Streaming qcow2->raw conversion and resource limits on qemu-img subprocess

.gitignore

@@ -7,3 +7,4 @@ release-announcement
 .project
 .vscode
 cluster/.*
+.history

hack/build/docker/builder/Dockerfile

@@ -1,4 +1,4 @@
-FROM fedora:27
+FROM fedora:28
 
 RUN dnf install -y qemu xz gzip git && dnf clean all
 

hack/build/docker/cdi-controller/Dockerfile

@@ -1,4 +1,4 @@
-FROM fedora:27
+FROM fedora:28
 
 COPY ./cdi-controller /usr/bin/cdi-controller
 

hack/build/docker/cdi-func-test-file-host-init/Dockerfile

@@ -2,7 +2,7 @@ FROM fedora:28
 
 RUN mkdir -p /tmp/shared /tmp/source
 
-RUN yum install -y qemu-img
+RUN yum install -y qemu-img qemu-block-curl && dnf clean all
 
 COPY cdi-func-test-file-host-init /usr/bin/
 

hack/build/docker/cdi-importer/Dockerfile

@@ -1,6 +1,6 @@
-FROM fedora:27
+FROM fedora:28
 
-RUN dnf install -y qemu-img
+RUN dnf install -y qemu-img qemu-block-curl && dnf clean all
 
 RUN mkdir /data
 

pkg/image/qemu.go

@@ -1,18 +1,119 @@
+/*
+Copyright 2018 The CDI 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 image
 
 import (
-	"os/exec"
+	"encoding/json"
+	"fmt"
+	"net/url"
 
+	"github.com/golang/glog"
 	"github.com/pkg/errors"
+
+	"kubevirt.io/containerized-data-importer/pkg/system"
 )
 
-// ConvertQcow2ToRaw is a wrapper for qemu-img convert which takes a qcow2 file (specified by src) and converts
-// it to a raw image (written to the provided dest file)
-func ConvertQcow2ToRaw(src, dest string) error {
-	cmd := exec.Command("qemu-img", "convert", "-f", "qcow2", "-O", "raw", src, dest)
-	err := cmd.Run()
+const (
+	networkTimeoutSecs = 3600    //max is 10000
+	maxMemory          = 1 << 30 //value from OpenStack Nova
+	maxCPUSecs         = 30      //value from OpenStack Nova
+)
+
+// QEMUOperations defines the interface for executing qemu subprocesses
+type QEMUOperations interface {
+	ConvertQcow2ToRaw(string, string) error
+	ConvertQcow2ToRawStream(*url.URL, string) error
+	Validate(string, string) error
+}
+
+type qemuOperations struct{}
+
+var qemuExecFunction = system.ExecWithLimits
+
+var qemuLimits = &system.ProcessLimitValues{AddressSpaceLimit: maxMemory, CPUTimeLimit: maxCPUSecs}
+
+var qemuIterface = NewQEMUOperations()
+
+// NewQEMUOperations returns the default implementation of QEMUOperations
+func NewQEMUOperations() QEMUOperations {
+	return &qemuOperations{}
+}
+
+func (o *qemuOperations) ConvertQcow2ToRaw(src, dest string) error {
+	_, err := qemuExecFunction(qemuLimits, "qemu-img", "convert", "-f", "qcow2", "-O", "raw", src, dest)
+	if err != nil {
+		return errors.Wrap(err, "could not convert local qcow2 image to raw")
+	}
+
+	return nil
+}
+
+func (o *qemuOperations) ConvertQcow2ToRawStream(url *url.URL, dest string) error {
+	jsonArg := fmt.Sprintf("json: {\"file.driver\": \"%s\", \"file.url\": \"%s\", \"file.timeout\": %d}", url.Scheme, url, networkTimeoutSecs)
+
+	_, err := qemuExecFunction(qemuLimits, "qemu-img", "convert", "-f", "qcow2", "-O", "raw", jsonArg, dest)
 	if err != nil {
-		return errors.Wrap(err, "could not convert qcow2 image to raw")
+		return errors.Wrap(err, "could not stream/convert qcow2 image to raw")
 	}
+
 	return nil
 }
+
+func (o *qemuOperations) Validate(image, format string) error {
+	type imageInfo struct {
+		Format      string `json:"format"`
+		BackingFile string `json:"backing-filename"`
+	}
+
+	output, err := qemuExecFunction(qemuLimits, "qemu-img", "info", "--output=json", image)
+	if err != nil {
+		return errors.Wrapf(err, "Error getting info on image %s", image)
+	}
+
+	var info imageInfo
+	err = json.Unmarshal(output, &info)
+	if err != nil {
+		glog.Errorf("Invalid JSON:\n%s\n", string(output))
+		return errors.Wrapf(err, "Invalid json for image %s", image)
+	}
+
+	if info.Format != format {
+		return errors.Errorf("Invalid format %s for image %s", info.Format, image)
+	}
+
+	if len(info.BackingFile) > 0 {
+		return errors.Errorf("Image %s is invalid because it has backing file %s", image, info.BackingFile)
+	}
+
+	return nil
+}
+
+// ConvertQcow2ToRaw is a wrapper for qemu-img convert which takes a qcow2 file (specified by src) and converts
+// it to a raw image (written to the provided dest file)
+func ConvertQcow2ToRaw(src, dest string) error {
+	return qemuIterface.ConvertQcow2ToRaw(src, dest)
+}
+
+// ConvertQcow2ToRawStream converts an http accessible qcow2 image to raw format without locally caching the qcow2 image
+func ConvertQcow2ToRawStream(url *url.URL, dest string) error {
+	return qemuIterface.ConvertQcow2ToRawStream(url, dest)
+}
+
+// Validate does basic validation of a qemu image
+func Validate(image, format string) error {
+	return qemuIterface.Validate(image, format)
+}