intel-device-plugins-for-ku.../cmd/fpga_admissionwebhook/fpga_admissionwebhook.go
2018-07-30 15:29:33 +03:00

435 lines
12 KiB
Go

// Copyright 2018 Intel Corporation. All Rights Reserved.
//
// 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 main
import (
"crypto/tls"
"encoding/json"
"errors"
"flag"
"fmt"
"io/ioutil"
"net/http"
"os"
"regexp"
"strings"
"github.com/golang/glog"
"k8s.io/api/admission/v1beta1"
admissionregistrationv1beta1 "k8s.io/api/admissionregistration/v1beta1"
corev1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/serializer"
"k8s.io/apimachinery/pkg/types"
)
const (
resourceReplaceOp = `{
"op": "remove",
"path": "/spec/containers/%d/resources/%s/%s"
}, {
"op": "add",
"path": "/spec/containers/%d/resources/%s/%s",
"value": %s
}`
envAddOp = `{
"op": "add",
"path": "/spec/containers/%d/env",
"value": [{
"name": "FPGA_REGION",
"value": "%s"
}, {
"name": "FPGA_AFU",
"value": "%s"
} %s]
}`
preprogrammed = "preprogrammed"
orchestrated = "orchestrated"
)
var (
scheme = runtime.NewScheme()
codecs = serializer.NewCodecFactory(scheme)
rfc6901Escaper = strings.NewReplacer("~", "~0", "/", "~1")
resourceRe = regexp.MustCompile(`fpga.intel.com/(?P<Region>[[:alnum:]]+)(-(?P<Af>[[:alnum:]]+))?`)
)
func init() {
addToScheme(scheme)
}
func addToScheme(scheme *runtime.Scheme) {
corev1.AddToScheme(scheme)
admissionregistrationv1beta1.AddToScheme(scheme)
}
// TODO: get rid of hardcoded translations of FPGA resource names to region interface IDs
func region2interfaceID(regionName string) (string, error) {
switch strings.ToLower(regionName) {
case "arria10":
return "ce48969398f05f33946d560708be108a", nil
}
return "", fmt.Errorf("Unknown region name: %s", regionName)
}
// TODO: get rid of hardcoded translations of FPGA resource names to region interface IDs
func af2afuID(afName string) (string, error) {
switch strings.ToLower(afName) {
case "nlb0":
return "d8424dc4a4a3c413f89e433683f9040b", nil
case "nlb3":
return "f7df405cbd7acf7222f144b0b93acd18", nil
}
return "", fmt.Errorf("Unknown AF name: %s", afName)
}
func parseResourceName(input string) (string, string, error) {
var interfaceID string
var afuID string
var err error
result := resourceRe.FindStringSubmatch(input)
if result == nil {
return "", "", nil
}
for num, group := range resourceRe.SubexpNames() {
switch group {
case "Region":
interfaceID, err = region2interfaceID(result[num])
if err != nil {
return "", "", err
}
case "Af":
afuID, err = af2afuID(result[num])
if err != nil {
return "", "", err
}
}
}
return interfaceID, afuID, nil
}
// TODO: get rid of hardcoded translations of FPGA resource names to region interface IDs
func translateFpgaResourceName(oldname corev1.ResourceName) string {
switch strings.ToLower(string(oldname)) {
case "fpga.intel.com/arria10":
return rfc6901Escaper.Replace("fpga.intel.com/region-ce48969398f05f33946d560708be108a")
case "fpga.intel.com/arria10-nlb0":
return rfc6901Escaper.Replace("fpga.intel.com/af-d8424dc4a4a3c413f89e433683f9040b")
case "fpga.intel.com/arria10-nlb3":
return rfc6901Escaper.Replace("fpga.intel.com/af-f7df405cbd7acf7222f144b0b93acd18")
}
return ""
}
func getTLSConfig(certFile string, keyFile string) *tls.Config {
sCert, err := tls.LoadX509KeyPair(certFile, keyFile)
if err != nil {
glog.Fatal(err)
}
return &tls.Config{
Certificates: []tls.Certificate{sCert},
}
}
func getPatchOpsPreprogrammed(containerIdx int, container corev1.Container) ([]string, error) {
var ops []string
for resourceName, resourceQuantity := range container.Resources.Limits {
