fix(relay-proxy): Allow overide of array configuration by environment variables

cmd/relayproxy/config/config.go

@@ -2,12 +2,6 @@ package config
 
 import (
 	"fmt"
-	"net/http"
-	"os"
-	"path/filepath"
-	"strings"
-	"time"
-
 	"github.com/knadh/koanf/parsers/json"
 	"github.com/knadh/koanf/parsers/toml"
 	"github.com/knadh/koanf/parsers/yaml"
@@ -19,6 +13,12 @@ import (
 	"github.com/spf13/pflag"
 	"github.com/xitongsys/parquet-go/parquet"
 	"go.uber.org/zap"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
 )
 
 var k = koanf.New(".")
@@ -91,10 +91,18 @@ func New(flagSet *pflag.FlagSet, log *zap.Logger, version string) (*Config, erro
 			log.Error("error loading file", zap.Error(errBindFile))
 		}
 	}
-
 	// Map environment variables
-	_ = k.Load(env.Provider("", ".", func(s string) string {
-		return strings.ReplaceAll(strings.ToLower(s), "_", ".")
+	_ = k.Load(env.ProviderWithValue("", ".", func(s string, v string) (string, interface{}) {
+		if strings.HasPrefix(s, "RETRIEVERS") || strings.HasPrefix(s, "NOTIFIERS") {
+			configMap := k.Raw()
+			err := loadArrayEnv(s, v, configMap)
+			if err != nil {
+				log.Error("config: error loading array env", zap.String("key", s), zap.String("value", v), zap.Error(err))
+				return s, v
+			}
+			return s, v
+		}
+		return strings.ReplaceAll(strings.ToLower(s), "_", "."), v
 	}), nil)
 
 	_ = k.Set("version", version)
@@ -322,3 +330,60 @@ func locateConfigFile(inputFilePath string) (string, error) {
 	return "", fmt.Errorf(
 		"impossible to find config file in the default locations [%s]", strings.Join(defaultLocations, ","))
 }
+
+// Load the ENV Like:RETRIEVERS_0_HEADERS_AUTHORIZATION
+func loadArrayEnv(s string, v string, configMap map[string]interface{}) error {
+	paths := strings.Split(s, "_")
+	for i, str := range paths {
+		paths[i] = strings.ToLower(str)
+	}
+	prefixKey := paths[0]
+	if configArray, ok := configMap[prefixKey].([]interface{}); ok {
+		index, err := strconv.Atoi(paths[1])
+		if err != nil {
+			return err
+		}
+		var configItem map[string]interface{}
+		outRange := index > len(configArray)-1
+		if outRange {
+			configItem = make(map[string]interface{})
+		} else {
+			configItem = configArray[index].(map[string]interface{})
+		}
+
+		keys := paths[2:]
+		currentMap := configItem
+		for i, key := range keys {
+			hasKey := false
+			lowerKey := key
+			for y := range currentMap {
+				if y != lowerKey {
+					continue
+				}
+				if nextMap, ok := currentMap[y].(map[string]interface{}); ok {
+					currentMap = nextMap
+					hasKey = true
+					break
+				}
+			}
+			if !hasKey && i != len(keys)-1 {
+				newMap := make(map[string]interface{})
+				currentMap[lowerKey] = newMap
+				currentMap = newMap
+			}
+		}
+		lastKey := keys[len(keys)-1]
+		currentMap[lastKey] = v
+		if outRange {
+			blank := index - len(configArray) + 1
+			for i := 0; i < blank; i++ {
+				configArray = append(configArray, make(map[string]interface{}))
+			}
+			configArray[index] = configItem
+		} else {
+			configArray[index] = configItem
+		}
+		_ = k.Set(prefixKey, configArray)
+	}
+	return nil
+}

