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go-micro/config/source/cli/cli.go
2019-06-21 13:36:11 +01:00

147 lines
2.9 KiB
Go

package cli
import (
"flag"
"io/ioutil"
"os"
"strings"
"time"
"github.com/imdario/mergo"
"github.com/micro/cli"
"github.com/micro/go-micro/config/cmd"
"github.com/micro/go-micro/config/source"
)
type cliSource struct {
opts source.Options
ctx *cli.Context
}
func (c *cliSource) Read() (*source.ChangeSet, error) {
var changes map[string]interface{}
for _, name := range c.ctx.GlobalFlagNames() {
tmp := toEntry(name, c.ctx.GlobalGeneric(name))
mergo.Map(&changes, tmp) // need to sort error handling
}
for _, name := range c.ctx.FlagNames() {
tmp := toEntry(name, c.ctx.Generic(name))
mergo.Map(&changes, tmp) // need to sort error handling
}
b, err := c.opts.Encoder.Encode(changes)
if err != nil {
return nil, err
}
cs := &source.ChangeSet{
Format: c.opts.Encoder.String(),
Data: b,
Timestamp: time.Now(),
Source: c.String(),
}
cs.Checksum = cs.Sum()
return cs, nil
}
func toEntry(name string, v interface{}) map[string]interface{} {
n := strings.ToLower(name)
keys := strings.FieldsFunc(n, split)
reverse(keys)
tmp := make(map[string]interface{})
for i, k := range keys {
if i == 0 {
tmp[k] = v
continue
}
tmp = map[string]interface{}{k: tmp}
}
return tmp
}
func reverse(ss []string) {
for i := len(ss)/2 - 1; i >= 0; i-- {
opp := len(ss) - 1 - i
ss[i], ss[opp] = ss[opp], ss[i]
}
}
func split(r rune) bool {
return r == '-' || r == '_'
}
func (c *cliSource) Watch() (source.Watcher, error) {
return source.NewNoopWatcher()
}
func (c *cliSource) String() string {
return "cli"
}
// NewSource returns a config source for integrating parsed flags from a micro/cli.Context.
// Hyphens are delimiters for nesting, and all keys are lowercased. The assumption is that
// command line flags have already been parsed.
//
// Example:
// cli.StringFlag{Name: "db-host"},
//
//
// {
// "database": {
// "host": "localhost"
// }
// }
func NewSource(opts ...source.Option) source.Source {
options := source.NewOptions(opts...)
var ctx *cli.Context
c, ok := options.Context.Value(contextKey{}).(*cli.Context)
if ok {
ctx = c
}
// no context
if ctx == nil {
// get the default app/flags
app := cmd.App()
flags := app.Flags
// create flagset
set := flag.NewFlagSet(app.Name, flag.ContinueOnError)
// apply flags to set
for _, f := range flags {
f.Apply(set)
}
// parse flags
set.SetOutput(ioutil.Discard)
set.Parse(os.Args[1:])
// normalise flags
normalizeFlags(app.Flags, set)
// create context
ctx = cli.NewContext(app, set, nil)
}
return &cliSource{
ctx: ctx,
opts: options,
}
}
// WithContext returns a new source with the context specified.
// The assumption is that Context is retrieved within an app.Action function.
func WithContext(ctx *cli.Context, opts ...source.Option) source.Source {
return &cliSource{
ctx: ctx,
opts: source.NewOptions(opts...),
}
}