feat: Add https tar.gz remote source for context (#1519)

* feat: Add https tar.gz remote source for context

* Add license header

* add license header

Co-authored-by: Tejal Desai <tejal29@gmail.com>

pkg/buildcontext/https.go

@@ -0,0 +1,79 @@
+/*
+Copyright 2018 Google LLC
+
+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 buildcontext
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+
+	"github.com/GoogleContainerTools/kaniko/pkg/constants"
+	"github.com/GoogleContainerTools/kaniko/pkg/util"
+	"github.com/sirupsen/logrus"
+)
+
+// HTTPSTar struct for https tar.gz files processing
+type HTTPSTar struct {
+	context string
+}
+
+// UnpackTarFromBuildContext downloads context file from https server
+func (h *HTTPSTar) UnpackTarFromBuildContext() (directory string, err error) {
+
+	logrus.Info("Retrieving https tar file")
+
+	// Create directory and target file for downloading the context file
+	directory = constants.BuildContextDir
+	tarPath := filepath.Join(directory, constants.ContextTar)
+	file, err := util.CreateTargetTarfile(tarPath)
+	if err != nil {
+		return
+	}
+
+	// Download tar file from remote https server
+	// and save it into the target tar file
+	resp, err := http.Get(h.context)
+	if err != nil {
+		return
+	}
+	defer func() {
+		if closeErr := resp.Body.Close(); err == nil && closeErr != nil {
+			err = closeErr
+		}
+	}()
+
+	if resp.StatusCode != http.StatusOK {
+		return directory, fmt.Errorf("HTTPSTar bad status from server: %s", resp.Status)
+	}
+
+	if _, err = io.Copy(file, resp.Body); err != nil {
+		return tarPath, err
+	}
+
+	logrus.Info("Retrieved https tar file")
+
+	if err = util.UnpackCompressedTar(tarPath, directory); err != nil {
+		return
+	}
+
+	logrus.Info("Extracted https tar file")
+
+	// Remove the tar so it doesn't interfere with subsequent commands
+	return directory, os.Remove(tarPath)
+}