storj/pkg/process/exec.go

138 lines
3.1 KiB
Go

// Copyright (C) 2018 Storj Labs, Inc.
// See LICENSE for copying information.
package process
import (
"context"
"flag"
"log"
"os"
"path/filepath"
homedir "github.com/mitchellh/go-homedir"
"github.com/spf13/cobra"
"github.com/spf13/pflag"
"github.com/spf13/viper"
)
// ReadFlags will read in and bind flags for viper and pflag
func readFlags() {
pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
pflag.Parse()
err := viper.BindPFlags(pflag.CommandLine)
if err != nil {
log.Print("error parsing command line flags into viper:", err)
}
}
// get default config folder
func configPath() string {
home, _ := homedir.Dir()
return filepath.Join(home, ".storj")
}
// get default config file
func defaultConfigFile(name string) string {
return filepath.Join(configPath(), name)
}
func generateConfig() error {
err := viper.WriteConfigAs(defaultConfigFile("main.json"))
return err
}
// ConfigEnvironment will read in command line flags, set the name of the config file,
// then look for configs in the current working directory and in $HOME/.storj
func ConfigEnvironment() (*viper.Viper, error) {
viper.SetEnvPrefix("storj")
viper.AutomaticEnv()
viper.SetConfigName("main")
viper.AddConfigPath(".")
viper.AddConfigPath(configPath())
// Override default config with a specific config
cfgFile := flag.String("config", "", "config file")
generate := flag.Bool("generate", false, "generate a default config in ~/.storj")
// if that file exists, set it as the config instead of reading in from default locations
if *cfgFile != "" && fileExists(*cfgFile) {
viper.SetConfigFile(*cfgFile)
}
err := viper.ReadInConfig()
if err != nil {
log.Print("could not read config file; defaulting to command line flags for configuration")
}
readFlags()
if *generate == true {
err := generateConfig()
if err != nil {
log.Print("unable to generate config file.", err)
}
}
v := viper.GetViper()
return v, nil
}
// check if file exists, handle error correctly if it doesn't
func fileExists(path string) bool {
_, err := os.Stat(path)
if err != nil {
if os.IsNotExist(err) {
return false
}
log.Fatalf("failed to check for file existence: %v", err)
}
return true
}
// Execute runs a *cobra.Command and sets up Storj-wide process configuration
// like a configuration file and logging.
func Execute(cmd *cobra.Command) {
cobra.OnInitialize(func() {
_, err := ConfigEnvironment()
if err != nil {
log.Fatal("error configuring environment", err)
}
})
Must(cmd.Execute())
}
// Main runs a Service
func Main(configFn func() (*viper.Viper, error), s ...Service) error {
if _, err := configFn(); err != nil {
return err
}
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
errors := make(chan error, len(s))
for _, service := range s {
go func(ctx context.Context, s Service, ch <-chan error) {
errors <- CtxService(s)(&cobra.Command{}, pflag.Args())
}(ctx, service, errors)
}
select {
case <-ctx.Done():
return nil
case err := <-errors:
return err
}
}
// Must checks for errors
func Must(err error) {
if err != nil {
log.Fatal(err)
}
}