Made error handling in the case of a client IP without a port more graceful, so that the ratelimiter doesn't return an error if X-Forwarded-For or X-Real-IP is set.

go.mod

@@ -8,6 +8,11 @@ require (
 	github.com/PuerkitoBio/goquery v1.5.0
 	github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 // indirect
 	github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d // indirect
+	github.com/aws/aws-sdk-go v1.35.7 // indirect
+	github.com/docker/distribution v2.7.1+incompatible // indirect
+	github.com/docker/docker v1.13.1 // indirect
+	github.com/docker/go-connections v0.4.0 // indirect
+	github.com/docker/go-units v0.4.0 // indirect
 	github.com/emersion/go-imap v1.0.4
 	github.com/emersion/go-message v0.12.0
 	github.com/go-sql-driver/mysql v1.5.0
@@ -23,6 +28,7 @@ require (
 	github.com/jordan-wright/unindexed v0.0.0-20181209214434-78fa79113c0f
 	github.com/kylelemons/go-gypsy v0.0.0-20160905020020-08cad365cd28 // indirect
 	github.com/mattn/go-sqlite3 v2.0.3+incompatible
+	github.com/opencontainers/go-digest v1.0.0 // indirect
 	github.com/oschwald/maxminddb-golang v1.6.0
 	github.com/sirupsen/logrus v1.4.2
 	github.com/ziutek/mymysql v1.5.4 // indirect

