open-consul/agent/consul/authmethod/kubeauth/testing.go
2020-06-24 13:00:14 -04:00

564 lines
16 KiB
Go

package kubeauth
import (
"bytes"
"encoding/json"
"encoding/pem"
"fmt"
"io/ioutil"
"log"
"net"
"net/http"
"net/http/httptest"
"net/url"
"regexp"
"strconv"
"strings"
"sync"
"time"
"github.com/hashicorp/consul/sdk/freeport"
"github.com/mitchellh/go-testing-interface"
"github.com/stretchr/testify/require"
authv1 "k8s.io/api/authentication/v1"
corev1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/types"
)
// TestAPIServer is a way to mock the Kubernetes API server as it is used by
// the consul kubernetes auth method.
//
// - POST /apis/authentication.k8s.io/v1/tokenreviews
// - GET /api/v1/namespaces/<NAMESPACE>/serviceaccounts/<NAME>
//
type TestAPIServer struct {
srv *httptest.Server
caCert string
returnFunc func()
mu sync.Mutex
authorizedJWT string // token review and sa read
allowedServiceAccountJWT string // general service account
replyStatus *authv1.TokenReview // general service account
replyRead *corev1.ServiceAccount // general service account
}
// StartTestAPIServer creates a disposable TestAPIServer and binds it to a
// random free port.
func StartTestAPIServer(t testing.T) *TestAPIServer {
s := &TestAPIServer{}
ports := freeport.MustTake(1)
s.returnFunc = func() {
freeport.Return(ports)
}
s.srv = httptestNewUnstartedServerWithPort(s, ports[0])
s.srv.Config.ErrorLog = log.New(ioutil.Discard, "", 0)
s.srv.StartTLS()
bs := s.srv.TLS.Certificates[0].Certificate[0]
var buf bytes.Buffer
require.NoError(t, pem.Encode(&buf, &pem.Block{Type: "CERTIFICATE", Bytes: bs}))
s.caCert = buf.String()
return s
}
// AuthorizeJWT allowlists the given JWT as able to use the API server.
func (s *TestAPIServer) AuthorizeJWT(jwt string) {
s.mu.Lock()
defer s.mu.Unlock()
s.authorizedJWT = jwt
}
// SetAllowedServiceAccount configures the singular known Service Account
// installed in this API server. If any of namespace/name/uid/jwt are empty
// it removes anything previously configured.
//
// It is up to the caller to ensure that the provided JWT matches the other
// data.
func (s *TestAPIServer) SetAllowedServiceAccount(
namespace, name, uid, overrideAnnotation, jwt string,
) {
s.mu.Lock()
defer s.mu.Unlock()
if namespace == "" || name == "" || uid == "" || jwt == "" {
s.allowedServiceAccountJWT = ""
s.replyStatus = nil
s.replyRead = nil
return
}
s.allowedServiceAccountJWT = jwt
s.replyRead = createReadServiceAccountFound(namespace, name, uid, overrideAnnotation)
s.replyStatus = createTokenReviewFound(namespace, name, uid, jwt)
}
// Stop stops the running TestAPIServer.
func (s *TestAPIServer) Stop() {
s.srv.Close()
if s.returnFunc != nil {
s.returnFunc()
s.returnFunc = nil
}
}
// Addr returns the current base URL for the running webserver.
func (s *TestAPIServer) Addr() string { return s.srv.URL }
// CACert returns the pem-encoded CA certificate used by the HTTPS server.
