Add virt-xml sidecar hook

The virt-xml tools is a command line utility for editing libvirt XML.

This setup introduces a new hook to integrate virt-xml in KubeVirt.
Using virt-xml allows to use a well-maintained tool to try and test unsupported
options by the KubeVirt APIs.

This feature is supposed to help developers to try and test unsupported
options without the need to develop their own sidecar.

Signed-off-by: Alice Frosi <afrosi@redhat.com>

BUILD.bazel

@@ -291,6 +291,15 @@ container_push(
     tag = "$(container_tag)",
 )
 
+container_push(
+    name = "push-virt-xml-hook",
+    format = "Docker",
+    image = "//cmd/virt-xml-hook:virt-xml-hook-image",
+    registry = "$(container_prefix)",
+    repository = "$(image_prefix)virt-xml-hook",
+    tag = "$(container_tag)",
+)
+
 genrule(
     name = "build-virtctl",
     srcs = [

cmd/virt-xml-hook/BUILD.bazel

@@ -0,0 +1,49 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+load(
+    "@io_bazel_rules_docker//container:container.bzl",
+    "container_image",
+)
+
+container_image(
+    name = "version-container",
+    tars = select({
+        "//conditions:default": [
+            "//rpm:hookxmlbase_x86_64",
+        ],
+    }),
+)
+
+container_image(
+    name = "virt-xml-hook-image",
+    architecture = select({
+        "@io_bazel_rules_go//go/platform:linux_arm64": "arm64",
+        "//conditions:default": "amd64",
+    }),
+    base = ":version-container",
+    directory = "/",
+    entrypoint = ["/virt-xml-hook"],
+    files = [":virt-xml-hook"],
+    visibility = ["//visibility:public"],
+)
+
+go_library(
+    name = "go_default_library",
+    srcs = ["virt_xml_hook.go"],
+    importpath = "kubevirt.io/kubevirt/cmd/virt-xml-hook",
+    visibility = ["//visibility:private"],
+    deps = [
+        "//pkg/hooks:go_default_library",
+        "//pkg/hooks/info:go_default_library",
+        "//pkg/hooks/v1alpha1:go_default_library",
+        "//pkg/hooks/v1alpha2:go_default_library",
+        "//staging/src/kubevirt.io/client-go/log:go_default_library",
+        "//vendor/github.com/spf13/pflag:go_default_library",
+        "@org_golang_google_grpc//:go_default_library",
+    ],
+)
+
+go_binary(
+    name = "virt-xml-hook",
+    embed = [":go_default_library"],
+    visibility = ["//visibility:public"],
+)

