From 675245722fe63a1d5234f0acd90db99bc0b57892 Mon Sep 17 00:00:00 2001 From: Daan Sprenkels Date: Thu, 5 Sep 2019 23:57:43 +0200 Subject: [PATCH] Revert "Format errors with HTML" This reverts commit 80092dea5b4fb1d16e16676feba1595add9f7281. After enabling both HTML and plain-text templating, I found that this introduces a lot more complexity in the code than was desirable for a project in this stage. The result looked fine, wrapping plain text in 
 tags. However, it was neccessary to keep duplicate
template files, for HTML and text. This was cumbersome, added a lot
of bloat, etc.

This feature is postponed to when there is more product.
---
 assets/layout.html |   8 --
 go.mod             |   2 +
 go.sum             |   6 ++
 handlers.go        | 240 ++++++++-------------------------------------
 4 files changed, 49 insertions(+), 207 deletions(-)
 delete mode 100644 assets/layout.html

diff --git a/assets/layout.html b/assets/layout.html
deleted file mode 100644
index 89b05ff..0000000
--- a/assets/layout.html
+++ /dev/null
@@ -1,8 +0,0 @@
-
-
-    
-    {{.Title}} | rushlink
-
-
-{{.Content}}
-

\ No newline at end of file
diff --git a/go.mod b/go.mod
index 08f20a7..7532190 100644
--- a/go.mod
+++ b/go.mod
@@ -5,6 +5,8 @@ go 1.12
 require (
 	github.com/go-bindata/go-bindata v3.1.2+incompatible // indirect
 	github.com/gorilla/mux v1.7.3
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.1 // indirect
 	github.com/pkg/errors v0.8.1
 	github.com/prometheus/client_golang v1.1.0
 	go.etcd.io/bbolt v1.3.3
diff --git a/go.sum b/go.sum
index 659278b..d31f809 100644
--- a/go.sum
+++ b/go.sum
@@ -6,6 +6,7 @@ github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-bindata/go-bindata v3.1.2+incompatible h1:5vjJMVhowQdPzjE1LdxyFF7YFTXg5IgGVW4gBr5IbvE=
 github.com/go-bindata/go-bindata v3.1.2+incompatible/go.mod h1:xK8Dsgwmeed+BBsSy2XTopBn/8uK2HWuGSnA11C3Joo=
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
 github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
@@ -18,7 +19,10 @@ github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/gorilla/mux v1.7.3 h1:gnP5JzjVOuiZD07fKKToCAOjS0yOpj/qPETTXCCS6hw=
 github.com/gorilla/mux v1.7.3/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
+github.com/joomcode/errorx v1.0.0 h1:RJAKLTy1Sv2Tszhu14m5RZP4VGRlhXutG/XlL1En5VM=
+github.com/joomcode/errorx v1.0.0/go.mod h1:kgco15ekB6cs+4Xjzo7SPeXzx38PbJzBwbnu9qfVNHQ=
 github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
 github.com/json-iterator/go v1.1.7/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
@@ -32,6 +36,7 @@ github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lN
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
@@ -53,6 +58,7 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+go.etcd.io/bbolt v1.3.3 h1:MUGmc65QhB3pIlaQ5bB4LwqSj6GIonVJXpZiaKNyaKk=
 go.etcd.io/bbolt v1.3.3/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
diff --git a/handlers.go b/handlers.go
index cf4a3eb..fdd71f0 100644
--- a/handlers.go
+++ b/handlers.go
@@ -10,15 +10,10 @@ import (
 	"crypto/subtle"
 	"encoding/base64"
 	"fmt"
-	"html/template"
 	"io"
 	"log"
 	"net/http"
 	"net/url"
-	"regexp"
-	"runtime/debug"
-	"sort"
-	"strconv"
 	"strings"
 	"time"
 	"unicode"
@@ -41,11 +36,6 @@ type StoredPaste struct {
 	TimeCreated time.Time
 }
 
-type HTMLPage struct {
-	Title   string
-	Content string
-}
-
 const (
 	TypePaste PasteType = iota
 	TypeRedirect
@@ -65,16 +55,8 @@ var ReservedPasteKeys [][]byte = [][]byte{[]byte("xd42"), []byte("example")}
 var base64Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"
 var base64Encoder = base64.NewEncoding(base64Alphabet).WithPadding(base64.NoPadding)
 
