Better error message when plugin cannot be found

diff --git a/invoke/exec.go b/invoke/exec.go
index 9056497..337bfcb 100644 (file)
--- a/invoke/exec.go
+++ b/invoke/exec.go
@@ -20,7 +20,6 @@ import (
        "fmt"
        "os"
        "os/exec"
-       "path/filepath"
 
        "github.com/appc/cni/pkg/types"
 )
@@ -58,10 +57,6 @@ func ExecPluginWithoutResult(pluginPath string, netconf []byte, args CNIArgs) er
 }
 
 func execPlugin(pluginPath string, netconf []byte, args CNIArgs) ([]byte, error) {
-       if pluginPath == "" {
-               return nil, fmt.Errorf("could not find %q plugin", filepath.Base(pluginPath))
-       }
-
        stdout := &bytes.Buffer{}
 
        c := exec.Cmd{

diff --git a/invoke/find.go b/invoke/find.go
index 82f9a9b..3b03790 100644 (file)
--- a/invoke/find.go
+++ b/invoke/find.go
@@ -15,23 +15,33 @@
 package invoke
 
 import (
+       "fmt"
        "os"
        "path/filepath"
-       "strings"
 )
 
-func FindInPath(plugin string, path []string) string {
-       for _, p := range path {
-               fullname := filepath.Join(p, plugin)
-               if fi, err := os.Stat(fullname); err == nil && fi.Mode().IsRegular() {
-                       return fullname
+// FindInPath returns the full path of the plugin by searching in the provided path
+func FindInPath(plugin string, paths []string) (string, error) {
+       if plugin == "" {
+               return "", fmt.Errorf("no plugin name provided")
+       }
+
+       if len(paths) == 0 {
+               return "", fmt.Errorf("no paths provided")
+       }
+
+       var fullpath string
+       for _, path := range paths {
+               full := filepath.Join(path, plugin)
+               if fi, err := os.Stat(full); err == nil && fi.Mode().IsRegular() {
+                       fullpath = full
+                       break
                }
        }
-       return ""
-}
 
-// Find returns the full path of the plugin by searching in CNI_PATH
-func Find(plugin string) string {
-       paths := strings.Split(os.Getenv("CNI_PATH"), ":")
-       return FindInPath(plugin, paths)
+       if fullpath == "" {
+               return "", fmt.Errorf("failed to find plugin %q in path %s", plugin, paths)
+       }
+
+       return fullpath, nil
 }

diff --git a/invoke/find_test.go b/invoke/find_test.go
new file mode 100644 (file)
index 0000000..00baa31
--- /dev/null
+++ b/invoke/find_test.go
@@ -0,0 +1,64 @@
+package invoke_test
+
+import (
+       "fmt"
+       "io/ioutil"
+       "path/filepath"
+
+       "github.com/appc/cni/pkg/invoke"
+       . "github.com/onsi/ginkgo"
+       . "github.com/onsi/gomega"
+)
+
+var _ = Describe("FindInPath", func() {
+       var (
+               multiplePaths  []string
+               pluginName     string
+               pluginDir      string
+               anotherTempDir string
+       )
+
+       BeforeEach(func() {
+               tempDir, err := ioutil.TempDir("", "cni-find")
+               Expect(err).NotTo(HaveOccurred())
+
+               plugin, err := ioutil.TempFile(tempDir, "a-cni-plugin")
+
+               anotherTempDir, err = ioutil.TempDir("", "nothing-here")
+
+               multiplePaths = []string{anotherTempDir, tempDir}
+               pluginDir, pluginName = filepath.Split(plugin.Name())
+       })
+
+       Context("when multiple paths are provided", func() {
+               It("returns only the path to the plugin", func() {
+                       pluginPath, err := invoke.FindInPath(pluginName, multiplePaths)
+                       Expect(err).NotTo(HaveOccurred())
+                       Expect(pluginPath).To(Equal(filepath.Join(pluginDir, pluginName)))
+               })
+       })
+
+       Context("when an error occurs", func() {
+               Context("when no paths are provided", func() {
+                       It("returns an error noting no paths were provided", func() {
+                               _, err := invoke.FindInPath(pluginName, []string{})
+                               Expect(err).To(MatchError("no paths provided"))
+                       })
+               })
+
+               Context("when no plugin is provided", func() {
+                       It("returns an error noting the plugin name wasn't found", func() {
+                               _, err := invoke.FindInPath("", multiplePaths)
+                               Expect(err).To(MatchError("no plugin name provided"))
+                       })
+               })
+
+               Context("when the plugin cannot be found", func() {
+                       It("returns an error noting the path", func() {
+                               pathsWithNothing := []string{anotherTempDir}
+                               _, err := invoke.FindInPath(pluginName, pathsWithNothing)
+                               Expect(err).To(MatchError(fmt.Sprintf("failed to find plugin %q in path %s", pluginName, pathsWithNothing)))
+                       })
+               })
+       })
+})

diff --git a/invoke/invoke_suite_test.go b/invoke/invoke_suite_test.go
new file mode 100644 (file)
index 0000000..e570c96
--- /dev/null
+++ b/invoke/invoke_suite_test.go
@@ -0,0 +1,13 @@
+package invoke_test
+
+import (
+       . "github.com/onsi/ginkgo"
+       . "github.com/onsi/gomega"
+
+       "testing"
+)
+
+func TestInvoke(t *testing.T) {
+       RegisterFailHandler(Fail)
+       RunSpecs(t, "Invoke Suite")
+}

diff --git a/ipam/ipam.go b/ipam/ipam.go
index 4920838..1d512ec 100644 (file)
--- a/ipam/ipam.go
+++ b/ipam/ipam.go
@@ -17,6 +17,7 @@ package ipam
 import (
        "fmt"
        "os"
+       "strings"
 
        "github.com/appc/cni/pkg/invoke"
        "github.com/appc/cni/pkg/ip"
@@ -29,14 +30,30 @@ func ExecAdd(plugin string, netconf []byte) (*types.Result, error) {
        if os.Getenv("CNI_COMMAND") != "ADD" {
                return nil, fmt.Errorf("CNI_COMMAND is not ADD")
        }
-       return invoke.ExecPluginWithResult(invoke.Find(plugin), netconf, invoke.ArgsFromEnv())
+
+       paths := strings.Split(os.Getenv("CNI_PATH"), ":")
+
+       pluginPath, err := invoke.FindInPath(plugin, paths)
+       if err != nil {
+               return nil, err
+       }
+
+       return invoke.ExecPluginWithResult(pluginPath, netconf, invoke.ArgsFromEnv())
 }
 
 func ExecDel(plugin string, netconf []byte) error {
        if os.Getenv("CNI_COMMAND") != "DEL" {
                return fmt.Errorf("CNI_COMMAND is not DEL")
        }
-       return invoke.ExecPluginWithoutResult(invoke.Find(plugin), netconf, invoke.ArgsFromEnv())
+
+       paths := strings.Split(os.Getenv("CNI_PATH"), ":")
+
+       pluginPath, err := invoke.FindInPath(plugin, paths)
+       if err != nil {
+               return err
+       }
+
+       return invoke.ExecPluginWithoutResult(pluginPath, netconf, invoke.ArgsFromEnv())
 }
 
 // ConfigureIface takes the result of IPAM plugin and