cmd/virt-xml-hook/virt_xml_hook.go

@@ -0,0 +1,139 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"net"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/spf13/pflag"
+	"google.golang.org/grpc"
+
+	"kubevirt.io/client-go/log"
+	"kubevirt.io/kubevirt/pkg/hooks"
+	hooksInfo "kubevirt.io/kubevirt/pkg/hooks/info"
+	hooksV1alpha1 "kubevirt.io/kubevirt/pkg/hooks/v1alpha1"
+	hooksV1alpha2 "kubevirt.io/kubevirt/pkg/hooks/v1alpha2"
+)
+
+const (
+	onDefineDomainLoggingMessage = "Hook's OnDefineDomain callback method has been called"
+	usage                        = `updater
+  --version v1alpha1|v1alpha2
+  --args ''`
+)
+
+type infoServer struct {
+	Version string
+}
+
+func (s infoServer) Info(ctx context.Context, params *hooksInfo.InfoParams) (*hooksInfo.InfoResult, error) {
+	log.Log.Info("Hook's Info method has been called")
+
+	return &hooksInfo.InfoResult{
+		Name: "update-xml",
+		Versions: []string{
+			s.Version,
+		},
+		HookPoints: []*hooksInfo.HookPoint{
+			{
+				Name:     hooksInfo.OnDefineDomainHookPointName,
+				Priority: 0,
+			},
+		},
+	}, nil
+}
+
+const virtXML = "virt-xml"
+
+type v1alpha1Server struct {
+	args []string
+}
+
+type v1alpha2Server struct {
+	args []string
+}
+
+func MergeKubeVirtXMLWithProvidedXML(domainXML []byte, args []string) ([]byte, error) {
+	args = append(args, "--edit")
+	args = append(args, "--print-xml")
+	cmd := exec.Command(virtXML, args...)
+	cmd.Stdin = strings.NewReader(string(domainXML))
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+	log.Log.Infof("Execute command: %s", cmd.String())
+	out, err := cmd.Output()
+	if err != nil {
+		log.Log.Errorf("Fail running command stdout:%s stderr: %s error:%v", out, stderr.String(), err)
+		return []byte{}, err
+	}
+
+	return []byte(out), nil
+}
+
+func (s v1alpha2Server) OnDefineDomain(ctx context.Context, params *hooksV1alpha2.OnDefineDomainParams) (*hooksV1alpha2.OnDefineDomainResult, error) {
+	log.Log.Info(onDefineDomainLoggingMessage)
+	newDomainXML, err := MergeKubeVirtXMLWithProvidedXML(params.GetDomainXML(), s.args)
+	if err != nil {
+		return nil, err
+	}
+	return &hooksV1alpha2.OnDefineDomainResult{
+		DomainXML: newDomainXML,
+	}, nil
+}
+func (s v1alpha2Server) PreCloudInitIso(_ context.Context, params *hooksV1alpha2.PreCloudInitIsoParams) (*hooksV1alpha2.PreCloudInitIsoResult, error) {
+	return &hooksV1alpha2.PreCloudInitIsoResult{
+		CloudInitData: params.GetCloudInitData(),
+	}, nil
+}
+
+func (s v1alpha1Server) OnDefineDomain(ctx context.Context, params *hooksV1alpha1.OnDefineDomainParams) (*hooksV1alpha1.OnDefineDomainResult, error) {
+	log.Log.Info(onDefineDomainLoggingMessage)
+	newDomainXML, err := MergeKubeVirtXMLWithProvidedXML(params.GetVmi(), s.args)
+	if err != nil {
+		return nil, err
+	}
+	return &hooksV1alpha1.OnDefineDomainResult{
+		DomainXML: newDomainXML,
+	}, nil
+}
+
+func main() {
+	log.InitializeLogging("xml update")
+
+	var version string
+	pflag.StringVar(&version, "version", "", "hook version to use")
+
+	var options string
+	pflag.StringVar(&options, "args", "", "params to pass to virt-xml")
+	pflag.Parse()
+
+	args := strings.Split(options, "|")
+
+	socketPath := hooks.HookSocketsSharedDirectory + "/update.sock"
+	socket, err := net.Listen("unix", socketPath)
+	if err != nil {
+		log.Log.Reason(err).Errorf("Failed to initialized socket on path: %s", socket)
+		log.Log.Error("Check whether given directory exists and socket name is not already taken by other file")
+		panic(err)
+	}
+	defer os.Remove(socketPath)
+
+	server := grpc.NewServer([]grpc.ServerOption{}...)
+
+	if version == "" {
+		panic(fmt.Errorf(usage))
+	}
+	if options == "" {
+		panic(fmt.Errorf(usage))
+	}
+
+	hooksInfo.RegisterInfoServer(server, infoServer{Version: version})
+	hooksV1alpha1.RegisterCallbacksServer(server, v1alpha1Server{args: args})
+	hooksV1alpha2.RegisterCallbacksServer(server, v1alpha2Server{args: args})
+	log.Log.Infof("Starting hook server exposing 'info' and 'v1alpha1' services on socket %s", socketPath)
+	server.Serve(socket)
+}

