath", "Set a sync provider e.g. filepath or remote",
-	)
 	flags.StringP(evaluatorFlagName, "e", "json", "Set an evaluator e.g. json")
 	flags.StringP(serverCertPathFlagName, "c", "", "Server side tls certificate path")
 	flags.StringP(serverKeyPathFlagName, "k", "", "Server side tls key path")
 	flags.StringToStringP(providerArgsFlagName,
 		"a", nil, "Sync provider arguments as key values separated by =")
 	flags.StringSliceP(
-		uriFlagName, "f", []string{}, "Set a sync provider uri to read data from this can be a filepath or url. "+
-			"Using multiple providers is supported where collisions between "+
-			"flags with the same key, the later will be used.")
+		uriFlagName, "f", []string{}, "Set a sync provider uri to read data from, this can be a filepath,"+
+			"url or FeatureFlagConfiguration. Using multiple providers is supported however if"+
+			"flag keys are duplicated across multiple sources it may lead to unexpected behavior ",
+	)
 	flags.StringP(
 		bearerTokenFlagName, "b", "", "Set a bearer token to use for remote sync")
 	flags.StringSliceP(corsFlagName, "C", []string{}, "CORS allowed origins, * will allow all origins")
+	flags.StringP(
+		syncProviderFlagName, "y", "", "DEPRECATED: Set a sync provider e.g. filepath or remote",
+	)
 
 	_ = viper.BindPFlag(portFlagName, flags.Lookup(portFlagName))
 	_ = viper.BindPFlag(metricsPortFlagName, flags.Lookup(metricsPortFlagName))
 	_ = viper.BindPFlag(socketPathFlagName, flags.Lookup(socketPathFlagName))
-	_ = viper.BindPFlag(syncProviderFlagName, flags.Lookup(syncProviderFlagName))
 	_ = viper.BindPFlag(providerArgsFlagName, flags.Lookup(providerArgsFlagName))
 	_ = viper.BindPFlag(evaluatorFlagName, flags.Lookup(evaluatorFlagName))
 	_ = viper.BindPFlag(serverCertPathFlagName, flags.Lookup(serverCertPathFlagName))
 	_ = viper.BindPFlag(serverKeyPathFlagName, flags.Lookup(serverKeyPathFlagName))
 	_ = viper.BindPFlag(uriFlagName, flags.Lookup(uriFlagName))
 	_ = viper.BindPFlag(bearerTokenFlagName, flags.Lookup(bearerTokenFlagName))
 	_ = viper.BindPFlag(corsFlagName, flags.Lookup(corsFlagName))
+	_ = viper.BindPFlag(syncProviderFlagName, flags.Lookup(syncProviderFlagName))
 }
 
 // startCmd represents the start command
@@ -87,22 +88,23 @@ var startCmd = &cobra.Command{
 		logger := logger.NewLogger(l)
 		rtLogger := logger.WithFields(zap.String("component", "start"))
 
+		if viper.GetString(syncProviderFlagName) != "" {
+			rtLogger.Warn("DEPRECATED: The --sync-provider flag has been deprecated. " +
+				"Docs: https://github.com/open-feature/flagd/blob/main/docs/configuration.md")
+		}
+
 		// Build Runtime -----------------------------------------------------------
 		rt, err := runtime.FromConfig(logger, runtime.Config{
 			ServicePort:       viper.GetInt32(portFlagName),
 			MetricsPort:       viper.GetInt32(metricsPortFlagName),
 			ServiceSocketPath: viper.GetString(socketPathFlagName),
 			ServiceCertPath:   viper.GetString(serverCertPathFlagName),
 			ServiceKeyPath:    viper.GetString(serverKeyPathFlagName),
-
-			SyncProvider:    viper.GetString(syncProviderFlagName),
-			ProviderArgs:    viper.GetStringMapString(providerArgsFlagName),
-			SyncURI:         viper.GetStringSlice(uriFlagName),
-			SyncBearerToken: viper.GetString(bearerTokenFlagName),
-
-			Evaluator: viper.GetString(evaluatorFlagName),
-
-			CORS: viper.GetStringSlice(corsFlagName),
+			ProviderArgs:      viper.GetStringMapString(providerArgsFlagName),
+			SyncURI:           viper.GetStringSlice(uriFlagName),
+			SyncBearerToken:   viper.GetString(bearerTokenFlagName),
+			Evaluator:         viper.GetString(evaluatorFlagName),
+			CORS:              viper.GetStringSlice(corsFlagName),
 		})
 		if err != nil {
 			rtLogger.Fatal(err.Error())

