First commit

core/setup/errors.go

@@ -0,0 +1,132 @@
+package setup
+
+import (
+	"io"
+	"log"
+	"os"
+
+	"github.com/hashicorp/go-syslog"
+	"github.com/miekg/coredns/middleware"
+	"github.com/miekg/coredns/middleware/errors"
+)
+
+// Errors configures a new errors middleware instance.
+func Errors(c *Controller) (middleware.Middleware, error) {
+	handler, err := errorsParse(c)
+	if err != nil {
+		return nil, err
+	}
+
+	// Open the log file for writing when the server starts
+	c.Startup = append(c.Startup, func() error {
+		var err error
+		var writer io.Writer
+
+		switch handler.LogFile {
+		case "visible":
+			handler.Debug = true
+		case "stdout":
+			writer = os.Stdout
+		case "stderr":
+			writer = os.Stderr
+		case "syslog":
+			writer, err = gsyslog.NewLogger(gsyslog.LOG_ERR, "LOCAL0", "caddy")
+			if err != nil {
+				return err
+			}
+		default:
+			if handler.LogFile == "" {
+				writer = os.Stderr // default
+				break
+			}
+
+			var file *os.File
+			file, err = os.OpenFile(handler.LogFile, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
+			if err != nil {
+				return err
+			}
+			if handler.LogRoller != nil {
+				file.Close()
+
+				handler.LogRoller.Filename = handler.LogFile
+
+				writer = handler.LogRoller.GetLogWriter()
+			} else {
+				writer = file
+			}
+		}
+
+		handler.Log = log.New(writer, "", 0)
+		return nil
+	})
+
+	return func(next middleware.Handler) middleware.Handler {
+		handler.Next = next
+		return handler
+	}, nil
+}
+
+func errorsParse(c *Controller) (*errors.ErrorHandler, error) {
+	// Very important that we make a pointer because the Startup
+	// function that opens the log file must have access to the
+	// same instance of the handler, not a copy.
+	handler := &errors.ErrorHandler{}
+
+	optionalBlock := func() (bool, error) {
+		var hadBlock bool
+
+		for c.NextBlock() {
+			hadBlock = true
+
+			what := c.Val()
+			if !c.NextArg() {
+				return hadBlock, c.ArgErr()
+			}
+			where := c.Val()
+
+			if what == "log" {
+				if where == "visible" {
+					handler.Debug = true
+				} else {
+					handler.LogFile = where
+					if c.NextArg() {
+						if c.Val() == "{" {
+							c.IncrNest()
+							logRoller, err := parseRoller(c)
+							if err != nil {
+								return hadBlock, err
+							}
+							handler.LogRoller = logRoller
+						}
+					}
+				}
+			}
+		}
+		return hadBlock, nil
+	}
+
+	for c.Next() {
+		// weird hack to avoid having the handler values overwritten.
+		if c.Val() == "}" {
+			continue
+		}
+		// Configuration may be in a block
+		hadBlock, err := optionalBlock()
+		if err != nil {
+			return handler, err
+		}
+
+		// Otherwise, the only argument would be an error log file name or 'visible'
+		if !hadBlock {
+			if c.NextArg() {
+				if c.Val() == "visible" {
+					handler.Debug = true
+				} else {
+					handler.LogFile = c.Val()
+				}
+			}
+		}
+	}
+
+	return handler, nil
+}