caddy/modules/caddyhttp/app.go

645 lines
24 KiB
Go

// Copyright 2015 Matthew Holt and The Caddy Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package caddyhttp
import (
"context"
"crypto/tls"
"fmt"
"net"
"net/http"
"net/netip"
"strconv"
"strings"
"sync"
"time"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/modules/caddyevents"
"github.com/caddyserver/caddy/v2/modules/caddytls"
"go.uber.org/zap"
"golang.org/x/net/http2"
"golang.org/x/net/http2/h2c"
)
func init() {
caddy.RegisterModule(App{})
}
// App is a robust, production-ready HTTP server.
//
// HTTPS is enabled by default if host matchers with qualifying names are used
// in any of routes; certificates are automatically provisioned and renewed.
// Additionally, automatic HTTPS will also enable HTTPS for servers that listen
// only on the HTTPS port but which do not have any TLS connection policies
// defined by adding a good, default TLS connection policy.
//
// In HTTP routes, additional placeholders are available (replace any `*`):
//
// Placeholder | Description
// ------------|---------------
// `{http.request.body}` | The request body (⚠️ inefficient; use only for debugging)
// `{http.request.cookie.*}` | HTTP request cookie
// `{http.request.duration}` | Time up to now spent handling the request (after decoding headers from client)
// `{http.request.duration_ms}` | Same as 'duration', but in milliseconds.
// `{http.request.uuid}` | The request unique identifier
// `{http.request.header.*}` | Specific request header field
// `{http.request.host.labels.*}` | Request host labels (0-based from right); e.g. for foo.example.com: 0=com, 1=example, 2=foo
// `{http.request.host}` | The host part of the request's Host header
// `{http.request.hostport}` | The host and port from the request's Host header
// `{http.request.method}` | The request method
// `{http.request.orig_method}` | The request's original method
// `{http.request.orig_uri.path.dir}` | The request's original directory
// `{http.request.orig_uri.path.file}` | The request's original filename
// `{http.request.orig_uri.path}` | The request's original path
// `{http.request.orig_uri.query}` | The request's original query string (without `?`)
// `{http.request.orig_uri}` | The request's original URI
// `{http.request.port}` | The port part of the request's Host header
// `{http.request.proto}` | The protocol of the request
// `{http.request.remote.host}` | The host (IP) part of the remote client's address
// `{http.request.remote.port}` | The port part of the remote client's address
// `{http.request.remote}` | The address of the remote client
// `{http.request.scheme}` | The request scheme
// `{http.request.tls.version}` | The TLS version name
// `{http.request.tls.cipher_suite}` | The TLS cipher suite
// `{http.request.tls.resumed}` | The TLS connection resumed a previous connection
// `{http.request.tls.proto}` | The negotiated next protocol
// `{http.request.tls.proto_mutual}` | The negotiated next protocol was advertised by the server
// `{http.request.tls.server_name}` | The server name requested by the client, if any
// `{http.request.tls.client.fingerprint}` | The SHA256 checksum of the client certificate
// `{http.request.tls.client.public_key}` | The public key of the client certificate.
// `{http.request.tls.client.public_key_sha256}` | The SHA256 checksum of the client's public key.
// `{http.request.tls.client.certificate_pem}` | The PEM-encoded value of the certificate.
// `{http.request.tls.client.certificate_der_base64}` | The base64-encoded value of the certificate.
