1 files changed, 81 insertions, 0 deletions
diff --git a/plugin_generate.go b/plugin_generate.go
new file mode 100644
index 000000000..fe8fef75d
--- /dev/null
+++ b/plugin_generate.go
@@ -0,0 +1,81 @@
+//+build ignore
+
+package main
+
+import (
+	"bytes"
+	"errors"
+	"go/ast"
+	"go/parser"
+	"go/printer"
+	"go/token"
+	"io/ioutil"
+	"log"
+	"strconv"
+)
+
+func AddImportToFile(file, imprt string) ([]byte, error) {
+	fset := token.NewFileSet()
+	f, err := parser.ParseFile(fset, file, nil, parser.ParseComments)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, s := range f.Imports {
+		iSpec := &ast.ImportSpec{Path: &ast.BasicLit{Value: s.Path.Value}}
+		if iSpec.Path.Value == strconv.Quote(imprt) {
+			return nil, errors.New("coredns import already found")
+		}
+	}
+
+	for i := 0; i < len(f.Decls); i++ {
+		d := f.Decls[i]
+
+		switch d.(type) {
+		case *ast.FuncDecl:
+			// No action
+		case *ast.GenDecl:
+			dd := d.(*ast.GenDecl)
+
+			// IMPORT Declarations
+			if dd.Tok == token.IMPORT {
+				// Add the new import
+				iSpec := &ast.ImportSpec{Name: &ast.Ident{Name: "_"}, Path: &ast.BasicLit{Value: strconv.Quote(imprt)}}
+				dd.Specs = append(dd.Specs, iSpec)
+				break
+			}
+		}
+	}
+
+	ast.SortImports(fset, f)
+
+	out, err := GenerateFile(fset, f)
+	return out, err
+}
+
+func GenerateFile(fset *token.FileSet, file *ast.File) ([]byte, error) {
+	var output []byte
+	buffer := bytes.NewBuffer(output)
+	if err := printer.Fprint(buffer, fset, file); err != nil {
+		return nil, err
+	}
+
+	return buffer.Bytes(), nil
+}
+
+const (
+	coredns = "github.com/miekg/coredns/core"
+	// If everything is OK and we are sitting in CoreDNS' dir, this is where run.go should be.
+	caddyrun = "../../mholt/caddy/caddy/caddymain/run.go"
+)
+
+func main() {
+	out, err := AddImportToFile(caddyrun, coredns)
+	if err != nil {
+		log.Printf("failed to add import: %s", err)
+		return
+	}
+	if err := ioutil.WriteFile(caddyrun, out, 0644); err != nil {
+		log.Fatalf("failed to write go file: %s", err)
+	}
+}