SUSE/stratos

package datastore

import (
    "database/sql"
    "fmt"
    "os"
    "path"
    "regexp"
    "strings"
    "time"

    goosedbversion "github.com/cloudfoundry-incubator/stratos/src/jetstream/repository/goose-db-version"
    "github.com/govau/cf-common/env"
    log "github.com/sirupsen/logrus"

    // Mysql driver
    _ "github.com/go-sql-driver/mysql"
    "github.com/kat-co/vala"

    // Sqlite driver
    _ "github.com/mattn/go-sqlite3"

    "bitbucket.org/liamstask/goose/lib/goose"
)

const (
    // SQLite DB Provider
    SQLITE string = "sqlite"
    // PGSQL DB Provider
    PGSQL = "pgsql"
    // MYSQL DB Provider
    MYSQL = "mysql"

    // TimeoutBoundary is the max time in minutes to wait for the DB Schema to be initialized
    TimeoutBoundary = 10
)

// DatabaseConfig represents the connection configuration parameters
type DatabaseConfig struct {
    DatabaseProvider        string `configName:"DATABASE_PROVIDER"`
    Username                string `configName:"DB_USER"`
    Password                string `configName:"DB_PASSWORD"`
    Database                string `configName:"DB_DATABASE_NAME"`
    Host                    string `configName:"DB_HOST"`
    Port                    int    `configName:"DB_PORT"`
    SSLMode                 string `configName:"DB_SSL_MODE"`
    ConnectionTimeoutInSecs int    `configName:"DB_CONNECT_TIMEOUT_IN_SECS"`
    SSLCertificate          string `configName:"DB_CERT"`
    SSLKey                  string `configName:"DB_CERT_KEY"`
    SSLRootCertificate      string `configName:"DB_ROOT_CERT"`
}

// SSLValidationMode is the PostgreSQL driver SSL validation modes
type SSLValidationMode string

const (
    // PGSQL SSL Modes
    // SSLDisabled means no checking of SSL
    SSLDisabled SSLValidationMode = "disable"
    // SSLRequired requires SSL without validation
    SSLRequired SSLValidationMode = "require"
    // SSLVerifyCA verifies the CA certificate
    SSLVerifyCA SSLValidationMode = "verify-ca"
    // SSLVerifyFull verifies the certificate and hostname and the CA
    SSLVerifyFull SSLValidationMode = "verify-full"
    // SQLiteSchemaFile - SQLite schema file
    SQLiteSchemaFile = "./deploy/db/sqlite_schema.sql"
    // SQLiteDatabaseFile - SQLite database file
    SQLiteDatabaseFile = "console-database.db"
    // DefaultDatabaseProvider is the efault database provider when not specified
    DefaultDatabaseProvider = MYSQL
)

const (
    // UniqueConstraintViolation is the error code for a unique constraint violation
    UniqueConstraintViolation = 23505

    // DefaultConnectionTimeout is the default to timeout on connections
    DefaultConnectionTimeout = 10
)

// NewDatabaseConnectionParametersFromConfig setup database connection parameters based on contents of config struct
func NewDatabaseConnectionParametersFromConfig(dc DatabaseConfig) (DatabaseConfig, error) {

    if len(dc.DatabaseProvider) == 0 {
        dc.DatabaseProvider = DefaultDatabaseProvider
    }

    // set default for connection timeout if necessary
    if dc.ConnectionTimeoutInSecs <= 0 {
        dc.ConnectionTimeoutInSecs = DefaultConnectionTimeout
    }

    // No configuration needed for SQLite
    if dc.DatabaseProvider == SQLITE {
        return dc, nil
    }

    // Database Config validation - check required values and the SSL Mode
    err := validateRequiredDatabaseParams(dc.Username, dc.Password, dc.Database, dc.Host, dc.Port)
    if err != nil {
        return dc, err
    }

