migrate ocs to the new config scheme

ocs/pkg/config/config.go

@@ -1,6 +1,12 @@
 package config
 
-import "context"
+import (
+	"context"
+	"fmt"
+	"reflect"
+
+	gofig "github.com/gookit/config/v2"
+)
 
 // Log defines the available logging configuration.
 type Log struct {
@@ -84,3 +90,93 @@ type Config struct {
 func New() *Config {
 	return &Config{}
 }
+
+// DefaultConfig provides default values for a config struct.
+func DefaultConfig() *Config {
+	return &Config{
+		Log: Log{},
+		Debug: Debug{
+			Addr:   "127.0.0.1:9114",
+			Token:  "",
+			Pprof:  false,
+			Zpages: false,
+		},
+		HTTP: HTTP{
+			Addr: "127.0.0.1:9110",
+			Root: "/ocs",
+			CORS: CORS{
+				AllowedOrigins:   []string{"*"},
+				AllowedMethods:   []string{"GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"},
+				AllowedHeaders:   []string{"Authorization", "Origin", "Content-Type", "Accept", "X-Requested-With"},
+				AllowCredentials: true,
+			},
+		},
+		Tracing: Tracing{
+			Enabled:   false,
+			Type:      "jaeger",
+			Endpoint:  "",
+			Collector: "",
+			Service:   "ocs",
+		},
+		TokenManager: TokenManager{
+			JWTSecret: "Pive-Fumkiu4",
+		},
+		Service: Service{
+			Name:      "ocs",
+			Namespace: "com.owncloud.web",
+		},
+		AccountBackend:     "accounts",
+		RevaAddress:        "127.0.0.1:9142",
+		StorageUsersDriver: "ocis",
+		MachineAuthAPIKey:  "change-me-please",
+		IdentityManagement: IdentityManagement{
+			Address: "https://localhost:9200",
+		},
+	}
+}
+
+// GetEnv fetches a list of known env variables for this extension. It is to be used by gookit, as it provides a list
+// with all the environment variables an extension supports.
+func GetEnv() []string {
+	var r = make([]string, len(structMappings(&Config{})))
+	for i := range structMappings(&Config{}) {
+		r = append(r, structMappings(&Config{})[i].EnvVars...)
+	}
+
+	return r
+}
+
+// UnmapEnv loads values from the gooconf.Config argument and sets them in the expected destination.
+func (c *Config) UnmapEnv(gooconf *gofig.Config) error {
+	vals := structMappings(c)
+	for i := range vals {
+		for j := range vals[i].EnvVars {
+			// we need to guard against v != "" because this is the condition that checks that the value is set from the environment.
+			// the `ok` guard is not enough, apparently.
+			if v, ok := gooconf.GetValue(vals[i].EnvVars[j]); ok && v != "" {
+
+				// get the destination type from destination
+				switch reflect.ValueOf(vals[i].Destination).Type().String() {
+				case "*bool":
+					r := gooconf.Bool(vals[i].EnvVars[j])
+					*vals[i].Destination.(*bool) = r
+				case "*string":
+					r := gooconf.String(vals[i].EnvVars[j])
+					*vals[i].Destination.(*string) = r
+				case "*int":
+					r := gooconf.Int(vals[i].EnvVars[j])
+					*vals[i].Destination.(*int) = r
+				case "*float64":
+					// defaults to float64
+					r := gooconf.Float(vals[i].EnvVars[j])
+					*vals[i].Destination.(*float64) = r
+				default:
+					// it is unlikely we will ever get here. Let this serve more as a runtime check for when debugging.
+					return fmt.Errorf("invalid type for env var: `%v`", vals[i].EnvVars[j])
+				}
+			}
+		}
+	}
+
+	return nil
+}

