Basic server app with WS connection.

server/internal/services/core/database/connection.go

@@ -0,0 +1,83 @@
+package database
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/jmoiron/sqlx"
+	// postgresql driver.
+	_ "github.com/jackc/pgx/v5/stdlib"
+)
+
+const (
+	databaseDSNEnvVar            = "BUNKERD_DATABASE_DSN"
+	databaseMaxIdleConnsEnvVar   = "BUNKERD_DATABASE_MAX_IDLE_CONNS"
+	databaseMaxOpenedConnsEnvVar = "BUNKERD_DATABASE_MAX_OPENED_CONNS"
+)
+
+var (
+	errDSNInvalid            = errors.New("BUNKERD_DATABASE_DSN environment variable is empty or invalid")
+	errNoMaxIdleConns        = errors.New("no BUNKERD_DATABASE_MAX_IDLE_CONNS defined")
+	errNoMaxOpenedConns      = errors.New("no BUNKERD_DATABASE_MAX_OPENED_CONNS defined")
+	errPostgresOnlySupported = errors.New("only PostgreSQL database is currently supported")
+)
+
+func (d *database) initializeConnection() error {
+	// Getting database DSN from environment as well as other required settings.
+	dsn, found := os.LookupEnv(databaseDSNEnvVar)
+	if !found {
+		return fmt.Errorf("initialize connection: getting database DSN: %w", errDSNInvalid)
+	}
+
+	maxOpenedConnsRaw, found := os.LookupEnv(databaseMaxOpenedConnsEnvVar)
+	if !found {
+		return fmt.Errorf("initialize connection: getting maximum number of opened conections: %w", errNoMaxOpenedConns)
+	}
+
+	maxOpenedConns, err := strconv.ParseInt(maxOpenedConnsRaw, 10, 64)
+	if err != nil {
+		return fmt.Errorf("initialize connection: parsing maximum number of opened conections: %w", err)
+	}
+
+	maxIdleConnsRaw, found := os.LookupEnv(databaseMaxIdleConnsEnvVar)
+	if !found {
+		return fmt.Errorf("initialize connection: getting maximum number of idle conections: %w", errNoMaxIdleConns)
+	}
+
+	maxIdleConns, err := strconv.ParseInt(maxIdleConnsRaw, 10, 64)
+	if err != nil {
+		return fmt.Errorf("initialize connection: parsing maximum number of opened conections: %w", err)
+	}
+
+	// While database/sql (and sqlx) supports all possible DSN formats, we will force user to use DSN in form
+	// "proto://user:passowrd@host:port/dbname" as it is easier to parse.
+	if _, err := url.Parse(dsn); err != nil {
+		return fmt.Errorf("initialize connection: validate DSN: %w", err)
+	}
+
+	// Currently we're support only postgresql, but this may change in future.
+	if !strings.HasPrefix(dsn, "postgres://") {
+		return fmt.Errorf("initialize connection: validate DSN: %w", errPostgresOnlySupported)
+	}
+
+	proto := strings.Split(dsn, ":")[0]
+	if proto == "postgres" {
+		proto = "pgx"
+	}
+
+	db, err := sqlx.Open(proto, dsn)
+	if err != nil {
+		return fmt.Errorf("initialize connection: open database: %w", err)
+	}
+
+	d.db = db
+
+	d.db.SetMaxOpenConns(int(maxOpenedConns))
+	d.db.SetMaxIdleConns(int(maxIdleConns))
+
+	return nil
+}

