mirror of
https://github.com/costela/docker-etchosts.git
synced 2025-05-11 09:55:48 +02:00
111 lines
3 KiB
Go
111 lines
3 KiB
Go
/*
|
|
Copyright © 2018 Leo Antunes <leo@costela.net>
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
package main
|
|
|
|
import (
|
|
"context"
|
|
"fmt"
|
|
|
|
"github.com/cenkalti/backoff"
|
|
|
|
docker "docker.io/go-docker"
|
|
"docker.io/go-docker/api/types"
|
|
"docker.io/go-docker/api/types/events"
|
|
"docker.io/go-docker/api/types/filters"
|
|
|
|
log "github.com/sirupsen/logrus"
|
|
)
|
|
|
|
func main() {
|
|
log.SetLevel(log.InfoLevel) // TODO: make configurable
|
|
|
|
client, err := docker.NewEnvClient()
|
|
if err != nil {
|
|
log.Fatalf("error starting docker client: %s", err)
|
|
}
|
|
defer client.Close()
|
|
|
|
var event events.Message
|
|
eventOpts := types.EventsOptions{
|
|
Filters: filters.NewArgs(
|
|
filters.Arg("type", "container"),
|
|
filters.Arg("event", "start"),
|
|
filters.Arg("event", "die"),
|
|
),
|
|
}
|
|
|
|
for {
|
|
initialContent, err := getAllIPsToNames(client)
|
|
if err != nil {
|
|
log.Fatalf("error getting containers: %s", err)
|
|
}
|
|
|
|
log.Info("writing current content")
|
|
syncEtcHosts(initialContent)
|
|
|
|
events, errors := client.Events(context.Background(), eventOpts)
|
|
innerLoop:
|
|
for {
|
|
select {
|
|
case event = <-events:
|
|
switch event.Action {
|
|
case "start":
|
|
ipsToNames, err := getIPsToNames(client, event.Actor.Attributes["name"])
|
|
if err != nil {
|
|
log.WithFields(
|
|
log.Fields{"container": event.Actor.ID},
|
|
).Errorf("could not get info for container: %s", err)
|
|
continue
|
|
}
|
|
err = addToEtcHosts(ipsToNames)
|
|
if err != nil {
|
|
log.WithFields(
|
|
log.Fields{"container": event.Actor.ID},
|
|
).Errorf("could not add container to hosts file: %s", err)
|
|
}
|
|
case "die":
|
|
// We remove by name because we cannot get the container's IP after it has been destroyed.
|
|
// Names are supposed to be kept unique by the docker deamon.}
|
|
removeFromEtcHosts(event.Actor.Attributes["name"])
|
|
}
|
|
case err = <-errors:
|
|
log.Errorf("error fetching event: %s", err)
|
|
|
|
client.Close()
|
|
err := backoff.Retry(func() error {
|
|
log.Info("retrying connection to docker")
|
|
client, err = docker.NewEnvClient()
|
|
if err != nil {
|
|
return fmt.Errorf("error starting docker client: %s", err)
|
|
}
|
|
_, err = client.Ping(context.Background())
|
|
if err != nil {
|
|
return fmt.Errorf("error pinging docker server: %s", err)
|
|
}
|
|
return nil
|
|
}, backoff.NewExponentialBackOff())
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
log.Info("reconnected to docker")
|
|
defer client.Close() // client changed
|
|
break innerLoop
|
|
}
|
|
}
|
|
}
|
|
}
|