-// Asset contents
-var layoutContents = string(MustAsset("assets/layout.html"))
-var indexContents = string(MustAsset("assets/index.txt"))
-
-// Templates
-var HtmlTemplate = template.Must(template.New("layout").Parse(layoutContents))
-
-var acceptHeaderMediaRangeRegex = regexp.MustCompile(`^\s*([^()<>@,;:\\"/\[\]?.=]+)/([^()<>@,;:\\"/\[\]?.=]+)\s*$`)
-var acceptHeaderAcceptParamsRegex = regexp.MustCompile(`^\s*(\w+)=([A-Za-z0-9.-])\s*$`)
-var acceptHeaderWeight = regexp.MustCompile(`^\s*q=0(?:\.([0-9]{0,3}))|1(?:\.0{0,3})\s*$`)
+// Page contents
+var indexContents = MustAsset("assets/index.txt")
 
 func (t PasteType) String() (string, error) {
 	switch t {
@@ -99,30 +81,36 @@ func (t PasteState) String() (string, error) {
 }
 
 func indexGetHandler(w http.ResponseWriter, r *http.Request) {
-	page := HTMLPage{Title: "rushlink", Content: indexContents}
-	RenderPage(w, r, page)
+	_, err := w.Write(indexContents)
+	if err != nil {
+		panic(err)
+	}
 }
 
 func indexPostHandler(w http.ResponseWriter, r *http.Request) {
 	if err := r.ParseMultipartForm(50 * 1000 * 1000); err != nil {
-		log.Printf("error: %v\n", err)
-		msg := fmt.Sprintf("internal server error: %v\n", err)
-		RenderError(w, r, http.StatusInternalServerError, msg)
+		w.WriteHeader(http.StatusInternalServerError)
+		fmt.Fprintf(w, "Internal server error: %v\n", err)
 		return
 	}
 
 	// Determine what kind of post this is, currently only `shorten=...`
 	if len(r.PostForm) == 0 {
-		RenderError(w, r, http.StatusBadRequest, "empty body in POST request\n")
+		w.WriteHeader(http.StatusBadRequest)
+		var buf []byte
+		r.Body.Read(buf)
+		io.WriteString(w, "empty body in POST request\n")
 		return
 	}
 	shorten_values, prs := r.PostForm["shorten"]
 	if !prs {
-		RenderError(w, r, http.StatusBadRequest, "no 'shorten' param supplied\n")
+		w.WriteHeader(http.StatusBadRequest)
+		io.WriteString(w, "no 'shorten' param supplied\n")
 		return
 	}
 	if len(shorten_values) != 1 {
-		RenderError(w, r, http.StatusBadRequest, "only one 'shorten' param is allowed per request\n")
+		w.WriteHeader(http.StatusBadRequest)
+		io.WriteString(w, "only one 'shorten' param is allowed per request\n")
 		return
 	}
 
@@ -150,29 +138,30 @@ func pasteGetHandlerInner(w http.ResponseWriter, r *http.Request, noRedirect, sh
 		storedPaste, err = getURL(tx, []byte(key))
 		return err
 	}); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
 		log.Printf("error: %v\n", err)
-		msg := fmt.Sprintf("internal server error: %v\n", err)
-		RenderError(w, r, http.StatusInternalServerError, msg)
+		fmt.Fprintf(w, "internal server error: %v\n", err)
 		return
 	}
 	if storedPaste == nil {
-		RenderError(w, r, http.StatusNotFound, "url key not found in the database\n")
+		w.WriteHeader(http.StatusNotFound)
+		fmt.Fprintf(w, "url key not found in the database\n")
 		return
 	}
 
 	if showMeta {
 		typeString, err := storedPaste.Type.String()
 		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
 			log.Printf("error: %v\n", err)
-			msg := fmt.Sprintf("internal server error: %v\n", err)
-			RenderError(w, r, http.StatusInternalServerError, msg)
+			fmt.Fprintf(w, "internal server error: %v\n", err)
 			return
 		}
 		stateString, err := storedPaste.State.String()
 		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
 			log.Printf("error: %v\n", err)
-			msg := fmt.Sprintf("internal server error: %v\n", err)
-			RenderError(w, r, http.StatusInternalServerError, msg)
+			fmt.Fprintf(w, "internal server error: %v\n", err)
 			return
 		}
 		isOwner := "no"
@@ -196,23 +185,21 @@ func pasteGetHandlerInner(w http.ResponseWriter, r *http.Request, noRedirect, sh
 			rawurl := string(storedPaste.Content)
 			urlParse, err := url.Parse(rawurl)
 			if err != nil {
+				w.WriteHeader(http.StatusInternalServerError)
 				log.Printf("error: invalid URL ('%v') in database for key '%v': %v\n", rawurl, storedPaste.Key, err)
-				msg := fmt.Sprintf("internal server error: invalid url in database\n")
-				RenderError(w, r, http.StatusInternalServerError, msg)
+				fmt.Fprintf(w, "internal server error: invalid url in database\n")
 				return
 			}
 			http.Redirect(w, r, urlParse.String(), http.StatusSeeOther)
 		}
 		w.Write(storedPaste.Content)
 	case StateDeleted:
-		RenderError(w, r, http.StatusGone, "paste has been deleted\n")
-		return
+		w.WriteHeader(http.StatusGone)
+		fmt.Fprintf(w, "key has been deleted\n")
 	default:
 		w.WriteHeader(http.StatusInternalServerError)
 		log.Printf("error: invalid storedPaste.State (%v) for key '%v'\n", storedPaste.State, storedPaste.Key)
-		msg := fmt.Sprintf("internal server error: invalid storedPaste.State (%v)\n", storedPaste.State)
-		RenderError(w, r, http.StatusInternalServerError, msg)
-		return
+		fmt.Fprintf(w, "internal server error: invalid storedPaste.State (%v\n)", storedPaste.State)
 	}
 }
 