examples/vmi-with-virt-xml-sidecar-hook.yaml

@@ -0,0 +1,34 @@
+---
+apiVersion: kubevirt.io/v1
+kind: VirtualMachineInstance
+metadata:
+  annotations:
+    hooks.kubevirt.io/hookSidecars: '[{"args": ["--version", "v1alpha2", "--args", "--disk=iotune.total_bytes_sec=52428800,iotune.total_iops_sec=1000|--edit=all"], "image":"registry:5000/kubevirt/virt-xml-hook:devel", "imagePullPolicy": "Always"}]'
+  labels:
+    special: vmi-with-virt-xml
+  name: vmi-with-virt-xml
+spec:
+  domain:
+    devices:
+      disks:
+      - disk:
+          bus: virtio
+        name: containerdisk
+      - disk:
+          bus: virtio
+        name: cloudinitdisk
+      rng: {}
+    resources:
+      requests:
+        memory: 1024M
+  terminationGracePeriodSeconds: 0
+  volumes:
+  - containerDisk:
+      image: registry:5000/kubevirt/fedora-with-test-tooling-container-disk:devel
+    name: containerdisk
+  - cloudInitNoCloud:
+      userData: |-
+        #cloud-config
+        password: fedora
+        chpasswd: { expire: False }
+    name: cloudinitdisk

hack/bazel-build-images.sh

@@ -30,7 +30,7 @@ bazel build \
     --define image_prefix= \
     --define container_tag= \
     //:build-other-images //cmd/virt-operator:virt-operator-image //cmd/virt-api:virt-api-image \
-    //cmd/virt-controller:virt-controller-image //cmd/virt-handler:virt-handler-image //cmd/virt-launcher:virt-launcher-image //cmd/libguestfs:libguestfs-tools-image //tests:conformance_image
+    //cmd/virt-controller:virt-controller-image //cmd/virt-handler:virt-handler-image //cmd/virt-launcher:virt-launcher-image //cmd/libguestfs:libguestfs-tools-image //cmd/virt-xml-hook //tests:conformance_image
 
 rm -rf ${DIGESTS_DIR}
 mkdir -p ${DIGESTS_DIR}

hack/bazel-push-images.sh

@@ -23,7 +23,7 @@ source hack/common.sh
 source hack/bootstrap.sh
 source hack/config.sh
 
-PUSH_TARGETS=(${PUSH_TARGETS:-other-images virt-operator virt-api virt-controller virt-handler virt-launcher conformance libguestfs})
+PUSH_TARGETS=(${PUSH_TARGETS:-other-images virt-operator virt-api virt-controller virt-handler virt-launcher conformance libguestfs virt-xml-hook})
 
 for tag in ${docker_tag} ${docker_tag_alt}; do
     for target in ${PUSH_TARGETS[@]}; do

hack/bootstrap.sh

@@ -26,7 +26,7 @@ KUBEVIRT_NO_BAZEL=${KUBEVIRT_NO_BAZEL:-false}
 HOST_ARCHITECTURE="$(uname -m)"
 
 sandbox_root=${SANDBOX_DIR}/default/root
-sandbox_hash="b0e5d57b5529f4b066f9e8719cee63f6f7d5c418"
+sandbox_hash="c3b12fc06fa2c519988f19abbd3d32b97fd3b07f"
 
 function kubevirt::bootstrap::regenerate() {
     (

hack/rpm-deps.sh

@@ -127,6 +127,10 @@ libguestfstools_x86_64="
   edk2-ovmf-${EDK2_VERSION}
 "
 
+hookxml_base="
+  virt-install
+"
+
 if [ -z "${SINGLE_ARCH}" ] || [ "${SINGLE_ARCH}" == "x86_64" ]; then
 
     bazel run \
@@ -207,6 +211,15 @@ if [ -z "${SINGLE_ARCH}" ] || [ "${SINGLE_ARCH}" == "x86_64" ]; then
         --force-ignore-with-dependencies '^(man-db|mandoc)' \
         --force-ignore-with-dependencies '^dbus'
 
+    # create a rpmtree for virt-handler
+    bazel run \
+        --config=${ARCHITECTURE} \
+        //:bazeldnf -- rpmtree --public --name hookxmlbase_x86_64 \
+        --basesystem centos-stream-release \
+        ${bazeldnf_repos} \
+        $centos_base \
+        $hookxml_base
+
     # remove all RPMs which are no longer referenced by a rpmtree
     bazel run \
         --config=${ARCHITECTURE} \