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authorMatthew Holt <mholt@users.noreply.github.com>2019-09-14 13:25:26 -0600
committerMatthew Holt <mholt@users.noreply.github.com>2019-09-14 13:25:26 -0600
commite73b117332a5606a986ee7e03e6f4b0cea7871c9 (patch)
treee2819a50e4bfdab7d0d1511bc433b1b41e403da2 /modules/caddyhttp/reverseproxy
parent2fd22139c6b7b6055ae53c77d56278fce38d1195 (diff)
reverse_proxy: Ability to mutate headers; set upstream placeholders
Diffstat (limited to 'modules/caddyhttp/reverseproxy')
-rw-r--r--modules/caddyhttp/reverseproxy/healthchecks.go6
-rw-r--r--modules/caddyhttp/reverseproxy/hosts.go23
-rw-r--r--modules/caddyhttp/reverseproxy/reverseproxy.go57
3 files changed, 74 insertions, 12 deletions
diff --git a/modules/caddyhttp/reverseproxy/healthchecks.go b/modules/caddyhttp/reverseproxy/healthchecks.go
index abe0f9c..084a693 100644
--- a/modules/caddyhttp/reverseproxy/healthchecks.go
+++ b/modules/caddyhttp/reverseproxy/healthchecks.go
@@ -111,10 +111,10 @@ func (h *Handler) doActiveHealthChecksForAllHosts() {
if network == "unix" || network == "unixgram" || network == "unixpacket" {
// this will be used as the Host portion of a http.Request URL, and
// paths to socket files would produce an error when creating URL,
- // so use a fake Host value instead
- hostAddr = network
+ // so use a fake Host value instead; unix sockets are usually local
+ hostAddr = "localhost"
}
- err = h.doActiveHealthCheck(DialInfo{network, addrs[0]}, hostAddr, host)
+ err = h.doActiveHealthCheck(NewDialInfo(network, addrs[0]), hostAddr, host)
if err != nil {
log.Printf("[ERROR] reverse_proxy: active health check for host %s: %v", networkAddr, err)
}
diff --git a/modules/caddyhttp/reverseproxy/hosts.go b/modules/caddyhttp/reverseproxy/hosts.go
index 1c0fae3..a8349bd 100644
--- a/modules/caddyhttp/reverseproxy/hosts.go
+++ b/modules/caddyhttp/reverseproxy/hosts.go
@@ -16,6 +16,8 @@ package reverseproxy
import (
"fmt"
+ "net"
+ "strings"
"sync/atomic"
"github.com/caddyserver/caddy/v2"
@@ -173,6 +175,27 @@ type DialInfo struct {
// The address to dial. Follows the same
// semantics and rules as net.Dial.
Address string
+
+ // Host and Port are components of Address,
+ // pre-split for convenience.
+ Host, Port string
+}
+
+// NewDialInfo creates and populates a DialInfo
+// for the given network and address. It splits
+// the address into host and port values if the
+// network type supports them, or uses the whole
+// address as the port if splitting fails.
+func NewDialInfo(network, address string) DialInfo {
+ var addrHost, addrPort string
+ if !strings.Contains(network, "unix") {
+ var err error
+ addrHost, addrPort, err = net.SplitHostPort(address)
+ if err != nil {
+ addrHost = address // assume there was no port
+ }
+ }
+ return DialInfo{network, address, addrHost, addrPort}
}
// String returns the Caddy network address form
diff --git a/modules/caddyhttp/reverseproxy/reverseproxy.go b/modules/caddyhttp/reverseproxy/reverseproxy.go
index a82c4e0..6a7ec70 100644
--- a/modules/caddyhttp/reverseproxy/reverseproxy.go
+++ b/modules/caddyhttp/reverseproxy/reverseproxy.go
@@ -21,11 +21,13 @@ import (
"net"
"net/http"
"regexp"
+ "strconv"
"strings"
"time"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+ "github.com/caddyserver/caddy/v2/modules/caddyhttp/headers"
"golang.org/x/net/http/httpguts"
)
@@ -35,12 +37,13 @@ func init() {
// Handler implements a highly configurable and production-ready reverse proxy.
