consul/command/connect/envoy/envoy.go

606 lines
18 KiB
Go

package envoy
import (
"errors"
"flag"
"fmt"
"io/ioutil"
"net"
"os"
"os/exec"
"strconv"
"strings"
"github.com/mitchellh/cli"
"github.com/mitchellh/mapstructure"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/agent/xds"
"github.com/hashicorp/consul/api"
proxyCmd "github.com/hashicorp/consul/command/connect/proxy"
"github.com/hashicorp/consul/command/flags"
"github.com/hashicorp/consul/ipaddr"
)
func New(ui cli.Ui) *cmd {
ui = &cli.PrefixedUi{
OutputPrefix: "==> ",
InfoPrefix: " ",
ErrorPrefix: "==> ",
Ui: ui,
}
c := &cmd{UI: ui}
c.init()
return c
}
const DefaultAdminAccessLogPath = "/dev/null"
type cmd struct {
UI cli.Ui
flags *flag.FlagSet
http *flags.HTTPFlags
help string
client *api.Client
// flags
meshGateway bool
gateway string
proxyID string
sidecarFor string
adminAccessLogPath string
adminBind string
envoyBin string
bootstrap bool
disableCentralConfig bool
grpcAddr string
envoyVersion string
// mesh gateway registration information
register bool
lanAddress ServiceAddressValue
wanAddress ServiceAddressValue
deregAfterCritical string
bindAddresses ServiceAddressMapValue
exposeServers bool
gatewaySvcName string
gatewayKind api.ServiceKind
}
const (
defaultEnvoyVersion = "1.13.1"
meshGatewayVal = "mesh"
)
var supportedGateways = map[string]api.ServiceKind{
"mesh": api.ServiceKindMeshGateway,
"terminating": api.ServiceKindTerminatingGateway,
}
func (c *cmd) init() {
c.flags = flag.NewFlagSet("", flag.ContinueOnError)
c.flags.StringVar(&c.proxyID, "proxy-id", os.Getenv("CONNECT_PROXY_ID"),
"The proxy's ID on the local agent.")
// Deprecated in favor of `gateway`
c.flags.BoolVar(&c.meshGateway, "mesh-gateway", false,
"Configure Envoy as a Mesh Gateway.")
c.flags.StringVar(&c.gateway, "gateway", "",
"The type of gateway to register. One of: terminating or mesh")
c.flags.StringVar(&c.sidecarFor, "sidecar-for", os.Getenv("CONNECT_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.envoyBin, "envoy-binary", "",
"The full path to the envoy binary to run. By default will just search "+
"$PATH. Ignored if -bootstrap is used.")
c.flags.StringVar(&c.adminAccessLogPath, "admin-access-log-path", DefaultAdminAccessLogPath,
fmt.Sprintf("The path to write the access log for the administration server. If no access "+
"log is desired specify %q. By default it will use %q.",
DefaultAdminAccessLogPath, DefaultAdminAccessLogPath))
c.flags.StringVar(&c.adminBind, "admin-bind", "localhost:19000",
"The address:port to start envoy's admin server on. Envoy requires this "+
"but care must be taken to ensure it's not exposed to an untrusted network "+
"as it has full control over the secrets and config of the proxy.")
c.flags.BoolVar(&c.bootstrap, "bootstrap", false,
"Generate the bootstrap.json but don't exec envoy")
c.flags.BoolVar(&c.disableCentralConfig, "no-central-config", false,
"By default the proxy's bootstrap configuration can be customized "+
"centrally. This requires that the command run on the same agent as the "+
"proxy will and that the agent is reachable when the command is run. In "+
"cases where either assumption is violated this flag will prevent the "+
"command attempting to resolve config from the local agent.")
c.flags.StringVar(&c.grpcAddr, "grpc-addr", os.Getenv(api.GRPCAddrEnvName),
"Set the agent's gRPC address and port (in http(s)://host:port format). "+
"Alternatively, you can specify CONSUL_GRPC_ADDR in ENV.")
c.flags.StringVar(&c.envoyVersion, "envoy-version", defaultEnvoyVersion,
"Sets the envoy-version that the envoy binary has.")
c.flags.BoolVar(&c.register, "register", false,
"Register a new gateway service before configuring and starting Envoy")
c.flags.Var(&c.lanAddress, "address",
"LAN address to advertise in the gateway service registration")
c.flags.Var(&c.wanAddress, "wan-address",
"WAN address to advertise in the gateway service registration")
c.flags.Var(&c.bindAddresses, "bind-address", "Bind "+
"address to use instead of the default binding rules given as `<name>=<ip>:<port>` "+
"pairs. This flag may be specified multiple times to add multiple bind addresses.")
