fix(config): supporting multiple env variables in a value.

ref #9

internal/config/environment.go

@@ -6,11 +6,13 @@ import (
 	"strconv"
 	"time"
 
+	"github.com/drone/envsubst"
 	"github.com/pkg/errors"
 	"gopkg.in/yaml.v3"
 )
 
-var reVar = regexp.MustCompile(`^\${(\w+)}$`)
+// var reVar = regexp.MustCompile(`^\${(\w+)}$`)
+var reVar = regexp.MustCompile(`\${(.*?)}`)
 
 type InterpolatedString string
 
@@ -130,14 +132,22 @@ type InterpolatedStringSlice []string
 
 func (iss *InterpolatedStringSlice) UnmarshalYAML(value *yaml.Node) error {
 	var data []string
+	var evErr error
 
 	if err := value.Decode(&data); err != nil {
 		return errors.Wrapf(err, "could not decode value '%v' (line '%d') into map", value.Value, value.Line)
 	}
 
 	for index, value := range data {
-		if match := reVar.FindStringSubmatch(value); len(match) > 0 {
-			value = os.Getenv(match[1])
+		//match := reVar.FindStringSubmatch(value)
+		re := regexp.MustCompile(`\${(.*?)}`)
+
+		res := re.FindAllStringSubmatch(value, 10)
+		if len(res) > 0 {
+			value, evErr = envsubst.EvalEnv(value)
+			if evErr != nil {
+				return evErr
+			}
 		}
 
 		data[index] = value

internal/config/testdata/config.yml

@@ -2,5 +2,5 @@ logger:
   level: 0
   format: human
 http:
-  host: "0.0.0.0"
-  port: 3000
+  host: "${LISTEN_ADDR}"
+  port: 3000