parse ocis root config down to subcommands

ocis/go.mod

@@ -30,6 +30,7 @@ require (
 	github.com/owncloud/ocis/webdav v0.0.0-00010101000000-000000000000
 	github.com/refs/pman v0.0.0-20200701173654-f05b8833071a
 	github.com/restic/calens v0.2.0
+	github.com/spf13/viper v1.7.1
 	go.opencensus.io v0.22.5
 )
 

ocis/pkg/command/root.go

@@ -2,6 +2,7 @@ package command
 
 import (
 	"os"
+	"strings"
 
 	"github.com/micro/cli/v2"
 	"github.com/owncloud/ocis/ocis-pkg/log"
@@ -10,6 +11,7 @@ import (
 	"github.com/owncloud/ocis/ocis/pkg/register"
 	"github.com/owncloud/ocis/ocis/pkg/runtime"
 	"github.com/owncloud/ocis/ocis/pkg/version"
+	"github.com/spf13/viper"
 )
 
 // Execute is the entry point for the ocis-ocis command.
@@ -22,6 +24,10 @@ func Execute() error {
 		Usage:    "ownCloud Infinite Scale Stack",
 		Compiled: version.Compiled(),
 
+		Before: func(c *cli.Context) error {
+			return ParseConfig(c, cfg)
+		},
+
 		Authors: []*cli.Author{
 			{
 				Name:  "ownCloud GmbH",
@@ -62,3 +68,46 @@ func NewLogger(cfg *config.Config) log.Logger {
 		log.Color(cfg.Log.Color),
 	)
 }
+
+// ParseConfig load configuration for every extension
+func ParseConfig(c *cli.Context, cfg *config.Config) error {
+	logger := NewLogger(cfg)
+
+	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
+	viper.SetEnvPrefix("OCIS")
+	viper.AutomaticEnv()
+
+	if c.IsSet("config-file") {
+		viper.SetConfigFile(c.String("config-file"))
+	} else {
+		viper.SetConfigName("ocis")
+
+		viper.AddConfigPath("/etc/ocis")
+		viper.AddConfigPath("$HOME/.ocis")
+		viper.AddConfigPath("./config")
+	}
+
+	if err := viper.ReadInConfig(); err != nil {
+		switch err.(type) {
+		case viper.ConfigFileNotFoundError:
+			logger.Info().
+				Msg("no config found on preconfigured location")
+		case viper.UnsupportedConfigError:
+			logger.Fatal().
+				Err(err).
+				Msg("unsupported config type")
+		default:
+			logger.Fatal().
+				Err(err).
+				Msg("failed to read config")
+		}
+	}
+
+	if err := viper.Unmarshal(&cfg); err != nil {
+		logger.Fatal().
+			Err(err).
+			Msg("failed to parse config")
+	}
+
+	return nil
+}