Add id= urlpart=

funcs.go

@@ -44,7 +44,7 @@ func (m *Ring) parseList() {
 	lines := strings.Split(string(file), "\n")
 	for _, line := range lines[:len(lines)-1] {
 		fields := strings.Fields(line)
-		m.ring = append(m.ring, RingMember{handle: fields[0], url: fields[1]})
+		m.ring = append(m.ring, RingMember{id: fields[0], url: fields[1]})
 	}
 	fileStat, err := os.Stat(*flagMembers)
 	if err != nil {

handlers.go

@@ -5,11 +5,13 @@
 package main
 
 import (
+	"fmt"
 	"html/template"
 	"log"
 	"math/rand"
 	"net/http"
 	"net/url"
+	"strings"
 	"time"
 )
 
@@ -26,16 +28,49 @@ func (m Ring) root(writer http.ResponseWriter, request *http.Request) {
 	var table string
 	for _, member := range m.ring {
 		table = table + "  <tr>\n"
-		table = table + "    <td>" + member.handle + "</td>\n"
+		table = table + "    <td>" + member.id + "</td>\n"
 		table = table + "    <td>" + link(member.url) + "</td>\n"
 		table = table + "  </tr>\n"
 	}
 	m.index.Execute(writer, template.HTML(table))
 }
 
-func (m Ring) match(query url.Values, item RingMember) bool {
-	host := query.Get("host")
-	return item.url == host
+type MemberSelector struct {
+	id      string // exact match
+	urlpart string
+}
+
+func parseQuery(query url.Values) (*MemberSelector, error) {
+	urlpart := query.Get("urlpart")
+	if urlpart == "" {
+		urlpart = query.Get("host")
+	}
+	n_valid := 0
+	if urlpart != "" {
+		n_valid += 1
+	}
+	id := query.Get("id")
+	if id != "" {
+		n_valid += 1
+	}
+	if n_valid != 1 {
+		return nil, fmt.Errorf("Please specify urlpart=xxx or id=xxx")
+	}
+
+	return &MemberSelector{
+		id:      id,
+		urlpart: urlpart,
+	}, nil
+}
+
+func (m Ring) match(selector *MemberSelector, item RingMember) bool {
+	if selector.id != "" {
+		return item.id == selector.id	
+	}
+	if selector.urlpart != "" {
+		return strings.Contains(item.url, selector.urlpart)
+	}
+	panic("unreachable")
 }
 
 // Redirects the visitor to the next member, wrapping around the list if the
@@ -48,9 +83,13 @@ func (m Ring) next(writer http.ResponseWriter, request *http.Request) {
 	}
 	success := false
 	query := request.URL.Query()
+	selector, err := parseQuery(query)
+	if err != nil {
+		http.Error(writer, fmt.Errorf("invalid query: %w", err).Error(), http.StatusBadRequest)
+	}
 	length := len(m.ring)
 	for i, item := range m.ring {
-		if m.match(query, item) {
+		if m.match(selector, item) {
 			for j := i + 1; j < length+i; j++ {
 				dest := m.ring[j%length].url
 				log.Println("Checking '" + dest + "'")
@@ -78,9 +117,13 @@ func (m Ring) previous(writer http.ResponseWriter, request *http.Request) {
 		m.parseList()
 	}
 	query := request.URL.Query()
+	selector, err := parseQuery(query)
+	if err != nil {
+		http.Error(writer, fmt.Errorf("invalid query: %w", err).Error(), http.StatusBadRequest)
+	}
 	length := len(m.ring)
 	for index, item := range m.ring {
-		if m.match(query, item) {
+		if m.match(selector, item) {
 			// from here to start of list
 			for i := index - 1; i > 0; i-- {
 				dest := m.ring[i].url
@@ -105,7 +148,7 @@ please email amolith@secluded.site and let him (me) know what's up.`, 500)
 			return
 		}
 	}
-	http.Error(writer, "Ring member '"+query.Encode()+"' not found.", 404)
+	http.Error(writer, "Ring member '"+query.Encode()+"' not )found.", 404)
 }
 
 // Redirects the visitor to a random member

main.go

@@ -16,8 +16,8 @@ import (
 )
 
 type RingMember struct {
-	handle string
-	url    string
+	id  string
+	url string
 }
 
 type Ring struct {
@@ -68,7 +68,7 @@ func main() {
 	mux.HandleFunc("/next", m.next)
 	mux.HandleFunc("/previous", m.previous)
 	mux.HandleFunc("/random", m.random)
-	
+
 	var err error
 	if strings.Contains(httpServer.Addr, ":") {
 		err = httpServer.ListenAndServe()