c.flags.StringVar(&c.gatewaySvcName, "service", "",
"Service name to use for the registration")
c.flags.BoolVar(&c.exposeServers, "expose-servers", false,
"Expose the servers for WAN federation via this mesh gateway")
c.flags.StringVar(&c.deregAfterCritical, "deregister-after-critical", "6h",
"The amount of time the gateway services health check can be failing before being deregistered")
c.http = &flags.HTTPFlags{}
flags.Merge(c.flags, c.http.ClientFlags())
flags.Merge(c.flags, c.http.NamespaceFlags())
c.help = flags.Usage(help, c.flags)
}
// canBindInternal is here mainly so we can unit test this with a constant net.Addr list
func canBindInternal(addr string, ifAddrs []net.Addr) bool {
if addr == "" {
return false
}
ip := net.ParseIP(addr)
if ip == nil {
return false
}
ipStr := ip.String()
for _, addr := range ifAddrs {
switch v := addr.(type) {
case *net.IPNet:
if v.IP.String() == ipStr {
return true
}
default:
if addr.String() == ipStr {
return true
}
}
}
return false
}
func canBind(addr api.ServiceAddress) bool {
ifAddrs, err := net.InterfaceAddrs()
if err != nil {
return false
}
return canBindInternal(addr.Address, ifAddrs)
}
func (c *cmd) Run(args []string) int {
if err := c.flags.Parse(args); err != nil {
return 1
}
passThroughArgs := c.flags.Args()
// 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
}
c.client = client
// Fixup for deprecated mesh-gateway flag
if c.meshGateway && c.gateway != "" {
c.UI.Error("The mesh-gateway flag is deprecated and cannot be used alongside the gateway flag")
return 1
}
if c.meshGateway {
c.gateway = meshGatewayVal
}
if c.exposeServers {
if c.gateway != meshGatewayVal {
c.UI.Error("'-expose-servers' can only be used for mesh gateways")
return 1
}
if !c.register {
c.UI.Error("'-expose-servers' requires '-register'")
return 1
}
}
// Gateway kind is set so that it is available even if not auto-registering the gateway
if c.gateway != "" {
kind, ok := supportedGateways[c.gateway]
if !ok {
c.UI.Error("Gateway must be one of: terminating or mesh")
return 1
}
c.gatewayKind = kind
}
if c.register {
if c.gateway == "" {
c.UI.Error("Auto-Registration can only be used for gateways")
return 1
}
if c.gatewaySvcName == "" {
c.gatewaySvcName = string(c.gatewayKind)
}
taggedAddrs := make(map[string]api.ServiceAddress)
lanAddr := c.lanAddress.Value()
if lanAddr.Address != "" {
taggedAddrs[structs.TaggedAddressLAN] = lanAddr
}
wanAddr := c.wanAddress.Value()
if wanAddr.Address != "" {
taggedAddrs[structs.TaggedAddressWAN] = wanAddr
}
tcpCheckAddr := lanAddr.Address
if tcpCheckAddr == "" {
// fallback to localhost as the gateway has to reside in the same network namespace
// as the agent
tcpCheckAddr = "127.0.0.1"
}
var proxyConf *api.AgentServiceConnectProxyConfig
if len(c.bindAddresses.value) > 0 {
// override all default binding rules and just bind to the user-supplied addresses
proxyConf = &api.AgentServiceConnectProxyConfig{
Config: map[string]interface{}{
"envoy_gateway_no_default_bind": true,
"envoy_gateway_bind_addresses": c.bindAddresses.value,
},
}
} else if canBind(lanAddr) && canBind(wanAddr) {
// when both addresses are bindable then we bind to the tagged addresses
// for creating the envoy listeners
proxyConf = &api.AgentServiceConnectProxyConfig{
Config: map[string]interface{}{
"envoy_gateway_no_default_bind": true,
"envoy_gateway_bind_tagged_addresses": true,
},
}
} else if !canBind(lanAddr) && lanAddr.Address != "" {
c.UI.Error(fmt.Sprintf("The LAN address %q will not be bindable. Either set a bindable address or override the bind addresses with -bind-address", lanAddr.Address))
return 1
}
var meta map[string]string
if c.exposeServers {
meta = map[string]string{structs.MetaWANFederationKey: "1"}
}
svc := api.AgentServiceRegistration{
Kind: c.gatewayKind,
Name: c.gatewaySvcName,
Address: lanAddr.Address,
Port: lanAddr.Port,
Meta: meta,
TaggedAddresses: taggedAddrs,
Proxy: proxyConf,
Check: &api.AgentServiceCheck{
Name: fmt.Sprintf("%s listening", c.gatewayKind),
TCP: ipaddr.FormatAddressPort(tcpCheckAddr, lanAddr.Port),
Interval: "10s",
DeregisterCriticalServiceAfter: c.deregAfterCritical,
},
}
if err := client.Agent().ServiceRegister(&svc); err != nil {
c.UI.Error(fmt.Sprintf("Error registering service %q: %s", svc.Name, err))
return 1
}
c.UI.Output(fmt.Sprintf("Registered service: %s", svc.Name))
}
// See if we need to lookup proxyID
if c.proxyID == "" && c.sidecarFor != "" {
proxyID, err := proxyCmd.LookupProxyIDForSidecar(c.client, c.sidecarFor)
if err != nil {
c.UI.Error(err.Error())
return 1
}
c.proxyID = proxyID
} else if c.proxyID == "" && c.gateway != "" {
gatewaySvc, err := proxyCmd.LookupGatewayProxy(c.client, c.gatewayKind)
if err != nil {
c.UI.Error(err.Error())
return 1
}
c.proxyID = gatewaySvc.ID
c.gatewaySvcName = gatewaySvc.Service
}
if c.proxyID == "" {
c.UI.Error("No proxy ID specified. One of -proxy-id or -sidecar-for/-gateway is " +
"required")
return 1
}
// See if we need to lookup grpcAddr
if c.grpcAddr == "" {
port, err := c.lookupGRPCPort()
if err != nil {
c.UI.Error(fmt.Sprintf("Error connecting to Consul agent: %s", err))
}
if port <= 0 {
// This is the dev mode default and recommended production setting if
// enabled.
