forked from zalando/skipper
/
modpath.go
73 lines (60 loc) · 1.95 KB
/
modpath.go
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// Copyright 2015 Zalando SE
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package builtin
import (
"fmt"
"github.com/zalando/skipper/filters"
"regexp"
)
type modPath struct {
rx *regexp.Regexp
replacement []byte
}
// Returns a new modpath filter Spec, whose instances execute
// regexp.ReplaceAll on the request path. Instances expect two
// parameters: the expression to match and the replacement string.
// Name: "modpath".
func NewModPath() filters.Spec { return &modPath{} }
// "modPath"
func (spec *modPath) Name() string { return ModPathName }
func invalidConfig(config []interface{}) error {
return fmt.Errorf("invalid filter config in %s, expecting regexp and string, got: %v", ModPathName, config)
}
// Creates instances of the modPath filter.
func (spec *modPath) CreateFilter(config []interface{}) (filters.Filter, error) {
if len(config) != 2 {
return nil, invalidConfig(config)
}
expr, ok := config[0].(string)
if !ok {
return nil, invalidConfig(config)
}
replacement, ok := config[1].(string)
if !ok {
return nil, invalidConfig(config)
}
rx, err := regexp.Compile(expr)
if err != nil {
return nil, err
}
f := &modPath{rx, []byte(replacement)}
return f, nil
}
// Modifies the path with regexp.ReplaceAll.
func (f *modPath) Request(ctx filters.FilterContext) {
req := ctx.Request()
req.URL.Path = string(f.rx.ReplaceAll([]byte(req.URL.Path), f.replacement))
}
// Noop.
func (f *modPath) Response(ctx filters.FilterContext) {}