Add stub backends

README.md

@@ -1,8 +1,28 @@
 # bacheca
 
+## What is bacheca?
+
 RSS/Atom feed generator with a simple REST API (and hopefully gRPC)
 
-Written using go-kit and Moa but should work fine alone, given you have a good enough reverse proxy setup.
+The service is written to be able to work both as a RSS/Atom feed server and as a static generator for one.
+
+## How does it work?
+
+In the `cmd` folder, you'll find 3 versions of bacheca:
+
+ - `bacheca-moa` works as a microservice in a [Moa](https://git.fromouter.space/Artificiale/moa) environment
+ - `bacheca-server` works as a stand-alone server
+ - `bacheca-static` generates a static XML file
+
+### Adding/removing items
+
+The server version will use REST APIs for [CRUD](https://en.wikipedia.org/wiki/Create,_read,_update_and_delete) operations. [AtomPub](https://tools.ietf.org/html/rfc5023) support would be nice but has to be investigated how well it works on a server mainly doing RSS.
+
+Another option, especially when using the static CLI, is to just make your own tools to modify the storage backend directly.
+
+### Storage backends
+
+Bacheca needs a backend to store its data, currently the main plan is to support at least 1 file-based backend (`file`) and a KV-based backend (`bolt`). If you want to implement and contribute your own storage backend (like PostgreSQL) feel free to!
 
 ## Things to note
 

cmd/bacheca-moa/main.go

@@ -8,18 +8,59 @@ import (
 	"os/signal"
 	"syscall"
 
+	"git.fromouter.space/Artificiale/consulconf"
 	"git.fromouter.space/Artificiale/moa/sd"
 
 	"github.com/go-kit/kit/log"
 
 	svc "git.abbiamoundominio.org/hamcha/bacheca"
+	"git.abbiamoundominio.org/hamcha/bacheca/storage"
+	boltbackend "git.abbiamoundominio.org/hamcha/bacheca/storage/bolt"
+	filebackend "git.abbiamoundominio.org/hamcha/bacheca/storage/file"
 )
 
+type bachecaConfig struct {
+	Bind        string
+	Advertise   string
+	StorageType string
+	StorageFile string
+}
+
 func main() {
-	httpPort := flag.Int("http.port", 8080, "HTTP listen port")
 	consulAddr := flag.String("consul.addr", "consul:8500", "Consul address")
+	consulConf := flag.String("consul.conf", "bacheca/config", "Consul KV prefix with configuration")
 	flag.Parse()
 
+	err := consulconf.UseDefaultClient(*consulAddr)
+	if err != nil {
+		panic(err)
+	}
+
+	var config bachecaConfig
+	err = consulconf.Get(*consulConf, &config)
+	if err != nil {
+		panic(err)
+	}
+
+	var backend storage.Backend
+	switch config.StorageType {
+	case "bolt":
+		boltdb, err := boltbackend.MakeBoltBackend(config.StorageFile)
+		if err != nil {
+			panic(err)
+		}
+		defer boltdb.Close()
+		backend = boltdb
+	case "file":
+		filebackend, err := filebackend.MakeFileBackend(config.StorageFile)
+		if err != nil {
+			panic(err)
+		}
+		backend = filebackend
+	default:
+		panic("unknown storage backend type (-storage.type), check help for supported backends")
+	}
+
 	var logger log.Logger
 	{
 		logger = log.NewLogfmtLogger(os.Stderr)
@@ -27,13 +68,13 @@ func main() {
 		logger = log.With(logger, "caller", log.DefaultCaller)
 	}
 
-	s := svc.MakeService()
+	s := svc.MakeService(backend)
 	handler := svc.MakeHTTPHandler(s, logger)
 
