refactored new code andded file validation

Author: Akshay2191

internal/config/config.go

@@ -506,6 +506,11 @@ func registerExternalDataSourceFlags(fs *flag.FlagSet) {
 		[]string{},
 		"List of allowed domains for external data sources.",
 	)
+	fs.StringSlice(
+		ExternalDataSourceAllowedFileTypesKey,
+		[]string{},
+		"List of allowed file types for external data sources.",
+	)
 	fs.Int64(
 		ExternalDataSourceMaxBytesKey,
 		DefExternalDataSourceMaxBytes,
@@ -1610,9 +1615,10 @@ func resolveExternalDataSource() *ExternalDataSource {
 		URL: viperInstance.GetString(ExternalDataSourceProxyUrlKey),
 	}
 	externalDataSource := &ExternalDataSource{
-		ProxyURL:       proxyURLStruct,
-		AllowedDomains: viperInstance.GetStringSlice(ExternalDataSourceAllowDomainsKey),
-		MaxBytes:       viperInstance.GetInt64(ExternalDataSourceMaxBytesKey),
+		ProxyURL:         proxyURLStruct,
+		AllowedDomains:   viperInstance.GetStringSlice(ExternalDataSourceAllowDomainsKey),
+		AllowedFileTypes: viperInstance.GetStringSlice(ExternalDataSourceAllowedFileTypesKey),
+		MaxBytes:         viperInstance.GetInt64(ExternalDataSourceMaxBytesKey),
 	}
 
 	if err := validateAllowedDomains(externalDataSource.AllowedDomains); err != nil {

internal/config/flags.go

@@ -146,10 +146,11 @@ var (
 	FileWatcherMonitoringFrequencyKey = pre(FileWatcherKey) + "monitoring_frequency"
 	NginxExcludeFilesKey              = pre(FileWatcherKey) + "exclude_files"
 
-	ExternalDataSourceProxyKey        = pre(ExternalDataSourceRootKey) + "proxy"
-	ExternalDataSourceProxyUrlKey     = pre(ExternalDataSourceProxyKey) + "url"
-	ExternalDataSourceMaxBytesKey     = pre(ExternalDataSourceRootKey) + "max_bytes"
-	ExternalDataSourceAllowDomainsKey = pre(ExternalDataSourceRootKey) + "allowed_domains"
+	ExternalDataSourceProxyKey            = pre(ExternalDataSourceRootKey) + "proxy"
+	ExternalDataSourceProxyUrlKey         = pre(ExternalDataSourceProxyKey) + "url"
+	ExternalDataSourceMaxBytesKey         = pre(ExternalDataSourceRootKey) + "max_bytes"
+	ExternalDataSourceAllowDomainsKey     = pre(ExternalDataSourceRootKey) + "allowed_domains"
+	ExternalDataSourceAllowedFileTypesKey = pre(ExternalDataSourceRootKey) + "allowed_file_types"
 )
 
 func pre(prefixes ...string) string {

internal/config/types.go

@@ -368,9 +368,10 @@ type (
 	}
 
 	ExternalDataSource struct {
-		ProxyURL       ProxyURL `yaml:"proxy"           mapstructure:"proxy"`
-		AllowedDomains []string `yaml:"allowed_domains" mapstructure:"allowed_domains"`
-		MaxBytes       int64    `yaml:"max_bytes"       mapstructure:"max_bytes"`
+		ProxyURL         ProxyURL `yaml:"proxy"              mapstructure:"proxy"`
+		AllowedDomains   []string `yaml:"allowed_domains"    mapstructure:"allowed_domains"`
+		AllowedFileTypes []string `yaml:"allowed_file_types" mapstructure:"allowed_file_types"`
+		MaxBytes         int64    `yaml:"max_bytes"          mapstructure:"max_bytes"`
 	}
 )