newName := translateFpgaResourceName(resourceName)
if len(newName) > 0 {
op := fmt.Sprintf(resourceReplaceOp, containerIdx,
"limits", rfc6901Escaper.Replace(string(resourceName)),
containerIdx, "limits", newName, resourceQuantity.String())
ops = append(ops, op)
}
}
for resourceName, resourceQuantity := range container.Resources.Requests {
newName := translateFpgaResourceName(resourceName)
if len(newName) > 0 {
op := fmt.Sprintf(resourceReplaceOp, containerIdx,
"requests", rfc6901Escaper.Replace(string(resourceName)),
containerIdx, "requests", newName, resourceQuantity.String())
ops = append(ops, op)
}
}
return ops, nil
}
func getEnvVars(container corev1.Container) (string, error) {
var jsonstrings []string
for _, envvar := range container.Env {
if envvar.Name == "FPGA_REGION" || envvar.Name == "FPGA_AFU" {
return "", fmt.Errorf("The env var '%s' is not allowed", envvar.Name)
}
jsonbytes, err := json.Marshal(envvar)
if err != nil {
return "", err
}
jsonstrings = append(jsonstrings, string(jsonbytes))
}
if len(jsonstrings) == 0 {
return "", nil
}
return fmt.Sprintf(", %s", strings.Join(jsonstrings, ",")), nil
}
func getPatchOpsOrchestrated(containerIdx int, container corev1.Container) ([]string, error) {
var ops []string
mutated := false
for resourceName, resourceQuantity := range container.Resources.Limits {
interfaceID, afuID, err := parseResourceName(string(resourceName))
if err != nil {
return nil, err
}
if interfaceID == "" && afuID == "" {
continue
}
if mutated {
return nil, fmt.Errorf("Only one FPGA resource per container is supported in '%s' mode", orchestrated)
}
op := fmt.Sprintf(resourceReplaceOp, containerIdx, "limits", rfc6901Escaper.Replace(string(resourceName)),
containerIdx, "limits", rfc6901Escaper.Replace("fpga.intel.com/region-"+interfaceID), resourceQuantity.String())
ops = append(ops, op)
oldVars, err := getEnvVars(container)
if err != nil {
return nil, err
}
op = fmt.Sprintf(envAddOp, containerIdx, interfaceID, afuID, oldVars)
ops = append(ops, op)
mutated = true
}
mutated = false
for resourceName, resourceQuantity := range container.Resources.Requests {
interfaceID, _, err := parseResourceName(string(resourceName))
if err != nil {
return nil, err
}
if interfaceID == "" {
continue
}
if mutated {
return nil, fmt.Errorf("Only one FPGA resource per container is supported in '%s' mode", orchestrated)
}
op := fmt.Sprintf(resourceReplaceOp, containerIdx, "requests", rfc6901Escaper.Replace(string(resourceName)),
containerIdx, "requests", rfc6901Escaper.Replace("fpga.intel.com/region-"+interfaceID), resourceQuantity.String())
ops = append(ops, op)
mutated = true
}
return ops, nil
}
type getPatchOpsFunc func(int, corev1.Container) ([]string, error)
func mutatePods(ar v1beta1.AdmissionReview, getPatchOps getPatchOpsFunc) *v1beta1.AdmissionResponse {
var ops []string
glog.V(2).Info("mutating pods")
podResource := metav1.GroupVersionResource{Group: "", Version: "v1", Resource: "pods"}
if ar.Request.Resource != podResource {
glog.Errorf("expect resource to be %s", podResource)
return nil
}
raw := ar.Request.Object.Raw
pod := corev1.Pod{}
deserializer := codecs.UniversalDeserializer()
if _, _, err := deserializer.Decode(raw, nil, &pod); err != nil {
glog.Error(err)
return toAdmissionResponse(err)
}
reviewResponse := v1beta1.AdmissionResponse{}
reviewResponse.Allowed = true
for containerIdx, container := range pod.Spec.Containers {
patchOps, err := getPatchOps(containerIdx, container)
if err != nil {
return toAdmissionResponse(err)
}
ops = append(ops, patchOps...)
