Rate limiting (#1385)

* Initial rate limiting

* Move rate limiting to client API

* Update rate limits to hopefully be self-cleaning

* Use X-Forwarded-For, add comments

* Reduce rate limit threshold

* Tweak interval

* Configurable backoff

* Review comments, set cleanup interval to 30 seconds

* Allow generate-config to produce sane CI config

* Fix Complement dockerfile

cmd/generate-config/main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 
 	"github.com/matrix-org/dendrite/internal/config"
@@ -8,6 +9,9 @@ import (
 )
 
 func main() {
+	defaultsForCI := flag.Bool("ci", false, "sane defaults for CI testing")
+	flag.Parse()
+
 	cfg := &config.Dendrite{}
 	cfg.Defaults()
 	cfg.Global.TrustedIDServers = []string{
@@ -56,6 +60,11 @@ func main() {
 		},
 	}
 
+	if *defaultsForCI {
+		cfg.ClientAPI.RateLimiting.Enabled = false
+		cfg.FederationSender.DisableTLSValidation = true
+	}
+
 	j, err := yaml.Marshal(cfg)
 	if err != nil {
 		panic(err)