func (s *TestAPIServer) CACert() string { return s.caCert }
var readServiceAccountPathRE = regexp.MustCompile("^/api/v1/namespaces/([^/]+)/serviceaccounts/([^/]+)$")
func (s *TestAPIServer) ServeHTTP(w http.ResponseWriter, req *http.Request) {
s.mu.Lock()
defer s.mu.Unlock()
w.Header().Set("content-type", "application/json")
if req.URL.Path == "/apis/authentication.k8s.io/v1/tokenreviews" {
s.handleTokenReview(w, req)
return
}
if m := readServiceAccountPathRE.FindStringSubmatch(req.URL.Path); m != nil {
namespace, err := url.QueryUnescape(m[1])
if err != nil {
w.WriteHeader(http.StatusBadRequest)
return
}
name, err := url.QueryUnescape(m[2])
if err != nil {
w.WriteHeader(http.StatusBadRequest)
return
}
s.handleReadServiceAccount(namespace, name, w, req)
return
}
w.WriteHeader(http.StatusNotFound)
}
func writeJSON(w http.ResponseWriter, out interface{}) error {
enc := json.NewEncoder(w)
return enc.Encode(out)
}
func (s *TestAPIServer) handleTokenReview(w http.ResponseWriter, req *http.Request) {
if req.Method != "POST" {
w.WriteHeader(http.StatusMethodNotAllowed)
return
}
if auth, anon := s.isAuthenticated(req); !auth {
var out interface{}
if anon {
out = createTokenReviewForbidden_NoAuthz()
} else {
out = createTokenReviewForbidden("default", "fake-account")
}
w.WriteHeader(http.StatusForbidden)
if err := writeJSON(w, out); err != nil {
w.WriteHeader(http.StatusInternalServerError)
}
return
}
if req.Body == nil {
w.WriteHeader(http.StatusBadRequest)
return
}
defer req.Body.Close()
b, err := ioutil.ReadAll(req.Body)
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
return
}
var trReq authv1.TokenReview
if err := json.Unmarshal(b, &trReq); err != nil {
w.WriteHeader(http.StatusInternalServerError)
return
}
reviewingJWT := trReq.Spec.Token
var out interface{}
if s.replyStatus == nil || reviewingJWT != s.allowedServiceAccountJWT {
out = createTokenReviewNotFound(reviewingJWT)
} else {
out = s.replyStatus
}
w.WriteHeader(http.StatusCreated)
if err := writeJSON(w, out); err != nil {
w.WriteHeader(http.StatusInternalServerError)
return
}
}
func (s *TestAPIServer) handleReadServiceAccount(
namespace, name string,
w http.ResponseWriter,
req *http.Request,
) {
if req.Method != "GET" {
w.WriteHeader(http.StatusMethodNotAllowed)
return
}
var out interface{}
if auth, anon := s.isAuthenticated(req); !auth {
if anon {
out = createReadServiceAccountForbidden_NoAuthz()
} else {
out = createReadServiceAccountForbidden(namespace, name)
}
w.WriteHeader(http.StatusForbidden)
} else if s.replyRead == nil {
out = createReadServiceAccountNotFound(name)
w.WriteHeader(http.StatusNotFound)
} else if s.replyRead.Namespace != namespace || s.replyRead.Name != name {
out = createReadServiceAccountNotFound(name)
w.WriteHeader(http.StatusNotFound)
} else {
out = s.replyRead
w.WriteHeader(http.StatusOK)
}
if err := writeJSON(w, out); err != nil {
w.WriteHeader(http.StatusInternalServerError)
return
}
}
func (s *TestAPIServer) isAuthenticated(req *http.Request) (auth, anonymous bool) {
authz := req.Header.Get("Authorization")
if !strings.HasPrefix(authz, "Bearer ") {
return false, true
}
jwt := strings.TrimPrefix(authz, "Bearer ")
return s.authorizedJWT == jwt, false
}
func createTokenReviewForbidden_NoAuthz() *metav1.Status {
/*
STATUS: 403
{
"kind": "Status",
"apiVersion": "v1",
"metadata": {},
"status": "Failure",
"message": "tokenreviews.authentication.k8s.io is forbidden: User \"system:anonymous\" cannot create resource \"tokenreviews\" in API group \"authentication.k8s.io\" at the cluster scope",
"reason": "Forbidden",
"details": {
"group": "authentication.k8s.io",
"kind": "tokenreviews"
},
"code": 403
}
*/
return createStatus(
metav1.StatusFailure,
"tokenreviews.authentication.k8s.io is forbidden: User \"system:anonymous\" cannot create resource \"tokenreviews\" in API group \"authentication.k8s.io\" in the cluster scope",
metav1.StatusReasonForbidden,
&metav1.StatusDetails{
Group: "authentication.k8s.io",
Kind: "tokenreviews",
},
403,
)
}