go.sum

@@ -10,11 +10,21 @@ github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d h1:UQZhZ2O0vMHr2c
 github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d/go.mod h1:rBZYJk541a8SKzHPHnH3zbiI+7dagKZ0cgpgrD7Fyho=
 github.com/andybalholm/cascadia v1.0.0 h1:hOCXnnZ5A+3eVDX8pvgl4kofXv2ELss0bKcqRySc45o=
 github.com/andybalholm/cascadia v1.0.0/go.mod h1:GsXiBklL0woXo1j/WYWtSYYC4ouU9PqHO0sqidkEA4Y=
+github.com/aws/aws-sdk-go v1.35.7 h1:FHMhVhyc/9jljgFAcGkQDYjpC9btM0B8VfkLBfctdNE=
+github.com/aws/aws-sdk-go v1.35.7/go.mod h1:tlPOdRjfxPBpNIwqDj61rmsnA85v9jc0Ps9+muhnW+k=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/denisenkom/go-mssqldb v0.0.0-20191124224453-732737034ffd h1:83Wprp6ROGeiHFAP8WJdI2RoxALQYgdllERc3N5N2DM=
 github.com/denisenkom/go-mssqldb v0.0.0-20191124224453-732737034ffd/go.mod h1:xbL0rPBG9cCiLr28tMa8zpbdarY27NDyej4t/EjAShU=
+github.com/docker/distribution v2.7.1+incompatible h1:a5mlkVzth6W5A4fOsS3D2EO5BUmsJpcB+cRlLU7cSug=
+github.com/docker/distribution v2.7.1+incompatible/go.mod h1:J2gT2udsDAN96Uj4KfcMRqY0/ypR+oyYUYmja8H+y+w=
+github.com/docker/docker v1.13.1 h1:IkZjBSIc8hBjLpqeAbeE5mca5mNgeatLHBy3GO78BWo=
+github.com/docker/docker v1.13.1/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
+github.com/docker/go-connections v0.4.0 h1:El9xVISelRB7BuFusrZozjnkIM5YnzCViNKohAFqRJQ=
+github.com/docker/go-connections v0.4.0/go.mod h1:Gbd7IOopHjR8Iph03tsViu4nIes5XhDvyHbTtUxmeec=
+github.com/docker/go-units v0.4.0 h1:3uh0PgVws3nIA0Q+MwDC8yjEPf9zjRfZZWXZYDct3Tw=
+github.com/docker/go-units v0.4.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
 github.com/emersion/go-imap v1.0.4 h1:uiCAIHM6Z5Jwkma1zdNDWWXxSCqb+/xHBkHflD7XBro=
 github.com/emersion/go-imap v1.0.4/go.mod h1:yKASt+C3ZiDAiCSssxg9caIckWF/JG7ZQTO7GAmvicU=
 github.com/emersion/go-message v0.11.1/go.mod h1:C4jnca5HOTo4bGN9YdqNQM9sITuT3Y0K6bSUw9RklvY=
@@ -52,6 +62,9 @@ github.com/jinzhu/inflection v1.0.0 h1:K317FqzuhWc8YvSVlFMCCUb36O/S9MCKRDI7QkRKD
 github.com/jinzhu/inflection v1.0.0/go.mod h1:h+uFLlag+Qp1Va5pdKtLDYj+kHp5pxUVkryuEj+Srlc=
 github.com/jinzhu/now v1.0.1 h1:HjfetcXq097iXP0uoPCdnM4Efp5/9MsM0/M+XOTeR3M=
 github.com/jinzhu/now v1.0.1/go.mod h1:d3SSVoowX0Lcu0IBviAWJpolVfI5UJVZZ7cO71lE/z8=
+github.com/jmespath/go-jmespath v0.4.0 h1:BEgLn5cpjn8UN1mAw4NjwDrS35OdebyEtFe+9YPoQUg=
+github.com/jmespath/go-jmespath v0.4.0/go.mod h1:T8mJZnbsbmF+m6zOOFylbeCJqk5+pHWvzYPziyZiYoo=
+github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfCI6z80xFu9LTZmf1ZRjMHUOPmWr69U=
 github.com/jordan-wright/email v4.0.1-0.20200824153738-3f5bafa1cd84+incompatible h1:d60x4RsAHk/UX/0OT8Gc6D7scVvhBbEANpTAWrDhA/I=
 github.com/jordan-wright/email v4.0.1-0.20200824153738-3f5bafa1cd84+incompatible/go.mod h1:1c7szIrayyPPB/987hsnvNzLushdWf4o/79s3P08L8A=
 github.com/jordan-wright/unindexed v0.0.0-20181209214434-78fa79113c0f h1:bYVTBvVHcAYDkH8hyVMRUW7J2mYQNNSmQPXGadYd1nY=
@@ -66,10 +79,14 @@ github.com/martinlindhe/base36 v1.0.0/go.mod h1:+AtEs8xrBpCeYgSLoY/aJ6Wf37jtBuR0
 github.com/mattn/go-sqlite3 v2.0.1+incompatible/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
 github.com/mattn/go-sqlite3 v2.0.3+incompatible h1:gXHsfypPkaMZrKbD5209QV9jbUTJKjyR5WD3HYQSd+U=
 github.com/mattn/go-sqlite3 v2.0.3+incompatible/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
+github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
+github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
 github.com/oschwald/maxminddb-golang v1.6.0 h1:KAJSjdHQ8Kv45nFIbtoLGrGWqHFajOIm7skTyz/+Dls=
 github.com/oschwald/maxminddb-golang v1.6.0/go.mod h1:DUJFucBg2cvqx42YmDa/+xHvb0elJtOm3o4aFQ/nb/w=
 github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/sirupsen/logrus v1.4.2 h1:SPIRibHv4MatM3XXNO2BJeFLZwZ2LvZgfQ5+UNI2im4=
@@ -92,6 +109,8 @@ golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73r
 golang.org/x/net v0.0.0-20181114220301-adae6a3d119a/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 h1:0GoQqolDA55aaLxZyTzK/Y2ePZzZTUrRacwib7cNsYQ=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20200202094626-16171245cfb2 h1:CCH4IOTTfewWjGOlSp+zGcjutRKlBEZQ6wTn8ozI/nI=
+golang.org/x/net v0.0.0-20200202094626-16171245cfb2/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -112,3 +131,5 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
+gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

middleware/ratelimit/ratelimit.go

@@ -131,9 +131,7 @@ func (limiter *PostLimiter) Limit(next http.Handler) http.HandlerFunc {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		clientIP, _, err := net.SplitHostPort(r.RemoteAddr)
 		if err != nil {
-			log.Errorf("Unable to determine client IP address: %v", err)
+			clientIP = r.RemoteAddr
-			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
-			return
 		}
 		if r.Method == http.MethodPost && !limiter.allow(clientIP) {
 			log.Error("")