@@ -220,18 +207,18 @@ func shortenPostHandler(w http.ResponseWriter, r *http.Request) {
 	rawurl := r.PostForm.Get("shorten")
 	userURL, err := url.ParseRequestURI(rawurl)
 	if err != nil {
-		msg := fmt.Sprintf("invalid url (%v): %v\n", err, rawurl)
-		RenderError(w, r, http.StatusBadRequest, msg)
+		w.WriteHeader(http.StatusBadRequest)
+		fmt.Fprintf(w, "invalid url (%v): %v\n", err, rawurl)
 		return
 	}
 	if userURL.Scheme == "" {
-		msg := fmt.Sprintf("invalid url (unspecified scheme)\n", rawurl)
-		RenderError(w, r, http.StatusBadRequest, msg)
+		w.WriteHeader(http.StatusBadRequest)
+		fmt.Fprintf(w, "invalid url (unspecified scheme)\n", rawurl)
 		return
 	}
 	if userURL.Host == "" {
-		msg := fmt.Sprintf("invalid url (unspecified host)\n", rawurl)
-		RenderError(w, r, http.StatusBadRequest, msg)
+		w.WriteHeader(http.StatusBadRequest)
+		fmt.Fprintf(w, "invalid url (unspecified host)\n", rawurl)
 		return
 	}
 
@@ -250,30 +237,23 @@ func shortenPostHandler(w http.ResponseWriter, r *http.Request) {
 		storedPaste = sp
 		return err
 	}); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
 		log.Printf("error: %v\n", err)
-		msg := fmt.Sprintf("internal server error: %v\n", err)
-		RenderError(w, r, http.StatusInternalServerError, msg)
+		fmt.Fprintf(w, "internal server error: %v\n", err)
 		return
 	}
 
 	saveURL, err := r.URL.Parse(string(storedPaste.Key))
 	if err != nil {
-		err = errors.Wrap(err, "parsing url")
-		log.Printf("error: %v\n", err)
-		msg := fmt.Sprintf("internal server error: %v\n", err)
-		RenderError(w, r, http.StatusInternalServerError, msg)
-		return
+		log.Printf("error: %v\n", errors.Wrap(err, "parsing url"))
 	}
 	var base64OwnerToken = make([]byte, 24)
 	base64Encoder.Encode(base64OwnerToken, storedPaste.OwnerToken[:])
 
+	w.WriteHeader(http.StatusOK)
+	fmt.Fprintf(w, "URL saved at %v\n", saveURL)
 	isNotPrint := func(r rune) bool { return !unicode.IsPrint(r) }
-	ownerKey := strings.TrimRightFunc(string(base64OwnerToken), isNotPrint)
-	page := HTMLPage{
-		Title:   fmt.Sprintf("URL saved at %v\n", saveURL),
-		Content: fmt.Sprintf("URL saved at %v\nOwner key is %s\n", saveURL, ownerKey),
-	}
-	RenderPage(w, r, page)
+	fmt.Fprintf(w, "Owner key is %s\n", strings.TrimRightFunc(string(base64OwnerToken), isNotPrint))
 }
 