ocs/pkg/config/env.go

@@ -0,0 +1,108 @@
+package config
+
+type mapping struct {
+	EnvVars     []string    // name of the EnvVars var.
+	Destination interface{} // memory address of the original config value to modify.
+}
+
+// structMappings binds a set of environment variables to a destination on cfg.
+func structMappings(cfg *Config) []mapping {
+	return []mapping{
+		{
+			EnvVars:     []string{"OCS_LOG_FILE", "OCIS_LOG_FILE"},
+			Destination: &cfg.Log.File,
+		},
+		{
+			EnvVars:     []string{"OCS_LOG_LEVEL", "OCIS_LOG_LEVEL"},
+			Destination: &cfg.Log.Level,
+		},
+		{
+			EnvVars:     []string{"OCS_LOG_PRETTY", "OCIS_LOG_PRETTY"},
+			Destination: &cfg.Log.Pretty,
+		},
+		{
+			EnvVars:     []string{"OCS_LOG_COLOR", "OCIS_LOG_COLOR"},
+			Destination: &cfg.Log.Color,
+		},
+		{
+			EnvVars:     []string{"OCS_CONFIG_FILE"},
+			Destination: &cfg.File,
+		},
+		{
+			EnvVars:     []string{"OCS_TRACING_ENABLED", "OCIS_TRACING_ENABLED"},
+			Destination: &cfg.Tracing.Enabled,
+		},
+		{
+			EnvVars:     []string{"OCS_TRACING_TYPE", "OCIS_TRACING_TYPE"},
+			Destination: &cfg.Tracing.Type,
+		},
+		{
+			EnvVars:     []string{"OCS_TRACING_ENDPOINT", "OCIS_TRACING_ENDPOINT"},
+			Destination: &cfg.Tracing.Endpoint,
+		},
+		{
+			EnvVars:     []string{"OCS_TRACING_COLLECTOR", "OCIS_TRACING_COLLECTOR"},
+			Destination: &cfg.Tracing.Collector,
+		},
+		{
+			EnvVars:     []string{"OCS_TRACING_SERVICE"},
+			Destination: &cfg.Tracing.Service,
+		},
+		{
+			EnvVars:     []string{"OCS_DEBUG_ADDR"},
+			Destination: &cfg.Debug.Addr,
+		},
+		{
+			EnvVars:     []string{"OCS_DEBUG_TOKEN"},
+			Destination: &cfg.Debug.Token,
+		},
+		{
+			EnvVars:     []string{"OCS_DEBUG_PPROF"},
+			Destination: &cfg.Debug.Pprof,
+		},
+		{
+			EnvVars:     []string{"OCS_DEBUG_ZPAGES"},
+			Destination: &cfg.Debug.Zpages,
+		},
+		{
+			EnvVars:     []string{"OCS_HTTP_ADDR"},
+			Destination: &cfg.HTTP.Addr,
+		},
+		{
+			EnvVars:     []string{"OCS_NAMESPACE"},
+			Destination: &cfg.Service.Namespace,
+		},
+		{
+			EnvVars:     []string{"OCS_NAME"},
+			Destination: &cfg.Service.Name,
+		},
+		{
+			EnvVars:     []string{"OCS_HTTP_ROOT"},
+			Destination: &cfg.HTTP.Root,
+		},
+		{
+			EnvVars:     []string{"OCS_JWT_SECRET", "OCIS_JWT_SECRET"},
+			Destination: &cfg.TokenManager.JWTSecret,
+		},
+		{
+			EnvVars:     []string{"OCS_ACCOUNT_BACKEND_TYPE"},
+			Destination: &cfg.AccountBackend,
+		},
+		{
+			EnvVars:     []string{"REVA_GATEWAY"},
+			Destination: &cfg.RevaAddress,
+		},
+		{
+			EnvVars:     []string{"OCS_MACHINE_AUTH_API_KEY", "OCIS_MACHINE_AUTH_API_KEY"},
+			Destination: &cfg.MachineAuthAPIKey,
+		},
+		{
+			EnvVars:     []string{"OCS_IDM_ADDRESS", "OCIS_URL"},
+			Destination: &cfg.IdentityManagement.Address,
+		},
+		{
+			EnvVars:     []string{"OCS_STORAGE_USERS_DRIVER", "STORAGE_USERS_DRIVER"},
+			Destination: &cfg.StorageUsersDriver,
+		},
+	}
+}