feat: support yaml evaluator

Signed-off-by: Suraj Banakar <surajrbanakar@gmail.com>

feat: wip try replacing json evaluator with a generic file type evaluator
- TODO:
 - still need a way to make the json_evaluator_model more composable
 - replace instances of `json` with the `MUaler` interface
 - implement `MUaler` interface for yaml and json

Signed-off-by: Suraj Banakar <surajrbanakar@gmail.com>

feat: wip pass `yaml` as filetype to `FilePathSync`
- check `yaml.Unmarshal` not able to `Unmarshal` to `json.rawMessage` which is just `[]byte` with `MarshalJSON` and `UnmarshalJSON`
- `FileTypeEvaluator` didn't turn out to be such a good idea because we are reliant on `gojsonschema` to test json schema
- add `example_flags.yaml` file based on `examples_flags.json`
refactor: remove traces of `FileTypeEvaluator`

Signed-off-by: Suraj Banakar <surajrbanakar@gmail.com>

feat: wip try yaml->map->json conversion
- the code compiles and the converted json seems to look good but flagd throws error
- need to look into this ^

Signed-off-by: Suraj Banakar <surajrbanakar@gmail.com>

feat: wip remove yaml annotationt and redundant code
- yaml config -> json config -> json.Unmarshal (<- error here)

Signed-off-by: Suraj Banakar <surajrbanakar@gmail.com>

feat: wip add indentations in the json converted from yaml
- because the evaluator transposer function doesn't understand json without indentations well
- needs more testing

Signed-off-by: Suraj Banakar <surajrbanakar@gmail.com>

feat: refactor

Signed-off-by: Suraj Banakar <surajrbanakar@gmail.com>

feat: add `yaml` and `yml` in evaluator switch case

feat: fix go.mod
- add json-iterator package

Signed-off-by: Suraj Banakar <surajrbanakar@gmail.com>

cmd/start.go

@@ -40,7 +40,7 @@ func init() {
 	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(evaluatorFlagName, "e", "json", "Set an evaluator e.g. json, yaml/yml")
 	flags.StringP(serverCertPathFlagName, "c", "", "Server side tls certificate path")
 	flags.StringP(serverKeyPathFlagName, "k", "", "Server side tls key path")
 	flags.StringToStringP(providerArgsFlagName,

config/samples/example_flags.yaml

@@ -0,0 +1,88 @@
+flags:
+  myBoolFlag:
+    state: ENABLED
+    variants:
+      'on': true
+      'off': false
+    defaultVariant: 'on'
+  myStringFlag:
+    state: ENABLED
+    variants:
+      key1: val1
+      key2: val2
+    defaultVariant: key1
+  myFloatFlag:
+    state: ENABLED
+    variants:
+      one: 1.23
+      two: 2.34
+    defaultVariant: one
+  myIntFlag:
+    state: ENABLED
+    variants:
+      one: 1
+      two: 2
+    defaultVariant: one
+  myObjectFlag:
+    state: ENABLED
+    variants:
+      object1:
+        key: val
+      object2:
+        key: true
+    defaultVariant: object1
+  isColorYellow:
+    state: ENABLED
+    variants:
+      'on': true
+      'off': false
+    defaultVariant: 'off'
+    targeting:
+      if:
+      - "==":
+        - var:
+          - color
+        - yellow
+      - 'on'
+      - 'off'
+  fibAlgo:
+    variants:
+      recursive: recursive
+      memo: memo
+      loop: loop
+      binet: binet
+    defaultVariant: recursive
+    state: ENABLED
+    targeting:
+      if:
+      - "$ref": emailWithFaas
+      - binet
+      - null
+  headerColor:
+    variants:
+      red: "#FF0000"
+      blue: "#0000FF"
+      green: "#00FF00"
+      yellow: "#FFFF00"
+    defaultVariant: red
+    state: ENABLED
+    targeting:
+      if:
+      - "$ref": emailWithFaas
+      - fractionalEvaluation:
+        - email
+        - - red
+          - 25
+        - - blue
+          - 25
+        - - green
+          - 25
+        - - yellow
+          - 25
+      - null
+"$evaluators":
+  emailWithFaas:
+    in:
+    - "@faas.com"
+    - var:
+      - email

