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>

2 files changed, 19 insertions, 3 deletions

diff --git a/docs/source/markdown/podman-network-create.1.md b/docs/source/markdown/podman-network-create.1.md
index cbf9d26dc..d787809cd 100644
--- a/docs/source/markdown/podman-network-create.1.md
+++ b/docs/source/markdown/podman-network-create.1.md
@@ -40,6 +40,10 @@ Restrict external access of this network
 Allocate container IP from a range.  The range must be a complete subnet and in CIDR notation.  The *ip-range* option
 must be used with a *subnet* option.
 
+#### **--label**
+
+Set metadata for a network (e.g., --label mykey=value).
+
 #### **--macvlan**
 
 Create a *Macvlan* based connection rather than a classic bridge.  You must pass an interface name from the host for the
diff --git a/docs/source/markdown/podman-network-ls.1.md b/docs/source/markdown/podman-network-ls.1.md
index 34b40b3ae..fcba51190 100644
--- a/docs/source/markdown/podman-network-ls.1.md
+++ b/docs/source/markdown/podman-network-ls.1.md
@@ -14,13 +14,25 @@ Displays a list of existing podman networks. This command is not available for r
 
 The `quiet` option will restrict the output to only the network names.
 
-#### **--format**, **-f**
+#### **--format**
 
 Pretty-print networks to JSON or using a Go template.
 
-#### **--filter**
+#### **--filter**, **-f**
 
-Provide filter values (e.g. 'name=podman').
+Filter output based on conditions given.
+Multiple filters can be given with multiple uses of the --filter flag.
+Filters with the same key work inclusive with the only exception being
+`label` which is exclusive. Filters with different keys always work exclusive.
+
+Valid filters are listed below:
+
+| **Filter** | **Description**                                                                       |
+| ---------- | ------------------------------------------------------------------------------------- |
+| name       | [Name] Network name (accepts regex)                                                   |
+| label      | [Key] or [Key=Value] Label assigned to a network                                      |
+| plugin     | [Plugin] CNI plugins included in a network (e.g `bridge`,`portmap`,`firewall`,`tuning`,`dnsname`,`macvlan`) |
+| driver     | [Driver] Only `bridge` is supported                                                   |
 
 ## EXAMPLE