Files
weave/common/docker/client.go
T
Bryan Boreham 81e8ba223f Do network attach on docker event rather than intercepting start and restart commands.
This means it also works when the docker daemon restarts a container.
2015-09-01 17:48:12 +01:00

83 lines
1.9 KiB
Go

package docker
import (
"github.com/fsouza/go-dockerclient"
. "github.com/weaveworks/weave/common"
)
// An observer for container events
type ContainerObserver interface {
ContainerStarted(ident string)
ContainerDied(ident string)
}
type Client struct {
*docker.Client
}
// NewClient creates a new Docker client and checks we can talk to Docker
func NewClient(apiPath string) (*Client, error) {
dc, err := docker.NewClient(apiPath)
if err != nil {
return nil, err
}
client := &Client{dc}
return client, client.checkWorking(apiPath)
}
func NewVersionedClient(apiPath string, apiVersionString string) (*Client, error) {
dc, err := docker.NewVersionedClient(apiPath, apiVersionString)
if err != nil {
return nil, err
}
client := &Client{dc}
return client, client.checkWorking(apiPath)
}
func (c *Client) checkWorking(apiPath string) error {
env, err := c.Version()
if err != nil {
return err
}
Log.Infof("[docker] Using Docker API on %s: %v", apiPath, env)
return nil
}
// AddObserver adds an observer for docker events
func (c *Client) AddObserver(ob ContainerObserver) error {
events := make(chan *docker.APIEvents)
if err := c.AddEventListener(events); err != nil {
Log.Errorf("[docker] Unable to add listener to Docker API: %s", err)
return err
}
go func() {
for event := range events {
switch event.Status {
case "start":
id := event.ID
ob.ContainerStarted(id)
case "die":
id := event.ID
ob.ContainerDied(id)
}
}
}()
return nil
}
// IsContainerNotRunning returns true if we have checked with Docker that the ID is not running
func (c *Client) IsContainerNotRunning(idStr string) bool {
container, err := c.InspectContainer(idStr)
if err == nil {
return !container.State.Running
}
if _, notThere := err.(*docker.NoSuchContainer); notThere {
return true
}
Log.Errorf("[docker] Could not check container status: %s", err)
return false
}