func createTokenReviewForbidden(namespace, name string) *metav1.Status {
/*
STATUS: 403
{
"kind": "Status",
"apiVersion": "v1",
"metadata": {},
"status": "Failure",
"message": "tokenreviews.authentication.k8s.io is forbidden: User \"system:serviceaccount:default:admin\" cannot create resource \"tokenreviews\" in API group \"authentication.k8s.io\" at the cluster scope",
"reason": "Forbidden",
"details": {
"group": "authentication.k8s.io",
"kind": "tokenreviews"
},
"code": 403
}
*/
return createStatus(
metav1.StatusFailure,
"tokenreviews.authentication.k8s.io is forbidden: User \"system:serviceaccount:"+namespace+":"+name+"\" cannot create resource \"tokenreviews\" in API group \"authentication.k8s.io\" in the cluster scope",
metav1.StatusReasonForbidden,
&metav1.StatusDetails{
Group: "authentication.k8s.io",
Kind: "tokenreviews",
},
403,
)
}
func createTokenReviewNotFound(jwt string) *authv1.TokenReview {
/*
STATUS: 201
{
"kind": "TokenReview",
"apiVersion": "authentication.k8s.io/v1",
"metadata": {
"creationTimestamp": null
},
"spec": {
"token": "eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJkZWZhdWx0Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZWNyZXQubmFtZSI6ImZha2UtdG9rZW4tano2YnYiLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC5uYW1lIjoiZmFrZSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6IjgxYTY1Mjg2LTU3YzEtMTFlOS1iYzJhLTQ4ZTZjOGI4ZWNiNSIsInN1YiI6InN5c3RlbTpzZXJ2aWNlYWNjb3VudDpkZWZhdWx0OmZha2UifQ.DqjUXe34SzCP4NCwbhqV9EuksfzmTSLhJzkE_URyufeGJDn-Gw0_JS-_KmxZSdAO0XXNzB1tJNM1NCVW-V6YbThnPUw5WY4V2J6U1W72c2dzNBx_ipBxGBZ632ZnpViIRu6tL2guT36lWa8YnMDF_OY8sHhl_3kJ6MRxNxY41vAuf45mohi3gri46Kpzc3pf1g6PJ-0oogvUsZ2nBFv1mIdciGBV0zejMKc5Bnxur1L-hEQ9EgZrJ7o0yQRCWYgam_yo_M38EsB8b-suTzQJMA-pRgApOb9dHIV6YAE_b3g_pGkJjrPYzV4IJC1CiPfdz1SAjm7e0ARXtZmaoPltjQ"
},
"status": {
"user": {},
"error": "[invalid bearer token, Token has been invalidated]"
}
}
*/
return &authv1.TokenReview{
TypeMeta: metav1.TypeMeta{
Kind: "TokenReview",
APIVersion: "authentication.k8s.io/v1",
},
ObjectMeta: metav1.ObjectMeta{},
Spec: authv1.TokenReviewSpec{
Token: jwt,
},
Status: authv1.TokenReviewStatus{
User: authv1.UserInfo{},
Error: "[invalid bearer token, Token has been invalidated]",
},
}
}
func createTokenReviewFound(namespace, name, uid, jwt string) *authv1.TokenReview {
/*
STATUS: 201
{
"kind": "TokenReview",
"apiVersion": "authentication.k8s.io/v1",
"metadata": {
"creationTimestamp": null
},
"spec": {
"token": "eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJkZWZhdWx0Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZWNyZXQubmFtZSI6ImRlbW8tdG9rZW4tbTljdm4iLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC5uYW1lIjoiZGVtbyIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6IjlmZjUxZmY0LTU1N2UtMTFlOS05Njg3LTQ4ZTZjOGI4ZWNiNSIsInN1YiI6InN5c3RlbTpzZXJ2aWNlYWNjb3VudDpkZWZhdWx0OmRlbW8ifQ.UJEphtrN261gy9WCl4ZKjm2PRDLDkc3Xg9VcDGfzyroOqFQ6sog5dVAb9voc5Nc0-H5b1yGwxDViEMucwKvZpA5pi7VEx_OskK-KTWXSmafM0Xg_AvzpU9Ed5TSRno-OhXaAraxdjXoC4myh1ay2DMeHUusJg_ibqcYJrWx-6MO1bH_ObORtAKhoST_8fzkqNAlZmsQ87FinQvYN5mzDXYukl-eeRdBgQUBkWvEb-Ju6cc0-QE4sUQ4IH_fs0fUyX_xc0om0SZGWLP909FTz4V8LxV8kr6L7irxROiS1jn3Fvyc9ur1PamVf3JOPPrOyfmKbaGRiWJM32b3buQw7cg"
},
"status": {
"authenticated": true,
"user": {
"username": "system:serviceaccount:default:demo",
"uid": "9ff51ff4-557e-11e9-9687-48e6c8b8ecb5",
"groups": [
"system:serviceaccounts",
"system:serviceaccounts:default",
"system:authenticated"
]
}
}
}
*/
return &authv1.TokenReview{
TypeMeta: metav1.TypeMeta{
Kind: "TokenReview",
APIVersion: "authentication.k8s.io/v1",
},
ObjectMeta: metav1.ObjectMeta{},
Spec: authv1.TokenReviewSpec{
Token: jwt,
},
Status: authv1.TokenReviewStatus{
Authenticated: true,
User: authv1.UserInfo{
Username: "system:serviceaccount:" + namespace + ":" + name,
UID: uid,
Groups: []string{
"system:serviceaccounts",
"system:serviceaccounts:default",
"system:authenticated",
},
},
},
}
}
func createReadServiceAccountForbidden(namespace, name string) *metav1.Status {
/*
STATUS: 403
{
"kind": "Status",
