Add /version to server and check it in client.

Will help detect client/version skew and prevent e2e test from passing
while running a version other than the one you think it's running.

cmd/kubecfg/kubecfg.go

@@ -22,6 +22,7 @@ import (
 	"io/ioutil"
 	"net/url"
 	"os"
+	"reflect"
 	"sort"
 	"strconv"
 	"strings"
@@ -31,28 +32,28 @@ import (
 	kube_client "github.com/GoogleCloudPlatform/kubernetes/pkg/client"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubecfg"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/version"
 	"github.com/golang/glog"
 )
 
-// AppVersion is the current version of kubecfg.
-const AppVersion = "0.1"
-
 var (
-	versionFlag  = flag.Bool("V", false, "Print the version number.")
-	httpServer   = flag.String("h", "", "The host to connect to.")
-	config       = flag.String("c", "", "Path to the config file.")
-	selector     = flag.String("l", "", "Selector (label query) to use for listing")
-	updatePeriod = flag.Duration("u", 60*time.Second, "Update interval period")
-	portSpec     = flag.String("p", "", "The port spec, comma-separated list of <external>:<internal>,...")
-	servicePort  = flag.Int("s", -1, "If positive, create and run a corresponding service on this port, only used with 'run'")
-	authConfig   = flag.String("auth", os.Getenv("HOME")+"/.kubernetes_auth", "Path to the auth info file.  If missing, prompt the user.  Only used if doing https.")
-	json         = flag.Bool("json", false, "If true, print raw JSON for responses")
-	yaml         = flag.Bool("yaml", false, "If true, print raw YAML for responses")
-	verbose      = flag.Bool("verbose", false, "If true, print extra information")
-	proxy        = flag.Bool("proxy", false, "If true, run a proxy to the api server")
-	www          = flag.String("www", "", "If -proxy is true, use this directory to serve static files")
-	templateFile = flag.String("template_file", "", "If present, load this file as a golang template and use it for output printing")
-	templateStr  = flag.String("template", "", "If present, parse this string as a golang template and use it for output printing")
+	versionFlag   = flag.Bool("V", false, "Print the version number.")
+	serverVersion = flag.Bool("server_version", false, "Print the server's version number.")
+	preventSkew   = flag.Bool("expect_version_match", false, "Fail if server's version doesn't match own version.")
+	httpServer    = flag.String("h", "", "The host to connect to.")
+	config        = flag.String("c", "", "Path to the config file.")
+	selector      = flag.String("l", "", "Selector (label query) to use for listing")
+	updatePeriod  = flag.Duration("u", 60*time.Second, "Update interval period")
+	portSpec      = flag.String("p", "", "The port spec, comma-separated list of <external>:<internal>,...")
+	servicePort   = flag.Int("s", -1, "If positive, create and run a corresponding service on this port, only used with 'run'")
+	authConfig    = flag.String("auth", os.Getenv("HOME")+"/.kubernetes_auth", "Path to the auth info file.  If missing, prompt the user.  Only used if doing https.")
+	json          = flag.Bool("json", false, "If true, print raw JSON for responses")
+	yaml          = flag.Bool("yaml", false, "If true, print raw YAML for responses")
+	verbose       = flag.Bool("verbose", false, "If true, print extra information")
+	proxy         = flag.Bool("proxy", false, "If true, run a proxy to the api server")
+	www           = flag.String("www", "", "If -proxy is true, use this directory to serve static files")
+	templateFile  = flag.String("template_file", "", "If present, load this file as a golang template and use it for output printing")
+	templateStr   = flag.String("template", "", "If present, parse this string as a golang template and use it for output printing")
 )
 
 func usage() {
@@ -107,7 +108,7 @@ func main() {
 	defer util.FlushLogs()
 
 	if *versionFlag {
-		fmt.Println("Version:", AppVersion)
+		fmt.Printf("Version: %#v\n", version.Get())
 		os.Exit(0)
 	}
 
