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Separate out PrepareBaseCmd, try to set env vars

pull/1842/head
Ethan Frey 8 years ago
parent
commit
b92bd8f6a8
1 changed files with 136 additions and 0 deletions
  1. +136
    -0
      cli/setup.go

+ 136
- 0
cli/setup.go View File

@ -0,0 +1,136 @@
package cli
import (
"fmt"
"os"
"strings"
"github.com/pkg/errors"
"github.com/spf13/cobra"
"github.com/spf13/viper"
data "github.com/tendermint/go-wire/data"
"github.com/tendermint/go-wire/data/base58"
)
const (
RootFlag = "root"
OutputFlag = "output"
EncodingFlag = "encoding"
)
// PrepareBaseCmd is meant for tendermint and other servers
func PrepareBaseCmd(cmd *cobra.Command, envPrefix, defautRoot string) func() {
cobra.OnInitialize(func() { initEnv(envPrefix) })
cmd.PersistentFlags().StringP(RootFlag, "r", defautRoot, "root directory for config and data")
cmd.PersistentPreRunE = multiE(bindFlags, cmd.PersistentPreRunE)
return func() { execute(cmd) }
}
// PrepareMainCmd is meant for client side libs that want some more flags
func PrepareMainCmd(cmd *cobra.Command, envPrefix, defautRoot string) func() {
cmd.PersistentFlags().StringP(EncodingFlag, "e", "hex", "Binary encoding (hex|b64|btc)")
cmd.PersistentFlags().StringP(OutputFlag, "o", "text", "Output format (text|json)")
cmd.PersistentPreRunE = multiE(setEncoding, validateOutput, cmd.PersistentPreRunE)
return PrepareBaseCmd(cmd, envPrefix, defautRoot)
}
// initEnv sets to use ENV variables if set.
func initEnv(prefix string) {
copyEnvVars(prefix)
// env variables with TM prefix (eg. TM_ROOT)
viper.SetEnvPrefix(prefix)
viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
viper.AutomaticEnv()
}
// This copies all variables like TMROOT to TM_ROOT,
// so we can support both formats for the user
func copyEnvVars(prefix string) {
prefix = strings.ToUpper(prefix)
ps := prefix + "_"
for _, e := range os.Environ() {
kv := strings.SplitN(e, "=", 1)
k, v := kv[0], kv[1]
if strings.HasPrefix(k, prefix) && !strings.HasPrefix(k, ps) {
k2 := strings.Replace(k, prefix, ps, 1)
os.Setenv(k2, v)
}
}
}
// execute adds all child commands to the root command sets flags appropriately.
// This is called by main.main(). It only needs to happen once to the rootCmd.
func execute(cmd *cobra.Command) {
// TODO: this can do something cooler with debug and log-levels
if err := cmd.Execute(); err != nil {
fmt.Println(err)
os.Exit(-1)
}
}
type wrapE func(cmd *cobra.Command, args []string) error
func multiE(fs ...wrapE) wrapE {
return func(cmd *cobra.Command, args []string) error {
for _, f := range fs {
if f != nil {
if err := f(cmd, args); err != nil {
return err
}
}
}
return nil
}
}
func bindFlags(cmd *cobra.Command, args []string) error {
// cmd.Flags() includes flags from this command and all persistent flags from the parent
if err := viper.BindPFlags(cmd.Flags()); err != nil {
return err
}
// rootDir is command line flag, env variable, or default $HOME/.tlc
rootDir := viper.GetString("root")
viper.SetConfigName("config") // name of config file (without extension)
viper.AddConfigPath(rootDir) // search root directory
// If a config file is found, read it in.
if err := viper.ReadInConfig(); err == nil {
// stderr, so if we redirect output to json file, this doesn't appear
// fmt.Fprintln(os.Stderr, "Using config file:", viper.ConfigFileUsed())
} else if _, ok := err.(viper.ConfigFileNotFoundError); !ok {
// we ignore not found error, only parse error
// stderr, so if we redirect output to json file, this doesn't appear
fmt.Fprintf(os.Stderr, "%#v", err)
}
return nil
}
// setEncoding reads the encoding flag
func setEncoding(cmd *cobra.Command, args []string) error {
// validate and set encoding
enc := viper.GetString("encoding")
switch enc {
case "hex":
data.Encoder = data.HexEncoder
case "b64":
data.Encoder = data.B64Encoder
case "btc":
data.Encoder = base58.BTCEncoder
default:
return errors.Errorf("Unsupported encoding: %s", enc)
}
return nil
}
func validateOutput(cmd *cobra.Command, args []string) error {
// validate output format
output := viper.GetString(OutputFlag)
switch output {
case "text", "json":
default:
return errors.Errorf("Unsupported output format: %s", output)
}
return nil
}

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