groundwork (#140)

kubernetes/migration/corefile/corefile.go

@@ -0,0 +1,178 @@
+package corefile
+
+import (
+	"github.com/mholt/caddy"
+	"strings"
+)
+
+type Corefile struct {
+	Servers []*Server
+}
+
+type Server struct {
+	DomPorts []string
+	Plugins  []*Plugin
+}
+
+type Plugin struct {
+	Name    string
+	Args    []string
+	Options []*Option
+}
+
+type Option struct {
+	Name string
+	Args []string
+}
+
+func New(s string) (Corefile, error) {
+	c := Corefile{}
+	cc := caddy.NewTestController("migration", s)
+	depth := 0
+	var cSvr *Server
+	var cPlg *Plugin
+	for cc.Next() {
+		if cc.Val() == "{" {
+			depth += 1
+			continue
+		} else if cc.Val() == "}" {
+			depth -= 1
+			continue
+		}
+		val := cc.Val()
+		args := cc.RemainingArgs()
+		switch depth {
+		case 0:
+			c.Servers = append(c.Servers,
+				&Server{
+					DomPorts: append([]string{val}, args...),
+				})
+			cSvr = c.Servers[len(c.Servers)-1]
+		case 1:
+			cSvr.Plugins = append(cSvr.Plugins,
+				&Plugin{
+					Name: val,
+					Args: args,
+				})
+			cPlg = cSvr.Plugins[len(cSvr.Plugins)-1]
+		case 2:
+			cPlg.Options = append(cPlg.Options,
+				&Option{
+					Name: val,
+					Args: args,
+				})
+		}
+	}
+	return c, nil
+}
+
+func (c *Corefile) ToString() (out string) {
+	strs := []string{}
+	for _, s := range c.Servers {
+		strs = append(strs, s.ToString())
+	}
+	return strings.Join(strs, "\n")
+}
+
+func (s *Server) ToString() (out string) {
+	str := strings.Join(s.DomPorts, " ")
+	strs := []string{}
+	for _, p := range s.Plugins {
+		strs = append(strs, strings.Repeat(" ", indent)+p.ToString())
+	}
+	if len(strs) > 0 {
+		str += " {\n" + strings.Join(strs, "\n") + "\n}\n"
+	}
+	return str
+}
+
+func (p *Plugin) ToString() (out string) {
+	str := strings.Join(append([]string{p.Name}, p.Args...), " ")
+	strs := []string{}
+	for _, o := range p.Options {
+		strs = append(strs, strings.Repeat(" ", indent*2)+o.ToString())
+	}
+	if len(strs) > 0 {
+		str += " {\n" + strings.Join(strs, "\n") + "\n" + strings.Repeat(" ", indent*1) + "}"
+	}
+	return str
+}
+
+func (o *Option) ToString() (out string) {
+	str := strings.Join(append([]string{o.Name}, o.Args...), " ")
+	return str
+}
+
+func (s *Server) FindMatch(def []*Server) (*Server, bool) {
+NextServer:
+	for _, sDef := range def {
+		for i, dp := range sDef.DomPorts {
+			if dp == "*" {
+				continue
+			}
+			if dp == "***" {
+				return sDef, true
+			}
+			if i >= len(s.DomPorts) || dp != s.DomPorts[i] {
+				continue NextServer
+			}
+		}
+		if len(sDef.DomPorts) != len(s.DomPorts) {
+			continue
+		}
+		return sDef, true
+	}
+	return nil, false
+}
+
+func (p *Plugin) FindMatch(def []*Plugin) (*Plugin, bool) {
+NextPlugin:
+	for _, pDef := range def {
+		if pDef.Name != p.Name {
+			continue
+		}
+		for i, arg := range pDef.Args {
+			if arg == "*" {
+				continue
+			}
+			if arg == "***" {
+				return pDef, true
+			}
+			if i >= len(p.Args) || arg != p.Args[i] {
+				continue NextPlugin
+			}
+		}
+		if len(pDef.Args) != len(p.Args) {
+			continue
+		}
+		return pDef, true
+	}
+	return nil, false
+}
+
+func (o *Option) FindMatch(def []*Option) (*Option, bool) {
+NextPlugin:
+	for _, oDef := range def {
+		if oDef.Name != o.Name {
+			continue
+		}
+		for i, arg := range oDef.Args {
+			if arg == "*" {
+				continue
+			}
+			if arg == "***" {
+				return oDef, true
+			}
+			if i >= len(o.Args) || arg != o.Args[i] {
+				continue NextPlugin
+			}
+		}
+		if len(oDef.Args) != len(o.Args) {
+			continue
+		}
+		return oDef, true
+	}
+	return nil, false
+}
+
+const indent = 4