@@ -136,6 +137,30 @@ func main() {
 		}
 	}
 
+	client := kube_client.New(masterServer, auth)
+
+	if *serverVersion {
+		got, err := client.ServerVersion()
+		if err != nil {
+			fmt.Printf("Couldn't read version from server: %v\n", err)
+			os.Exit(1)
+		}
+		fmt.Printf("Server Version: %#v\n", got)
+		os.Exit(0)
+	}
+
+	if *preventSkew {
+		got, err := client.ServerVersion()
+		if err != nil {
+			fmt.Printf("Couldn't read version from server: %v\n", err)
+			os.Exit(1)
+		}
+		if c, s := version.Get(), *got; !reflect.DeepEqual(c, s) {
+			fmt.Printf("Server version (%#v) differs from client version (%#v)!\n", s, c)
+			os.Exit(1)
+		}
+	}
+
 	if *proxy {
 		glog.Info("Starting to serve on localhost:8001")
 		server := kubecfg.NewProxyServer(*www, masterServer, auth)
@@ -148,8 +173,6 @@ func main() {
 	}
 	method := flag.Arg(0)
 
-	client := kube_client.New(masterServer, auth)
-
 	matchFound := executeAPIRequest(method, client) || executeControllerRequest(method, client)
 	if matchFound == false {
 		glog.Fatalf("Unknown command %s", method)

hack/e2e-test.sh

@@ -39,7 +39,7 @@ set -e
 # Use testing config
 export KUBE_CONFIG_FILE="config-test.sh"
 export KUBE_REPO_ROOT="$(dirname $0)/.."
-export CLOUDCFG="${KUBE_REPO_ROOT}/cluster/kubecfg.sh"
+export CLOUDCFG="${KUBE_REPO_ROOT}/cluster/kubecfg.sh -expect_version_match"
 
 # Build a release required by the test provider [if any]
 test-build-release

hack/test-cmd.sh

@@ -106,7 +106,7 @@ APISERVER_PID=$!
 
 wait_for_url "http://127.0.0.1:${API_PORT}/healthz" "apiserver: "
 
-KUBE_CMD="${GO_OUT}/kubecfg -h http://127.0.0.1:${API_PORT}"
+KUBE_CMD="${GO_OUT}/kubecfg -h http://127.0.0.1:${API_PORT} -expect_version_match"
 
 ${KUBE_CMD} list pods
 echo "kubecfg(pods): ok"
@@ -130,4 +130,4 @@ echo "kubecfg(minions): ok"
 #PROXY_LOG=/tmp/kube-proxy.log
 #${GO_OUT}/proxy \
 #  --etcd_servers="http://127.0.0.1:${ETCD_PORT}" 1>&2 &
-#PROXY_PID=$!
+#PROXY_PID=$!

pkg/apiserver/apiserver.go

@@ -39,6 +39,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/tools"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/version"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/watch"
 	"github.com/golang/glog"
 )
@@ -151,6 +152,7 @@ func New(storage map[string]RESTStorage, prefix string) *APIServer {
 	healthz.InstallHandler(s.mux)
 
 	s.mux.HandleFunc("/", s.handleIndex)
+	s.mux.HandleFunc("/version", s.handleVersionReq)
 
 	// Handle both operations and operations/* with the same handler
 	s.mux.HandleFunc(s.operationPrefix(), s.handleOperationRequest)
@@ -182,6 +184,11 @@ func (server *APIServer) handleIndex(w http.ResponseWriter, req *http.Request) {
 	fmt.Fprint(w, data)
 }
 
+// handleVersionReq writes the server's version information.
+func (server *APIServer) handleVersionReq(w http.ResponseWriter, req *http.Request) {
+	server.writeRawJSON(http.StatusOK, version.Get(), w)
+}
+
 func (server *APIServer) handleMinionReq(w http.ResponseWriter, req *http.Request) {
 	minionPrefix := "/proxy/minion/"
 	if !strings.HasPrefix(req.URL.Path, minionPrefix) {
@@ -344,14 +351,27 @@ func (server *APIServer) notFound(w http.ResponseWriter, req *http.Request) {
 	fmt.Fprintf(w, "Not Found: %#v", req)
 }
 
+// write writes an API object in wire format.
 func (server *APIServer) write(statusCode int, object interface{}, w http.ResponseWriter) {
-	w.Header().Set("Content-Type", "application/json")
-	w.WriteHeader(statusCode)
 	output, err := api.Encode(object)
 	if err != nil {
 		server.error(err, w)
 		return
 	}
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(statusCode)
+	w.Write(output)
+}
+
+// writeRawJSON writes a non-API object in JSON.
+func (server *APIServer) writeRawJSON(statusCode int, object interface{}, w http.ResponseWriter) {
+	output, err := json.Marshal(object)
+	if err != nil {
+		server.error(err, w)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(statusCode)
 	w.Write(output)
 }
 

pkg/client/client.go

@@ -18,6 +18,7 @@ package client
 
 import (
 	"crypto/tls"
+	"encoding/json"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -26,6 +27,7 @@ import (
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/version"
 	"github.com/golang/glog"
 )
 
