open-consul/command/connect/proxy/proxy.go

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package proxy
import (
"flag"
"fmt"
"log"
"net"
"net/http"
_ "net/http/pprof" // Expose pprof if configured
"os"
"sort"
"strconv"
"strings"
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"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/command/flags"
proxyImpl "github.com/hashicorp/consul/connect/proxy"
"github.com/hashicorp/go-hclog"
"github.com/hashicorp/consul/logging"
"github.com/mitchellh/cli"
)
func New(ui cli.Ui, shutdownCh <-chan struct{}) *cmd {
ui = &cli.PrefixedUi{
OutputPrefix: "==> ",
InfoPrefix: " ",
ErrorPrefix: "==> ",
Ui: ui,
}
c := &cmd{UI: ui, shutdownCh: shutdownCh}
c.init()
return c
}
type cmd struct {
UI cli.Ui
flags *flag.FlagSet
http *flags.HTTPFlags
help string
shutdownCh <-chan struct{}
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logger hclog.Logger
// flags
logLevel string
logJSON bool
cfgFile string
proxyID string
sidecarFor string
pprofAddr string
service string
serviceAddr string
upstreams map[string]proxyImpl.UpstreamConfig
listen string
register bool
registerId string
// test flags
testNoStart bool // don't start the proxy, just exit 0
}
func (c *cmd) init() {
c.flags = flag.NewFlagSet("", flag.ContinueOnError)
c.flags.StringVar(&c.proxyID, "proxy-id", "",
"The proxy's ID on the local agent.")
c.flags.StringVar(&c.sidecarFor, "sidecar-for", "",
"The ID of a service instance on the local agent that this proxy should "+
"become a sidecar for. It requires that the proxy service is registered "+
"with the agent as a connect-proxy with Proxy.DestinationServiceID set "+
"to this value. If more than one such proxy is registered it will fail.")
c.flags.StringVar(&c.logLevel, "log-level", "INFO",
"Specifies the log level.")
c.flags.BoolVar(&c.logJSON, "log-json", false,
"Output logs in JSON format.")
c.flags.StringVar(&c.pprofAddr, "pprof-addr", "",
"Enable debugging via pprof. Providing a host:port (or just ':port') "+
"enables profiling HTTP endpoints on that address.")
c.flags.StringVar(&c.service, "service", "",
"Name of the service this proxy is representing.")
c.flags.Var((*FlagUpstreams)(&c.upstreams), "upstream",
"Upstream service to support connecting to. The format should be "+
"'name:addr', such as 'db:8181'. This will make 'db' available "+
"on port 8181. This can be repeated multiple times.")
c.flags.StringVar(&c.serviceAddr, "service-addr", "",
"Address of the local service to proxy. Only useful if -listen "+
"and -service are both set.")
c.flags.StringVar(&c.listen, "listen", "",
"Address to listen for inbound connections to the proxied service. "+
"Must be specified with -service and -service-addr.")
c.flags.BoolVar(&c.register, "register", false,
"Self-register with the local Consul agent. Only useful with "+
"-listen.")
c.flags.StringVar(&c.registerId, "register-id", "",
"ID suffix for the service. Use this to disambiguate with other proxies.")
c.http = &flags.HTTPFlags{}
flags.Merge(c.flags, c.http.ClientFlags())
flags.Merge(c.flags, c.http.ServerFlags())
c.help = flags.Usage(help, c.flags)
}
func (c *cmd) Run(args []string) int {
if err := c.flags.Parse(args); err != nil {
return 1
}
if len(c.flags.Args()) > 0 {
c.UI.Error(fmt.Sprintf("Should have no non-flag arguments."))
return 1
}
// Load the proxy ID and token from env vars if they're set
if c.proxyID == "" {
c.proxyID = os.Getenv("CONNECT_PROXY_ID")
}
if c.sidecarFor == "" {
c.sidecarFor = os.Getenv("CONNECT_SIDECAR_FOR")
}
// Setup the log outputs
logConfig := &logging.Config{
LogLevel: c.logLevel,
Name: logging.Proxy,
LogJSON: c.logJSON,
}
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logger, logGate, _, ok := logging.Setup(logConfig, c.UI)
if !ok {
return 1
}
c.logger = logger
// Enable Pprof if needed
if c.pprofAddr != "" {
go func() {
c.UI.Output(fmt.Sprintf("Starting pprof HTTP endpoints on "+
"http://%s/debug/pprof", c.pprofAddr))
log.Fatal(http.ListenAndServe(c.pprofAddr, nil))
}()
}
// Setup Consul client
client, err := c.http.APIClient()
if err != nil {
c.UI.Error(fmt.Sprintf("Error connecting to Consul agent: %s", err))
return 1
}
// Output this first since the config watcher below will output
// other information.
c.UI.Output("Consul Connect proxy starting...")