// `{http.request.tls.client.issuer}` | The issuer DN of the client certificate
// `{http.request.tls.client.serial}` | The serial number of the client certificate
// `{http.request.tls.client.subject}` | The subject DN of the client certificate
// `{http.request.tls.client.san.dns_names.*}` | SAN DNS names(index optional)
// `{http.request.tls.client.san.emails.*}` | SAN email addresses (index optional)
// `{http.request.tls.client.san.ips.*}` | SAN IP addresses (index optional)
// `{http.request.tls.client.san.uris.*}` | SAN URIs (index optional)
// `{http.request.uri.path.*}` | Parts of the path, split by `/` (0-based from left)
// `{http.request.uri.path.dir}` | The directory, excluding leaf filename
// `{http.request.uri.path.file}` | The filename of the path, excluding directory
// `{http.request.uri.path}` | The path component of the request URI
// `{http.request.uri.query.*}` | Individual query string value
// `{http.request.uri.query}` | The query string (without `?`)
// `{http.request.uri}` | The full request URI
// `{http.response.header.*}` | Specific response header field
// `{http.vars.*}` | Custom variables in the HTTP handler chain
// `{http.shutting_down}` | True if the HTTP app is shutting down
// `{http.time_until_shutdown}` | Time until HTTP server shutdown, if scheduled
type App struct {
// HTTPPort specifies the port to use for HTTP (as opposed to HTTPS),
// which is used when setting up HTTP->HTTPS redirects or ACME HTTP
// challenge solvers. Default: 80.
HTTPPort int `json:"http_port,omitempty"`
// HTTPSPort specifies the port to use for HTTPS, which is used when
// solving the ACME TLS-ALPN challenges, or whenever HTTPS is needed
// but no specific port number is given. Default: 443.
HTTPSPort int `json:"https_port,omitempty"`
// GracePeriod is how long to wait for active connections when shutting
// down the servers. During the grace period, no new connections are
// accepted, idle connections are closed, and active connections will
// be given the full length of time to become idle and close.
// Once the grace period is over, connections will be forcefully closed.
// If zero, the grace period is eternal. Default: 0.
GracePeriod caddy.Duration `json:"grace_period,omitempty"`
// ShutdownDelay is how long to wait before initiating the grace
// period. When this app is stopping (e.g. during a config reload or
// process exit), all servers will be shut down. Normally this immediately
// initiates the grace period. However, if this delay is configured, servers
// will not be shut down until the delay is over. During this time, servers
// continue to function normally and allow new connections. At the end, the
// grace period will begin. This can be useful to allow downstream load
// balancers time to move this instance out of the rotation without hiccups.
//
// When shutdown has been scheduled, placeholders {http.shutting_down} (bool)
// and {http.time_until_shutdown} (duration) may be useful for health checks.
ShutdownDelay caddy.Duration `json:"shutdown_delay,omitempty"`
// Servers is the list of servers, keyed by arbitrary names chosen
// at your discretion for your own convenience; the keys do not
// affect functionality.
Servers map[string]*Server `json:"servers,omitempty"`
ctx caddy.Context
logger *zap.Logger
tlsApp *caddytls.TLS
// used temporarily between phases 1 and 2 of auto HTTPS
allCertDomains []string
}
// CaddyModule returns the Caddy module information.
func (App) CaddyModule() caddy.ModuleInfo {
return caddy.ModuleInfo{
ID: "http",
New: func() caddy.Module { return new(App) },
}
}
// Provision sets up the app.
func (app *App) Provision(ctx caddy.Context) error {
// store some references
tlsAppIface, err := ctx.App("tls")
if err != nil {
return fmt.Errorf("getting tls app: %v", err)
}
app.tlsApp = tlsAppIface.(*caddytls.TLS)
app.ctx = ctx
app.logger = ctx.Logger()
eventsAppIface, err := ctx.App("events")
if err != nil {
return fmt.Errorf("getting events app: %v", err)
}
repl := caddy.NewReplacer()