server/internal/services/core/database/database.go

@@ -0,0 +1,73 @@
+package database
+
+import (
+	"fmt"
+	"io/fs"
+	"log/slog"
+
+	"bunker/server/internal/application"
+	"bunker/server/internal/services/core"
+
+	"github.com/jmoiron/sqlx"
+)
+
+var _ = core.Database(&database{})
+
+type database struct {
+	app        *application.Application
+	db         *sqlx.DB
+	logger     *slog.Logger
+	migrations map[string]fs.FS
+	version    int64
+}
+
+// Initialize initializes service.
+func Initialize(app *application.Application) error {
+	db := &database{
+		app: app,
+	}
+
+	if err := app.RegisterService(db); err != nil {
+		return fmt.Errorf("%w: %w", core.ErrDatabase, err)
+	}
+
+	return nil
+}
+
+func (d *database) Configure() error {
+	if err := d.initializeConnection(); err != nil {
+		return fmt.Errorf("configure: %w", err)
+	}
+
+	return nil
+}
+
+func (d *database) ConnectDependencies() error {
+	return nil
+}
+
+func (d *database) Initialize() error {
+	d.logger = d.app.NewLogger("service", core.ServiceNameDatabase)
+
+	d.logger.Info("Initializing...")
+
+	d.migrations = make(map[string]fs.FS, 0)
+
+	return nil
+}
+
+func (d *database) Name() string {
+	return core.ServiceNameDatabase
+}
+
+func (d *database) LaunchStartupTasks() error {
+	if err := d.applyMigrations(); err != nil {
+		return fmt.Errorf("launch startup tasks: %w", err)
+	}
+
+	return nil
+}
+
+func (d *database) Shutdown() error {
+	return nil
+}

server/internal/services/core/database/migrations.go

@@ -0,0 +1,82 @@
+package database
+
+import (
+	"errors"
+	"fmt"
+	"io/fs"
+	"log/slog"
+	"sort"
+	"strings"
+
+	"bunker/commons"
+	"bunker/server/internal/services/core"
+
+	"github.com/pressly/goose/v3"
+)
+
+var errMigrationsAlreadyRegistered = errors.New("migrations already registered")
+
+func (d *database) applyMigrations() error {
+	d.logger.Info("Migrating database...")
+
+	modules := make([]string, 0)
+
+	for module := range d.migrations {
+		modules = append(modules, module)
+	}
+
+	sort.Strings(modules)
+
+	_ = goose.SetDialect(string(goose.DialectPostgres))
+
+	gooseLogger := commons.NewGooseLogger(d.logger)
+	goose.SetLogger(gooseLogger)
+
+	for _, module := range modules {
+		d.logger.Info("Migrating database for module...", "module", module)
+
+		goose.SetBaseFS(d.migrations[module])
+		goose.SetTableName(strings.ReplaceAll(module, "/", "_") + "_migrations")
+
+		if err := goose.Up(d.db.DB, "migrations"); err != nil {
+			return fmt.Errorf("%w: applying migrations for module '%s': %w", core.ErrDatabase, module, err)
+		}
+
+		moduleDBVersion, err := goose.GetDBVersion(d.db.DB)
+		if err != nil {
+			return fmt.Errorf("%w: get database version for module '%s': %w", core.ErrDatabase, module, err)
+		}
+
+		d.version += moduleDBVersion
+
+		d.logger.Info(
+			"Database for module migrated to latest version",
+			"module", module,
+			"module_db_version", moduleDBVersion,
+			"db_version", d.version,
+		)
+	}
+
+	d.logger.Info("Database migrated.", "version", d.version)
+
+	return nil
+}
+
+func (d *database) RegisterMigrations(moduleName string, fSys fs.FS) error {
+	slog.Debug("Registering migrations for service.", "service", moduleName)
+
+	if _, found := d.migrations[moduleName]; found {
+		return fmt.Errorf(
+			"%w: RegisterMigrations: module '%s': %w",
+			core.ErrDatabase,
+			moduleName,
+			errMigrationsAlreadyRegistered,
+		)
+	}
+
+	d.migrations[moduleName] = fSys
+
+	slog.Debug("Migrations for service successfully registered.", "service", moduleName)
+
+	return nil
+}

