open-nomad/drivers/docker/network.go

108 lines
3.3 KiB
Go

package docker
import (
"fmt"
docker "github.com/fsouza/go-dockerclient"
"github.com/hashicorp/nomad/plugins/drivers"
)
// dockerNetSpecLabelKey is used when creating a parent container for
// shared networking. It is a label whos value identifies the container ID of
// the parent container so tasks can configure their network mode accordingly
const dockerNetSpecLabelKey = "docker_sandbox_container_id"
func (d *Driver) CreateNetwork(allocID string) (*drivers.NetworkIsolationSpec, bool, error) {
// Initialize docker API clients
client, _, err := d.dockerClients()
if err != nil {
return nil, false, fmt.Errorf("failed to connect to docker daemon: %s", err)
}
repo, _ := parseDockerImage(d.config.InfraImage)
authOptions, err := firstValidAuth(repo, []authBackend{
authFromDockerConfig(d.config.Auth.Config),
authFromHelper(d.config.Auth.Helper),
})
if err != nil {
d.logger.Debug("auth failed for infra container image pull", "image", d.config.InfraImage, "error", err)
}
_, err = d.coordinator.PullImage(d.config.InfraImage, authOptions, allocID, noopLogEventFn, d.config.infraImagePullTimeoutDuration, d.config.pullActivityTimeoutDuration)
if err != nil {
return nil, false, err
}
config, err := d.createSandboxContainerConfig(allocID)
if err != nil {
return nil, false, err
}
specFromContainer := func(c *docker.Container) *drivers.NetworkIsolationSpec {
return &drivers.NetworkIsolationSpec{
Mode: drivers.NetIsolationModeGroup,
Path: c.NetworkSettings.SandboxKey,
Labels: map[string]string{
dockerNetSpecLabelKey: c.ID,
},
}
}
// We want to return a flag that tells us if the container already
// existed so that callers can decide whether or not to recreate
// the task's network namespace associations.
container, err := d.containerByName(config.Name)
if err != nil {
return nil, false, err
}
if container != nil && container.State.Running {
return specFromContainer(container), false, nil
}
container, err = d.createContainer(client, *config, d.config.InfraImage)
if err != nil {
return nil, false, err
}
if err = d.startContainer(container); err != nil {
return nil, false, err
}
// until the container is started, InspectContainer
// returns a mostly-empty struct
container, err = client.InspectContainer(container.ID)
if err != nil {
return nil, false, err
}
return specFromContainer(container), true, nil
}
func (d *Driver) DestroyNetwork(allocID string, spec *drivers.NetworkIsolationSpec) error {
client, _, err := d.dockerClients()
if err != nil {
return fmt.Errorf("failed to connect to docker daemon: %s", err)
}
return client.RemoveContainer(docker.RemoveContainerOptions{
Force: true,
ID: spec.Labels[dockerNetSpecLabelKey],
})
}
// createSandboxContainerConfig creates a docker container configuration which
// starts a container with an empty network namespace
func (d *Driver) createSandboxContainerConfig(allocID string) (*docker.CreateContainerOptions, error) {
return &docker.CreateContainerOptions{
Name: fmt.Sprintf("nomad_init_%s", allocID),
Config: &docker.Config{
Image: d.config.InfraImage,
},
HostConfig: &docker.HostConfig{
// set the network mode to none which creates a network namespace with
// only a loopback interface
NetworkMode: "none",
},
}, nil
}