Merge pull request #214 from skobkin/feature_postgresql_support

[Partial] PostgreSQL support for magneticod

cmd/magneticod/README.md

@@ -36,7 +36,11 @@ the repository `boramalper/magnetico`. Images are tagged as `d-vMAJOR.MINOR.PATC
 ## Usage
 ### Database
 **magneticod** is designed to be able to use different database engines to store its data, but
-currently only SQLite 3 is supported. The database file can be found in:
+currently only SQLite 3 and PostgreSQL 9+ are supported.
+
+#### SQLite
+
+The database file can be found in:
 
 - **On Linux**
 
@@ -45,6 +49,10 @@ currently only SQLite 3 is supported. The database file can be found in:
 **magneticod** uses write-ahead logging (WAL) for its database, so there might be multiple
 files while it is operating, but ``database.sqlite3`` is *the database*.
 
+#### More engines (PostgreSQL and others)
+
+You can read about other supported persistence engines [here](pkg/README.md).
+
 ### Using the Docker Image
 You need to mount
 

go.mod

@@ -11,22 +11,20 @@ require (
 	github.com/google/pprof v0.0.0-20190515194954-54271f7e092f // indirect
 	github.com/gorilla/mux v1.7.4
 	github.com/gorilla/schema v1.1.0
-	github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6 // indirect
+	github.com/jackc/pgx/v4 v4.9.2
 	github.com/jessevdk/go-flags v1.4.0
 	github.com/kevinburke/go-bindata v3.16.0+incompatible // indirect
 	github.com/libp2p/go-sockaddr v0.0.1
 	github.com/mattn/go-sqlite3 v2.0.3+incompatible
 	github.com/pkg/errors v0.9.1
 	github.com/pkg/profile v1.4.0
 	github.com/willf/bloom v2.0.3+incompatible
-	go.uber.org/atomic v1.5.1 // indirect
-	go.uber.org/multierr v1.4.0 // indirect
 	go.uber.org/zap v1.14.0
-	golang.org/x/crypto v0.0.0-20200221231518-2aa609cf4a9d
+	golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9
 	golang.org/x/lint v0.0.0-20200130185559-910be7a94367 // indirect
 	golang.org/x/net v0.0.0-20200222125558-5a598a2470a0 // indirect
-	golang.org/x/sys v0.0.0-20200219091948-cb0a6d8edb6c
-	golang.org/x/text v0.3.2
+	golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae
+	golang.org/x/text v0.3.3
 	golang.org/x/tools v0.0.0-20200221224223-e1da425f72fd // indirect
 	honnef.co/go/tools v0.0.1-2020.1.3 // indirect
 )

pkg/README.md

@@ -2,10 +2,33 @@
 [![GoDoc](https://godoc.org/github.com/boramalper/magnetico?status.svg)](https://godoc.org/github.com/boramalper/magnetico)
 
 - The most significant package is `persistence`, that abstracts access to the
-  magnetico databases with different engines (currently, only SQLite).
+  magnetico databases with different engines (currently, SQLite, stdout and partly PostgreSQL).
 
 **For REST-ful magneticow API, see [https://app.swaggerhub.com/apis/boramalper/magneticow-api/](https://app.swaggerhub.com/apis/boramalper/magneticow-api/).**
 
+## PostgreSQL database engine (only `magneticod` part implemented)
+
+PostgreSQL database engine uses [PostgreSQL](https://www.postgresql.org/) to store indexed
+torrents. It's more performant and flexible than SQLite but requires additional software configuration.
+
+**WARNING:** `pg_trgm` extension required. You need to enable it for your database before starting `magneticod`:
+
+```postgresql
+CREATE EXTENSION pg_trgm;
+```
+
+Engine usage example:
+
+```shell
+magneticod --database=postgres://username:[email protected]:5432/database?schema=custom_schema_name&sslmode=disable
+```
+
+See [pgx repository](https://github.com/jackc/pgx/blob/master/stdlib/sql.go)
+for more examples.
+
+Optional parameter `schema` was added to choose which schema will be used to store magnetico tables,
+sequences and indexes.
+
 ## Stdout Dummy Database Engine for magneticod
 
 Stdout dummy database engine for **magneticod** prints a new [JSON Line](http://jsonlines.org/)

pkg/persistence/interface.go

@@ -59,7 +59,8 @@ const (
 type databaseEngine uint8
 
 const (
-	Sqlite3 databaseEngine = 1
+	Sqlite3  databaseEngine = 1
+	Postgres databaseEngine = 2
 	Stdout
 )
 
@@ -113,12 +114,12 @@ func MakeDatabase(rawURL string, logger *zap.Logger) (Database, error) {
 	case "sqlite3":
 		return makeSqlite3Database(url_)
 
+	case "postgres":
+		return makePostgresDatabase(url_)
+
 	case "stdout":
 		return makeStdoutDatabase(url_)
 
-	case "postgresql":
-		return nil, fmt.Errorf("postgresql is not yet supported")
-
 	case "mysql":
 		return nil, fmt.Errorf("mysql is not yet supported")