harness-drone/shared/docker/docker.go

136 lines
3.2 KiB
Go
Raw Normal View History

2015-09-30 01:21:17 +00:00
package docker
import (
"errors"
2015-09-30 01:21:17 +00:00
"io"
"io/ioutil"
log "github.com/Sirupsen/logrus"
2015-09-30 01:21:17 +00:00
"github.com/samalba/dockerclient"
)
var (
LogOpts = &dockerclient.LogOptions{
Stdout: true,
Stderr: true,
}
LogOptsTail = &dockerclient.LogOptions{
Follow: true,
Stdout: true,
Stderr: true,
}
)
// Run creates the docker container, pulling images if necessary, starts
// the container and blocks until the container exits, returning the exit
// information.
func Run(client dockerclient.Client, conf *dockerclient.ContainerConfig, name string) (*dockerclient.ContainerInfo, error) {
info, err := RunDaemon(client, conf, name)
if err != nil {
return nil, err
}
return Wait(client, info.Id)
}
// RunDaemon creates the docker container, pulling images if necessary, starts
// the container and returns the container information. It does not wait for
// the container to exit.
func RunDaemon(client dockerclient.Client, conf *dockerclient.ContainerConfig, name string) (*dockerclient.ContainerInfo, error) {
// attempts to create the contianer
id, err := client.CreateContainer(conf, name)
if err != nil {
// and pull the image and re-create if that fails
err = client.PullImage(conf.Image, nil)
if err != nil {
return nil, err
}
id, err = client.CreateContainer(conf, name)
if err != nil {
client.RemoveContainer(id, true, true)
return nil, err
}
}
// fetches the container information
info, err := client.InspectContainer(id)
if err != nil {
client.RemoveContainer(id, true, true)
return nil, err
}
// starts the container
err = client.StartContainer(id, &conf.HostConfig)
if err != nil {
client.RemoveContainer(id, true, true)
return nil, err
}
return info, err
}
// Wait blocks until the named container exits, returning the exit information.
func Wait(client dockerclient.Client, name string) (*dockerclient.ContainerInfo, error) {
defer func() {
client.StopContainer(name, 5)
client.KillContainer(name, "9")
}()
errc := make(chan error, 1)
infoc := make(chan *dockerclient.ContainerInfo, 1)
go func() {
// options to fetch the stdout and stderr logs
// by tailing the output.
logOptsTail := &dockerclient.LogOptions{
Follow: true,
Stdout: true,
Stderr: true,
2015-09-30 01:21:17 +00:00
}
for attempts := 0; attempts < 5; attempts++ {
if attempts > 0 {
// When resuming the stream, only grab the last line when starting
// the tailing.
logOptsTail.Tail = 1
}
// blocks and waits for the container to finish
// by streaming the logs (to /dev/null). Ideally
// we could use the `wait` function instead
rc, err := client.ContainerLogs(name, logOptsTail)
if err != nil {
errc <- err
return
}
io.Copy(ioutil.Discard, rc)
rc.Close()
info, err := client.InspectContainer(name)
if err != nil {
errc <- err
return
}
if !info.State.Running {
// The container is no longer running, there should be no more logs to tail.
infoc <- info
return
}
log.Debugf("Attempting to resume log tailing after %d attempts.\n", attempts)
2015-09-30 01:21:17 +00:00
}
errc <- errors.New("Maximum number of attempts made while tailing logs.")
2015-09-30 01:21:17 +00:00
}()
select {
case info := <-infoc:
return info, nil
case err := <-errc:
return nil, err
}
}