database/sqlite: make optional

SQLite requires cgo, for some use cases this is undesirable.

README.md

@@ -18,7 +18,7 @@ Dependencies:
 
 - Go
 - BSD or GNU make
-- a C89 compiler (for SQLite)
+- a C89 compiler (optional, for SQLite)
 - scdoc (optional, for man pages)
 
 For end users, a `Makefile` is provided:
@@ -28,7 +28,8 @@ For end users, a `Makefile` is provided:
 
 For development, you can use `go run ./cmd/soju` as usual.
 
-To link with the system libsqlite3, set `GOFLAGS="-tags=libsqlite3"`.
+To link with the system libsqlite3, set `GOFLAGS="-tags=libsqlite3"`. To disable
+SQLite support, set `GOFLAGS="-tags=nosqlite"`.
 
 ## Contributing
 

database/database.go

@@ -2,6 +2,7 @@ package database
 
 import (
 	"context"
+	"database/sql"
 	"fmt"
 	"net/url"
 	"strings"
@@ -235,3 +236,10 @@ type WebPushSubscription struct {
 		VAPID  string
 	}
 }
+
+func toNullString(s string) sql.NullString {
+	return sql.NullString{
+		String: s,
+		Valid:  s != "",
+	}
+}

database/sqlite.go

@@ -1,3 +1,5 @@
+//go:build !nosqlite
+
 package database
 
 import (
@@ -13,6 +15,8 @@ import (
 	promcollectors "github.com/prometheus/client_golang/prometheus/collectors"
 )
 
+const SqliteEnabled = true
+
 const sqliteQueryTimeout = 5 * time.Second
 
 const sqliteTimeLayout = "2006-01-02T15:04:05.000Z"
@@ -339,13 +343,6 @@ func (db *SqliteDB) Stats(ctx context.Context) (*DatabaseStats, error) {
 	return &stats, nil
 }
 
-func toNullString(s string) sql.NullString {
-	return sql.NullString{
-		String: s,
-		Valid:  s != "",
-	}
-}
-
 func (db *SqliteDB) ListUsers(ctx context.Context) ([]User, error) {
 	ctx, cancel := context.WithTimeout(ctx, sqliteQueryTimeout)
 	defer cancel()

database/sqlite_stub.go

@@ -0,0 +1,17 @@
+//go:build nosqlite
+
+package database
+
+import (
+	"errors"
+)
+
+const SqliteEnabled = false
+
+func OpenSqliteDB(source string) (Database, error) {
+	return nil, errors.New("SQLite support is disabled")
+}
+
+func OpenTempSqliteDB() (Database, error) {
+	return OpenSqliteDB("")
+}

database/sqlite_test.go

@@ -1,3 +1,5 @@
+//go:build !nosqlite
+
 package database
 
 import (

server_test.go

@@ -20,6 +20,10 @@ const (
 )
 
 func createTempSqliteDB(t *testing.T) database.Database {
+	if !database.SqliteEnabled {
+		t.Skip("SQLite support is disabled")
+	}
+
 	db, err := database.OpenTempSqliteDB()
 	if err != nil {
 		t.Fatalf("failed to create temporary SQLite database: %v", err)