podman network create: add option to set custom network driver settings, eg like MTU

[pschiffe]

Is this a BUG REPORT or FEATURE REQUEST? (leave only one on its own line)

/kind feature

Description

Docker command docker network create has the -o, --opt map Set driver specific options (default map[]) option.

With podman, one have to modify the config file in /etc/cni/ once the network is created to change its settings, which is not very automation friendly.

Related ansible collection RFE: containers/ansible-podman-collections#147

[rhatdan]

@pschiffe interested in opening a PR to fix this?

[afbjorklund]

This would be useful for minikube as well, I can probably do a PR for it

[rhatdan]

You got it.

[afbjorklund]

Most likely it will be a simple option to "network create", rather than -o com.docker.network.driver.mtu=1500

But I suppose it could eventually be some kind of passthrough to the CNI parameters, not current code though

[afbjorklund]

Seems to be working:

$ sudo ./bin/podman network create podman1
/etc/cni/net.d/podman1.conflist
$ sudo ./bin/podman network create podman2 --mtu 5000
/etc/cni/net.d/podman2.conflist

27: cni-podman1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000

29: cni-podman2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 5000 qdisc noqueue state UP group default qlen 1000

[pschiffe]

Looking great and good enough for me, thank you!

[afbjorklund]

Syntax now changed to:

podman network create podman2 --opt mtu=5000

Resulting configuration diff:

@@ -1,12 +1,13 @@
 {
    "cniVersion": "0.4.0",
-   "name": "podman1",
+   "name": "podman2",
    "plugins": [
       {
          "type": "bridge",
-         "bridge": "cni-podman1",
+         "bridge": "cni-podman2",
          "isGateway": true,
          "ipMasq": true,
+         "mtu": 5000,
          "hairpinMode": true,
          "ipam": {
             "type": "host-local",
@@ -18,7 +19,7 @@
             "ranges": [
                [
                   {
-                     "subnet": "10.89.0.0/24"
+                     "subnet": "10.89.1.0/24"
                   }
                ]
             ]

[pschiffe]

Resolved via #8457