aboutsummaryrefslogtreecommitdiffstats
path: root/ui/build/environment.go
blob: 8589937965bd1bd8b770e35b1385611baa97599e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
// Copyright 2017 Google Inc. All rights reserved.
//
// 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.

package build

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strings"
)

// Environment adds a number of useful manipulation functions to the list of
// strings returned by os.Environ() and used in exec.Cmd.Env.
type Environment []string

// OsEnvironment wraps the current environment returned by os.Environ()
func OsEnvironment() *Environment {
	env := Environment(os.Environ())
	return &env
}

// Get returns the value associated with the key, and whether it exists.
// It's equivalent to the os.LookupEnv function, but with this copy of the
// Environment.
func (e *Environment) Get(key string) (string, bool) {
	for _, env := range *e {
		if k, v, ok := decodeKeyValue(env); ok && k == key {
			return v, true
		}
	}
	return "", false
}

// Set sets the value associated with the key, overwriting the current value
// if it exists.
func (e *Environment) Set(key, value string) {
	e.Unset(key)
	*e = append(*e, key+"="+value)
}

// Unset removes the specified keys from the Environment.
func (e *Environment) Unset(keys ...string) {
	out := (*e)[:0]
	for _, env := range *e {
		if key, _, ok := decodeKeyValue(env); ok && inList(key, keys) {
			continue
		}
		out = append(out, env)
	}
	*e = out
}

// UnsetWithPrefix removes all keys that start with prefix.
func (e *Environment) UnsetWithPrefix(prefix string) {
	out := (*e)[:0]
	for _, env := range *e {
		if key, _, ok := decodeKeyValue(env); ok && strings.HasPrefix(key, prefix) {
			continue
		}
		out = append(out, env)
	}
	*e = out
}

// Environ returns the []string required for exec.Cmd.Env
func (e *Environment) Environ() []string {
	return []string(*e)
}

// Copy returns a copy of the Environment so that independent changes may be made.
func (e *Environment) Copy() *Environment {
	ret := Environment(make([]string, len(*e)))
	for i, v := range *e {
		ret[i] = v
	}
	return &ret
}

// IsTrue returns whether an environment variable is set to a positive value (1,y,yes,on,true)
func (e *Environment) IsEnvTrue(key string) bool {
	if value, ok := e.Get(key); ok {
		return value == "1" || value == "y" || value == "yes" || value == "on" || value == "true"
	}
	return false
}

// IsFalse returns whether an environment variable is set to a negative value (0,n,no,off,false)
func (e *Environment) IsFalse(key string) bool {
	if value, ok := e.Get(key); ok {
		return value == "0" || value == "n" || value == "no" || value == "off" || value == "false"
	}
	return false
}

// AppendFromKati reads a shell script written by Kati that exports or unsets
// environment variables, and applies those to the local Environment.
func (e *Environment) AppendFromKati(filename string) error {
	file, err := os.Open(filename)
	if err != nil {
		return err
	}
	defer file.Close()

	return e.appendFromKati(file)
}

func (e *Environment) appendFromKati(reader io.Reader) error {
	scanner := bufio.NewScanner(reader)
	for scanner.Scan() {
		text := strings.TrimSpace(scanner.Text())

		if len(text) == 0 || text[0] == '#' {
			continue
		}

		cmd := strings.SplitN(text, " ", 2)
		if len(cmd) != 2 {
			return fmt.Errorf("Unknown kati environment line: %q", text)
		}

		if cmd[0] == "unset" {
			str, ok := singleUnquote(cmd[1])
			if !ok {
				fmt.Errorf("Failed to unquote kati line: %q", text)
			}
			e.Unset(str)
		} else if cmd[0] == "export" {
			key, value, ok := decodeKeyValue(cmd[1])
			if !ok {
				return fmt.Errorf("Failed to parse export: %v", cmd)
			}

			key, ok = singleUnquote(key)
			if !ok {
				return fmt.Errorf("Failed to unquote kati line: %q", text)
			}
			value, ok = singleUnquote(value)
			if !ok {
				return fmt.Errorf("Failed to unquote kati line: %q", text)
			}

			e.Set(key, value)
		} else {
			return fmt.Errorf("Unknown kati environment command: %q", text)
		}
	}
	if err := scanner.Err(); err != nil {
		return err
	}
	return nil
}