@@ -238,3 +240,17 @@ func (c *Client) UpdateService(svc api.Service) (result api.Service, err error)
 func (c *Client) DeleteService(name string) error {
 	return c.Delete().Path("services").Path(name).Do().Error()
 }
+
+// ServerVersion retrieves and parses the server's version.
+func (c *Client) ServerVersion() (*version.Info, error) {
+	body, err := c.Get().AbsPath("/version").Do().Raw()
+	if err != nil {
+		return nil, err
+	}
+	var info version.Info
+	err = json.Unmarshal(body, &info)
+	if err != nil {
+		return nil, fmt.Errorf("Got '%s': %v", string(body), err)
+	}
+	return &info, nil
+}

pkg/client/client_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package client
 
 import (
+	"encoding/json"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -26,6 +27,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/version"
 )
 
 // TODO: Move this to a common place, it's needed in multiple tests.
@@ -456,3 +458,30 @@ func TestDoRequestAcceptedSuccess(t *testing.T) {
 	}
 	fakeHandler.ValidateRequest(t, "/foo/bar", "GET", nil)
 }
+
+func TestGetServerVersion(t *testing.T) {
+	expect := version.Info{
+		Major:     "foo",
+		Minor:     "bar",
+		GitCommit: "baz",
+	}
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		output, err := json.Marshal(expect)
+		if err != nil {
+			t.Errorf("unexpected encoding error: %v", err)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		w.Write(output)
+	}))
+	client := New(server.URL, nil)
+
+	got, err := client.ServerVersion()
+	if err != nil {
+		t.Fatalf("unexpected encoding error: %v", err)
+	}
+	if e, a := expect, *got; !reflect.DeepEqual(e, a) {
+		t.Errorf("expected %v, got %v", e, a)
+	}
+}

pkg/kubecfg/kubecfg.go

@@ -29,10 +29,24 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/version"
 	"github.com/golang/glog"
 	"gopkg.in/v1/yaml"
 )
 
+func GetServerVersion(client *client.Client) (*version.Info, error) {
+	body, err := client.Get().AbsPath("/version").Do().Raw()
+	if err != nil {
+		return nil, err
+	}
+	var info version.Info
+	err = json.Unmarshal(body, &info)
+	if err != nil {
+		return nil, fmt.Errorf("Got '%s': %v", string(body), err)
+	}
+	return &info, nil
+}
+
 func promptForString(field string, r io.Reader) string {
 	fmt.Printf("Please enter %s: ", field)
 	var result string

pkg/kubecfg/kubecfg_test.go

@@ -317,9 +317,9 @@ func TestMakePorts(t *testing.T) {
 		{
 			"8080:80,8081:8081,443:444",
 			[]api.Port{
-				api.Port{HostPort: 8080, ContainerPort: 80},
-				api.Port{HostPort: 8081, ContainerPort: 8081},
-				api.Port{HostPort: 443, ContainerPort: 444},
+				{HostPort: 8080, ContainerPort: 80},
+				{HostPort: 8081, ContainerPort: 8081},
+				{HostPort: 443, ContainerPort: 444},
 			},
 		},
 	}

pkg/version/version.go

@@ -16,6 +16,21 @@ limitations under the License.
 
 package version
 
-func Get() (major, minor, gitCommit string) {
-	return "v1beta", "1", commitFromGit
+// Info contains versioning information.
+// TODO: Add []string of api versions supported? It's still unclear
+// how we'll want to distribute that information.
+type Info struct {
+	Major     string `json:"major" yaml:"major"`
+	Minor     string `json:"minor" yaml:"minor"`
+	GitCommit string `json:"gitCommit" yaml:"gitCommit"`
+}
+
+// Get returns the overall codebase version. It's for detecting
+// what code a binary was built from.
+func Get() Info {
+	return Info{
+		Major:     "0",
+		Minor:     "1",
+		GitCommit: commitFromGit,
+	}
 }