prometheus-to-sd/flags/flags.go

/*
Copyright 2017 Google Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

// This file was copied from https://github.com/kubernetes/heapster/tree/master/common/flags.
// TODO: Move this file to a repository that can be accessed both by heapster and contrib repos.

package flags

import (
	"bytes"
	"fmt"
	"net/url"
	"os"
	"strings"
)

// Uri contains information about one flag instance.
type Uri struct {
	Key string
	Val url.URL
}

func (u *Uri) String() string {
	val := u.Val.String()
	if val == "" {
		return fmt.Sprintf("%s", u.Key)
	}
	return fmt.Sprintf("%s:%s", u.Key, val)
}

// Set parses single instance of a flag.
func (u *Uri) Set(value string) error {
	s := strings.SplitN(value, ":", 2)
	u.Key = s[0]
	if len(s) != 2 || s[1] == "" {
		return fmt.Errorf("unproperly formatted url %s", value)
	}
	e := os.ExpandEnv(s[1])
	uri, err := url.Parse(e)
	if err != nil {
		return err
	}
	u.Val = *uri
	return nil
}

// Uris holds values of a repeated flag.
type Uris []Uri

// String returns human-readable representation of a repeated flag.
func (us *Uris) String() string {
	var b bytes.Buffer
	b.WriteString("[")
	for i, u := range *us {
		if i > 0 {
			b.WriteString(" ")
		}
		b.WriteString(u.String())
	}
	b.WriteString("]")
	return b.String()
}

// Set parses value and appends to us.
func (us *Uris) Set(value string) error {
	var u Uri
	if err := u.Set(value); err != nil {
		return err
	}
	*us = append(*us, u)
	return nil
}

// Type returns type.
func (us *Uris) Type() string {
	return fmt.Sprintf("%T", us)
}