// this provisions the matchers for each route,
// and prepares auto HTTP->HTTPS redirects, and
// is required before we provision each server
err = app.automaticHTTPSPhase1(ctx, repl)
if err != nil {
return err
}
// prepare each server
oldContext := ctx.Context
for srvName, srv := range app.Servers {
ctx.Context = context.WithValue(oldContext, ServerCtxKey, srv)
srv.name = srvName
srv.tlsApp = app.tlsApp
srv.events = eventsAppIface.(*caddyevents.App)
srv.ctx = ctx
srv.logger = app.logger.Named("log")
srv.errorLogger = app.logger.Named("log.error")
srv.shutdownAtMu = new(sync.RWMutex)
// only enable access logs if configured
if srv.Logs != nil {
srv.accessLogger = app.logger.Named("log.access")
}
// the Go standard library does not let us serve only HTTP/2 using
// http.Server; we would probably need to write our own server
if !srv.protocol("h1") && (srv.protocol("h2") || srv.protocol("h2c")) {
return fmt.Errorf("server %s: cannot enable HTTP/2 or H2C without enabling HTTP/1.1; add h1 to protocols or remove h2/h2c", srvName)
}
// if no protocols configured explicitly, enable all except h2c
if len(srv.Protocols) == 0 {
srv.Protocols = []string{"h1", "h2", "h3"}
}
// if not explicitly configured by the user, disallow TLS
// client auth bypass (domain fronting) which could
// otherwise be exploited by sending an unprotected SNI
// value during a TLS handshake, then putting a protected
// domain in the Host header after establishing connection;
// this is a safe default, but we allow users to override
// it for example in the case of running a proxy where
// domain fronting is desired and access is not restricted
// based on hostname
if srv.StrictSNIHost == nil && srv.hasTLSClientAuth() {
app.logger.Warn("enabling strict SNI-Host enforcement because TLS client auth is configured",
zap.String("server_id", srvName))
trueBool := true
srv.StrictSNIHost = &trueBool
}
// parse trusted proxy CIDRs ahead of time
for _, str := range srv.TrustedProxies {
if strings.Contains(str, "/") {
ipNet, err := netip.ParsePrefix(str)
if err != nil {
return fmt.Errorf("parsing CIDR expression: '%s': %v", str, err)
}
srv.trustedProxies = append(srv.trustedProxies, ipNet)
} else {
ipAddr, err := netip.ParseAddr(str)
if err != nil {
return fmt.Errorf("invalid IP address: '%s': %v", str, err)
}
ipNew := netip.PrefixFrom(ipAddr, ipAddr.BitLen())
srv.trustedProxies = append(srv.trustedProxies, ipNew)
}
}
// process each listener address
for i := range srv.Listen {
lnOut, err := repl.ReplaceOrErr(srv.Listen[i], true, true)
if err != nil {
return fmt.Errorf("server %s, listener %d: %v", srvName, i, err)
}
srv.Listen[i] = lnOut
}
// set up each listener modifier
if srv.ListenerWrappersRaw != nil {
vals, err := ctx.LoadModule(srv, "ListenerWrappersRaw")
if err != nil {
return fmt.Errorf("loading listener wrapper modules: %v", err)
}
var hasTLSPlaceholder bool
for i, val := range vals.([]any) {
if _, ok := val.(*tlsPlaceholderWrapper); ok {
if i == 0 {
// putting the tls placeholder wrapper first is nonsensical because
// that is the default, implicit setting: without it, all wrappers
// will go after the TLS listener anyway
return fmt.Errorf("it is unnecessary to specify the TLS listener wrapper in the first position because that is the default")
}
if hasTLSPlaceholder {
return fmt.Errorf("TLS listener wrapper can only be specified once")
}
hasTLSPlaceholder = true
}
srv.listenerWrappers = append(srv.listenerWrappers, val.(caddy.ListenerWrapper))
}
// if any wrappers were configured but the TLS placeholder wrapper is
// absent, prepend it so all defined wrappers come after the TLS
// handshake; this simplifies logic when starting the server, since we
// can simply assume the TLS placeholder will always be there
if !hasTLSPlaceholder && len(srv.listenerWrappers) > 0 {
srv.listenerWrappers = append([]caddy.ListenerWrapper{new(tlsPlaceholderWrapper)}, srv.listenerWrappers...)
}
}
// pre-compile the primary handler chain, and be sure to wrap it in our
// route handler so that important security checks are done, etc.
