Skip to content

Commit

Permalink
cmd: Enhance .env (dotenv) file parsing
Browse files Browse the repository at this point in the history
Basic support for quoted values, newlines in quoted values, and comments.

Does not support variable or command expansion.
  • Loading branch information
mholt committed Apr 13, 2022
1 parent bc15b4b commit 30b6d1f
Show file tree
Hide file tree
Showing 2 changed files with 212 additions and 16 deletions.
58 changes: 42 additions & 16 deletions cmd/main.go
Original file line number Diff line number Diff line change
Expand Up @@ -368,42 +368,68 @@ func loadEnvFromFile(envFile string) error {
return nil
}

// parseEnvFile parses an env file from KEY=VALUE format.
// It's pretty naive. Limited value quotation is supported,
// but variable and command expansions are not supported.
func parseEnvFile(envInput io.Reader) (map[string]string, error) {
envMap := make(map[string]string)

scanner := bufio.NewScanner(envInput)
var line string
lineNumber := 0
var lineNumber int

for scanner.Scan() {
line = strings.TrimSpace(scanner.Text())
line := strings.TrimSpace(scanner.Text())
lineNumber++

// skip lines starting with comment
if strings.HasPrefix(line, "#") {
continue
}

// skip empty line
if len(line) == 0 {
// skip empty lines and lines starting with comment
if line == "" || strings.HasPrefix(line, "#") {
continue
}

// split line into key and value
fields := strings.SplitN(line, "=", 2)
if len(fields) != 2 {
return nil, fmt.Errorf("can't parse line %d; line should be in KEY=VALUE format", lineNumber)
}
key, val := fields[0], fields[1]

if strings.Contains(fields[0], " ") {
return nil, fmt.Errorf("bad key on line %d: contains whitespace", lineNumber)
}

key := fields[0]
val := fields[1]
// sometimes keys are prefixed by "export " so file can be sourced in bash; ignore it here
key = strings.TrimPrefix(key, "export ")

// validate key and value
if key == "" {
return nil, fmt.Errorf("missing or empty key on line %d", lineNumber)
}
if strings.Contains(key, " ") {
return nil, fmt.Errorf("invalid key on line %d: contains whitespace: %s", lineNumber, key)
}
if strings.HasPrefix(val, " ") || strings.HasPrefix(val, "\t") {
return nil, fmt.Errorf("invalid value on line %d: whitespace before value: '%s'", lineNumber, val)
}

// remove any trailing comment after value
if commentStart := strings.Index(val, "#"); commentStart > 0 {
before := val[commentStart-1]
if before == '\t' || before == ' ' {
val = strings.TrimRight(val[:commentStart], " \t")
}
}

// quoted value: support newlines
if strings.HasPrefix(val, `"`) {
for !(strings.HasSuffix(line, `"`) && !strings.HasSuffix(line, `\"`)) {
val = strings.ReplaceAll(val, `\"`, `"`)
if !scanner.Scan() {
break
}
lineNumber++
line = strings.ReplaceAll(scanner.Text(), `\"`, `"`)
val += "\n" + line
}
val = strings.TrimPrefix(val, `"`)
val = strings.TrimSuffix(val, `"`)
}

envMap[key] = val
}

Expand Down
170 changes: 170 additions & 0 deletions cmd/main_test.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,170 @@
package caddycmd

import (
"reflect"
"strings"
"testing"
)

func TestParseEnvFile(t *testing.T) {
for i, tc := range []struct {
input string
expect map[string]string
shouldErr bool
}{
{
input: `KEY=value`,
expect: map[string]string{
"KEY": "value",
},
},
{
input: `
KEY=value
OTHER_KEY=Some Value
`,
expect: map[string]string{
"KEY": "value",
"OTHER_KEY": "Some Value",
},
},
{
input: `
KEY=value
INVALID KEY=asdf
OTHER_KEY=Some Value
`,
shouldErr: true,
},
{
input: `
KEY=value
SIMPLE_QUOTED="quoted value"
OTHER_KEY=Some Value
`,
expect: map[string]string{
"KEY": "value",
"SIMPLE_QUOTED": "quoted value",
"OTHER_KEY": "Some Value",
},
},
{
input: `
KEY=value
NEWLINES="foo
bar"
OTHER_KEY=Some Value
`,
expect: map[string]string{
"KEY": "value",
"NEWLINES": "foo\n\tbar",
"OTHER_KEY": "Some Value",
},
},
{
input: `
KEY=value
ESCAPED="\"escaped quotes\"
here"
OTHER_KEY=Some Value
`,
expect: map[string]string{
"KEY": "value",
"ESCAPED": "\"escaped quotes\"\nhere",
"OTHER_KEY": "Some Value",
},
},
{
input: `
export KEY=value
OTHER_KEY=Some Value
`,
expect: map[string]string{
"KEY": "value",
"OTHER_KEY": "Some Value",
},
},
{
input: `
=value
OTHER_KEY=Some Value
`,
shouldErr: true,
},
{
input: `
EMPTY=
OTHER_KEY=Some Value
`,
expect: map[string]string{
"EMPTY": "",
"OTHER_KEY": "Some Value",
},
},
{
input: `
EMPTY=""
OTHER_KEY=Some Value
`,
expect: map[string]string{
"EMPTY": "",
"OTHER_KEY": "Some Value",
},
},
{
input: `
KEY=value
#OTHER_KEY=Some Value
`,
expect: map[string]string{
"KEY": "value",
},
},
{
input: `
KEY=value
COMMENT=foo bar # some comment here
OTHER_KEY=Some Value
`,
expect: map[string]string{
"KEY": "value",
"COMMENT": "foo bar",
"OTHER_KEY": "Some Value",
},
},
{
input: `
KEY=value
WHITESPACE= foo
OTHER_KEY=Some Value
`,
shouldErr: true,
},
{
input: `
KEY=value
WHITESPACE=" foo bar "
OTHER_KEY=Some Value
`,
expect: map[string]string{
"KEY": "value",
"WHITESPACE": " foo bar ",
"OTHER_KEY": "Some Value",
},
},
} {
actual, err := parseEnvFile(strings.NewReader(tc.input))
if err != nil && !tc.shouldErr {
t.Errorf("Test %d: Got error but shouldn't have: %v", i, err)
}
if err == nil && tc.shouldErr {
t.Errorf("Test %d: Did not get error but should have", i)
}
if tc.shouldErr {
continue
}
if !reflect.DeepEqual(tc.expect, actual) {
t.Errorf("Test %d: Expected %v but got %v", i, tc.expect, actual)
}
}
}

0 comments on commit 30b6d1f

Please sign in to comment.