open-nomad/client/taskenv/network.go
James Rasell 0e926ef3fd
allow configuration of Docker hostnames in bridge mode (#11173)
Add a new hostname string parameter to the network block which
allows operators to specify the hostname of the network namespace.
Changing this causes a destructive update to the allocation and it
is omitted if empty from API responses. This parameter also supports
interpolation.

In order to have a hostname passed as a configuration param when
creating an allocation network, the CreateNetwork func of the
DriverNetworkManager interface needs to be updated. In order to
minimize the disruption of future changes, rather than add another
string func arg, the function now accepts a request struct along with
the allocID param. The struct has the hostname as a field.

The in-tree implementations of DriverNetworkManager.CreateNetwork
have been modified to account for the function signature change.
In updating for the change, the enhancement of adding hostnames to
network namespaces has also been added to the Docker driver, whilst
the default Linux manager does not current implement it.
2021-09-16 08:13:09 +02:00

30 lines
814 B
Go

package taskenv
import (
"github.com/hashicorp/nomad/nomad/structs"
)
// InterpolateNetworks returns an interpolated copy of the task group networks
// with values from the task's environment.
//
// Current interoperable fields:
// - Hostname
func InterpolateNetworks(taskEnv *TaskEnv, networks structs.Networks) structs.Networks {
// Guard against not having a valid taskEnv. This can be the case if the
// PreKilling or Exited hook is run before Poststart.
if taskEnv == nil || networks == nil {
return nil
}
// Create a copy of the networks array, so we can manipulate the copy.
interpolated := networks.Copy()
// Iterate the copy and perform the interpolation.
for i := range interpolated {
interpolated[i].Hostname = taskEnv.ReplaceEnv(interpolated[i].Hostname)
}
return interpolated
}