docs/configuration.md

@@ -15,16 +15,26 @@ Supported flags are as follows (result of running `./flagd start --help`):
   -k, --server-key-path string    Server side tls key path
   -a, --sync-provider-args        Sync provider arguments as key values separated by =
   -d, --socket-path string        Set the flagd socket path.
-  -y, --sync-provider string      Set a sync provider e.g. filepath or remote (default "filepath")
   -f, --uri strings               Set a sync provider uri to read data from this can be a filepath or url. Using multiple providers is supported where collisions between flags with the same key, the later will be used.
   -C, --cors-origin strings       Set a CORS allow origin header, setting "*" will allow all origins (by default CORS headers are not set)
 ```
 
 Environment variable keys are uppercased, prefixed with `FLAGD_` and all `-` are replaced with `_`. For example,
-`sync-provider` in environment variable form is `FLAGD_SYNC_PROVIDER`.
+`sync-provider-args` in environment variable form is `FLAGD_SYNC_PROVIDER_ARGS`.
 
 Config file expects the keys to have the exact naming as the flags.
 
+### URI patterns
+
+Any URI passed to flagd via the `--uri` flag must follow one of the 3 following patterns to ensure that it is passed to the correct implementation: 
+
+| Sync      | Pattern | Example |
+| ----------- | ----------- | ----------- |
+| Kubernetes      | `core.openfeature.dev/namespace/name`       | `core.openfeature.dev/default/my-crd`       |
+| Filepath   | `file:path/to/my/flag`        | `file:etc/flagd/my-flags.json`       |
+| Remote   | `http(s)://flag-source-url`        | `https://my-flags.com/flags`       |
+
+
 
 ### Customising sync providers
 
@@ -37,12 +47,11 @@ The Kubernetes provider allows flagD to connect to a Kubernetes cluster and eval
 To use an existing FeatureFlagConfiguration custom resource, start flagD with the following command:
 
 ```shell
-flagd start --sync-provider=kubernetes --sync-provider-args=featureflagconfiguration=my-example --sync-provider-args=namespace=default
+flagd start --uri core.openfeature.dev/default.my_example
 ```
 
 An additional optional flag `refreshtime` can be applied to shorten the cache refresh when using the Kubernetes provider ( The default is 5s ). As an example: 
 