 // Retrieve a URL from the database
@@ -407,141 +387,3 @@ func getOwnerTokenFromRequest(r *http.Request) ([16]byte, bool) {
 	}
 	return ownerKey, false
 }
-
-func RenderPage(w http.ResponseWriter, r *http.Request, page HTMLPage) {
-	contentType, err := resolveResponseContentType(r, []string{"text/plain", "text/html"})
-	if err != nil {
-		w.WriteHeader(http.StatusInternalServerError)
-		log.Printf("error: %v\n", err)
-		fmt.Fprintf(w, "internal server error: %v\n", err)
-	}
-
-	switch contentType {
-	case "text/plain":
-		w.Header().Set("Content-Type", "text/plain")
-		io.WriteString(w, page.Content)
-	case "text/html":
-		w.Header().Set("Content-Type", "text/html")
-		err = HtmlTemplate.Execute(w, page)
-	default:
-		w.WriteHeader(http.StatusNotAcceptable)
-		io.WriteString(w, "could not resolve an acceptable content-type\n")
-	}
-	if err != nil {
-		panic(err)
-	}
-}
-
-func RenderError(w http.ResponseWriter, r *http.Request, status int, msg string) {
-	statusText := http.StatusText(status)
-	if statusText == "" {
-		statusText = "Unkown"
-	}
-	w.WriteHeader(status)
-	page := HTMLPage{
-		Title:   fmt.Sprintf("%v %v", status, statusText),
-		Content: msg,
-	}
-	RenderPage(w, r, page)
-}
-
-// Try to resolve the preferred content-type for the response to this request.
-//
-// This is done by reading from the `types` argument. If one of them matches
-// the preferences supplied by the client in their Accept header, we will
-// return that one. We will take the clients preferences into account.
-//
-// Iff no match could be found, this function will return an empty string, and
-// the caller should probably respond with a 406 Not Acceptable status code.
-// Iff the Accept header was invalid, we will return an error. In this case,
-// the situation calls for a 400 Bad Request.
-func resolveResponseContentType(r *http.Request, types []string) (string, error) {
-	// Ref: https://tools.ietf.org/html/rfc7231#section-5.3.2
-	if len(types) == 0 {
-		return "", nil
-	}
-	acceptHeader := r.Header.Get("Accept")
-	if acceptHeader == "" {
-		return types[0], nil
-	}
-
-	type AcceptValue struct {
-		Type    string
-		Subtype string
-		Weight  int
-	}
-
-	avStrings := strings.Split(acceptHeader, ",")
-	avs := make([]AcceptValue, len(avStrings))
-	for i, avString := range avStrings {
-		av := AcceptValue{Weight: 1000}
-		choiceParts := strings.Split(avString, ";")
-		mediaRange := acceptHeaderMediaRangeRegex.FindStringSubmatch(choiceParts[0])
-		if mediaRange == nil {
-			return "", fmt.Errorf("bad media-range (\"%v\")", choiceParts[0])
-		}
-		av.Type = mediaRange[1]
-		av.Subtype = mediaRange[2]
-		// Go through the rest to see if there is a q=... parameter
-		for choiceParts = choiceParts[1:]; len(choiceParts) > 0; choiceParts = choiceParts[1:] {
-			// Try to parse the weight param
-			weight := acceptHeaderWeight.FindStringSubmatch(choiceParts[0])
-			if weight != nil {
-				if weight[1] == "" {
-					av.Weight = 0
-				} else {
-					var err error
-					av.Weight, err = strconv.Atoi((weight[1] + "000")[:3])
-					if err != nil {
-						log.Println("error: unreachable statement")
-						debug.PrintStack()
-						av.Weight = 1000 // Reset to default value
-					}
-				}
-				break
-			}
-			// Check if this parameter is still invalid in any case
-			acceptParams := acceptHeaderAcceptParamsRegex.FindStringSubmatchIndex(choiceParts[0])
-			if acceptParams == nil {
-				return "", fmt.Errorf("bad accept-params (\"%v\")", choiceParts[0])
-			}
-		}
-		avs[i] = av
-	}
-
-	sort.SliceStable(avs, func(i, j int) bool {
-		if avs[i].Weight > avs[j].Weight {
-			return true
-		}
-		if avs[i].Type != "*" && avs[j].Type == "*" {
-			return true
-		}
-		if avs[i].Subtype != "*" && avs[j].Subtype == "*" {
-			return true
-		}
-		return false
-	})
-
-	avArgs := make([]AcceptValue, len(types))
-	for i, fulltype := range types {
-		split := strings.Split(fulltype, "/")
-		if len(split) == 1 {
-			avArgs[i] = AcceptValue{Type: split[0]}
-		} else {
-			avArgs[i] = AcceptValue{Type: split[0], Subtype: split[1]}
-		}
-	}
-
-	for _, av := range avs {
-		for j, avArg := range avArgs {
-			if !(av.Type == avArg.Type || av.Type == "*" || avArg.Type == "*") {
-				continue
-			}
-			if !(av.Subtype == avArg.Subtype || av.Subtype == "*" || avArg.Subtype == "*") {
-				continue
-			}
-			return types[j], nil
-		}
-	}
-	return "", nil
-}