1 files changed, 54 insertions, 0 deletions
diff --git a/opts/envfile.go b/opts/envfile.go
new file mode 100644
index 0000000000..19ee8955f9
--- /dev/null
+++ b/opts/envfile.go
@@ -0,0 +1,54 @@
+package opts
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+)
+
+/*
+Read in a line delimited file with environment variables enumerated
+*/
+func ParseEnvFile(filename string) ([]string, error) {
+	fh, err := os.Open(filename)
+	if err != nil {
+		return []string{}, err
+	}
+	defer fh.Close()
+
+	lines := []string{}
+	scanner := bufio.NewScanner(fh)
+	for scanner.Scan() {
+		line := scanner.Text()
+		// line is not empty, and not starting with '#'
+		if len(line) > 0 && !strings.HasPrefix(line, "#") {
+			if strings.Contains(line, "=") {
+				data := strings.SplitN(line, "=", 2)
+
+				// trim the front of a variable, but nothing else
+				variable := strings.TrimLeft(data[0], whiteSpaces)
+				if strings.ContainsAny(variable, whiteSpaces) {
+					return []string{}, ErrBadEnvVariable{fmt.Sprintf("variable '%s' has white spaces", variable)}
+				}
+
+				// pass the value through, no trimming
+				lines = append(lines, fmt.Sprintf("%s=%s", variable, data[1]))
+			} else {
+				// if only a pass-through variable is given, clean it up.
+				lines = append(lines, fmt.Sprintf("%s=%s", strings.TrimSpace(line), os.Getenv(line)))
+			}
+		}
+	}
+	return lines, nil
+}
+
+var whiteSpaces = " \t"
+
+type ErrBadEnvVariable struct {
+	msg string
+}
+
+func (e ErrBadEnvVariable) Error() string {
+	return fmt.Sprintf("poorly formatted environment: %s", e.msg)
+}