Better API version parsing.

cmd/skaffold/app/cmd/util/util.go

@@ -17,6 +17,7 @@ limitations under the License.
 package util
 
 import (
+	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/apiversion"
 	yaml "gopkg.in/yaml.v2"
 
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/config"
@@ -35,10 +36,19 @@ func ParseConfig(filename string) (*config.SkaffoldConfig, error) {
 		return nil, errors.Wrap(err, "parsing api version")
 	}
 
-	if apiVersion.Version != config.LatestVersion {
+	parsedVersion, err := apiversion.ParseVersion(apiVersion.Version)
+	if err != nil {
+		return nil, errors.Wrap(err, "parsing api version")
+	}
+
+	if parsedVersion.LT(config.LatestAPIVersion) {
 		return nil, errors.New("Config version out of date: run `skaffold fix`")
 	}
 
+	if parsedVersion.GT(config.LatestAPIVersion) {
+		return nil, errors.New("Config version is too new for this version of skaffold: upgrade skaffold")
+	}
+
 	cfg, err := config.GetConfig(buf, true)
 	if err != nil {
 		return nil, errors.Wrap(err, "parsing skaffold config")

cmd/skaffold/app/cmd/util/util_test.go

@@ -0,0 +1,97 @@
+/*
+Copyright 2018 The Skaffold 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 util
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/schema/v1alpha1"
+
+	yaml "gopkg.in/yaml.v2"
+
+	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/config"
+)
+
+func TestParseConfig(t *testing.T) {
+	type args struct {
+		apiVersion string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{
+			name: "good api version",
+			args: args{
+				apiVersion: config.LatestVersion,
+			},
+			wantErr: false,
+		},
+		{
+			name: "old api version",
+			args: args{
+				apiVersion: v1alpha1.Version,
+			},
+			wantErr: true,
+		},
+		{
+			name: "new api version",
+			args: args{
+				apiVersion: "skaffold/v9",
+			},
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cfg, err := config.NewConfig()
+			if err != nil {
+				t.Fatalf("error generating config: %s", err)
+			}
+			cfg.APIVersion = tt.args.apiVersion
+			cfgStr, err := yaml.Marshal(cfg)
+			if err != nil {
+				t.Fatalf("error marshalling config: %s", err)
+			}
+
+			p := writeTestConfig(t, cfgStr)
+			defer os.Remove(p)
+
+			_, err = ParseConfig(p)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("ParseConfig() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+		})
+	}
+}
+
+func writeTestConfig(t *testing.T, cfg []byte) string {
+	t.Helper()
+	f, err := ioutil.TempFile("", "")
+	if err != nil {
+		t.Fatalf("error getting temp file: %s", err)
+	}
+	defer f.Close()
+	if _, err := f.Write(cfg); err != nil {
+		t.Fatalf("error writing config: %s", err)
+	}
+	return f.Name()
+}

pkg/skaffold/apiversion/apiversion.go

@@ -0,0 +1,119 @@
+/*
+Copyright 2018 The Skaffold 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 apiversion
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+)
+
+type ReleaseTrack int
+
+const (
+	alpha ReleaseTrack = 0
+	beta  ReleaseTrack = 1
+	ga    ReleaseTrack = 2
+)
+
+type Version struct {
+	Major   int
+	Minor   int
+	Release ReleaseTrack
+}
+
+var re = regexp.MustCompile(`^skaffold/v(\d)(?:(alpha|beta)(\d))?$`)
+
+// ParseAPIVersion parses a string into a Version.
+func ParseVersion(v string) (*Version, error) {
+	res := re.FindStringSubmatch(v)
+	if len(res) == 0 {
+		return nil, fmt.Errorf("%s is an invalid api version", v)
+	}
+
+	major, err := strconv.Atoi(res[1])
+	if err != nil {
+		return nil, fmt.Errorf("%s is an invalid major version number", res[1])
+	}
+
+	track := ga
+	switch res[2] {
+	case "alpha":
+		track = alpha
+	case "beta":
+		track = beta
+	}
+
+	av := Version{
+		Major:   major,
+		Release: track,
+	}
+
+	if track != ga {
+		minor, err := strconv.Atoi(res[3])
+		if err != nil {
+			return nil, fmt.Errorf("%s is an invalid major version number", res[1])
+		}
+		av.Minor = minor
+	}
+	return &av, nil
+}
+
+// MustParseVersion parses the version and panics if there is an error.
+func MustParseVersion(v string) *Version {
+	av, err := ParseVersion(v)
+	if err != nil {
+		panic(err)
+	}
+	return av
+}
+
+// Compare compares the Version to another Version, and returns -1 if v is less than ov, 0 if they are equal and 1 if v is greater than ov.
+func (v *Version) Compare(ov *Version) int {
+	// GA is always higher than beta, beta is always higher than alpha
+	if v.Release != ov.Release {
+		if v.Release > ov.Release {
+			return 1
+		}
+		return -1
+	}
+
+	// v2alpha > v1beta
+	if v.Major != ov.Major {
+		if v.Major > ov.Major {
+			return 1
+		}
+		return -1
+	}
+
+	if v.Minor > ov.Minor {
+		return 1
+	}
+	if v.Minor < ov.Minor {
+		return -1
+	}
+	return 0
+}
+
+// LT returns true if v is less than ov
+func (v *Version) LT(ov *Version) bool {
+	return v.Compare(ov) == -1
+}
+
+// GT returns true if v is greather than ov
+func (v *Version) GT(ov *Version) bool {
+	return v.Compare(ov) == 1
+}