Use go-ucfg based variable expansion support

libbeat/cfgfile/cfgfile.go

@@ -3,7 +3,6 @@ package cfgfile
 import (
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 
@@ -60,22 +59,7 @@ func Load(path string) (*common.Config, error) {
 	if path == "" {
 		path = *configfile
 	}
-
-	fileContent, err := ioutil.ReadFile(path)
-	if err != nil {
-		return nil, fmt.Errorf("failed to read %s: %v", path, err)
-	}
-	fileContent, err = expandEnv(filepath.Base(path), fileContent)
-	if err != nil {
-		return nil, err
-	}
-
-	config, err := common.NewConfigWithYAML(fileContent, path)
-	if err != nil {
-		return nil, fmt.Errorf("YAML config parsing failed on %s: %v", path, err)
-	}
-
-	return config, nil
+	return common.LoadFile(path)
 }
 
 // IsTestConfig returns whether or not this is configuration used for testing

libbeat/cfgfile/cfgfile_test.go

@@ -11,7 +11,9 @@ import (
 )
 
 type TestConfig struct {
-	Output ElasticsearchConfig
+	Output     ElasticsearchConfig
+	Env        string `config:"env.test_key"`
+	EnvDefault string `config:"env.default"`
 }
 
 type ElasticsearchConfig struct {
@@ -25,6 +27,7 @@ type Connection struct {
 
 func TestRead(t *testing.T) {
 	absPath, err := filepath.Abs("../tests/files/")
+	os.Setenv("TEST_KEY", "test_value")
 
 	assert.NotNil(t, absPath)
 	assert.Nil(t, err)
@@ -34,72 +37,9 @@ func TestRead(t *testing.T) {
 	err = Read(config, absPath+"/config.yml")
 	assert.Nil(t, err)
 
-	// Access config
+	// validate
 	assert.Equal(t, "localhost", config.Output.Elasticsearch.Host)
-
-	// Chat that it is integer
 	assert.Equal(t, 9200, config.Output.Elasticsearch.Port)
-}
-
-func TestExpandEnv(t *testing.T) {
-	var tests = []struct {
-		in  string
-		out string
-		err string
-	}{
-		// Environment variables can be specified as ${env} only.
-		{"${y}", "y", ""},
-		{"$y", "$y", ""},
-
-		// Environment variables are case-sensitive.
-		{"${Y}", "", ""},
-
-		// Defaults can be specified.
-		{"x${Z:D}", "xD", ""},
-		{"x${Z:A B C D}", "xA B C D", ""}, // Spaces are allowed in the default.
-		{"x${Z:}", "x", ""},
-
-		// Un-matched braces cause an error.
-		{"x${Y ${Z:Z}", "", "unexpected character in variable expression: " +
-			"U+0020 ' ', expected a default value or closing brace"},
-
-		// Special environment variables are not replaced.
-		{"$*", "$*", ""},
-		{"${*}", "", "shell variable cannot start with U+002A '*'"},
-		{"$@", "$@", ""},
-		{"${@}", "", "shell variable cannot start with U+0040 '@'"},
-		{"$1", "$1", ""},
-		{"${1}", "", "shell variable cannot start with U+0031 '1'"},
-
-		{"", "", ""},
-		{"$$", "$$", ""},
-
-		{"${a_b}", "", ""}, // Underscores are allowed in variable names.
-
-		// ${} cannot be split across newlines.
-		{"hello ${name: world\n}", "", "unterminated brace"},
-
-		// To use a literal '${' you write '$${'.
-		{`password: "abc$${!"`, `password: "abc${!"`, ""},
-
-		// The full error contains the line number.
-		{"test:\n  name: ${var", "", "failure while expanding environment " +
-			"variables in config.yml at line=2, unterminated brace"},
-	}
-
-	for _, test := range tests {
-		os.Setenv("y", "y")
-		output, err := expandEnv("config.yml", []byte(test.in))
-
-		switch {
-		case test.err != "" && err == nil:
-			t.Errorf("Expected an error for test case %+v", test)
-		case test.err == "" && err != nil:
-			t.Errorf("Unexpected error for test case %+v, %v", test, err)
-		case err != nil:
-			assert.Contains(t, err.Error(), test.err)
-		default:
-			assert.Equal(t, test.out, string(output), "Input: %s", test.in)
-		}
-	}
+	assert.Equal(t, "test_value", config.Env)
+	assert.Equal(t, "default", config.EnvDefault)
 }