Improvement expand value env

README.md

@@ -84,6 +84,7 @@ some:
 ttl: 30s
 service:
   name: ${NAME||go-archaius}
+  addr: ${IP||127.0.0.1}:${PORT||80} 
 ```
 after adding file
 ```go
@@ -96,10 +97,13 @@ you can get value
 ttl := archaius.GetString("ttl", "60s")
 i := archaius.GetInt("some.config", "")
 serviceName := archaius.GetString("service.name", "")
+serviceAddr := archaius.GetString("service.addr", "")
 ```
 note:
 
-For `service.name` config with value of  `${NAME||go-archaius}` is support env syntax. If environment variable `${NAME}` isn't setting, return default value `go-archaius`. It's setted, will get real environment variable value.
+1. For `service.name` config with value of  `${NAME||go-archaius}` is support env syntax. If environment variable `${NAME}` isn't setting, return default value `go-archaius`. It's setted, will get real environment variable value.
+2. For `service.addr` config is support "expand syntax". If environment variable `${IP}` or `${PORT}` is setted, will get env config. 
+eg: `export IP=0.0.0.0 PORT=443` , `archaius.GetString("service.addr", "")` will return `0.0.0.0:443` .
 
 if you want to read some.config from env
 you can run

source/util/expand.go

@@ -1,40 +1,43 @@
 package util
 
-import "os"
+import (
+	"os"
+	"regexp"
+	"strings"
+)
+
+// The name of a variable can contain only letters (a to z or A to Z), numbers ( 0 to 9) or
+// the underscore character ( _), and can't begin with number.
+const envVariable = `\${([a-zA-Z_]{1}[\w]+)[\|]{2}(.*?)}`
+
+// reg exp
+var variableReg *regexp.Regexp
+
+func init() {
+	variableReg = regexp.MustCompile(envVariable)
+}
 
 // if string like ${NAME||archaius}
 // will query environment variable for ${NAME}
 // if environment variable is "" return default string `archaius`
+// support multi variable, eg:
+//    value string => addr:${IP||127.0.0.1}:${PORT||8080}
+//    if environment variable =>  IP=0.0.0.0 PORT=443 , result => addr:0.0.0.0:443
+//    if no exist environment variable                , result => addr:127.0.0.1:8080
 func ExpandValueEnv(value string) (realValue string) {
-	realValue = value
-
-	vLen := len(value)
-	// 3 = ${}
-	if vLen < 3 {
-		return
-	}
-	// Need start with "${" and end with "}", then return.
-	if value[0] != '$' || value[1] != '{' || value[vLen-1] != '}' {
-		return
+	value = strings.TrimSpace(value)
+	submatch := variableReg.FindAllStringSubmatch(value, -1)
+	if len(submatch) == 0 {
+		return value
 	}
 
-	key := ""
-	defaultV := ""
-	// value start with "${"
-	for i := 2; i < vLen; i++ {
-		if value[i] == '|' && (i+1 < vLen && value[i+1] == '|') {
-			key = value[2:i]
-			defaultV = value[i+2 : vLen-1] // other string is default value.
-			break
-		} else if value[i] == '}' {
-			key = value[2:i]
-			break
+	realValue = value
+	for _, sub := range submatch {
+		item := os.Getenv(sub[1])
+		if item == "" {
+			item = sub[2]
 		}
-	}
-
-	realValue = os.Getenv(key)
-	if realValue == "" {
-		realValue = defaultV
+		realValue = strings.ReplaceAll(realValue, sub[0], item)
 	}
 
 	return

source/util/expand_test.go

@@ -1,15 +1,51 @@
 package util
 
 import (
+	"github.com/stretchr/testify/assert"
 	"os"
 	"testing"
 )
 
 func TestExpandValueEnv(t *testing.T) {
-	str := "${NAME||archaius}"
-	if e := os.Setenv("NAM", "go-archaius"); e != nil {
+	str1 := "${NAME||archaius}=${IP||}:${PORT||8080}+++${0PORT||8080}+++${_PORT||8080}"
+	assert.Equal(t, "archaius=:8080+++${0PORT||8080}+++8080", ExpandValueEnv(str1))
+
+	str2 := "${IP||}:${PORT||8080}:${||8080}"
+	assert.Equal(t, ":8080:${||8080}", ExpandValueEnv(str2))
+
+	str3 := "${IP|}:${PORT||8080}"
+	assert.Equal(t, "${IP|}:8080", ExpandValueEnv(str3))
+
+	str4 := "        $${IP_09090||}  "
+	assert.Equal(t, "$", ExpandValueEnv(str4))
+
+	str5 := "${IP||}:8080${ADD R||:8080}"
+	assert.Equal(t, ":8080${ADD R||:8080}", ExpandValueEnv(str5))
+
+	str6 := "${IP||0.0.0.0}:8080"
+	assert.Equal(t, "0.0.0.0:8080", ExpandValueEnv(str6))
+
+	str7 := "${NAME||archaius}:${IP||github.com}"
+	if e := os.Setenv("NAME", "go-archaius"); e != nil {
+		t.Logf("err:%+v", e)
+	}
+	assert.Equal(t, "go-archaius:github.com", ExpandValueEnv(str7))
+
+	str8 := "addr:${IP||127.0.0.1}:${PORT||8080}"
+	if e := os.Setenv("IP", "0.0.0.0"); e != nil {
+		t.Logf("err:%+v", e)
+	}
+	assert.Equal(t, "addr:0.0.0.0:8080", ExpandValueEnv(str8))
+
+	str9 := "${POD_IP||}"
+	if e := os.Setenv("POD_IP", "0.0.0.0"); e != nil {
+		t.Logf("err:%+v", e)
+	}
+	assert.Equal(t, "0.0.0.0", ExpandValueEnv(str9))
+
+	str10 := "${IP|}"
+	if e := os.Setenv("IP", "0.0.0.0"); e != nil {
 		t.Logf("err:%+v", e)
 	}
-	realStr := ExpandValueEnv(str)
-	t.Logf("realStr: %s", realStr)
+	assert.Equal(t, "${IP|}", ExpandValueEnv(str10))
 }