port = 8502
c.UI.Info(fmt.Sprintf("Defaulting to grpc port = %d", port))
}
c.grpcAddr = fmt.Sprintf("localhost:%v", port)
}
// Generate config
bootstrapJson, err := c.generateConfig()
if err != nil {
c.UI.Error(err.Error())
return 1
}
if c.bootstrap {
// Just output it and we are done
os.Stdout.Write(bootstrapJson)
return 0
}
// Find Envoy binary
binary, err := c.findBinary()
if err != nil {
c.UI.Error("Couldn't find envoy binary: " + err.Error())
return 1
}
err = execEnvoy(binary, nil, passThroughArgs, bootstrapJson)
if err == errUnsupportedOS {
c.UI.Error("Directly running Envoy is only supported on linux and macOS " +
"since envoy itself doesn't build on other platforms currently.")
c.UI.Error("Use the -bootstrap option to generate the JSON to use when running envoy " +
"on a supported OS or via a container or VM.")
return 1
} else if err != nil {
c.UI.Error(err.Error())
return 1
}
return 0
}
var errUnsupportedOS = errors.New("envoy: not implemented on this operating system")
func (c *cmd) findBinary() (string, error) {
if c.envoyBin != "" {
return c.envoyBin, nil
}
return exec.LookPath("envoy")
}
func (c *cmd) templateArgs() (*BootstrapTplArgs, error) {
httpCfg := api.DefaultConfig()
c.http.MergeOntoConfig(httpCfg)
// Trigger the Client init to do any last-minute updates to the Config.
if _, err := api.NewClient(httpCfg); err != nil {
return nil, err
}
// Decide on TLS if the scheme is provided and indicates it, if the HTTP env
// suggests TLS is supported explicitly (CONSUL_HTTP_SSL) or implicitly
// (CONSUL_HTTP_ADDR) is https://
useTLS := false
if strings.HasPrefix(strings.ToLower(c.grpcAddr), "https://") {
useTLS = true
} else if useSSLEnv := os.Getenv(api.HTTPSSLEnvName); useSSLEnv != "" {
if enabled, err := strconv.ParseBool(useSSLEnv); err == nil {
useTLS = enabled
}
} else if strings.HasPrefix(strings.ToLower(httpCfg.Address), "https://") {
useTLS = true
}
// We want to allow grpcAddr set as host:port with no scheme but if the host
// is an IP this will fail to parse as a URL with "parse 127.0.0.1:8500: first
// path segment in URL cannot contain colon". On the other hand we also
// support both http(s)://host:port and unix:///path/to/file.
var agentAddr, agentPort, agentSock string
if grpcAddr := strings.TrimPrefix(c.grpcAddr, "unix://"); grpcAddr != c.grpcAddr {
// Path to unix socket
agentSock = grpcAddr
} else {
// Parse as host:port with option http prefix
grpcAddr = strings.TrimPrefix(c.grpcAddr, "http://")
grpcAddr = strings.TrimPrefix(c.grpcAddr, "https://")
var err error
agentAddr, agentPort, err = net.SplitHostPort(grpcAddr)
if err != nil {
return nil, fmt.Errorf("Invalid Consul HTTP address: %s", err)
}
if agentAddr == "" {
agentAddr = "127.0.0.1"
}
// We use STATIC for agent which means we need to resolve DNS names like
// `localhost` ourselves. We could use STRICT_DNS or LOGICAL_DNS with envoy
// but Envoy resolves `localhost` differently to go on macOS at least which
// causes paper cuts like default dev agent (which binds specifically to
// 127.0.0.1) isn't reachable since Envoy resolves localhost to `[::]` and
// can't connect.
