Support environment vars (#155)

* updage flag values from environment variables

* add log and removing unused constants

* removing unused code

* Docker build client

* fix indentation

* Documentation with docker command

* use docker volume

client/Dockerfile

@@ -0,0 +1,4 @@
+FROM gcr.io/distroless/base:debug
+ENV WT_LOG_FILE=console
+ENTRYPOINT [ "/go/bin/wiretrustee","up"]
+COPY wiretrustee /go/bin/wiretrustee

client/cmd/login.go

@@ -18,12 +18,12 @@ import (
 )
 
 var (
-	setupKey string
-
 	loginCmd = &cobra.Command{
 		Use:   "login",
 		Short: "login to the Wiretrustee Management Service (first run)",
 		RunE: func(cmd *cobra.Command, args []string) error {
+			SetFlagsFromEnvVars()
+
 			err := util.InitLog(logLevel, logFile)
 			if err != nil {
 				log.Errorf("failed initializing log %v", err)
@@ -151,6 +151,3 @@ func promptPeerSetupKey() (string, error) {
 
 	return "", s.Err()
 }
-
-//func init() {
-//}

client/cmd/root.go

@@ -4,19 +4,15 @@ import (
 	"fmt"
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
 	"github.com/wiretrustee/wiretrustee/client/internal"
 	"os"
 	"os/signal"
 	"runtime"
+	"strings"
 	"syscall"
 )
 
-const (
-	// ExitSetupFailed defines exit code
-	ExitSetupFailed   = 1
-	DefaultConfigPath = ""
-)
-
 var (
 	configPath        string
 	defaultConfigPath string
@@ -24,6 +20,7 @@ var (
 	defaultLogFile    string
 	logFile           string
 	managementURL     string
+	setupKey          string
 	rootCmd           = &cobra.Command{
 		Use:   "wiretrustee",
 		Short: "",
@@ -75,3 +72,28 @@ func SetupCloseHandler() {
 		}
 	}()
 }
+
+// SetFlagsFromEnvVars reads and updates flag values from environment variables with prefix WT_
+func SetFlagsFromEnvVars() {
+	flags := rootCmd.PersistentFlags()
+	flags.VisitAll(func(f *pflag.Flag) {
+
+		envVar := FlagNameToEnvVar(f.Name)
+
+		if value, present := os.LookupEnv(envVar); present {
+			err := flags.Set(f.Name, value)
+			if err != nil {
+				log.Infof("unable to configure flag %s using variable %s, err: %v", f.Name, envVar, err)
+			}
+		}
+	})
+}
+
+// FlagNameToEnvVar converts flag name to environment var name adding a prefix,
+// replacing dashes and making all uppercase (e.g. setup-keys is converted to WT_SETUP_KEYS)
+func FlagNameToEnvVar(f string) string {
+	prefix := "WT_"
+	parsed := strings.ReplaceAll(f, "-", "_")
+	upper := strings.ToUpper(parsed)
+	return prefix + upper
+}

client/cmd/service.go

@@ -34,6 +34,3 @@ var (
 		Short: "manages wiretrustee service",
 	}
 )
-
-func init() {
-}

client/cmd/service_controller.go

@@ -8,7 +8,7 @@ import (
 	"time"
 )
 
-func (p *program) Start(s service.Service) error {
+func (p *program) Start(service.Service) error {
 
 	// Start should not block. Do the actual work async.
 	log.Info("starting service") //nolint
@@ -22,7 +22,7 @@ func (p *program) Start(s service.Service) error {
 	return nil
 }
 
-func (p *program) Stop(s service.Service) error {
+func (p *program) Stop(service.Service) error {
 	go func() {
 		stopCh <- 1
 	}()
@@ -41,6 +41,7 @@ var (
 		Use:   "run",
 		Short: "runs wiretrustee as service",
 		Run: func(cmd *cobra.Command, args []string) {
+			SetFlagsFromEnvVars()
 
 			err := util.InitLog(logLevel, logFile)
 			if err != nil {
@@ -75,6 +76,8 @@ var (
 		Use:   "start",
 		Short: "starts wiretrustee service",
 		RunE: func(cmd *cobra.Command, args []string) error {
+			SetFlagsFromEnvVars()
+
 			err := util.InitLog(logLevel, logFile)
 			if err != nil {
 				log.Errorf("failed initializing log %v", err)
@@ -101,6 +104,8 @@ var (
 		Use:   "stop",
 		Short: "stops wiretrustee service",
 		Run: func(cmd *cobra.Command, args []string) {
+			SetFlagsFromEnvVars()
+
 			err := util.InitLog(logLevel, logFile)
 			if err != nil {
 				log.Errorf("failed initializing log %v", err)
@@ -125,6 +130,8 @@ var (
 		Use:   "restart",
 		Short: "restarts wiretrustee service",
 		Run: func(cmd *cobra.Command, args []string) {
+			SetFlagsFromEnvVars()
+
 			err := util.InitLog(logLevel, logFile)
 			if err != nil {
 				log.Errorf("failed initializing log %v", err)
@@ -143,6 +150,3 @@ var (
 		},
 	}
 )
-
-func init() {
-}

client/cmd/service_installer.go

@@ -10,6 +10,7 @@ var (
 		Use:   "install",
 		Short: "installs wiretrustee service",
 		RunE: func(cmd *cobra.Command, args []string) error {
+			SetFlagsFromEnvVars()
 
 			svcConfig := newSVCConfig()
 
@@ -49,6 +50,7 @@ var (
 		Use:   "uninstall",
 		Short: "uninstalls wiretrustee service from system",
 		Run: func(cmd *cobra.Command, args []string) {
+			SetFlagsFromEnvVars()
 
 			s, err := newSVC(&program{}, newSVCConfig())
 			if err != nil {
@@ -65,6 +67,3 @@ var (
 		},
 	}
 )
-
-func init() {
-}

client/cmd/up.go

@@ -21,7 +21,7 @@ var (
 		Use:   "up",
 		Short: "install, login and start wiretrustee client",
 		RunE: func(cmd *cobra.Command, args []string) error {
-
+			SetFlagsFromEnvVars()
 			err := loginCmd.RunE(cmd, args)
 			if err != nil {
 				return err