    if dc.DatabaseProvider == PGSQL {
        if dc.SSLMode == string(SSLDisabled) || dc.SSLMode == string(SSLRequired) ||
            dc.SSLMode == string(SSLVerifyCA) || dc.SSLMode == string(SSLVerifyFull) {
            return dc, nil
        }
        // Invalid SSL mode
        return dc, fmt.Errorf("Invalid SSL mode: %s", dc.SSLMode)
    } else if dc.DatabaseProvider == MYSQL {
        // Map default of disabled to false for MySQL
        if dc.SSLMode == "disable" {
            dc.SSLMode = "false"
        }
        if dc.SSLMode == "true" || dc.SSLMode == "false" || dc.SSLMode == "skip-verify" || dc.SSLMode == "preferred" {
            return dc, nil
        }
        // Invalid SSL mode
        return dc, fmt.Errorf("Invalid SSL mode: %s", dc.SSLMode)
    }
    return dc, fmt.Errorf("Invalid provider %v", dc)
}

func validateRequiredDatabaseParams(username, password, database, host string, port int) (err error) {
    log.Debug("validateRequiredDatabaseParams")

    err = vala.BeginValidation().Validate(
        vala.IsNotNil(username, "username"),
        vala.IsNotNil(password, "password"),
        vala.IsNotNil(database, "database name"),
        vala.IsNotNil(host, "host/hostname"),
        vala.GreaterThan(port, 0, "port"),
        vala.Not(vala.GreaterThan(port, 65535, "port")),
    ).Check()

    if err != nil {
        return err
    }
    return nil
}

// GetConnection returns a database connection to either MySQL, PostgreSQL or SQLite
func GetConnection(dc DatabaseConfig, env *env.VarSet) (*sql.DB, *goose.DBConf, error) {
    log.Debug("GetConnection")

    // Get a Goose Configuration so that we can pass that to the schema migrator
    conf, err := NewGooseDBConf(dc, env)
    if err != nil {
        return nil, nil, err
    }

    db, err := sql.Open(conf.Driver.Name, conf.Driver.OpenStr)
    return db, conf, err
}

// GetInMemorySQLLiteConnection returns an SQLite DB Connection
func GetInMemorySQLLiteConnection() (*sql.DB, *goose.DBConf, error) {

    databaseFile := "file::memory:?cache=shared"
    log.Info("Using In Memory Database file")
    db, err := sql.Open("sqlite3", databaseFile)
    if err != nil {
        return nil, nil, err
    }

    driver := newDBDriver("sqlite3", databaseFile)
    conf := &goose.DBConf{
        Driver: driver,
    }

    err = ApplyMigrations(conf, db)
    if err != nil {
        return nil, nil, err
    }

    return db, conf, nil
}

// NewGooseDBConf creates a new Goose config for database migrations
func NewGooseDBConf(dc DatabaseConfig, env *env.VarSet) (*goose.DBConf, error) {

    var openStr, name string

    if dc.DatabaseProvider == PGSQL {
        name = "postgres"
        openStr = buildConnectionString(dc)
    } else if dc.DatabaseProvider == MYSQL {
        name = "mysql"
        openStr = buildConnectionStringForMysql(dc)
    } else {
        name = "sqlite3"
        sqlDbDir := env.String("SQLITE_DB_DIR", ".")
        openStr = path.Join(sqlDbDir, SQLiteDatabaseFile)
        sqliteKeepDB := env.MustBool("SQLITE_KEEP_DB")
        log.Infof("SQLite Database file: %s", openStr)

        if !sqliteKeepDB {
            os.Remove(openStr)
        }
    }

    driver := newDBDriver(name, openStr)
    return &goose.DBConf{
        MigrationsDir: ".",
        Env:           fmt.Sprintf("%s_dbenv", name),
        Driver:        driver,
        PgSchema:      "",
    }, nil
}

// Create a new DBDriver and populate driver specific
// fields for drivers that we know about.
func newDBDriver(name, open string) goose.DBDriver {

    d := goose.DBDriver{
        Name:    name,
        OpenStr: open,
    }

    switch name {
    case "postgres":
        d.Import = "github.com/lib/pq"
        d.Dialect = &goose.PostgresDialect{}

    case "mysql":
        d.Import = "github.com/go-sql-driver/mysql"
        d.Dialect = &goose.MySqlDialect{}

    case "sqlite3":
        d.Import = "github.com/mattn/go-sqlite3"
        d.Dialect = &goose.Sqlite3Dialect{}
    }

    return d
}

func buildConnectionString(dc DatabaseConfig) string {
    log.Debug("buildConnectionString")
    escapeStr := func(in string) string {
        return strings.Replace(in, `'`, `\'`, -1)
    }

