Add invoke.Delegate{Add,Del} for use by meta-plugins

The 'flannel' meta plugin delegates to other plugins to do the actual
OS-level work. It used the ipam.Exec{Add,Del} procedures for this
delegation, since those do precisely what's needed.

However this is a bit misleading, since the flannel plugin _isn't_
doing this for IPAM, and the ipam.Exec* procedures aren't doing
something specific to IPAM plugins.

So: anticipating that there may be more meta plugins that want to
delegate in the same way, this commit moves generic delegation
procedures to `pkg/invoke`, and makes the `pkg/ipam` procedures (still
used, accurately, in the non-meta plugins) shims.

diff --git a/pkg/invoke/delegate.go b/pkg/invoke/delegate.go
new file mode 100644 (file)
index 0000000..9864e6f
--- /dev/null
+++ b/pkg/invoke/delegate.go
@@ -0,0 +1,39 @@
+package invoke
+
+import (
+       "fmt"
+       "os"
+       "strings"
+
+       "github.com/appc/cni/pkg/types"
+)
+
+func DelegateAdd(delegatePlugin string, netconf []byte) (*types.Result, error) {
+       if os.Getenv("CNI_COMMAND") != "ADD" {
+               return nil, fmt.Errorf("CNI_COMMAND is not ADD")
+       }
+
+       paths := strings.Split(os.Getenv("CNI_PATH"), ":")
+
+       pluginPath, err := FindInPath(delegatePlugin, paths)
+       if err != nil {
+               return nil, err
+       }
+
+       return ExecPluginWithResult(pluginPath, netconf, ArgsFromEnv())
+}
+
+func DelegateDel(delegatePlugin string, netconf []byte) error {
+       if os.Getenv("CNI_COMMAND") != "DEL" {
+               return fmt.Errorf("CNI_COMMAND is not DEL")
+       }
+
+       paths := strings.Split(os.Getenv("CNI_PATH"), ":")
+
+       pluginPath, err := FindInPath(delegatePlugin, paths)
+       if err != nil {
+               return err
+       }
+
+       return ExecPluginWithoutResult(pluginPath, netconf, ArgsFromEnv())
+}

diff --git a/pkg/ipam/ipam.go b/pkg/ipam/ipam.go
index 1d512ec..f0adfb7 100644 (file)
--- a/pkg/ipam/ipam.go
+++ b/pkg/ipam/ipam.go
@@ -17,7 +17,6 @@ package ipam
 import (
        "fmt"
        "os"
-       "strings"
 
        "github.com/appc/cni/pkg/invoke"
        "github.com/appc/cni/pkg/ip"
@@ -27,33 +26,11 @@ import (
 )
 
 func ExecAdd(plugin string, netconf []byte) (*types.Result, error) {
-       if os.Getenv("CNI_COMMAND") != "ADD" {
-               return nil, fmt.Errorf("CNI_COMMAND is not ADD")
-       }
-
-       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())
+       return invoke.DelegateAdd(plugin, netconf)
 }
 
 func ExecDel(plugin string, netconf []byte) error {
-       if os.Getenv("CNI_COMMAND") != "DEL" {
-               return fmt.Errorf("CNI_COMMAND is not DEL")
-       }
-
-       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())
+       return invoke.DelegateDel(plugin, netconf)
 }
 
 // ConfigureIface takes the result of IPAM plugin and

diff --git a/plugins/meta/flannel/flannel.go b/plugins/meta/flannel/flannel.go
index af62973..6653bac 100644 (file)
--- a/plugins/meta/flannel/flannel.go
+++ b/plugins/meta/flannel/flannel.go
@@ -29,7 +29,7 @@ import (
        "strconv"
        "strings"
 
-       "github.com/appc/cni/pkg/ipam"
+       "github.com/appc/cni/pkg/invoke"
        "github.com/appc/cni/pkg/skel"
        "github.com/appc/cni/pkg/types"
 )
@@ -155,7 +155,7 @@ func delegateAdd(cid string, netconf map[string]interface{}) error {
                return err
        }
 
-       result, err := ipam.ExecAdd(netconf["type"].(string), netconfBytes)
+       result, err := invoke.DelegateAdd(netconf["type"].(string), netconfBytes)
        if err != nil {
                return err
        }
@@ -245,7 +245,7 @@ func cmdDel(args *skel.CmdArgs) error {
                return fmt.Errorf("failed to parse netconf: %v", err)
        }
 
-       return ipam.ExecDel(n.Type, netconfBytes)
+       return invoke.DelegateDel(n.Type, netconfBytes)
 }
 
 func main() {