 	// Register with consul
 	registrar := sd.Register(*consulAddr, sd.Options{
 		Name:      "bacheca",
-		Advertise: fmt.Sprintf("bacheca:%d", *httpPort),
+		Advertise: config.Advertise,
 		Tags: []string{
 			"http",              // Expose via HTTP
 			"match-path:events", // Publish at /events/*
@@ -51,9 +92,8 @@ func main() {
 	}()
 
 	go func() {
-		bind := fmt.Sprintf(":%d", *httpPort)
-		logger.Log("transport", "HTTP", "addr", bind)
-		errs <- http.ListenAndServe(bind, handler)
+		logger.Log("transport", "HTTP", "addr", config.Bind)
+		errs <- http.ListenAndServe(config.Bind, handler)
 	}()
 
 	logger.Log("exit", <-errs)

cmd/bacheca-server/main.go

@@ -11,12 +11,36 @@ import (
 	"github.com/go-kit/kit/log"
 
 	svc "git.abbiamoundominio.org/hamcha/bacheca"
+	"git.abbiamoundominio.org/hamcha/bacheca/storage"
+	boltbackend "git.abbiamoundominio.org/hamcha/bacheca/storage/bolt"
+	filebackend "git.abbiamoundominio.org/hamcha/bacheca/storage/file"
 )
 
 func main() {
 	httpPort := flag.Int("http.port", 8080, "HTTP listen port")
+	dbtype := flag.String("storage.type", "bolt", "Storage backend type")
+	dbfile := flag.String("storage.file", "bacheca.db", "Storage file or path, for file-based backends (bolt)")
 	flag.Parse()
 
+	var backend storage.Backend
+	switch *dbtype {
+	case "bolt":
+		boltdb, err := boltbackend.MakeBoltBackend(*dbfile)
+		if err != nil {
+			panic(err)
+		}
+		defer boltdb.Close()
+		backend = boltdb
+	case "file":
+		filebackend, err := filebackend.MakeFileBackend(*dbfile)
+		if err != nil {
+			panic(err)
+		}
+		backend = filebackend
+	default:
+		panic("unknown storage backend type (-storage.type), check help for supported backends")
+	}
+
 	var logger log.Logger
 	{
 		logger = log.NewLogfmtLogger(os.Stderr)
@@ -24,7 +48,7 @@ func main() {
 		logger = log.With(logger, "caller", log.DefaultCaller)
 	}
 
-	s := svc.MakeService()
+	s := svc.MakeService(backend)
 	handler := svc.MakeHTTPHandler(s, logger)
 
 	//TODO Add auth middleware

cmd/bacheca-static/main.go

@@ -4,18 +4,19 @@ import (
 	"context"
 	"flag"
 	"fmt"
-	"os"
 	"strings"
 
-	proto "git.abbiamoundominio.org/hamcha/bacheca/proto"
-
-	"github.com/go-kit/kit/log"
-
 	svc "git.abbiamoundominio.org/hamcha/bacheca"
+	proto "git.abbiamoundominio.org/hamcha/bacheca/proto"
+	"git.abbiamoundominio.org/hamcha/bacheca/storage"
+	boltbackend "git.abbiamoundominio.org/hamcha/bacheca/storage/bolt"
+	filebackend "git.abbiamoundominio.org/hamcha/bacheca/storage/file"
 )
 
 func main() {
 	format := flag.String("fmt", "rss", "Feed format (rss, atom, json)")
+	dbtype := flag.String("storage.type", "bolt", "Storage backend type")
+	dbfile := flag.String("storage.file", "bacheca.db", "Storage file or path, for file-based backends (bolt)")
 	flag.Parse()
 
 	ftype := strings.ToUpper(*format)
@@ -24,14 +25,26 @@ func main() {
 		panic("invalid format (-fmt), check help for supported formats")
 	}
 
-	var logger log.Logger
-	{
-		logger = log.NewLogfmtLogger(os.Stderr)
-		logger = log.With(logger, "ts", log.DefaultTimestampUTC)
-		logger = log.With(logger, "caller", log.DefaultCaller)
+	var backend storage.Backend
+	switch *dbtype {
+	case "bolt":
+		boltdb, err := boltbackend.MakeBoltBackend(*dbfile)
+		if err != nil {
+			panic(err)
+		}
+		defer boltdb.Close()
+		backend = boltdb
+	case "file":
+		filebackend, err := filebackend.MakeFileBackend(*dbfile)
+		if err != nil {
+			panic(err)
+		}
+		backend = filebackend
+	default:
+		panic("unknown storage backend type (-storage.type), check help for supported backends")
 	}
 
