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watchtower/main.go
Ross Cadogan 1c59200565 Registry authentication was failing silently when pulling images.
Load authentication credentials for available credential stores in order of preference:
 1. Environment variables REPO_USER, REPO_PASS
 2. Docker config files
Request image pull with authentication header.
Wait until pull request is complete before exiting function.
2016-10-18 14:04:55 +01:00

154 lines
3.0 KiB
Go

package main // import "github.com/CenturyLinkLabs/watchtower"
import (
"fmt"
"os"
"os/signal"
"sync"
"syscall"
"time"
"github.com/CenturyLinkLabs/watchtower/actions"
"github.com/CenturyLinkLabs/watchtower/container"
log "github.com/Sirupsen/logrus"
"github.com/urfave/cli"
)
var (
wg sync.WaitGroup
client container.Client
pollInterval time.Duration
cleanup bool
)
func init() {
log.SetLevel(log.InfoLevel)
}
func main() {
app := cli.NewApp()
app.Name = "watchtower"
app.Usage = "Automatically update running Docker containers"
app.Before = before
app.Action = start
app.Flags = []cli.Flag{
cli.StringFlag{
Name: "host, H",
Usage: "daemon socket to connect to",
Value: "unix:///var/run/docker.sock",
EnvVar: "DOCKER_HOST",
},
cli.IntFlag{
Name: "interval, i",
Usage: "poll interval (in seconds)",
Value: 300,
},
cli.BoolFlag{
Name: "no-pull",
Usage: "do not pull new images",
},
cli.BoolFlag{
Name: "cleanup",
Usage: "remove old images after updating",
},
cli.BoolFlag{
Name: "tlsverify",
Usage: "use TLS and verify the remote",
EnvVar: "DOCKER_TLS_VERIFY",
},
cli.BoolFlag{
Name: "debug",
Usage: "enable debug mode with verbose logging",
},
cli.StringFlag{
Name: "apiversion",
Usage: "the version of the docker api",
EnvVar: "DOCKER_API_VERSION",
},
}
if err := app.Run(os.Args); err != nil {
log.Fatal(err)
}
}
func before(c *cli.Context) error {
if c.GlobalBool("debug") {
log.SetLevel(log.DebugLevel)
}
pollInterval = time.Duration(c.Int("interval")) * time.Second
cleanup = c.GlobalBool("cleanup")
// configure environment vars for client
err := envConfig(c)
if err != nil {
return err
}
client = container.NewClient(!c.GlobalBool("no-pull"))
handleSignals()
return nil
}
func start(c *cli.Context) {
names := c.Args()
if err := actions.CheckPrereqs(client, cleanup); err != nil {
log.Fatal(err)
}
for {
wg.Add(1)
if err := actions.Update(client, names, cleanup); err != nil {
fmt.Println(err)
}
wg.Done()
time.Sleep(pollInterval)
}
}
func handleSignals() {
// Graceful shut-down on SIGINT/SIGTERM
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt)
signal.Notify(c, syscall.SIGTERM)
go func() {
<-c
wg.Wait()
os.Exit(1)
}()
}
func setEnvOptStr(env string, opt string) error {
if opt != "" && opt != os.Getenv(env) {
err := os.Setenv(env, opt)
if err != nil {
return err
}
}
return nil
}
func setEnvOptBool(env string, opt bool) error {
if opt == true {
return setEnvOptStr(env, "1")
}
return nil
}
// envConfig translates the command-line options into environment variables
// that will initialize the api client
func envConfig(c *cli.Context) error {
var err error
err = setEnvOptStr("DOCKER_HOST", c.GlobalString("host"))
err = setEnvOptBool("DOCKER_TLS_VERIFY", c.GlobalBool("tlsverify"))
err = setEnvOptStr("DOCKER_API_VERSION", c.GlobalString("apiversion"))
return err
}