}
if len(ops) > 0 {
reviewResponse.Patch = []byte("[ " + strings.Join(ops, ",") + " ]")
pt := v1beta1.PatchTypeJSONPatch
reviewResponse.PatchType = &pt
}
return &reviewResponse
}
type admitFunc func(v1beta1.AdmissionReview) *v1beta1.AdmissionResponse
func toAdmissionResponse(err error) *v1beta1.AdmissionResponse {
return &v1beta1.AdmissionResponse{
Result: &metav1.Status{
Message: err.Error(),
},
}
}
func serve(w http.ResponseWriter, r *http.Request, admit admitFunc) {
var body []byte
var reviewResponse *v1beta1.AdmissionResponse
var reqUID types.UID
if r.Body != nil {
if data, err := ioutil.ReadAll(r.Body); err == nil {
body = data
}
}
if len(body) == 0 {
glog.Error("No body in request")
w.WriteHeader(http.StatusBadRequest)
return
}
// verify the content type is accurate
contentType := r.Header.Get("Content-Type")
if contentType != "application/json" {
glog.Errorf("contentType=%s, expect application/json", contentType)
w.WriteHeader(http.StatusBadRequest)
return
}
glog.V(2).Info(fmt.Sprintf("handling request: %v", body))
ar := v1beta1.AdmissionReview{}
deserializer := codecs.UniversalDeserializer()
if _, _, err := deserializer.Decode(body, nil, &ar); err != nil {
glog.Error(err)
reviewResponse = toAdmissionResponse(err)
} else {
if ar.Request == nil {
err = errors.New("Request is empty")
reviewResponse = toAdmissionResponse(err)
} else {
reqUID = ar.Request.UID
reviewResponse = admit(ar)
}
}
glog.V(2).Info(fmt.Sprintf("sending response: %v", reviewResponse))
response := v1beta1.AdmissionReview{}
if reviewResponse != nil {
response.Response = reviewResponse
response.Response.UID = reqUID
}
// reset the Object and OldObject, they are not needed in a response.
if ar.Request != nil {
ar.Request.Object = runtime.RawExtension{}
ar.Request.OldObject = runtime.RawExtension{}
}
resp, err := json.Marshal(response)
if err != nil {
glog.Error(err)
return
}
if _, err := w.Write(resp); err != nil {
glog.Error(err)
}
}
func makePodsHandler(mode string) (func(w http.ResponseWriter, r *http.Request), error) {
var getPatchOps getPatchOpsFunc
switch mode {
case preprogrammed:
getPatchOps = getPatchOpsPreprogrammed
case orchestrated:
getPatchOps = getPatchOpsOrchestrated
default:
return nil, fmt.Errorf("Wrong mode: %s", mode)
}
return func(w http.ResponseWriter, r *http.Request) {
serve(w, r, func(ar v1beta1.AdmissionReview) *v1beta1.AdmissionResponse {
return mutatePods(ar, getPatchOps)
})
}, nil
}
func main() {
var certFile string
var keyFile string
var mode string
flag.StringVar(&certFile, "tls-cert-file", certFile,
"File containing the x509 Certificate for HTTPS. (CA cert, if any, concatenated after server cert).")
flag.StringVar(&keyFile, "tls-private-key-file", keyFile, "File containing the x509 private key matching --tls-cert-file.")
flag.StringVar(&mode, "mode", preprogrammed, fmt.Sprintf("webhook mode: '%s' (default) or '%s'", preprogrammed, orchestrated))
flag.Parse()
if certFile == "" {
glog.Error("TLS certificate file is not set")
os.Exit(1)
}
if keyFile == "" {
glog.Error("TLS private key is not set")
os.Exit(1)
}
if _, err := os.Stat(certFile); err != nil {
glog.Error("TLS certificate not found")
os.Exit(1)
}
if _, err := os.Stat(keyFile); err != nil {
glog.Error("TLS private key not found")
os.Exit(1)
}
servePods, err := makePodsHandler(mode)
if err != nil {
glog.Error(err)
os.Exit(1)
}
http.HandleFunc("/pods", servePods)
glog.V(2).Info("Webhook started")
server := &http.Server{
Addr: ":443",
TLSConfig: getTLSConfig(certFile, keyFile),
}
glog.Fatal(server.ListenAndServeTLS("", ""))
}