libcni: up-convert a Config to a ConfigList when no other configs are…

… found.

cnitool/cni.go

@@ -1,4 +1,4 @@
-// Copyright 2015 CoreOS, Inc.
+// Copyright 2015 CNI authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -42,7 +42,7 @@ func main() {
 	if netdir == "" {
 		netdir = DefaultNetDir
 	}
-	netconf, err := libcni.LoadConf(netdir, os.Args[2])
+	netconf, err := libcni.LoadConfList(netdir, os.Args[2])
 	if err != nil {
 		exit(err)
 	}
@@ -61,10 +61,13 @@ func main() {
 
 	switch os.Args[1] {
 	case CmdAdd:
-		_, err := cninet.AddNetwork(netconf, rt)
+		result, err := cninet.AddNetworkList(netconf, rt)
+		if result != nil {
+			_ = result.Print()
+		}
 		exit(err)
 	case CmdDel:
-		exit(cninet.DelNetwork(netconf, rt))
+		exit(cninet.DelNetworkList(netconf, rt))
 	}
 }
 

libcni/conf.go

@@ -16,13 +16,25 @@ package libcni
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
 )
 
+type NotFoundError struct {
+	Dir  string
+	Name string
+}
+
+func (e NotFoundError) Error() string {
+	return fmt.Sprintf(`no net configuration with name "%s" in %s`, e.Name, e.Dir)
+}
+
+var NoConfigsFoundError = errors.New("no net configurations found")
+
 func ConfFromBytes(bytes []byte) (*NetworkConfig, error) {
 	conf := &NetworkConfig{Bytes: bytes}
 	if err := json.Unmarshal(bytes, &conf.Network); err != nil {
@@ -137,7 +149,7 @@ func LoadConf(dir, name string) (*NetworkConfig, error) {
 	case err != nil:
 		return nil, err
 	case len(files) == 0:
-		return nil, fmt.Errorf("no net configurations found")
+		return nil, NoConfigsFoundError
 	}
 	sort.Strings(files)
 
@@ -150,16 +162,13 @@ func LoadConf(dir, name string) (*NetworkConfig, error) {
 			return conf, nil
 		}
 	}
-	return nil, fmt.Errorf(`no net configuration with name "%s" in %s`, name, dir)
+	return nil, NotFoundError{dir, name}
 }
 
 func LoadConfList(dir, name string) (*NetworkConfigList, error) {
 	files, err := ConfFiles(dir, []string{".conflist"})
-	switch {
-	case err != nil:
+	if err != nil {
 		return nil, err
-	case len(files) == 0:
-		return nil, fmt.Errorf("no net configuration lists found")
 	}
 	sort.Strings(files)
 
@@ -172,7 +181,23 @@ func LoadConfList(dir, name string) (*NetworkConfigList, error) {
 			return conf, nil
 		}
 	}
-	return nil, fmt.Errorf(`no net configuration list with name "%s" in %s`, name, dir)
+
+	// Try and load a network configuration file (instead of list)
+	// from the same name, then upconvert.
+	singleConf, err := LoadConf(dir, name)
+	if err != nil {
+		switch {
+		// no files at all
+		case len(files) == 0 && err == NoConfigsFoundError:
+			return nil, err
+		// some files found
+		case len(files) != 0 && err == NoConfigsFoundError:
+			return nil, NotFoundError{dir, name}
+		default: // either not found or parse error
+			return nil, err
+		}
+	}
+	return ConfListFromConf(singleConf)
 }
 
 func InjectConf(original *NetworkConfig, key string, newValue interface{}) (*NetworkConfig, error) {
@@ -199,3 +224,29 @@ func InjectConf(original *NetworkConfig, key string, newValue interface{}) (*Net
 
 	return ConfFromBytes(newBytes)
 }
+
+// ConfListFromConf "upconverts" a network config in to a NetworkConfigList,
+// with the single network as the only entry in the list.
+func ConfListFromConf(original *NetworkConfig) (*NetworkConfigList, error) {
+	// Re-deserialize the config's json, then make a raw map configlist.
+	// This may seem a bit strange, but it's to make the Bytes fields
+	// actually make sense. Otherwise, the generated json is littered with
+	// golang default values.
+
+	rawConfig := make(map[string]interface{})
+	err := json.Unmarshal(original.Bytes, &rawConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	rawConfigList := make(map[string]interface{})
+	rawConfigList["name"] = original.Network.Name
+	rawConfigList["cniVersion"] = original.Network.CNIVersion
+	rawConfigList["plugins"] = []interface{}{rawConfig}
+
+	b, err := json.Marshal(rawConfigList)
+	if err != nil {
+		return nil, err
+	}
+	return ConfListFromBytes(b)
+}

libcni/conf_test.go

@@ -184,21 +184,47 @@ var _ = Describe("Loading configuration from disk", func() {
 			}))
 		})
 
