open-consul/connect/proxy/proxy.go
2018-06-25 12:25:40 -07:00

151 lines
4 KiB
Go

package proxy
import (
"bytes"
"crypto/x509"
"log"
"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/connect"
"github.com/hashicorp/consul/lib"
)
// Proxy implements the built-in connect proxy.
type Proxy struct {
client *api.Client
cfgWatcher ConfigWatcher
stopChan chan struct{}
logger *log.Logger
service *connect.Service
}
// New returns a proxy with the given configuration source.
//
// The ConfigWatcher can be used to update the configuration of the proxy.
// Whenever a new configuration is detected, the proxy will reconfigure itself.
func New(client *api.Client, cw ConfigWatcher, logger *log.Logger) (*Proxy, error) {
return &Proxy{
client: client,
cfgWatcher: cw,
stopChan: make(chan struct{}),
logger: logger,
}, nil
}
// Serve the proxy instance until a fatal error occurs or proxy is closed.
func (p *Proxy) Serve() error {
var cfg *Config
// failCh is used to stop Serve and return an error from another goroutine we
// spawn.
failCh := make(chan error, 1)
// Watch for config changes (initial setup happens on first "change")
for {
select {
case err := <-failCh:
// don't log here, we can log with better context at the point where we
// write the err to the chan
return err
case newCfg := <-p.cfgWatcher.Watch():
p.logger.Printf("[DEBUG] got new config")
if cfg == nil {
// Initial setup
// Setup telemetry if configured
_, err := lib.InitTelemetry(newCfg.Telemetry)
if err != nil {
p.logger.Printf("[ERR] proxy telemetry config error: %s", err)
}
// Setup Service instance now we know target ID etc
service, err := newCfg.Service(p.client, p.logger)
if err != nil {
return err
}
p.service = service
go func() {
<-service.ReadyWait()
p.logger.Printf("[INFO] proxy loaded config and ready to serve")
tcfg := service.ServerTLSConfig()
cert, _ := tcfg.GetCertificate(nil)
leaf, _ := x509.ParseCertificate(cert.Certificate[0])
p.logger.Printf("[DEBUG] leaf: %s roots: %s", leaf.URIs[0],
bytes.Join(tcfg.RootCAs.Subjects(), []byte(",")))
// Only start a listener if we have a port set. This allows
// the configuration to disable our public listener.
if newCfg.PublicListener.BindPort != 0 {
newCfg.PublicListener.applyDefaults()
l := NewPublicListener(p.service, newCfg.PublicListener, p.logger)
err = p.startListener("public listener", l)
if err != nil {
// This should probably be fatal.
p.logger.Printf("[ERR] failed to start public listener: %s", err)
failCh <- err
}
}
}()
}
// TODO(banks) update/remove upstreams properly based on a diff with current. Can
// store a map of uc.String() to Listener here and then use it to only
// start one of each and stop/modify if changes occur.
for _, uc := range newCfg.Upstreams {
uc.applyDefaults()
uc.resolver = UpstreamResolverFromClient(p.client, uc)
if uc.LocalBindPort < 1 {
p.logger.Printf("[ERR] upstream %s has no local_bind_port. "+
"Can't start upstream.", uc.String())
continue
}
l := NewUpstreamListener(p.service, uc, p.logger)
err := p.startListener(uc.String(), l)
if err != nil {
p.logger.Printf("[ERR] failed to start upstream %s: %s", uc.String(),
err)
}
}
cfg = newCfg
case <-p.stopChan:
return nil
}
}
}
// startPublicListener is run from the internal state machine loop
func (p *Proxy) startListener(name string, l *Listener) error {
p.logger.Printf("[INFO] %s starting on %s", name, l.BindAddr())
go func() {
err := l.Serve()
if err != nil {
p.logger.Printf("[ERR] %s stopped with error: %s", name, err)
return
}
p.logger.Printf("[INFO] %s stopped", name)
}()
go func() {
<-p.stopChan
l.Close()
}()
return nil
}
// Close stops the proxy and terminates all active connections. It must be
// called only once.
func (p *Proxy) Close() {
close(p.stopChan)
if p.service != nil {
p.service.Close()
}
}