podman network label support

Add label support for podman network create. Use the `args`
field in the cni config file to store the podman labels.
Use `podman_labels` as key name and store the labels as
map[string]string.

For reference: https://github.com/containernetworking/cni/blob/master/CONVENTIONS.md#args-in-network-config
https://github.com/containernetworking/cni/blob/spec-v0.4.0/SPEC.md#network-configuration

Example snippet:

```
...
"args": {
	"podman_labels": {
		"key1":"value1",
		"key2":"value2"
	}
}
...
```

Make podman network list support several filters. Supported filters are name,
plugin, driver and label. Filters with different keys work exclusive. Several label
filters work exclusive and the other filter keys are working inclusive.

Also adjust the compat api to support labels in network create and list.

Breaking changes:

- podman network ls -f shortform is used for --filter instead --format
This matches docker and other podman commands (container ps, volume ps)

- libpod network list endpoint filter parameter is removed. Instead the
filters paramter should be used as json encoded map[string][]string.

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

1 files changed, 30 insertions, 0 deletions

diff --git a/libpod/network/files.go b/libpod/network/files.go
index 846e5c62d..34cc5fa73 100644
--- a/libpod/network/files.go
+++ b/libpod/network/files.go
@@ -12,6 +12,7 @@ import (
 	"github.com/containers/common/pkg/config"
 	"github.com/containers/podman/v2/libpod/define"
 	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 )
 
 // GetCNIConfDir get CNI configuration directory
@@ -86,6 +87,35 @@ func GetCNIPlugins(list *libcni.NetworkConfigList) string {
 	return strings.Join(plugins, ",")
 }
 
+// GetNetworkLabels returns a list of labels as a string
+func GetNetworkLabels(list *libcni.NetworkConfigList) NcLabels {
+	cniJSON := make(map[string]interface{})
+	err := json.Unmarshal(list.Bytes, &cniJSON)
+	if err != nil {
+		logrus.Errorf("failed to unmarshal network config %v %v", cniJSON["name"], err)
+		return nil
+	}
+	if args, ok := cniJSON["args"]; ok {
+		if key, ok := args.(map[string]interface{}); ok {
+			if labels, ok := key[PodmanLabelKey]; ok {
+				if labels, ok := labels.(map[string]interface{}); ok {
+					result := make(NcLabels, len(labels))
+					for k, v := range labels {
+						if v, ok := v.(string); ok {
+							result[k] = v
+						} else {
+							logrus.Errorf("network config %v invalid label value type %T should be string", cniJSON["name"], labels)
+						}
+					}
+					return result
+				}
+				logrus.Errorf("network config %v invalid label type %T should be map[string]string", cniJSON["name"], labels)
+			}
+		}
+	}
+	return nil
+}
+
 // GetNetworksFromFilesystem gets all the networks from the cni configuration
 // files
 func GetNetworksFromFilesystem(config *config.Config) ([]*allocator.Net, error) {