+		Context("when there is a config file with the same name as the list", func() {
+			BeforeEach(func() {
+				configFile := []byte(`{
+					"name": "some-list",
+					"cniVersion": "0.2.0",
+					"type": "bridge"
+				}`)
+				Expect(ioutil.WriteFile(filepath.Join(configDir, "49-whatever.conf"), configFile, 0600)).To(Succeed())
+			})
+
+			It("Loads the config list first", func() {
+				netConfigList, err := libcni.LoadConfList(configDir, "some-list")
+				Expect(err).NotTo(HaveOccurred())
+				Expect(len(netConfigList.Plugins)).To(Equal(3))
+			})
+
+			It("falls back to the config file", func() {
+				Expect(os.Remove(filepath.Join(configDir, "50-whatever.conflist"))).To(Succeed())
+
+				netConfigList, err := libcni.LoadConfList(configDir, "some-list")
+				Expect(err).NotTo(HaveOccurred())
+				Expect(len(netConfigList.Plugins)).To(Equal(1))
+				Expect(netConfigList.Plugins[0].Network.Type).To(Equal("bridge"))
+			})
+		})
+
 		Context("when the config directory does not exist", func() {
 			BeforeEach(func() {
 				Expect(os.RemoveAll(configDir)).To(Succeed())
 			})
 
 			It("returns a useful error", func() {
 				_, err := libcni.LoadConfList(configDir, "some-plugin")
-				Expect(err).To(MatchError("no net configuration lists found"))
+				Expect(err).To(MatchError("no net configurations found"))
 			})
 		})
 
 		Context("when there is no config for the desired plugin list", func() {
 			It("returns a useful error", func() {
 				_, err := libcni.LoadConfList(configDir, "some-other-plugin")
-				Expect(err).To(MatchError(ContainSubstring(`no net configuration list with name "some-other-plugin" in`)))
+				Expect(err).To(MatchError(libcni.NotFoundError{configDir, "some-other-plugin"}))
 			})
 		})
 
@@ -233,7 +259,7 @@ var _ = Describe("Loading configuration from disk", func() {
 
 			It("will not find the config", func() {
 				_, err := libcni.LoadConfList(configDir, "deep")
-				Expect(err).To(MatchError(HavePrefix("no net configuration list with name")))
+				Expect(err).To(MatchError(HavePrefix("no net configuration with name")))
 			})
 		})
 	})
@@ -339,3 +365,40 @@ var _ = Describe("Loading configuration from disk", func() {
 		})
 	})
 })
+
+var _ = Describe("ConfListFromConf", func() {
+	var testNetConfig *libcni.NetworkConfig
+
+	BeforeEach(func() {
+		pb := []byte(`{"name":"some-plugin","cniVersion":"0.3.0" }`)
+		tc, err := libcni.ConfFromBytes(pb)
+		Expect(err).NotTo(HaveOccurred())
+		testNetConfig = tc
+	})
+
+	It("correctly upconverts a NetworkConfig to a NetworkConfigList", func() {
+		ncl, err := libcni.ConfListFromConf(testNetConfig)
+		Expect(err).NotTo(HaveOccurred())
+		bytes := ncl.Bytes
+
+		// null out the json - we don't care about the exact marshalling
+		ncl.Bytes = nil
+		ncl.Plugins[0].Bytes = nil
+		testNetConfig.Bytes = nil
+
+		Expect(ncl).To(Equal(&libcni.NetworkConfigList{
+			Name:       "some-plugin",
+			CNIVersion: "0.3.0",
+			Plugins:    []*libcni.NetworkConfig{testNetConfig},
+		}))
+
+		//Test that the json unmarshals to the same data
+		ncl2, err := libcni.ConfListFromBytes(bytes)
+		Expect(err).NotTo(HaveOccurred())
+		ncl2.Bytes = nil
+		ncl2.Plugins[0].Bytes = nil
+
+		Expect(ncl2).To(Equal(ncl))
+	})
+
+})