group host mode network did not passed to driver

[ttys3]

demo job:

job "redis-host" {
  datacenters = ["dc1"]

  type = "service"

  group "redis-host" {
    count = 1

    network {
      mode = "host"

      port "redis" {
        to = 6349
      }
    }

    task "redis-host" {
      env {
        PORT    = "${NOMAD_PORT_redis}"
        NODE_IP = "${NOMAD_IP_redis}"
      }

      driver = "podman"

      config {
        image        = "redis"
        cap_add      = ["NET_RAW"]
#    this line is comment out to demo the problem
#      network_mode = "host"
        command      = "redis-server"
        args         = ["--port", "6349"]
      }
    }
  }
}

the container actually runs in a bridged network (the default podman bridge network)

do some digging, I found that,

the condition is we did not set driverConfig.NetworkMode (I want its value passed from group - network - mode ).

if group - network - mode is set to host, nomad will not set cfg.NetworkIsolation, so it is nil
thus the logic goes here

nomad-driver-podman/driver.go

Lines 468 to 483 in 7e3d018

	if driverConfig.NetworkMode == "" {
	if !rootless {
	// should we join the group shared network namespace?
	if cfg.NetworkIsolation != nil && cfg.NetworkIsolation.Mode == drivers.NetIsolationModeGroup {
	// yes, join the group ns namespace
	createOpts.ContainerNetworkConfig.NetNS.NSMode = api.Path
	createOpts.ContainerNetworkConfig.NetNS.Value = cfg.NetworkIsolation.Path
	} else {
	// no, simply attach a rootful container to the default podman bridge
	createOpts.ContainerNetworkConfig.NetNS.NSMode = api.Bridge
	}
	} else {
	// slirp4netns is default for rootless podman
	createOpts.ContainerNetworkConfig.NetNS.NSMode = api.Slirp
	}
	} else if driverConfig.NetworkMode == "bridge" {

so here is the problem. when we need host network mode, we need set this both in group - network - mode and driver's config - network_mode.

[slonopotamus]

Hello from 2024, this bug is still here.

I want to note that current behavior contradicts documentation that explicitly says:

By default the task uses the network stack defined in the task group network block.

---

There is also a confusing part in the same documentation:

If the groups network behavior is also undefined, it will fallback to bridge in rootful mode or slirp4netns for rootless containers.

This doesn't make any sense because you can't have group network undefined, it defaults to host.