primaryRoute := emptyHandler
if srv.Routes != nil {
err := srv.Routes.ProvisionHandlers(ctx, srv.Metrics)
if err != nil {
return fmt.Errorf("server %s: setting up route handlers: %v", srvName, err)
}
primaryRoute = srv.Routes.Compile(emptyHandler)
}
srv.primaryHandlerChain = srv.wrapPrimaryRoute(primaryRoute)
// pre-compile the error handler chain
if srv.Errors != nil {
err := srv.Errors.Routes.Provision(ctx)
if err != nil {
return fmt.Errorf("server %s: setting up server error handling routes: %v", srvName, err)
}
srv.errorHandlerChain = srv.Errors.Routes.Compile(errorEmptyHandler)
}
// prepare the TLS connection policies
err = srv.TLSConnPolicies.Provision(ctx)
if err != nil {
return fmt.Errorf("server %s: setting up TLS connection policies: %v", srvName, err)
}
// if there is no idle timeout, set a sane default; users have complained
// before that aggressive CDNs leave connections open until the server
// closes them, so if we don't close them it leads to resource exhaustion
if srv.IdleTimeout == 0 {
srv.IdleTimeout = defaultIdleTimeout
}
}
ctx.Context = oldContext
return nil
}
// Validate ensures the app's configuration is valid.
func (app *App) Validate() error {
// each server must use distinct listener addresses
lnAddrs := make(map[string]string)
for srvName, srv := range app.Servers {
for _, addr := range srv.Listen {
listenAddr, err := caddy.ParseNetworkAddress(addr)
if err != nil {
return fmt.Errorf("invalid listener address '%s': %v", addr, err)
}
// check that every address in the port range is unique to this server;
// we do not use <= here because PortRangeSize() adds 1 to EndPort for us
for i := uint(0); i < listenAddr.PortRangeSize(); i++ {
addr := caddy.JoinNetworkAddress(listenAddr.Network, listenAddr.Host, strconv.Itoa(int(listenAddr.StartPort+i)))
if sn, ok := lnAddrs[addr]; ok {
return fmt.Errorf("server %s: listener address repeated: %s (already claimed by server '%s')", srvName, addr, sn)
}
lnAddrs[addr] = srvName
}
}
}
return nil
}
// Start runs the app. It finishes automatic HTTPS if enabled,
// including management of certificates.
func (app *App) Start() error {
// get a logger compatible with http.Server
serverLogger, err := zap.NewStdLogAt(app.logger.Named("stdlib"), zap.DebugLevel)
if err != nil {
return fmt.Errorf("failed to set up server logger: %v", err)
}
for srvName, srv := range app.Servers {
srv.server = &http.Server{
ReadTimeout: time.Duration(srv.ReadTimeout),
ReadHeaderTimeout: time.Duration(srv.ReadHeaderTimeout),
WriteTimeout: time.Duration(srv.WriteTimeout),
IdleTimeout: time.Duration(srv.IdleTimeout),
MaxHeaderBytes: srv.MaxHeaderBytes,
Handler: srv,
ErrorLog: serverLogger,
}
// disable HTTP/2, which we enabled by default during provisioning
if !srv.protocol("h2") {
srv.server.TLSNextProto = make(map[string]func(*http.Server, *tls.Conn, http.Handler))
for _, cp := range srv.TLSConnPolicies {
// the TLSConfig was already provisioned, so... manually remove it
for i, np := range cp.TLSConfig.NextProtos {
if np == "h2" {
cp.TLSConfig.NextProtos = append(cp.TLSConfig.NextProtos[:i], cp.TLSConfig.NextProtos[i+1:]...)
break
}
}
// remove it from the parent connection policy too, just to keep things tidy
for i, alpn := range cp.ALPN {
if alpn == "h2" {
cp.ALPN = append(cp.ALPN[:i], cp.ALPN[i+1:]...)
