config environment variables replacement implemented.

dcp.go

@@ -7,6 +7,8 @@ import (
 	"os"
 	"os/signal"
 	"reflect"
+	"regexp"
+	"strings"
 	"syscall"
 
 	"github.com/asaskevich/EventBus"
@@ -313,6 +315,23 @@ func newDcpConfig(path string) (config.Dcp, error) {
 	if err != nil {
 		return config.Dcp{}, err
 	}
+
+	envPattern := regexp.MustCompile(`\${([^}]+)}`)
+
+	matches := envPattern.FindAllStringSubmatch(string(file), -1)
+	for _, match := range matches {
+		envVar := match[1]
+		if value, exists := os.LookupEnv(envVar); exists {
+			updatedFile := strings.ReplaceAll(string(file), "${"+envVar+"}", value)
+			file = []byte(updatedFile)
+		}
+	}
+
+	err = yaml.Unmarshal(file, &c)
+	if err != nil {
+		return config.Dcp{}, err
+	}
+
 	return c, nil
 }
 

dcp_test.go

@@ -251,3 +251,43 @@ func TestDcp(t *testing.T) {
 		test(t, version)
 	})
 }
+
+func TestNewDcpConfigWithEnvVariables(t *testing.T) {
+	os.Setenv("DCP_USERNAME", "envUser")
+	os.Setenv("DCP_PASSWORD", "envPass")
+	os.Setenv("DCP_BUCKET_NAME", "envBucket")
+
+	configContent := `
+hosts: ["localhost:8091"]
+username: ${DCP_USERNAME}
+password: ${DCP_PASSWORD}
+bucketName: ${DCP_BUCKET_NAME}
+`
+	tmpFile, err := os.CreateTemp("", "config-*.yaml")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.Remove(tmpFile.Name())
+
+	if _, err := tmpFile.Write([]byte(configContent)); err != nil {
+		t.Fatal(err)
+	}
+	if err := tmpFile.Close(); err != nil {
+		t.Fatal(err)
+	}
+
+	config, err := newDcpConfig(tmpFile.Name())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if config.Username != "envUser" {
+		t.Errorf("expected username to be 'envUser', got '%s'", config.Username)
+	}
+	if config.Password != "envPass" {
+		t.Errorf("expected password to be 'envPass', got '%s'", config.Password)
+	}
+	if config.BucketName != "envBucket" {
+		t.Errorf("expected bucketName to be 'envBucket', got '%s'", config.BucketName)
+	}
+}