-	s := svc.MakeService()
+	s := svc.MakeService(backend)
 
 	req := &proto.GetFeedRequest{
 		FeedType: proto.GetFeedRequest_FeedType(fid),

go.mod

@@ -3,10 +3,13 @@ module git.abbiamoundominio.org/hamcha/bacheca
 go 1.12
 
 require (
+	git.fromouter.space/Artificiale/consulconf v0.3.1
 	git.fromouter.space/Artificiale/moa v0.0.1
-	git.fromouter.space/mcg/cardgage v0.0.5 // indirect
+	github.com/boltdb/bolt v1.3.1
 	github.com/go-kit/kit v0.8.0
 	github.com/golang/protobuf v1.3.2
+	github.com/gorilla/feeds v1.1.1
 	github.com/gorilla/mux v1.7.2
+	github.com/kr/pretty v0.1.0 // indirect
 	google.golang.org/grpc v1.22.0
 )

go.sum

@@ -1,4 +1,6 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
+git.fromouter.space/Artificiale/consulconf v0.3.1 h1:WXtNqdbspFQ3KxhE5PbYt7o4YVWXInJJgT2VW3D36vo=
+git.fromouter.space/Artificiale/consulconf v0.3.1/go.mod h1:hhQNBaRAwJiKe6pnwTaWcyMCGuDIRZjAa/32Hw8UY1A=
 git.fromouter.space/Artificiale/moa v0.0.1-p2/go.mod h1:dHYul6vVMwDCzre18AFs6NmI22yeI7AE0iQC1jFEQi0=
 git.fromouter.space/Artificiale/moa v0.0.1 h1:1mVML0v3Bh5Fya9dz7pKtlt7+Z6hRzXxmlY7sBvw0FI=
 git.fromouter.space/Artificiale/moa v0.0.1/go.mod h1:dHYul6vVMwDCzre18AFs6NmI22yeI7AE0iQC1jFEQi0=
@@ -16,6 +18,8 @@ github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24
 github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kBD4zp0CCIs=
 github.com/bitly/go-hostpool v0.0.0-20171023180738-a3a6125de932/go.mod h1:NOuUCSz6Q9T7+igc/hlvDOUdtWKryOrtFyIVABv/p7k=
 github.com/bmizerany/assert v0.0.0-20160611221934-b7ed37b82869/go.mod h1:Ekp36dRnpXw/yCqJaO+ZrUyxD+3VXMFFr56k5XYrpB4=
+github.com/boltdb/bolt v1.3.1 h1:JQmyP4ZBrce+ZQu0dY660FMfatumYDLun9hBCUVIkF4=
+github.com/boltdb/bolt v1.3.1/go.mod h1:clJnj/oiGkjum5o1McbSZDSLxVThjynRyGBgiAx27Ps=
 github.com/cenkalti/backoff v2.0.0+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
 github.com/circonus-labs/circonus-gometrics v2.3.1+incompatible/go.mod h1:nmEj6Dob7S7YxXgwXpfOuvO54S+tGdZdw9fuRZt25Ag=
 github.com/circonus-labs/circonusllhist v0.1.3/go.mod h1:kMXHVDlOchFAehlya5ePtbp5jckzBHf4XRpQvBOLI+I=
@@ -43,6 +47,8 @@ github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5y
 github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
+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 v1.7.2 h1:zoNxOV7WjqXptQOVngLmcSQgXmgk4NMz1HibBchjl/I=
 github.com/gorilla/mux v1.7.2/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
@@ -86,8 +92,10 @@ github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpO
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/konsorten/go-windows-terminal-sequences v1.0.2/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
 github.com/mattn/go-isatty v0.0.3/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=

service.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 
 	proto "git.abbiamoundominio.org/hamcha/bacheca/proto"
+	"git.abbiamoundominio.org/hamcha/bacheca/storage"
 )
 