break
}
}
}
}
// this TLS config is used by the std lib to choose the actual TLS config for connections
// by looking through the connection policies to find the first one that matches
tlsCfg := srv.TLSConnPolicies.TLSConfig(app.ctx)
srv.configureServer(srv.server)
// enable H2C if configured
if srv.protocol("h2c") {
h2server := &http2.Server{
IdleTimeout: time.Duration(srv.IdleTimeout),
}
srv.server.Handler = h2c.NewHandler(srv, h2server)
}
for _, lnAddr := range srv.Listen {
listenAddr, err := caddy.ParseNetworkAddress(lnAddr)
if err != nil {
return fmt.Errorf("%s: parsing listen address '%s': %v", srvName, lnAddr, err)
}
srv.addresses = append(srv.addresses, listenAddr)
for portOffset := uint(0); portOffset < listenAddr.PortRangeSize(); portOffset++ {
// create the listener for this socket
hostport := listenAddr.JoinHostPort(portOffset)
lnAny, err := listenAddr.Listen(app.ctx, portOffset, net.ListenConfig{KeepAlive: time.Duration(srv.KeepAliveInterval)})
if err != nil {
return fmt.Errorf("listening on %s: %v", listenAddr.At(portOffset), err)
}
ln := lnAny.(net.Listener)
// wrap listener before TLS (up to the TLS placeholder wrapper)
var lnWrapperIdx int
for i, lnWrapper := range srv.listenerWrappers {
if _, ok := lnWrapper.(*tlsPlaceholderWrapper); ok {
lnWrapperIdx = i + 1 // mark the next wrapper's spot
break
}
ln = lnWrapper.WrapListener(ln)
}
// enable TLS if there is a policy and if this is not the HTTP port
useTLS := len(srv.TLSConnPolicies) > 0 && int(listenAddr.StartPort+portOffset) != app.httpPort()
if useTLS {
// create TLS listener - this enables and terminates TLS
ln = tls.NewListener(ln, tlsCfg)
// enable HTTP/3 if configured
if srv.protocol("h3") {
// Can't serve HTTP/3 on the same socket as HTTP/1 and 2 because it uses
// a different transport mechanism... which is fine, but the OS doesn't
// differentiate between a SOCK_STREAM file and a SOCK_DGRAM file; they
// are still one file on the system. So even though "unixpacket" and
// "unixgram" are different network types just as "tcp" and "udp" are,
// the OS will not let us use the same file as both STREAM and DGRAM.
if len(srv.Protocols) > 1 && listenAddr.IsUnixNetwork() {
app.logger.Warn("HTTP/3 disabled because Unix can't multiplex STREAM and DGRAM on same socket",
zap.String("file", hostport))
for i := range srv.Protocols {
if srv.Protocols[i] == "h3" {
srv.Protocols = append(srv.Protocols[:i], srv.Protocols[i+1:]...)
break
}
}
} else {
app.logger.Info("enabling HTTP/3 listener", zap.String("addr", hostport))
if err := srv.serveHTTP3(listenAddr.At(portOffset), tlsCfg); err != nil {
return err
}
}
}
}
// finish wrapping listener where we left off before TLS
for i := lnWrapperIdx; i < len(srv.listenerWrappers); i++ {
ln = srv.listenerWrappers[i].WrapListener(ln)
}
// if binding to port 0, the OS chooses a port for us;
// but the user won't know the port unless we print it
if !listenAddr.IsUnixNetwork() && listenAddr.StartPort == 0 && listenAddr.EndPort == 0 {
app.logger.Info("port 0 listener",
zap.String("input_address", lnAddr),
zap.String("actual_address", ln.Addr().String()))
}
app.logger.Debug("starting server loop",
zap.String("address", ln.Addr().String()),
zap.Bool("tls", useTLS),
zap.Bool("http3", srv.h3server != nil))
srv.listeners = append(srv.listeners, ln)
// enable HTTP/1 if configured
if srv.protocol("h1") {
//nolint:errcheck
go srv.server.Serve(ln)
}
}
}
srv.logger.Info("server running",
zap.String("name", srvName),
zap.Strings("protocols", srv.Protocols))
}
// finish automatic HTTPS by finally beginning
// certificate management
err = app.automaticHTTPSPhase2()
if err != nil {
return fmt.Errorf("finalizing automatic HTTPS: %v", err)
}
return nil
}
// Stop gracefully shuts down the HTTP server.