agentIP, err := net.ResolveIPAddr("ip", agentAddr)
if err != nil {
return nil, fmt.Errorf("Failed to resolve agent address: %s", err)
}
agentAddr = agentIP.String()
}
adminAddr, adminPort, err := net.SplitHostPort(c.adminBind)
if err != nil {
return nil, fmt.Errorf("Invalid Consul HTTP address: %s", err)
}
// Envoy requires IP addresses to bind too when using static so resolve DNS or
// localhost here.
adminBindIP, err := net.ResolveIPAddr("ip", adminAddr)
if err != nil {
return nil, fmt.Errorf("Failed to resolve admin bind address: %s", err)
}
// Ideally the cluster should be the service name. We may or may not have that
// yet depending on the arguments used so make a best effort here. In the
// common case, even if the command was invoked with proxy-id and we don't
// know service name yet, we will after we resolve the proxy's config in a bit
// and will update this then.
cluster := c.proxyID
if c.sidecarFor != "" {
cluster = c.sidecarFor
} else if c.gateway != "" && c.gatewaySvcName != "" {
cluster = c.gatewaySvcName
}
adminAccessLogPath := c.adminAccessLogPath
if adminAccessLogPath == "" {
adminAccessLogPath = DefaultAdminAccessLogPath
}
var caPEM string
if httpCfg.TLSConfig.CAFile != "" {
content, err := ioutil.ReadFile(httpCfg.TLSConfig.CAFile)
if err != nil {
return nil, fmt.Errorf("Failed to read CA file: %s", err)
}
caPEM = strings.Replace(string(content), "\n", "\\n", -1)
}
return &BootstrapTplArgs{
ProxyCluster: cluster,
ProxyID: c.proxyID,
AgentAddress: agentAddr,
AgentPort: agentPort,
AgentSocket: agentSock,
AgentTLS: useTLS,
AgentCAPEM: caPEM,
AdminAccessLogPath: adminAccessLogPath,
AdminBindAddress: adminBindIP.String(),
AdminBindPort: adminPort,
Token: httpCfg.Token,
LocalAgentClusterName: xds.LocalAgentClusterName,
Namespace: httpCfg.Namespace,
EnvoyVersion: c.envoyVersion,
}, nil
}
func (c *cmd) generateConfig() ([]byte, error) {
args, err := c.templateArgs()
if err != nil {
return nil, err
}
var bsCfg BootstrapConfig
if !c.disableCentralConfig {
// Fetch any customization from the registration
svc, _, err := c.client.Agent().Service(c.proxyID, nil)
if err != nil {
return nil, fmt.Errorf("failed fetch proxy config from local agent: %s", err)
}
if svc.Proxy == nil {
return nil, errors.New("service is not a Connect proxy or mesh gateway")
}
// Parse the bootstrap config
if err := mapstructure.WeakDecode(svc.Proxy.Config, &bsCfg); err != nil {
return nil, fmt.Errorf("failed parsing Proxy.Config: %s", err)
}
if svc.Proxy.DestinationServiceName != "" {
// Override cluster now we know the actual service name
args.ProxyCluster = svc.Proxy.DestinationServiceName
}
}
return bsCfg.GenerateJSON(args)
}
func (c *cmd) lookupGRPCPort() (int, error) {
self, err := c.client.Agent().Self()
if err != nil {
return 0, err
}
cfg, ok := self["DebugConfig"]
if !ok {
return 0, fmt.Errorf("unexpected agent response: no debug config")
}
port, ok := cfg["GRPCPort"]
if !ok {
return 0, fmt.Errorf("agent does not have grpc port enabled")
}
portN, ok := port.(float64)
if !ok {
return 0, fmt.Errorf("invalid grpc port in agent response")
}
return int(portN), nil
}
func (c *cmd) Synopsis() string {
return synopsis
}
func (c *cmd) Help() string {
return c.help
}
const synopsis = "Runs or Configures Envoy as a Connect proxy"
const help = `
Usage: consul connect envoy [options]
Generates the bootstrap configuration needed to start an Envoy proxy instance
for use as a Connect sidecar for a particular service instance. By default it
will generate the config and then exec Envoy directly until it exits normally.
It will search $PATH for the envoy binary but this can be overridden with
-envoy-binary.
It can instead only generate the bootstrap.json based on the current ENV and
arguments using -bootstrap.
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
variable.
The example below shows how to start a local proxy as a sidecar to a "web"
service instance. It assumes that the proxy was already registered with it's
Config for example via a sidecar_service block.
$ consul connect envoy -sidecar-for web
`