versioning: add basic version decode for network config

diff --git a/pkg/version/conf.go b/pkg/version/conf.go
new file mode 100644 (file)
index 0000000..3cca58b
--- /dev/null
+++ b/pkg/version/conf.go
@@ -0,0 +1,37 @@
+// Copyright 2016 CNI 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 version
+
+import (
+       "encoding/json"
+       "fmt"
+)
+
+// ConfigDecoder can decode the CNI version available in network config data
+type ConfigDecoder struct{}
+
+func (*ConfigDecoder) Decode(jsonBytes []byte) (string, error) {
+       var conf struct {
+               CNIVersion string `json:"cniVersion"`
+       }
+       err := json.Unmarshal(jsonBytes, &conf)
+       if err != nil {
+               return "", fmt.Errorf("decoding version from network config: %s", err)
+       }
+       if conf.CNIVersion == "" {
+               return "0.1.0", nil
+       }
+       return conf.CNIVersion, nil
+}

diff --git a/pkg/version/conf_test.go b/pkg/version/conf_test.go
new file mode 100644 (file)
index 0000000..881c57a
--- /dev/null
+++ b/pkg/version/conf_test.go
@@ -0,0 +1,69 @@
+// Copyright 2016 CNI 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 version_test
+
+import (
+       "github.com/containernetworking/cni/pkg/version"
+
+       . "github.com/onsi/ginkgo"
+       . "github.com/onsi/gomega"
+)
+
+var _ = Describe("Decoding the version of network config", func() {
+       var (
+               decoder     *version.ConfigDecoder
+               configBytes []byte
+       )
+
+       BeforeEach(func() {
+               decoder = &version.ConfigDecoder{}
+               configBytes = []byte(`{ "cniVersion": "4.3.2" }`)
+       })
+
+       Context("when the version is explict", func() {
+               It("returns the version", func() {
+                       version, err := decoder.Decode(configBytes)
+                       Expect(err).NotTo(HaveOccurred())
+
+                       Expect(version).To(Equal("4.3.2"))
+               })
+       })
+
+       Context("when the version is not present in the config", func() {
+               BeforeEach(func() {
+                       configBytes = []byte(`{ "not-a-version-field": "foo" }`)
+               })
+
+               It("assumes the config is version 0.1.0", func() {
+                       version, err := decoder.Decode(configBytes)
+                       Expect(err).NotTo(HaveOccurred())
+
+                       Expect(version).To(Equal("0.1.0"))
+               })
+       })
+
+       Context("when the config data is malformed", func() {
+               BeforeEach(func() {
+                       configBytes = []byte(`{{{`)
+               })
+
+               It("returns a useful error", func() {
+                       _, err := decoder.Decode(configBytes)
+                       Expect(err).To(MatchError(HavePrefix(
+                               "decoding version from network config: invalid character",
+                       )))
+               })
+       })
+})