plugeth/cmd/puppeth/module.go

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// Copyright 2017 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum 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.
//
// go-ethereum 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 go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package main
import (
"encoding/json"
"errors"
"fmt"
"net"
"strconv"
"strings"
"time"
"github.com/ethereum/go-ethereum/log"
)
var (
// ErrServiceUnknown is returned when a service container doesn't exist.
ErrServiceUnknown = errors.New("service unknown")
// ErrServiceOffline is returned when a service container exists, but it is not
// running.
ErrServiceOffline = errors.New("service offline")
// ErrServiceUnreachable is returned when a service container is running, but
// seems to not respond to communication attempts.
ErrServiceUnreachable = errors.New("service unreachable")
// ErrNotExposed is returned if a web-service doesn't have an exposed port, nor
// a reverse-proxy in front of it to forward requests.
ErrNotExposed = errors.New("service not exposed, nor proxied")
)
// containerInfos is a heavily reduced version of the huge inspection dataset
// returned from docker inspect, parsed into a form easily usable by puppeth.
type containerInfos struct {
running bool // Flag whether the container is running currently
envvars map[string]string // Collection of environmental variables set on the container
portmap map[string]int // Port mapping from internal port/proto combos to host binds
volumes map[string]string // Volume mount points from container to host directories
}
// inspectContainer runs docker inspect against a running container
func inspectContainer(client *sshClient, container string) (*containerInfos, error) {
// Check whether there's a container running for the service
out, err := client.Run(fmt.Sprintf("docker inspect %s", container))
if err != nil {
return nil, ErrServiceUnknown
}
// If yes, extract various configuration options
type inspection struct {
State struct {
Running bool
}
Mounts []struct {
Source string
Destination string
}
Config struct {
Env []string
}
HostConfig struct {
PortBindings map[string][]map[string]string
}
}
var inspects []inspection
if err = json.Unmarshal(out, &inspects); err != nil {
return nil, err
}
inspect := inspects[0]
// Infos retrieved, parse the above into something meaningful
infos := &containerInfos{
running: inspect.State.Running,
envvars: make(map[string]string),
portmap: make(map[string]int),
volumes: make(map[string]string),
}
for _, envvar := range inspect.Config.Env {
if parts := strings.Split(envvar, "="); len(parts) == 2 {
infos.envvars[parts[0]] = parts[1]
}
}
for portname, details := range inspect.HostConfig.PortBindings {
if len(details) > 0 {
port, _ := strconv.Atoi(details[0]["HostPort"])
infos.portmap[portname] = port
}
}
for _, mount := range inspect.Mounts {
infos.volumes[mount.Destination] = mount.Source
}
return infos, err
}
// tearDown connects to a remote machine via SSH and terminates docker containers
// running with the specified name in the specified network.
func tearDown(client *sshClient, network string, service string, purge bool) ([]byte, error) {
// Tear down the running (or paused) container
out, err := client.Run(fmt.Sprintf("docker rm -f %s_%s_1", network, service))
if err != nil {
return out, err
}
// If requested, purge the associated docker image too
if purge {
return client.Run(fmt.Sprintf("docker rmi %s/%s", network, service))
}
return nil, nil
}
// resolve retrieves the hostname a service is running on either by returning the
// actual server name and port, or preferably an nginx virtual host if available.
func resolve(client *sshClient, network string, service string, port int) (string, error) {
// Inspect the service to get various configurations from it
infos, err := inspectContainer(client, fmt.Sprintf("%s_%s_1", network, service))
if err != nil {
return "", err
}
if !infos.running {
return "", ErrServiceOffline
}
// Container online, extract any environmental variables
if vhost := infos.envvars["VIRTUAL_HOST"]; vhost != "" {
return vhost, nil
}
return fmt.Sprintf("%s:%d", client.server, port), nil
}
// checkPort tries to connect to a remote host on a given
func checkPort(host string, port int) error {
log.Trace("Verifying remote TCP connectivity", "server", host, "port", port)
conn, err := net.DialTimeout("tcp", fmt.Sprintf("%s:%d", host, port), time.Second)
if err != nil {
return err
}
conn.Close()
return nil
}