 ```shell
-flagd start --sync-provider=kubernetes --sync-provider-args=featureflagconfiguration=my-example --sync-provider-args=namespace=default
---sync-provider-args=refreshtime=1s
+flagd start --uri core.openfeature.dev/default.my_example --sync-provider-args=refreshtime=1s
 ```

go.mod

@@ -7,13 +7,13 @@ require (
 	github.com/deepmap/oapi-codegen v1.11.0
 	github.com/diegoholiveira/jsonlogic/v3 v3.2.6
 	github.com/dimiro1/banner v1.1.0
-	github.com/fsnotify/fsnotify v1.5.4
+	github.com/fsnotify/fsnotify v1.6.0
 	github.com/go-chi/chi/v5 v5.0.7
 	github.com/golang/mock v1.6.0
 	github.com/mattn/go-colorable v0.1.12
-	github.com/open-feature/open-feature-operator v0.0.10-0.20220826061622-a6421d66936a
-	github.com/open-feature/schemas v0.0.0-20220809125333-185e3bd77775
-	github.com/prometheus/client_golang v1.13.0
+	github.com/open-feature/open-feature-operator v0.2.20
+	github.com/open-feature/schemas v0.0.0-20221123004631-302d0fa1f813
+	github.com/prometheus/client_golang v1.14.0
 	github.com/robfig/cron v1.2.0
 	github.com/rs/cors v1.8.2
 	github.com/rs/xid v1.4.0
@@ -23,29 +23,40 @@ require (
 	github.com/xeipuuv/gojsonschema v1.2.0
 	github.com/zeebo/xxh3 v1.0.2
 	go.buf.build/open-feature/flagd-connect/open-feature/flagd v1.1.4
-	go.uber.org/zap v1.21.0
-	golang.org/x/net v0.0.0-20221002022538-bcab6841153b
+	go.uber.org/zap v1.23.0
+	golang.org/x/net v0.2.0
 	golang.org/x/sync v0.0.0-20220929204114-8fcdb60fdcc0
-	google.golang.org/grpc v1.49.0
+	google.golang.org/grpc v1.50.1
 	google.golang.org/protobuf v1.28.1
-	k8s.io/api v0.25.2
-	k8s.io/apimachinery v0.25.2
-	k8s.io/client-go v0.25.2
-	sigs.k8s.io/controller-runtime v0.13.0
+	k8s.io/api v0.25.4
+	k8s.io/apimachinery v0.25.4
+	k8s.io/client-go v0.25.4
+	sigs.k8s.io/controller-runtime v0.13.1
 )
 
 require (
+	cloud.google.com/go/compute v1.12.1 // indirect
+	cloud.google.com/go/compute/metadata v0.2.1 // indirect
+	github.com/Azure/go-autorest v14.2.0+incompatible // indirect
+	github.com/Azure/go-autorest/autorest v0.11.28 // indirect
+	github.com/Azure/go-autorest/autorest/adal v0.9.21 // indirect
+	github.com/Azure/go-autorest/autorest/date v0.3.0 // indirect
+	github.com/Azure/go-autorest/logger v0.2.1 // indirect
+	github.com/Azure/go-autorest/tracing v0.6.0 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/common-nighthawk/go-figure v0.0.0-20200609044655-c4b36f998cf2 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/emicklei/go-restful/v3 v3.9.0 // indirect
+	github.com/emicklei/go-restful/v3 v3.10.1 // indirect
 	github.com/evanphx/json-patch/v5 v5.6.0 // indirect
 	github.com/go-logr/logr v1.2.3 // indirect
+	github.com/go-logr/zapr v1.2.3 // indirect
 	github.com/go-openapi/jsonpointer v0.19.5 // indirect
 	github.com/go-openapi/jsonreference v0.20.0 // indirect
 	github.com/go-openapi/swag v0.22.3 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang-jwt/jwt/v4 v4.4.3 // indirect
+	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/gnostic v0.6.9 // indirect
 	github.com/google/go-cmp v0.5.9 // indirect
@@ -60,7 +71,7 @@ require (
 	github.com/magiconair/properties v1.8.6 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mattn/go-isatty v0.0.16 // indirect
-	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
@@ -71,7 +82,7 @@ require (
 	github.com/pelletier/go-toml/v2 v2.0.5 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/client_model v0.3.0 // indirect
 	github.com/prometheus/common v0.37.0 // indirect
 	github.com/prometheus/procfs v0.8.0 // indirect
 	github.com/spf13/afero v1.8.2 // indirect
@@ -81,23 +92,27 @@ require (
 	github.com/subosito/gotenv v1.4.1 // indirect
 	github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb // indirect
 	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
-	go.uber.org/atomic v1.7.0 // indirect
-	go.uber.org/multierr v1.6.0 // indirect
-	golang.org/x/oauth2 v0.0.0-20220909003341-f21342109be1 // indirect
-	golang.org/x/sys v0.0.0-20220928140112-f11e5e49a4ec // indirect
-	golang.org/x/term v0.0.0-20220919170432-7a66f970e087 // indirect
+	go.uber.org/atomic v1.10.0 // indirect
+	go.uber.org/multierr v1.8.0 // indirect
+	golang.org/x/crypto v0.3.0 // indirect
+	golang.org/x/oauth2 v0.2.0 // indirect
+	golang.org/x/sys v0.2.0 // indirect
+	golang.org/x/term v0.2.0 // indirect
 	golang.org/x/text v0.4.0 // indirect
-	golang.org/x/time v0.0.0-20220922220347-f3bd1da661af // indirect
+	golang.org/x/time v0.2.0 // indirect
+	gomodules.xyz/jsonpatch/v2 v2.2.0 // indirect
 	google.golang.org/appengine v1.6.7 // indirect
-	google.golang.org/genproto v0.0.0-20220930163606-c98284e70a91 // indirect
+	google.golang.org/genproto v0.0.0-20221024183307-1bc688fe9f3e // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
+	k8s.io/apiextensions-apiserver v0.25.4 // indirect
+	k8s.io/component-base v0.25.4 // indirect
 	k8s.io/klog/v2 v2.80.1 // indirect
-	k8s.io/kube-openapi v0.0.0-20220928191237-829ce0c27909 // indirect
-	k8s.io/utils v0.0.0-20220922133306-665eaaec4324 // indirect
-	sigs.k8s.io/json v0.0.0-20220713155537-f223a00ba0e2 // indirect
+	k8s.io/kube-openapi v0.0.0-20221123214604-86e75ddd809a // indirect
+	k8s.io/utils v0.0.0-20221128185143-99ec85e7a448 // indirect
+	sigs.k8s.io/json v0.0.0-20221116044647-bc3834ca7abd // indirect
 	sigs.k8s.io/structured-merge-diff/v4 v4.2.3 // indirect
 	sigs.k8s.io/yaml v1.3.0 // indirect
 )