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// Get the proper configuration watcher
cfgWatcher, err := c.configWatcher(client)
if err != nil {
c.UI.Error(fmt.Sprintf("Error preparing configuration: %s", err))
return 1
}
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p, err := proxyImpl.New(client, cfgWatcher, c.logger)
if err != nil {
c.UI.Error(fmt.Sprintf("Failed initializing proxy: %s", err))
return 1
}
// Hook the shutdownCh up to close the proxy
go func() {
<-c.shutdownCh
p.Close()
}()
// Register the service if we requested it
if c.register {
monitor, err := c.registerMonitor(client)
if err != nil {
c.UI.Error(fmt.Sprintf("Failed initializing registration: %s", err))
return 1
}
go monitor.Run()
defer monitor.Close()
}
c.UI.Info("")
c.UI.Output("Log data will now stream in as it occurs:\n")
logGate.Flush()
// Run the proxy unless our tests require we don't
if !c.testNoStart {
if err := p.Serve(); err != nil {
c.UI.Error(fmt.Sprintf("Failed running proxy: %s", err))
}
}
c.UI.Output("Consul Connect proxy shutdown")
return 0
}
func (c *cmd) lookupProxyIDForSidecar(client *api.Client) (string, error) {
return LookupProxyIDForSidecar(client, c.sidecarFor)
}
// LookupProxyIDForSidecar finds candidate local proxy registrations that are a
// sidecar for the given service. It will return an ID if and only if there is
// exactly one registered connect proxy with `Proxy.DestinationServiceID` set to
// the specified service ID.
//
// This is exported to share it with the connect envoy command.
func LookupProxyIDForSidecar(client *api.Client, sidecarFor string) (string, error) {
svcs, err := client.Agent().Services()
if err != nil {
return "", fmt.Errorf("Failed looking up sidecar proxy info for %s: %s",
sidecarFor, err)
}
var proxyIDs []string
for _, svc := range svcs {
if svc.Kind == api.ServiceKindConnectProxy && svc.Proxy != nil &&
strings.ToLower(svc.Proxy.DestinationServiceID) == sidecarFor {
proxyIDs = append(proxyIDs, svc.ID)
}
}
if len(proxyIDs) == 0 {
return "", fmt.Errorf("No sidecar proxy registered for %s", sidecarFor)
}
if len(proxyIDs) > 1 {
return "", fmt.Errorf("More than one sidecar proxy registered for %s.\n"+
" Start proxy with -proxy-id and one of the following IDs: %s",
sidecarFor, strings.Join(proxyIDs, ", "))
}
return proxyIDs[0], nil
}
// LookupGatewayProxy finds the gateway service registered with the local
// agent. If exactly one gateway exists it will be returned, otherwise an error
// is returned.
func LookupGatewayProxy(client *api.Client, kind api.ServiceKind) (*api.AgentService, error) {
svcs, err := client.Agent().ServicesWithFilter(fmt.Sprintf("Kind == `%s`", kind))
if err != nil {
return nil, fmt.Errorf("Failed looking up %s instances: %v", kind, err)
}
switch len(svcs) {
case 0:
return nil, fmt.Errorf("No %s services registered with this agent", kind)
case 1:
for _, svc := range svcs {
return svc, nil
}
return nil, fmt.Errorf("This should be unreachable")
default:
return nil, fmt.Errorf("Cannot lookup the %s's proxy ID because multiple are registered with the agent", kind)
}
}
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func (c *cmd) configWatcher(client *api.Client) (proxyImpl.ConfigWatcher, error) {
// Use the configured proxy ID
if c.proxyID != "" {
c.UI.Info("Configuration mode: Agent API")
c.UI.Info(fmt.Sprintf(" Proxy ID: %s", c.proxyID))
return proxyImpl.NewAgentConfigWatcher(client, c.proxyID, c.logger)
}
if c.sidecarFor != "" {
// Running as a sidecar, we need to find the proxy-id for the requested
// service
var err error
c.proxyID, err = c.lookupProxyIDForSidecar(client)
if err != nil {
return nil, err
}
c.UI.Info("Configuration mode: Agent API")
c.UI.Info(fmt.Sprintf(" Sidecar for ID: %s", c.sidecarFor))
c.UI.Info(fmt.Sprintf(" Proxy ID: %s", c.proxyID))
return proxyImpl.NewAgentConfigWatcher(client, c.proxyID, c.logger)
}
// Otherwise, we're representing a manually specified service.
if c.service == "" {
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return nil, fmt.Errorf(
"-service or -proxy-id must be specified so that proxy can " +
"configure itself.")
