Use more restrictive interface when initializing the config (#29799)

pkg/config/model/types.go

@@ -130,6 +130,12 @@ type Setup interface {
 	// If env is provided, it will override the name of the environment variable used for this
 	// config key
 	BindEnvAndSetDefault(key string, val interface{}, env ...string)
+
+	AddConfigPath(in string)
+	AddExtraConfigPaths(in []string) error
+	SetConfigName(in string)
+	SetConfigFile(in string)
+	SetConfigType(in string)
 }
 
 // Compound is an interface for retrieving compound elements from the config, plus
@@ -144,12 +150,6 @@ type Compound interface {
 	MergeConfig(in io.Reader) error
 	MergeConfigMap(cfg map[string]any) error
 	MergeFleetPolicy(configPath string) error
-
-	AddConfigPath(in string)
-	AddExtraConfigPaths(in []string) error
-	SetConfigName(in string)
-	SetConfigFile(in string)
-	SetConfigType(in string)
 }
 
 // Config represents an object that can load and store configuration parameters

pkg/config/setup/config.go

@@ -267,15 +267,15 @@ func init() {
 
 // initCommonWithServerless initializes configs that are common to all agents, in particular serverless.
 // Initializing the config keys takes too much time for serverless, so we try to initialize only what is reachable.
-func initCommonWithServerless(config pkgconfigmodel.Config) {
+func initCommonWithServerless(config pkgconfigmodel.Setup) {
 	for _, f := range serverlessConfigComponents {
 		f(config)
 	}
 }
 
 // InitConfig initializes the config defaults on a config used by all agents
 // (in particular more than just the serverless agent).
-func InitConfig(config pkgconfigmodel.Config) {
+func InitConfig(config pkgconfigmodel.Setup) {
 	initCommonWithServerless(config)
 
 	// Auto exit configuration

pkg/config/setup/process.go

@@ -90,7 +90,7 @@ var processesAddOverrideOnce sync.Once
 
 // procBindEnvAndSetDefault is a helper function that generates both "DD_PROCESS_CONFIG_" and "DD_PROCESS_AGENT_" prefixes from a key.
 // We need this helper function because the standard BindEnvAndSetDefault can only generate one prefix from a key.
-func procBindEnvAndSetDefault(config pkgconfigmodel.Config, key string, val interface{}) {
+func procBindEnvAndSetDefault(config pkgconfigmodel.Setup, key string, val interface{}) {
 	// Uppercase, replace "." with "_" and add "DD_" prefix to key so that we follow the same environment
 	// variable convention as the core agent.
 	processConfigKey := "DD_" + strings.Replace(strings.ToUpper(key), ".", "_", -1)
@@ -102,14 +102,14 @@ func procBindEnvAndSetDefault(config pkgconfigmodel.Config, key string, val inte
 
 // procBindEnv is a helper function that generates both "DD_PROCESS_CONFIG_" and "DD_PROCESS_AGENT_" prefixes from a key, but does not set a default.
 // We need this helper function because the standard BindEnv can only generate one prefix from a key.
-func procBindEnv(config pkgconfigmodel.Config, key string) {
+func procBindEnv(config pkgconfigmodel.Setup, key string) {
 	processConfigKey := "DD_" + strings.Replace(strings.ToUpper(key), ".", "_", -1)
 	processAgentKey := strings.Replace(processConfigKey, "PROCESS_CONFIG", "PROCESS_AGENT", 1)
 
 	config.BindEnv(key, processConfigKey, processAgentKey)
 }
 
-func setupProcesses(config pkgconfigmodel.Config) {
+func setupProcesses(config pkgconfigmodel.Setup) {
 	// "process_config.enabled" is deprecated. We must still be able to detect if it is present, to know if we should use it
 	// or container_collection.enabled and process_collection.enabled.
 	procBindEnv(config, "process_config.enabled")