type Handler struct {
- TransportRaw json.RawMessage `json:"transport,omitempty"`
- CBRaw json.RawMessage `json:"circuit_breaker,omitempty"`
- LoadBalancing *LoadBalancing `json:"load_balancing,omitempty"`
- HealthChecks *HealthChecks `json:"health_checks,omitempty"`
- Upstreams UpstreamPool `json:"upstreams,omitempty"`
- FlushInterval caddy.Duration `json:"flush_interval,omitempty"`
+ TransportRaw json.RawMessage `json:"transport,omitempty"`
+ CBRaw json.RawMessage `json:"circuit_breaker,omitempty"`
+ LoadBalancing *LoadBalancing `json:"load_balancing,omitempty"`
+ HealthChecks *HealthChecks `json:"health_checks,omitempty"`
+ Upstreams UpstreamPool `json:"upstreams,omitempty"`
+ FlushInterval caddy.Duration `json:"flush_interval,omitempty"`
+ Headers *headers.Handler `json:"headers,omitempty"`
Transport http.RoundTripper `json:"-"`
CB CircuitBreaker `json:"-"`
@@ -178,7 +181,7 @@ func (h *Handler) Provision(ctx caddy.Context) error {
// make a new upstream based on the original
// that has a singular dial address
upstreamCopy := *upstream
- upstreamCopy.dialInfo = DialInfo{network, addr}
+ upstreamCopy.dialInfo = NewDialInfo(network, addr)
upstreamCopy.Dial = upstreamCopy.dialInfo.String()
upstreamCopy.cb = h.CB
@@ -187,7 +190,7 @@ func (h *Handler) Provision(ctx caddy.Context) error {
// TODO: make hosts modular, so that their state can be distributed in enterprise for example
// TODO: If distributed, the pool should be stored in storage...
var host Host = new(upstreamHost)
- activeHost, loaded := hosts.LoadOrStore(upstreamCopy.Dial, host)
+ activeHost, loaded := hosts.LoadOrStore(upstreamCopy.dialInfo.String(), host)
if loaded {
host = activeHost.(Host)
}
@@ -243,6 +246,8 @@ func (h *Handler) Cleanup() error {
}
func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
+ repl := r.Context().Value(caddy.ReplacerCtxKey).(caddy.Replacer)
+
// prepare the request for proxying; this is needed only once
err := h.prepareRequest(r)
if err != nil {
@@ -250,6 +255,11 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyht
fmt.Errorf("preparing request for upstream round-trip: %v", err))
}
+ // we will need the original headers and Host
+ // value if header operations are configured
+ reqHeader := r.Header
+ reqHost := r.Host
+
start := time.Now()
var proxyErr error
@@ -258,7 +268,7 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyht
upstream := h.LoadBalancing.SelectionPolicy.Select(h.Upstreams, r)
if upstream == nil {
if proxyErr == nil {
- proxyErr = fmt.Errorf("no available upstreams")
+ proxyErr = fmt.Errorf("no upstreams available")
}
if !h.tryAgain(start, proxyErr) {
break
@@ -272,6 +282,26 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyht
ctx := context.WithValue(r.Context(), DialInfoCtxKey, upstream.dialInfo)
r = r.WithContext(ctx)
+ // set placeholders with information about this upstream
+ repl.Set("http.handlers.reverse_proxy.upstream.address", upstream.dialInfo.String())
+ repl.Set("http.handlers.reverse_proxy.upstream.hostport", upstream.dialInfo.Address)
+ repl.Set("http.handlers.reverse_proxy.upstream.host", upstream.dialInfo.Host)
+ repl.Set("http.handlers.reverse_proxy.upstream.port", upstream.dialInfo.Port)
+ repl.Set("http.handlers.reverse_proxy.upstream.requests", strconv.Itoa(upstream.Host.NumRequests()))
+ repl.Set("http.handlers.reverse_proxy.upstream.max_requests", strconv.Itoa(upstream.MaxRequests))
+ repl.Set("http.handlers.reverse_proxy.upstream.fails", strconv.Itoa(upstream.Host.Fails()))
+
+ // mutate request headers according to this upstream;
+ // because we're in a retry loop, we have to copy
+ // headers (and the r.Host value) from the original
+ // so that each retry is identical to the first
+ if h.Headers != nil && h.Headers.Request != nil {
+ r.Header = make(http.Header)
+ copyHeader(r.Header, reqHeader)
+ r.Host = reqHost
+ h.Headers.Request.ApplyToRequest(r)
+ }
+
// proxy the request to that upstream
proxyErr = h.reverseProxy(w, r, upstream)
if proxyErr == nil || proxyErr == context.Canceled {
@@ -428,6 +458,15 @@ func (h *Handler) reverseProxy(rw http.ResponseWriter, req *http.Request, upstre
rw.Header().Add("Trailer", strings.Join(trailerKeys, ", "))
}
+ // apply any response header operations
+ if h.Headers != nil && h.Headers.Response != nil {
+ if h.Headers.Response.Require == nil ||
+ h.Headers.Response.Require.Match(res.StatusCode, rw.Header()) {
+ repl := req.Context().Value(caddy.ReplacerCtxKey).(caddy.Replacer)
+ h.Headers.Response.ApplyTo(rw.Header(), repl)
+ }
+ }
+
rw.WriteHeader(res.StatusCode)
err = h.copyResponse(rw, res.Body, h.flushInterval(req, res))