clair/worker/detectors/data.go
Jimmy Zelinskie 53e62577bc api/worker: s/Authorization/Headers (#167)
This allows clients to specify any HTTP headers that need to be used in
order to allow Clair to download a layer, rather than just the
Authorization header.
2016-05-05 13:48:10 -04:00

123 lines
3.7 KiB
Go

// Copyright 2015 clair authors
//
// 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 detectors exposes functions to register and use container
// information extractors.
package detectors
import (
"fmt"
"io"
"math"
"net/http"
"os"
"strings"
"sync"
cerrors "github.com/coreos/clair/utils/errors"
"github.com/coreos/pkg/capnslog"
)
// The DataDetector interface defines a way to detect the required data from input path
type DataDetector interface {
//Support check if the input path and format are supported by the underling detector
Supported(path string, format string) bool
// Detect detects the required data from input path
Detect(layerReader io.ReadCloser, toExtract []string, maxFileSize int64) (data map[string][]byte, err error)
}
var (
dataDetectorsLock sync.Mutex
dataDetectors = make(map[string]DataDetector)
log = capnslog.NewPackageLogger("github.com/coreos/clair", "detectors")
// ErrCouldNotFindLayer is returned when we could not download or open the layer file.
ErrCouldNotFindLayer = cerrors.NewBadRequestError("could not find layer")
)
// RegisterDataDetector provides a way to dynamically register an implementation of a
// DataDetector.
//
// If RegisterDataDetector is called twice with the same name if DataDetector is nil,
// or if the name is blank, it panics.
func RegisterDataDetector(name string, f DataDetector) {
if name == "" {
panic("Could not register a DataDetector with an empty name")
}
if f == nil {
panic("Could not register a nil DataDetector")
}
dataDetectorsLock.Lock()
defer dataDetectorsLock.Unlock()
if _, alreadyExists := dataDetectors[name]; alreadyExists {
panic(fmt.Sprintf("Detector '%s' is already registered", name))
}
dataDetectors[name] = f
}
// DetectData finds the Data of the layer by using every registered DataDetector
func DetectData(format, path string, headers map[string]string, toExtract []string, maxFileSize int64) (data map[string][]byte, err error) {
var layerReader io.ReadCloser
if strings.HasPrefix(path, "http://") || strings.HasPrefix(path, "https://") {
// Create a new HTTP request object.
request, err := http.NewRequest("GET", path, nil)
if err != nil {
return nil, ErrCouldNotFindLayer
}
// Set any provided HTTP Headers.
if headers != nil {
for k, v := range headers {
request.Header.Set(k, v)
}
}
// Send the request and handle the response.
r, err := http.DefaultClient.Do(request)
if err != nil {
log.Warningf("could not download layer: %s", err)
return nil, ErrCouldNotFindLayer
}
// Fail if we don't receive a 2xx HTTP status code.
if math.Floor(float64(r.StatusCode/100)) != 2 {
log.Warningf("could not download layer: got status code %d, expected 2XX", r.StatusCode)
return nil, ErrCouldNotFindLayer
}
layerReader = r.Body
} else {
layerReader, err = os.Open(path)
if err != nil {
return nil, ErrCouldNotFindLayer
}
}
defer layerReader.Close()
for _, detector := range dataDetectors {
if detector.Supported(path, format) {
data, err = detector.Detect(layerReader, toExtract, maxFileSize)
if err != nil {
return nil, err
}
return data, nil
}
}
return nil, cerrors.NewBadRequestError(fmt.Sprintf("unsupported image format '%s'", format))
}