Add feed generator

api.go

@@ -2,18 +2,29 @@ package main
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"net/http"
+	"net/url"
 	"strconv"
+	"strings"
+	"time"
 
 	"github.com/Luzifer/go-latestver/internal/config"
 	"github.com/Luzifer/go-latestver/internal/database"
 	"github.com/Luzifer/go-latestver/internal/fetcher"
+	"github.com/gorilla/feeds"
 	"github.com/gorilla/mux"
+	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
 )
 
+func buildFullURL(u *url.URL) string {
+	return strings.Join([]string{
+		strings.TrimRight(cfg.BaseURL, "/"),
+		strings.TrimLeft(u.String(), "/"),
+	}, "/")
+}
+
 func handleCatalogGet(w http.ResponseWriter, r *http.Request) {
 	var (
 		vars      = mux.Vars(r)
@@ -101,6 +112,78 @@ func handleCatalogList(w http.ResponseWriter, r *http.Request) {
 }
 
 func handleLog(w http.ResponseWriter, r *http.Request) {
+	logs, err := prepareLogForRequest(r)
+	switch err {
+	case nil:
+		// This is fine
+
+	case config.ErrCatalogEntryNotFound:
+		http.Error(w, "Not found", http.StatusNotFound)
+
+	default:
+		http.Error(w, "Unable to fetch logs", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	if err = json.NewEncoder(w).Encode(logs); err != nil {
+		log.WithError(err).Error("Unable to encode logs")
+		http.Error(w, "Unable to encode logs", http.StatusInternalServerError)
+		return
+	}
+}
+
+func handleLogFeed(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+
+	logs, err := prepareLogForRequest(r)
+	switch err {
+	case nil:
+		// This is fine
+
+	case config.ErrCatalogEntryNotFound:
+		http.Error(w, "Not found", http.StatusNotFound)
+
+	default:
+		http.Error(w, "Unable to fetch logs", http.StatusInternalServerError)
+		return
+	}
+
+	var (
+		feedTitle  = "Latestver Update Log"
+		feedURL, _ = router.Get("catalog").URL()
+	)
+	if vars["name"] != "" {
+		feedTitle = fmt.Sprintf("Latestver Update Log of %s:%s", vars["name"], vars["tag"])
+		feedURL, _ = router.Get("catalog-entry").URL("name", vars["name"], "tag", vars["tag"])
+	}
+
+	feed := &feeds.Feed{
+		Description: "Generated by go-latestver: https://github.com/Luzifer/go-latestver",
+		Link:        &feeds.Link{Href: buildFullURL(feedURL)},
+		Title:       feedTitle,
+	}
+
+	for _, le := range logs {
+		catalogEntryURL, _ := router.Get("catalog-entry").URL("name", le.CatalogName, "tag", le.CatalogTag)
+		feed.Add(&feeds.Item{
+			Created:     le.Timestamp.UTC(),
+			Description: fmt.Sprintf("%s:%s updated to version %s from %s", le.CatalogName, le.CatalogTag, le.VersionTo, le.VersionFrom),
+			Id:          fmt.Sprintf("%s:%s-%s", le.CatalogName, le.CatalogTag, le.Timestamp.UTC().Format(time.RFC3339)),
+			Link:        &feeds.Link{Href: buildFullURL(catalogEntryURL)},
+			Title:       fmt.Sprintf("%s:%s %s", le.CatalogName, le.CatalogTag, le.VersionTo),
+		})
+	}
+
+	w.Header().Set("Content-Type", "application/rss+xml; charset=utf-8")
+	if err = feed.WriteRss(w); err != nil {
+		log.WithError(err).Error("Unable to render RSS")
+		http.Error(w, "Unable to render RSS", http.StatusInternalServerError)
+		return
+	}
+}
+
+func prepareLogForRequest(r *http.Request) ([]database.LogEntry, error) {
 	var (
 		vars      = mux.Vars(r)
 		name, tag = vars["name"], vars["tag"]
@@ -124,19 +207,11 @@ func handleLog(w http.ResponseWriter, r *http.Request) {
 	} else {
 		ce, err := configFile.CatalogEntryByTag(name, tag)
 		if errors.Is(err, config.ErrCatalogEntryNotFound) {
-			http.Error(w, "Not found", http.StatusNotFound)
+			return nil, config.ErrCatalogEntryNotFound
-			return
 		}
 