cmd/relayproxy/config/config_test.go

@@ -692,3 +692,104 @@ func TestConfig_APIAdminKeyExists(t *testing.T) {
 		})
 	}
 }
+
+func TestMergeConfig_FromOSEnv(t *testing.T) {
+	tests := []struct {
+		name                       string
+		want                       *config.Config
+		fileLocation               string
+		wantErr                    assert.ErrorAssertionFunc
+		disableDefaultFileCreation bool
+	}{
+		{
+			name:         "Valid file",
+			fileLocation: "../testdata/config/validate-array-env-file.yaml",
+			want: &config.Config{
+				ListenPort:      1031,
+				PollingInterval: 1000,
+				FileFormat:      "yaml",
+				Host:            "localhost",
+				Retrievers: &[]config.RetrieverConf{
+					config.RetrieverConf{
+						Kind: "http",
+						URL:  "https://github.com/thomaspoignant/go-feature-flag/main/examples/retriever_file/flags.goff.yaml",
+						HTTPHeaders: map[string][]string{
+							"authorization": []string{
+								"test",
+							},
+							"token": []string{"token"},
+						},
+					},
+					config.RetrieverConf{
+						Kind: "file",
+						Path: "examples/retriever_file/flags.goff.yaml",
+						HTTPHeaders: map[string][]string{
+							"token": []string{
+								"11213123",
+							},
+							"authorization": []string{
+								"test1",
+							},
+						},
+					},
+					config.RetrieverConf{
+						HTTPHeaders: map[string][]string{
+
+							"authorization": []string{
+								"test1",
+							},
+							"x-goff-custom": []string{
+								"custom",
+							},
+						},
+					},
+				},
+				Exporter: &config.ExporterConf{
+					Kind: "log",
+				},
+				StartWithRetrieverError: false,
+				RestAPITimeout:          5000,
+				Version:                 "1.X.X",
+				EnableSwagger:           true,
+				AuthorizedKeys: config.APIKeys{
+					Admin: []string{
+						"apikey3",
+					},
+					Evaluation: []string{
+						"apikey1",
+						"apikey2",
+					},
+				},
+			},
+			wantErr: assert.NoError,
+		},
+	}
+	for _, tt := range tests {
+		os.Setenv("RETRIEVERS_0_HEADERS_AUTHORIZATION", "test")
+		os.Setenv("RETRIEVERS_X_HEADERS_AUTHORIZATION", "test")
+		os.Setenv("RETRIEVERS_1_HEADERS_AUTHORIZATION", "test1")
+		os.Setenv("RETRIEVERS_0_HEADERS_TOKEN", "token")
+		os.Setenv("RETRIEVERS_2_HEADERS_AUTHORIZATION", "test1")
+		os.Setenv("RETRIEVERS_2_HEADERS_X-GOFF-CUSTOM", "custom")
+		t.Run(tt.name, func(t *testing.T) {
+			_ = os.Remove("./goff-proxy.yaml")
+			if !tt.disableDefaultFileCreation {
+				source, _ := os.Open(tt.fileLocation)
+				destination, _ := os.Create("./goff-proxy.yaml")
+				defer destination.Close()
+				defer source.Close()
+				defer os.Remove("./goff-proxy.yaml")
+				_, _ = io.Copy(destination, source)
+			}
+
+			f := pflag.NewFlagSet("config", pflag.ContinueOnError)
+			f.String("config", "", "Location of your config file")
+			_ = f.Parse([]string{fmt.Sprintf("--config=%s", tt.fileLocation)})
+			got, err := config.New(f, zap.L(), "1.X.X")
+			if !tt.wantErr(t, err) {
+				return
+			}
+			assert.Equal(t, tt.want, got, "Config not matching")
+		})
+	}
+}

cmd/relayproxy/testdata/config/validate-array-env-file.yaml

@@ -0,0 +1,19 @@
+listen: 1031
+pollingInterval: 1000
+startWithRetrieverError: false
+retrievers:
+  - kind: http
+    url: https://github.com/thomaspoignant/go-feature-flag/main/examples/retriever_file/flags.goff.yaml
+  - kind: file
+    path: examples/retriever_file/flags.goff.yaml
+    headers:
+      token: 11213123
+exporter:
+  kind: log
+enableSwagger: true
+authorizedKeys:
+  evaluation:
+    - apikey1 # owner: userID1
+    - apikey2 # owner: userID2
+  admin:
+    - apikey3