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/fsnotify/fsnotify v1.5.4
 	github.com/go-chi/chi/v5 v5.0.7
 	github.com/golang/mock v1.6.0
+	github.com/json-iterator/go v1.1.12
 	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
@@ -28,6 +29,7 @@ require (
 	golang.org/x/sync v0.0.0-20220929204114-8fcdb60fdcc0
 	google.golang.org/grpc v1.49.0
 	google.golang.org/protobuf v1.28.1
+	gopkg.in/yaml.v2 v2.4.0
 	k8s.io/api v0.25.2
 	k8s.io/apimachinery v0.25.2
 	k8s.io/client-go v0.25.2
@@ -55,7 +57,6 @@ require (
 	github.com/imdario/mergo v0.3.13 // indirect
 	github.com/inconshreveable/mousetrap v1.0.1 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
-	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/klauspost/cpuid/v2 v2.1.1 // indirect
 	github.com/magiconair/properties v1.8.6 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
@@ -92,7 +93,6 @@ require (
 	google.golang.org/genproto v0.0.0-20220930163606-c98284e70a91 // 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/klog/v2 v2.80.1 // indirect
 	k8s.io/kube-openapi v0.0.0-20220928191237-829ce0c27909 // indirect

pkg/runtime/from_config.go

@@ -49,6 +49,10 @@ func (r *Runtime) setService(logger *logger.Logger) {
 
 func (r *Runtime) setEvaluatorFromConfig(logger *logger.Logger) error {
 	switch r.config.Evaluator {
+	case "yaml":
+		fallthrough
+	case "yml":
+		fallthrough
 	case "json":
 		r.Evaluator = eval.NewJSONEvaluator(logger)
 	default:
@@ -71,6 +75,8 @@ func (r *Runtime) setSyncImplFromConfig(logger *logger.Logger) error {
 					zap.String("sync", "filepath"),
 				),
 				ProviderArgs: r.config.ProviderArgs,
+				// evaluator here is file type: `json`, `yaml` etc.,
+				FileType: r.config.Evaluator,
 			})
 			rtLogger.Debug(fmt.Sprintf("Using %s sync-provider on %q", r.config.SyncProvider, u))
 		}

pkg/sync/filepath_sync.go

@@ -6,6 +6,9 @@ import (
 	"fmt"
 	"os"
 
+	jsoniter "github.com/json-iterator/go"
+	"gopkg.in/yaml.v2"
+
 	"github.com/fsnotify/fsnotify"
 	"github.com/open-feature/flagd/pkg/logger"
 )
@@ -14,6 +17,9 @@ type FilePathSync struct {
 	URI          string
 	Logger       *logger.Logger
 	ProviderArgs ProviderArgs
+	// FileType indicates the file type e.g., json, yaml/yml etc.,
+	// TODO: limit this to `json` or `yaml only?`
+	FileType string
 }
 
 func (fs *FilePathSync) Source() string {
@@ -28,7 +34,17 @@ func (fs *FilePathSync) Fetch(_ context.Context) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	return string(rawFile), nil
+
+	switch fs.FileType {
+	case "yaml":
+		fallthrough
+	case "yml":
+		return yamlToJson(rawFile)
+	case "json":
+		return string(rawFile), nil
+	default:
+		return "", fmt.Errorf("filepath extension '%v' is not supported", fs.FileType)
+	}
 }
 
 func (fs *FilePathSync) Notify(ctx context.Context, w chan<- INotify) {
@@ -90,3 +106,25 @@ func (fs *FilePathSync) Notify(ctx context.Context, w chan<- INotify) {
 	w <- &Notifier{Event: Event[DefaultEventType]{DefaultEventTypeReady}} // signal readiness to the caller
 	<-ctx.Done()
 }
+
+// yamlToJson is a generic helper function to convert
+// yaml to json
+func yamlToJson(rawFile []byte) (string, error) {
+	var ms map[string]interface{}
+	if err := yaml.Unmarshal(rawFile, &ms); err != nil {
+		return "", fmt.Errorf("unmarshal yaml: %w", err)
+	}
+
+	// Using jsoniter library here because json.Marshal doesn't understand keys of
+	// interface{} type (it can only understand string keys)
+	// More info:https://stackoverflow.com/q/35377477/6874596
+	var jsonit = jsoniter.ConfigCompatibleWithStandardLibrary
+	// Adding spaces here because our evaluator transposer function
+	// doesn't understand json without indentations quite well
+	r, err := jsonit.MarshalIndent(ms, "", "  ")
+	if err != nil {
+		return "", fmt.Errorf("convert yaml to json: %w", err)
+	}
+
+	return string(r), err
+}