"apiVersion": "v1",
"metadata": {},
"status": "Failure",
"message": "serviceaccounts \"demo\" is forbidden: User \"system:serviceaccount:default:admin\" cannot get resource \"serviceaccounts\" in API group \"\" in the namespace \"default\"",
"reason": "Forbidden",
"details": {
"name": "demo",
"kind": "serviceaccounts"
},
"code": 403
}
*/
return createStatus(
metav1.StatusFailure,
"serviceaccounts \""+name+"\" is forbidden: User \"system:serviceaccount:"+namespace+":"+name+"\" cannot get resource \"serviceaccounts\" in API group \"\" in the namespace \""+namespace+"\"",
metav1.StatusReasonForbidden,
&metav1.StatusDetails{
Kind: "serviceaccounts",
Name: name,
},
403,
)
}
func createReadServiceAccountForbidden_NoAuthz() *metav1.Status {
// missing bearer token header 403
/*
{
"kind": "Status",
"apiVersion": "v1",
"metadata": {},
"status": "Failure",
"message": "serviceaccounts \"demo\" is forbidden: User \"system:anonymous\" cannot get resource \"serviceaccounts\" in API group \"\" in the namespace \"default\"",
"reason": "Forbidden",
"details": {
"name": "demo",
"kind": "serviceaccounts"
},
"code": 403
}
*/
return createStatus(
metav1.StatusFailure,
"serviceaccounts \"PLACEHOLDER\" is forbidden: User \"system:anonymous\" cannot get resource \"serviceaccounts\" in API group \"\" in the namespace \"default\"",
metav1.StatusReasonForbidden,
&metav1.StatusDetails{
Kind: "serviceaccounts",
Name: "PLACEHOLDER",
},
403,
)
}
func createReadServiceAccountNotFound(name string) *metav1.Status {
/*
STATUS: 404
{
"kind": "Status",
"apiVersion": "v1",
"metadata": {},
"status": "Failure",
"message": "serviceaccounts \"demo\" not found",
"reason": "NotFound",
"details": {
"name": "demo",
"kind": "serviceaccounts"
},
"code": 404
}
*/
return createStatus(
metav1.StatusFailure,
"serviceaccounts \""+name+"\" not found",
metav1.StatusReasonNotFound,
&metav1.StatusDetails{
Kind: "serviceaccounts",
Name: name,
},
404,
)
}
func createReadServiceAccountFound(namespace, name, uid, overrideAnnotation string) *corev1.ServiceAccount {
/*
STATUS: 200
{
"kind": "ServiceAccount",
"apiVersion": "v1",
"metadata": {
"name": "demo",
"namespace": "default",
"selfLink": "/api/v1/namespaces/default/serviceaccounts/demo",
"uid": "9ff51ff4-557e-11e9-9687-48e6c8b8ecb5",
"resourceVersion": "2101",
"creationTimestamp": "2019-04-02T19:36:34Z",
"annotations": {
"consul.hashicorp.com/service-name": "actual",
"kubectl.kubernetes.io/last-applied-configuration": "{\"apiVersion\":\"v1\",\"kind\":\"ServiceAccount\",\"metadata\":{\"annotations\":{\"consul.hashicorp.com/service-name\":\"actual\"},\"name\":\"demo\",\"namespace\":\"default\"}}\n"
}
},
"secrets": [
{
"name": "demo-token-m9cvn"
}
]
}
*/
sa := &corev1.ServiceAccount{
TypeMeta: metav1.TypeMeta{
Kind: "ServiceAccount",
APIVersion: "v1",
},
ObjectMeta: metav1.ObjectMeta{
Name: name,
Namespace: namespace,
SelfLink: "/api/v1/namespaces/" + namespace + "/serviceaccounts/" + name,
UID: types.UID(uid),
ResourceVersion: "123",
CreationTimestamp: metav1.Time{Time: time.Now()},
},
Secrets: []corev1.ObjectReference{
{
Name: name + "-token-m9cvn",
},
},
}
if overrideAnnotation != "" {
sa.ObjectMeta.Annotations = map[string]string{
"consul.hashicorp.com/service-name": overrideAnnotation,
}
}
return sa
}
func createStatus(status, message string, reason metav1.StatusReason, details *metav1.StatusDetails, code int32) *metav1.Status {
return &metav1.Status{
TypeMeta: metav1.TypeMeta{
Kind: "Status",
APIVersion: "v1",
},
ListMeta: metav1.ListMeta{},
Status: status,
Message: message,
Reason: reason,
Details: details,
Code: code,
}
}
func httptestNewUnstartedServerWithPort(handler http.Handler, port int) *httptest.Server {
if port == 0 {
return httptest.NewUnstartedServer(handler)
}
addr := net.JoinHostPort("127.0.0.1", strconv.Itoa(port))
l, err := net.Listen("tcp", addr)
if err != nil {
panic(fmt.Sprintf("httptest: failed to listen on a port: %v", err))
}
return &httptest.Server{
Listener: l,
Config: &http.Server{Handler: handler},
}
}