traefik/rules.go
2016-11-17 15:36:10 +01:00

202 lines
5.2 KiB
Go

package main
import (
"errors"
"fmt"
"github.com/BurntSushi/ty/fun"
"github.com/containous/mux"
"github.com/containous/traefik/types"
"net"
"net/http"
"reflect"
"sort"
"strings"
)
// Rules holds rule parsing and configuration
type Rules struct {
route *serverRoute
err error
}
func (r *Rules) host(hosts ...string) *mux.Route {
return r.route.route.MatcherFunc(func(req *http.Request, route *mux.RouteMatch) bool {
reqHost, _, err := net.SplitHostPort(req.Host)
if err != nil {
reqHost = req.Host
}
for _, host := range hosts {
if types.CanonicalDomain(reqHost) == types.CanonicalDomain(host) {
return true
}
}
return false
})
}
func (r *Rules) hostRegexp(hosts ...string) *mux.Route {
router := r.route.route.Subrouter()
for _, host := range hosts {
router.Host(types.CanonicalDomain(host))
}
return r.route.route
}
func (r *Rules) path(paths ...string) *mux.Route {
router := r.route.route.Subrouter()
for _, path := range paths {
router.Path(strings.TrimSpace(path))
}
return r.route.route
}
func (r *Rules) pathPrefix(paths ...string) *mux.Route {
router := r.route.route.Subrouter()
for _, path := range paths {
router.PathPrefix(strings.TrimSpace(path))
}
return r.route.route
}
type bySize []string
func (a bySize) Len() int { return len(a) }
func (a bySize) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a bySize) Less(i, j int) bool { return len(a[i]) > len(a[j]) }
func (r *Rules) pathStrip(paths ...string) *mux.Route {
sort.Sort(bySize(paths))
r.route.stripPrefixes = paths
router := r.route.route.Subrouter()
for _, path := range paths {
router.Path(strings.TrimSpace(path))
}
return r.route.route
}
func (r *Rules) pathPrefixStrip(paths ...string) *mux.Route {
sort.Sort(bySize(paths))
r.route.stripPrefixes = paths
router := r.route.route.Subrouter()
for _, path := range paths {
router.PathPrefix(strings.TrimSpace(path))
}
return r.route.route
}
func (r *Rules) methods(methods ...string) *mux.Route {
return r.route.route.Methods(methods...)
}
func (r *Rules) headers(headers ...string) *mux.Route {
return r.route.route.Headers(headers...)
}
func (r *Rules) headersRegexp(headers ...string) *mux.Route {
return r.route.route.HeadersRegexp(headers...)
}
func (r *Rules) parseRules(expression string, onRule func(functionName string, function interface{}, arguments []string) error) error {
functions := map[string]interface{}{
"Host": r.host,
"HostRegexp": r.hostRegexp,
"Path": r.path,
"PathStrip": r.pathStrip,
"PathPrefix": r.pathPrefix,
"PathPrefixStrip": r.pathPrefixStrip,
"Method": r.methods,
"Headers": r.headers,
"HeadersRegexp": r.headersRegexp,
}
if len(expression) == 0 {
return errors.New("Empty rule")
}
f := func(c rune) bool {
return c == ':'
}
// Allow multiple rules separated by ;
splitRule := func(c rune) bool {
return c == ';'
}
parsedRules := strings.FieldsFunc(expression, splitRule)
for _, rule := range parsedRules {
// get function
parsedFunctions := strings.FieldsFunc(rule, f)
if len(parsedFunctions) == 0 {
return errors.New("Error parsing rule: '" + rule + "'")
}
functionName := strings.TrimSpace(parsedFunctions[0])
parsedFunction, ok := functions[functionName]
if !ok {
return errors.New("Error parsing rule: '" + rule + "'. Unknown function: '" + parsedFunctions[0] + "'")
}
parsedFunctions = append(parsedFunctions[:0], parsedFunctions[1:]...)
fargs := func(c rune) bool {
return c == ','
}
// get function
parsedArgs := strings.FieldsFunc(strings.Join(parsedFunctions, ":"), fargs)
if len(parsedArgs) == 0 {
return errors.New("Error parsing args from rule: '" + rule + "'")
}
for i := range parsedArgs {
parsedArgs[i] = strings.TrimSpace(parsedArgs[i])
}
err := onRule(functionName, parsedFunction, parsedArgs)
if err != nil {
return fmt.Errorf("Parsing error on rule: %v", err)
}
}
return nil
}
// Parse parses rules expressions
func (r *Rules) Parse(expression string) (*mux.Route, error) {
var resultRoute *mux.Route
err := r.parseRules(expression, func(functionName string, function interface{}, arguments []string) error {
inputs := make([]reflect.Value, len(arguments))
for i := range arguments {
inputs[i] = reflect.ValueOf(arguments[i])
}
method := reflect.ValueOf(function)
if method.IsValid() {
resultRoute = method.Call(inputs)[0].Interface().(*mux.Route)
if r.err != nil {
return r.err
}
if resultRoute.GetError() != nil {
return resultRoute.GetError()
}
} else {
return errors.New("Method not found: '" + functionName + "'")
}
return nil
})
if err != nil {
return nil, fmt.Errorf("Error parsing rule: %v", err)
}
return resultRoute, nil
}
// ParseDomains parses rules expressions and returns domains
func (r *Rules) ParseDomains(expression string) ([]string, error) {
domains := []string{}
err := r.parseRules(expression, func(functionName string, function interface{}, arguments []string) error {
if functionName == "Host" {
domains = append(domains, arguments...)
}
return nil
})
if err != nil {
return nil, fmt.Errorf("Error parsing domains: %v", err)
}
return fun.Map(types.CanonicalDomain, domains).([]string), nil
}