    connStr := fmt.Sprintf("user='%s' password='%s' dbname='%s' host='%s' port=%d connect_timeout=%d",
        escapeStr(dc.Username),
        escapeStr(dc.Password),
        escapeStr(dc.Database),
        dc.Host,
        dc.Port,
        dc.ConnectionTimeoutInSecs)

    if dc.SSLMode != "" {
        connStr = connStr + fmt.Sprintf(" sslmode='%s'", dc.SSLMode)
    }

    if dc.SSLCertificate != "" {
        connStr = connStr + fmt.Sprintf(" sslcert='%s'", escapeStr(dc.SSLCertificate))
    }

    if dc.SSLKey != "" {
        connStr = connStr + fmt.Sprintf(" sslkey='%s'", escapeStr(dc.SSLKey))
    }

    if dc.SSLRootCertificate != "" {
        connStr = connStr + fmt.Sprintf(" sslrootcert='%s'", escapeStr(dc.SSLRootCertificate))
    }

    log.Printf("DB Connection string: dbname='%s' host='%s' port=%d connect_timeout=%d",
        escapeStr(dc.Database),
        dc.Host,
        dc.Port,
        dc.ConnectionTimeoutInSecs)

    return connStr
}

func buildConnectionStringForMysql(dc DatabaseConfig) string {
    log.Debug("buildConnectionStringForMysql")
    escapeStr := func(in string) string {
        return strings.Replace(in, `'`, `\'`, -1)
    }

    connStr := fmt.Sprintf("%s:%%s@tcp(%s:%d)/%s?parseTime=true",
        escapeStr(dc.Username),
        dc.Host,
        dc.Port,
        escapeStr(dc.Database))

    if len(dc.SSLMode) > 0 {
        log.Infof("Setting SSL Mode for mysql: %s", dc.SSLMode)
        connStr = fmt.Sprintf("%s&tls=%s", connStr, dc.SSLMode)
    }
    log.Infof(connStr, "*********")
    return fmt.Sprintf(connStr, escapeStr(dc.Password))
}

// Ping - ping the database to ensure the connection/pool works.
func Ping(db *sql.DB) error {
    log.Debug("Ping database")
    err := db.Ping()
    if err != nil {
        return fmt.Errorf("Unable to ping the database: %+v", err)
    }

    return nil
}

// ModifySQLStatement - Modify the given DB statement for the specified provider, as appropraite
// e.g Postgres uses $1, $2 etc
// SQLite uses ?
func ModifySQLStatement(sql string, databaseProvider string) string {
    if databaseProvider == SQLITE || databaseProvider == MYSQL {
        sqlParamReplace := regexp.MustCompile("\\$[0-9]+")
        return sqlParamReplace.ReplaceAllString(sql, "?")
    }

    // Default is to return the SQL provided directly
    return sql
}

// WaitForMigrations will wait until all migrations have been applied
func WaitForMigrations(db *sql.DB) error {
    migrations := GetOrderedMigrations()
    targetVersion := migrations[len(migrations)-1]

    // Timeout after which we will give up
    timeout := time.Now().Add(time.Minute * TimeoutBoundary)

    for {
        dbVersionRepo, _ := goosedbversion.NewPostgresGooseDBVersionRepository(db)
        databaseVersionRec, err := dbVersionRepo.GetCurrentVersion()
        if err != nil {
            var errorMsg = err.Error()
            if strings.Contains(err.Error(), "no such table") {
                errorMsg = "Waiting for versions table to be created"
            } else if strings.Contains(err.Error(), "No database versions found") {
                errorMsg = "Versions table is empty - waiting for migrations"
            }
            log.Infof("Database schema check: %s", errorMsg)
        } else if databaseVersionRec.VersionID == targetVersion.Version {
            log.Infof("Database schema is up to date (%d)", databaseVersionRec.VersionID)
            break
        } else {
            log.Info("Waiting for database schema to be initialized")
        }

        // If our timeout boundary has been exceeded, bail out
        if timeout.Sub(time.Now()) < 0 {
            // If we timed out and the last request was a db error, show the error
            if err != nil {
                log.Error(err)
            }
            return fmt.Errorf("Timed out waiting for database schema to be initialized")
        }

        time.Sleep(3 * time.Second)
    }

    return nil
}