 		logs, err = storage.Logs.ListForCatalogEntry(&ce, num, page)
 	}
 
-	w.Header().Set("Content-Type", "application/json")
+	return logs, errors.Wrap(err, "listing log entries")
-	if err = json.NewEncoder(w).Encode(logs); err != nil {
-		log.WithError(err).Error("Unable to encode logs")
-		http.Error(w, "Unable to encode logs", http.StatusInternalServerError)
-		return
-	}
 }
-
-func handleLogFeed(w http.ResponseWriter, r *http.Request) {} // FIXME

go.mod

@@ -29,6 +29,7 @@ require (
 	github.com/go-git/go-git/v5 v5.4.2 // indirect
 	github.com/go-sql-driver/mysql v1.6.0 // indirect
 	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
+	github.com/gorilla/feeds v1.1.1 // indirect
 	github.com/imdario/mergo v0.3.12 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect

go.sum

@@ -66,6 +66,8 @@ github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMyw
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/gorilla/feeds v1.1.1 h1:HwKXxqzcRNg9to+BbvJog4+f3s/xzvtZXICcQGutYfY=
+github.com/gorilla/feeds v1.1.1/go.mod h1:Nk0jZrvPFZX1OBe5NPiddPw7CfwF6Q9eqzaBbaightA=
 github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
 github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=

main.go

@@ -18,6 +18,7 @@ import (
 
 var (
 	cfg = struct {
+		BaseURL        string        `flag:"base-url" default:"https://example.com/" description:"Base-URL the application is reachable at"`
 		Config         string        `flag:"config,c" default:"config.yaml" description:"Configuration file with catalog entries"`
 		Listen         string        `flag:"listen" default:":3000" description:"Port/IP to listen on"`
 		LogLevel       string        `flag:"log-level" default:"info" description:"Log level (debug, info, warn, error, fatal)"`
@@ -28,6 +29,7 @@ var (
 	}{}
 
 	configFile = config.New()
+	router     *mux.Router
 	storage    *database.Client
 
 	version = "dev"
@@ -73,14 +75,18 @@ func main() {
 	scheduler.AddFunc("@every 1m", schedulerRun)
 	scheduler.Start()
 
-	router := mux.NewRouter()
+	router = mux.NewRouter()
 	router.HandleFunc("/v1/catalog", handleCatalogList).Methods(http.MethodGet)
 	router.HandleFunc("/v1/catalog/{name}/{tag}", handleCatalogGet).Methods(http.MethodGet)
 	router.HandleFunc("/v1/catalog/{name}/{tag}/log", handleLog).Methods(http.MethodGet)
-	router.HandleFunc("/v1/catalog/{name}/{tag}/log.rss", handleLogFeed).Methods(http.MethodGet)
 	router.HandleFunc("/v1/catalog/{name}/{tag}/version", handleCatalogGetVersion).Methods(http.MethodGet)
 	router.HandleFunc("/v1/log", handleLog).Methods(http.MethodGet)
-	router.HandleFunc("/v1/log.rss", handleLogFeed).Methods(http.MethodGet)
+
+	router.HandleFunc("/", nil).Methods(http.MethodGet).Name("catalog")
+	router.HandleFunc("/{name}/{tag}", nil).Methods(http.MethodGet).Name("catalog-entry")
+	router.HandleFunc("/{name}/{tag}/log.rss", handleLogFeed).Methods(http.MethodGet).Name("catalog-entry-rss")
+	router.HandleFunc("/log", nil).Methods(http.MethodGet)
+	router.HandleFunc("/log.rss", handleLogFeed).Methods(http.MethodGet).Name("log-rss")
 
 	var handler http.Handler = router
 	handler = httpHelper.GzipHandler(handler)