Read secrets from a file, where secrets are the format `KEY=VALUE`, and returns a map. Access by calling secret["KEY"] => "VALUE".

readsecret.go

package main

import (
	"bufio"
	"log"
	"os"
	"strings"
)

// ReadSecret gets API Key from a file
func ReadSecret(file string) map[string]string {
	config := make(map[string]string)

	f, err := os.Open(file)
	if err != nil {
		log.Fatal(err)
	}
	defer f.Close()
	reader := bufio.NewReader(f)

	// Reads only the first line; ignores all other lines
	for {
		line, err := reader.ReadString('\n')
		if err != nil {
			return config
		}
		// Check presence of "=" sign in line
		equals := strings.Index(line, "=")

		// Test for presence of config;
		// if present, return value of config key.
		switch {
		case strings.Index(line, "#") >= 0:
			// Skip if line is a comment
			break
		case equals < 0, strings.Index(line, " ") >= 0:
			// Log as invalid config if line does not contain "=", or if contains spaces.
			//log.Printf("Invalid config at %s", line)
		case equals >= 0:
			k := Chomp(strings.Split(line, "=")[0])
			v := Chomp(strings.Split(line, "=")[1])
			config[k] = v
		default:
			break
		}
	}
}

// Chomp removes trailing spaces and newline chars from strings
func Chomp(in string) string {
	// Inelegantly removing extraneous spaces
	s := strings.Split(in, " ")
	if len(s) > 1 {
		var in2 string
		for _, v := range s {
			in2 = in2 + v
		}
		in = in2
	}

	if strings.HasSuffix(in, "\r") {
		// Check for CRLF
		return Chomp(in[:len(in)-1])
	} else if strings.HasSuffix(in, "\n") {
		// Check for LF
		return Chomp(in[:len(in)-1])
	} else if strings.HasSuffix(in, " ") {
		// Check for trailing spaces at end of input.
		return Chomp(in[:len(in)-1])
	} else if strings.HasPrefix(in, " ") {
		// Check for traling spaces at start of input.
		return Chomp(in[1:])
	}
	return in
}

readsecret_test.go

package main

import (
	"log"
	"testing"
)

func TestReadSecret(t *testing.T) {
	file := ".env_test"
	out := ReadSecret(file)
	if len(out) == 0 {
		t.Errorf("Couldn't read %s file", file)
	}
	for i := range out {
		log.Println(out[i])
	}
}

func TestChomp(t *testing.T) {
	out := Chomp("    Test\n\r  \n\n\r")
	if out != "Test" {
		t.Error("Failed: chomp failed to remove LF line endings and trailing spaces.")
	}
	out = Chomp("    T  e st \n\r  \n\n\r")
	if out != "Test" {
		t.Error("Failed: chomp failed to remove extraneous spaces.")
	}
}