server/internal/services/core/database/queries.go

@@ -0,0 +1,69 @@
+package database
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"bunker/server/internal/services/core"
+)
+
+// Exec is a proxy for ExecContext from sqlx.
+func (d *database) Exec(ctx context.Context, query string, params ...interface{}) error {
+	if strings.Contains(query, "?") {
+		query = d.db.Rebind(query)
+	}
+
+	d.logger.Debug("Executing query.", "query", query, "params", fmt.Sprintf("%+v", params))
+
+	if _, err := d.db.ExecContext(ctx, query, params...); err != nil {
+		return fmt.Errorf("%w: failed to Exec(): %w", core.ErrDatabase, err)
+	}
+
+	return nil
+}
+
+// Get is a proxy for GetContext from sqlx.
+func (d *database) Get(ctx context.Context, target interface{}, query string, params ...interface{}) error {
+	if strings.Contains(query, "?") {
+		query = d.db.Rebind(query)
+	}
+
+	d.logger.Debug("Getting single data from database with query.", "query", query, "params", fmt.Sprintf("%+v", params))
+
+	if err := d.db.GetContext(ctx, target, query, params...); err != nil {
+		return fmt.Errorf("%w: failed to Get(): %w", core.ErrDatabase, err)
+	}
+
+	return nil
+}
+
+// NamedExec is a proxy for NamedExecContext from sqlx.
+func (d *database) NamedExec(ctx context.Context, query string, param interface{}) error {
+	if strings.Contains(query, "?") {
+		query = d.db.Rebind(query)
+	}
+
+	d.logger.Debug("Executing named query.", "query", query, "params", fmt.Sprintf("%+v", param))
+
+	if _, err := d.db.NamedExecContext(ctx, query, param); err != nil {
+		return fmt.Errorf("%w: failed to NamedExec(): %w", core.ErrDatabase, err)
+	}
+
+	return nil
+}
+
+// Select is a proxy for SelectContext from sqlx.
+func (d *database) Select(ctx context.Context, target interface{}, query string, params ...interface{}) error {
+	if strings.Contains(query, "?") {
+		query = d.db.Rebind(query)
+	}
+
+	d.logger.Debug("Selecting from database with query.", "query", query, "params", fmt.Sprintf("%+v", params))
+
+	if err := d.db.SelectContext(ctx, target, query, params...); err != nil {
+		return fmt.Errorf("%w: failed to Select(): %w", core.ErrDatabase, err)
+	}
+
+	return nil
+}

server/internal/services/core/database/transaction.go

@@ -0,0 +1,81 @@
+package database
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+
+	"bunker/server/internal/services/core"
+
+	"github.com/jmoiron/sqlx"
+)
+
+type transaction struct {
+	transaction *sqlx.Tx
+	logger      *slog.Logger
+}
+
+func (d *database) Transaction(ctx context.Context) (core.DatabaseTransaction, error) {
+	txn, err := d.db.BeginTxx(ctx, nil)
+	if err != nil {
+		return nil, fmt.Errorf("%w: starting transaction: %w", core.ErrDatabase, err)
+	}
+
+	txHandler := &transaction{
+		transaction: txn,
+		logger:      d.logger.With("module", "transactioner"),
+	}
+
+	return txHandler, nil
+}
+
+func (t *transaction) Apply(steps ...core.TransactionFunc) error {
+	for stepNumber, stepFunc := range steps {
+		if err := stepFunc(t.transaction); err != nil {
+			t.logger.Error(
+				"Error occurred.",
+				"step", stepNumber,
+				"error", err.Error(),
+				"module", "core/database",
+				"subsystem", "transaction",
+			)
+
+			if rollbackErr := t.transaction.Rollback(); rollbackErr != nil {
+				t.logger.Error(
+					"Transaction rollback failed.",
+					"error", err.Error(),
+					"module", "core/database",
+					"subsystem", "transaction",
+				)
+
+				return fmt.Errorf("%w: transaction rollback: %w", core.ErrDatabase, rollbackErr)
+			}
+
+			return err
+		}
+	}
+
+	if err := t.transaction.Commit(); err != nil {
+		t.logger.Error(
+			"Transaction commit failed.",
+			"error", err.Error(),
+			"module", "core/database",
+			"subsystem", "transaction",
+		)
+
+		if rollbackErr := t.transaction.Rollback(); rollbackErr != nil {
+			t.logger.Error(
+				"Transaction rollback failed.",
+				"error", err.Error(),
+				"module", "core/database",
+				"subsystem", "transaction",
+			)
+
+			return fmt.Errorf("%w: transaction rollback: %w", core.ErrDatabase, rollbackErr)
+		}
+
+		return fmt.Errorf("%w: transaction commit: %w", core.ErrDatabase, err)
+	}
+
+	return nil
+}