}
c.UI.Info("Configuration mode: Flags")
c.UI.Info(fmt.Sprintf(" Service: %s", c.service))
// Convert our upstreams to a slice of configurations. We do this
// deterministically by alphabetizing the upstream keys. We do this so
// that tests can compare the upstream values.
upstreamKeys := make([]string, 0, len(c.upstreams))
for k := range c.upstreams {
upstreamKeys = append(upstreamKeys, k)
}
sort.Strings(upstreamKeys)
upstreams := make([]proxyImpl.UpstreamConfig, 0, len(c.upstreams))
for _, k := range upstreamKeys {
config := c.upstreams[k]
c.UI.Info(fmt.Sprintf(
" Upstream: %s => %s:%d",
k, config.LocalBindAddress, config.LocalBindPort))
upstreams = append(upstreams, config)
}
// Parse out our listener if we have one
var listener proxyImpl.PublicListenerConfig
if c.listen != "" {
host, port, err := c.listenParts()
if err != nil {
return nil, err
}
if c.serviceAddr == "" {
return nil, fmt.Errorf(
"-service-addr must be specified with -listen so the proxy " +
"knows the backend service address.")
}
c.UI.Info(fmt.Sprintf(" Public listener: %s:%d => %s", host, port, c.serviceAddr))
listener.BindAddress = host
listener.BindPort = port
listener.LocalServiceAddress = c.serviceAddr
} else {
c.UI.Info(fmt.Sprintf(" Public listener: Disabled"))
}
return proxyImpl.NewStaticConfigWatcher(&proxyImpl.Config{
ProxiedServiceName: c.service,
PublicListener: listener,
Upstreams: upstreams,
}), nil
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}
// registerMonitor returns the registration monitor ready to be started.
func (c *cmd) registerMonitor(client *api.Client) (*RegisterMonitor, error) {
if c.service == "" || c.listen == "" {
return nil, fmt.Errorf("-register may only be specified with -service and -listen")
}
host, port, err := c.listenParts()
if err != nil {
return nil, err
}
m := NewRegisterMonitor(c.logger)
m.Logger = c.logger
m.Client = client
m.Service = c.service
m.IDSuffix = c.registerId
m.LocalAddress = host
m.LocalPort = port
return m, nil
}
// listenParts returns the host and port parts of the -listen flag. The
// -listen flag must be non-empty prior to calling this.
func (c *cmd) listenParts() (string, int, error) {
host, portRaw, err := net.SplitHostPort(c.listen)
if err != nil {
return "", 0, err
}
port, err := strconv.ParseInt(portRaw, 0, 0)
if err != nil {
return "", 0, err
}
return host, int(port), nil
}
func (c *cmd) Synopsis() string {
return synopsis
}
func (c *cmd) Help() string {
return c.help
}
const synopsis = "Runs a Consul Connect proxy"
const help = `
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Usage: consul connect proxy [options]
Starts a Consul Connect proxy and runs until an interrupt is received.
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The proxy can be used to accept inbound connections for a service,
wrap outbound connections to upstream services, or both. This enables
a non-Connect-aware application to use Connect.
The proxy requires service:write permissions for the service it represents.
The token may be passed via the CLI or the CONSUL_HTTP_TOKEN environment
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variable.
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Consul can automatically start and manage this proxy by specifying the
"proxy" configuration within your service definition.
The example below shows how to start a local proxy for establishing outbound
connections to "db" representing the frontend service. Once running, any
process that creates a TCP connection to the specified port (8181) will
establish a mutual TLS connection to "db" identified as "frontend".
$ consul connect proxy -service frontend -upstream db:8181
The next example starts a local proxy that also accepts inbound connections
on port 8443, authorizes the connection, then proxies it to port 8080:
$ consul connect proxy \
-service frontend \
-service-addr 127.0.0.1:8080 \
-listen ':8443'
A proxy can accept both inbound connections as well as proxy to upstream
services by specifying both the "-listen" and "-upstream" flags.
`