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>

test/e2e/network_test.go

@@ -66,6 +66,65 @@ var _ = Describe("Podman network", func() {
 		Expect(session.LineInOutputContains(name)).To(BeTrue())
 	})
 
+	It("podman network list --filter plugin and name", func() {
+		name, path := generateNetworkConfig(podmanTest)
+		defer removeConf(path)
+
+		session := podmanTest.Podman([]string{"network", "ls", "--filter", "plugin=bridge", "--filter", "name=" + name})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(ContainSubstring(name))
+	})
+
+	It("podman network list --filter two names", func() {
+		name1, path1 := generateNetworkConfig(podmanTest)
+		defer removeConf(path1)
+
+		name2, path2 := generateNetworkConfig(podmanTest)
+		defer removeConf(path2)
+
+		session := podmanTest.Podman([]string{"network", "ls", "--filter", "name=" + name1, "--filter", "name=" + name2})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(ContainSubstring(name1))
+		Expect(session.OutputToString()).To(ContainSubstring(name2))
+	})
+
+	It("podman network list --filter labels", func() {
+		net1 := "labelnet" + stringid.GenerateNonCryptoID()
+		label1 := "testlabel1=abc"
+		label2 := "abcdef"
+		session := podmanTest.Podman([]string{"network", "create", "--label", label1, net1})
+		session.WaitWithDefaultTimeout()
+		defer podmanTest.removeCNINetwork(net1)
+		Expect(session.ExitCode()).To(BeZero())
+
+		net2 := "labelnet" + stringid.GenerateNonCryptoID()
+		session = podmanTest.Podman([]string{"network", "create", "--label", label1, "--label", label2, net2})
+		session.WaitWithDefaultTimeout()
+		defer podmanTest.removeCNINetwork(net2)
+		Expect(session.ExitCode()).To(BeZero())
+
+		session = podmanTest.Podman([]string{"network", "ls", "--filter", "label=" + label1})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(ContainSubstring(net1))
+		Expect(session.OutputToString()).To(ContainSubstring(net2))
+
+		session = podmanTest.Podman([]string{"network", "ls", "--filter", "label=" + label1, "--filter", "label=" + label2})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).ToNot(ContainSubstring(net1))
+		Expect(session.OutputToString()).To(ContainSubstring(net2))
+	})
+
+	It("podman network list --filter invalid value", func() {
+		session := podmanTest.Podman([]string{"network", "ls", "--filter", "namr=ab"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).To(ExitWithError())
+		Expect(session.ErrorToString()).To(ContainSubstring(`invalid filter "namr"`))
+	})
+
 	It("podman network list --filter failure", func() {
 		name, path := generateNetworkConfig(podmanTest)
 		defer removeConf(path)