func (app *App) Stop() error {
ctx := context.Background()
// see if any listeners in our config will be closing or if they are continuing
// hrough a reload; because if any are closing, we will enforce shutdown delay
var delay bool
scheduledTime := time.Now().Add(time.Duration(app.ShutdownDelay))
if app.ShutdownDelay > 0 {
for _, server := range app.Servers {
for _, na := range server.addresses {
for _, addr := range na.Expand() {
if caddy.ListenerUsage(addr.Network, addr.JoinHostPort(0)) < 2 {
app.logger.Debug("listener closing and shutdown delay is configured", zap.String("address", addr.String()))
server.shutdownAtMu.Lock()
server.shutdownAt = scheduledTime
server.shutdownAtMu.Unlock()
delay = true
} else {
app.logger.Debug("shutdown delay configured but listener will remain open", zap.String("address", addr.String()))
}
}
}
}
}
// honor scheduled/delayed shutdown time
if delay {
app.logger.Debug("shutdown scheduled",
zap.Duration("delay_duration", time.Duration(app.ShutdownDelay)),
zap.Time("time", scheduledTime))
time.Sleep(time.Duration(app.ShutdownDelay))
}
// enforce grace period if configured
if app.GracePeriod > 0 {
var cancel context.CancelFunc
ctx, cancel = context.WithTimeout(ctx, time.Duration(app.GracePeriod))
defer cancel()
app.logger.Debug("servers shutting down; grace period initiated", zap.Duration("duration", time.Duration(app.GracePeriod)))
} else {
app.logger.Debug("servers shutting down with eternal grace period")
}
// goroutines aren't guaranteed to be scheduled right away,
// so we'll use one WaitGroup to wait for all the goroutines
// to start their server shutdowns, and another to wait for
// them to finish; we'll always block for them to start so
// that when we return the caller can be confident* that the
// old servers are no longer accepting new connections
// (* the scheduler might still pause them right before
// calling Shutdown(), but it's unlikely)
var startedShutdown, finishedShutdown sync.WaitGroup
// these will run in goroutines
stopServer := func(server *Server) {
defer finishedShutdown.Done()
startedShutdown.Done()
if err := server.server.Shutdown(ctx); err != nil {
app.logger.Error("server shutdown",
zap.Error(err),
zap.Strings("addresses", server.Listen))
}
}
stopH3Server := func(server *Server) {
defer finishedShutdown.Done()
startedShutdown.Done()
if server.h3server == nil {
return
}
// TODO: we have to manually close our listeners because quic-go won't
// close listeners it didn't create along with the server itself...
// see https://github.com/quic-go/quic-go/issues/3560
for _, el := range server.h3listeners {
if err := el.Close(); err != nil {
app.logger.Error("HTTP/3 listener close",
zap.Error(err),
zap.String("address", el.LocalAddr().String()))
}
}
// TODO: CloseGracefully, once implemented upstream (see https://github.com/quic-go/quic-go/issues/2103)
if err := server.h3server.Close(); err != nil {
app.logger.Error("HTTP/3 server shutdown",
zap.Error(err),
zap.Strings("addresses", server.Listen))
}
}
for _, server := range app.Servers {
startedShutdown.Add(2)
finishedShutdown.Add(2)
go stopServer(server)
go stopH3Server(server)
}
// block until all the goroutines have been run by the scheduler;
// this means that they have likely called Shutdown() by now
startedShutdown.Wait()
// if the process is exiting, we need to block here and wait
// for the grace periods to complete, otherwise the process will
// terminate before the servers are finished shutting down; but
// we don't really need to wait for the grace period to finish
// if the process isn't exiting (but note that frequent config
// reloads with long grace periods for a sustained length of time
// may deplete resources)
if caddy.Exiting() {
finishedShutdown.Wait()
}
return nil
}
func (app *App) httpPort() int {
if app.HTTPPort == 0 {
return DefaultHTTPPort
}
return app.HTTPPort
}
func (app *App) httpsPort() int {
if app.HTTPSPort == 0 {
return DefaultHTTPSPort
}
return app.HTTPSPort
}
// defaultIdleTimeout is the default HTTP server timeout
// for closing idle connections; useful to avoid resource
// exhaustion behind hungry CDNs, for example (we've had
// several complaints without this).
const defaultIdleTimeout = caddy.Duration(5 * time.Minute)
// Interface guards
var (
_ caddy.App = (*App)(nil)
_ caddy.Provisioner = (*App)(nil)
_ caddy.Validator = (*App)(nil)
)