 // Service is the definition of the Bacheca service
@@ -13,10 +14,14 @@ type Service interface {
 }
 
 type bachecaService struct {
+	backend storage.Backend
 }
 
-func MakeService() Service {
-	return &bachecaService{}
+// MakeService returns an instance of the bacheca service
+func MakeService(store storage.Backend) Service {
+	return &bachecaService{
+		backend: store,
+	}
 }
 
 func (b *bachecaService) GetFeed(ctx context.Context, req *proto.GetFeedRequest, rsp *proto.GetFeedResponse) error {

storage/bolt/backend.go

@@ -0,0 +1,51 @@
+package boltbackend
+
+import (
+	"errors"
+
+	"github.com/boltdb/bolt"
+	"github.com/gorilla/feeds"
+)
+
+// BoltBackend is a Bolt-powered storage backend for bacheca
+type BoltBackend struct {
+	db *bolt.DB
+}
+
+// MakeBoltBackend returns a BoltBackend instance
+func MakeBoltBackend(path string) (*BoltBackend, error) {
+	db, err := bolt.Open(path, 0600, nil)
+	return &BoltBackend{
+		db: db,
+	}, err
+}
+
+// Close closes the underlying bolt handler
+func (b *BoltBackend) Close() error {
+	return b.db.Close()
+}
+
+// GetFeed returns the whole feed
+func (b *BoltBackend) GetFeed() (*feeds.Feed, error) {
+	return nil, errors.New("not implemented")
+}
+
+// AddItem adds an item to the feed
+func (b *BoltBackend) AddItem(item feeds.Item) (string, error) {
+	return "", errors.New("not implemented")
+}
+
+// RemoveItem removes an item by ID
+func (b *BoltBackend) RemoveItem(id string) error {
+	return errors.New("not implemented")
+}
+
+// ReplaceItem replaces the item at a specified ID with the data provided
+func (b *BoltBackend) ReplaceItem(id string, item feeds.Item) error {
+	return errors.New("not implemented")
+}
+
+// SetInfo sets the feed metadata (like title and description)
+func (b *BoltBackend) SetInfo(info feeds.Feed) error {
+	return errors.New("not implemented")
+}

storage/file/backend.go

@@ -0,0 +1,49 @@
+package filebackend
+
+import (
+	"errors"
+	"os"
+
+	"github.com/gorilla/feeds"
+)
+
+// FileBackend is a file-based storage backend for bacheca
+type FileBackend struct {
+	path string
+}
+
+// MakeFileBackend returns a FileBackend instance
+func MakeFileBackend(path string) (*FileBackend, error) {
+	stat, err := os.Stat(path)
+	if err == nil && stat.IsDir() {
+		return nil, errors.New("file backend must be a file")
+	}
+	return &FileBackend{
+		path: path,
+	}, err
+}
+
+// GetFeed returns the whole feed
+func (b *FileBackend) GetFeed() (*feeds.Feed, error) {
+	return nil, errors.New("not implemented")
+}
+
+// AddItem adds an item to the feed
+func (b *FileBackend) AddItem(item feeds.Item) (string, error) {
+	return "", errors.New("not implemented")
+}
+
+// RemoveItem removes an item by ID
+func (b *FileBackend) RemoveItem(id string) error {
+	return errors.New("not implemented")
+}
+
+// ReplaceItem replaces the item at a specified ID with the data provided
+func (b *FileBackend) ReplaceItem(id string, item feeds.Item) error {
+	return errors.New("not implemented")
+}
+
+// SetInfo sets the feed metadata (like title and description)
+func (b *FileBackend) SetInfo(info feeds.Feed) error {
+	return errors.New("not implemented")
+}

storage/storage.go

@@ -0,0 +1,23 @@
+package storage
+
+import "github.com/gorilla/feeds"
+
+// Backend is a storage backend for bacheca
+type Backend interface {
+	// GetFeed returns the whole feed
+	GetFeed() (*feeds.Feed, error)
+
+	// AddItem adds an item to the feed
+	// If an ID is not specified, one will be generated randomly
+	// The return value is the ID, generated or provided
+	AddItem(item feeds.Item) (string, error)
+
+	// RemoveItem removes an item by ID
+	RemoveItem(id string) error
+
+	// ReplaceItem replaces the item at a specified ID with the data provided
+	ReplaceItem(id string, item feeds.Item) error
+
+	// SetInfo sets the feed metadata (like title and description)
+	SetInfo(info feeds.Feed) error
+}