feat(eventstore): increase parallel write capabilities (#5940)

This implementation increases parallel write capabilities of the eventstore.
Please have a look at the technical advisories: [05](https://zitadel.com/docs/support/advisory/a10005) and  [06](https://zitadel.com/docs/support/advisory/a10006).
The implementation of eventstore.push is rewritten and stored events are migrated to a new table `eventstore.events2`.
If you are using cockroach: make sure that the database user of ZITADEL has `VIEWACTIVITY` grant. This is used to query events.

internal/database/cockroach/crdb.go

@@ -1,6 +1,15 @@
 package cockroach
 
 import (
+	"database/sql"
+	"strconv"
+	"strings"
+	"time"
+
+	_ "github.com/jackc/pgx/v4/stdlib"
+	"github.com/mitchellh/mapstructure"
+	"github.com/zitadel/logging"
+
 	"github.com/zitadel/zitadel/internal/database/dialect"
 )
 
@@ -8,3 +17,173 @@ func init() {
 	config := &Config{}
 	dialect.Register(config, config, true)
 }
+
+const (
+	sslDisabledMode = "disable"
+	sslRequireMode  = "require"
+	sslAllowMode    = "allow"
+	sslPreferMode   = "prefer"
+)
+
+type Config struct {
+	Host            string
+	Port            uint16
+	Database        string
+	MaxOpenConns    uint32
+	MaxIdleConns    uint32
+	MaxConnLifetime time.Duration
+	MaxConnIdleTime time.Duration
+	User            User
+	Admin           User
+	// Additional options to be appended as options=<Options>
+	// The value will be taken as is. Multiple options are space separated.
+	Options string
+}
+
+func (c *Config) MatchName(name string) bool {
+	for _, key := range []string{"crdb", "cockroach"} {
+		if strings.TrimSpace(strings.ToLower(name)) == key {
+			return true
+		}
+	}
+	return false
+}
+
+func (c *Config) Decode(configs []interface{}) (dialect.Connector, error) {
+	decoder, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
+		DecodeHook:       mapstructure.StringToTimeDurationHookFunc(),
+		WeaklyTypedInput: true,
+		Result:           c,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	for _, config := range configs {
+		if err = decoder.Decode(config); err != nil {
+			return nil, err
+		}
+	}
+
+	return c, nil
+}
+
+func (c *Config) Connect(useAdmin, isEventPusher bool, pusherRatio float32, appName string) (*sql.DB, error) {
+	client, err := sql.Open("pgx", c.String(useAdmin, appName))
+	if err != nil {
+		return nil, err
+	}
+
+	connInfo, err := dialect.NewConnectionInfo(c.MaxOpenConns, c.MaxIdleConns, float64(pusherRatio))
+	if err != nil {
+		return nil, err
+	}
+
+	var maxConns, maxIdleConns uint32
+	if isEventPusher {
+		maxConns = connInfo.EventstorePusher.MaxOpenConns
+		maxIdleConns = connInfo.EventstorePusher.MaxIdleConns
+	} else {
+		maxConns = connInfo.ZITADEL.MaxOpenConns
+		maxIdleConns = connInfo.ZITADEL.MaxIdleConns
+	}
+
+	client.SetMaxOpenConns(int(maxConns))
+	client.SetMaxIdleConns(int(maxIdleConns))
+	client.SetConnMaxLifetime(c.MaxConnLifetime)
+	client.SetConnMaxIdleTime(c.MaxConnIdleTime)
+
+	return client, nil
+}
+
+func (c *Config) DatabaseName() string {
+	return c.Database
+}
+
+func (c *Config) Username() string {
+	return c.User.Username
+}
+
+func (c *Config) Password() string {
+	return c.User.Password
+}
+
+func (c *Config) Type() string {
+	return "cockroach"
+}
+
+func (c *Config) Timetravel(d time.Duration) string {
+	return ""
+}
+
+type User struct {
+	Username string
+	Password string
+	SSL      SSL
+}
+
+type SSL struct {
+	// type of connection security
+	Mode string
+	// RootCert Path to the CA certificate
+	RootCert string
+	// Cert Path to the client certificate
+	Cert string
+	// Key Path to the client private key
+	Key string
+}
+
+func (c *Config) checkSSL(user User) {
+	if user.SSL.Mode == sslDisabledMode || user.SSL.Mode == "" {
+		user.SSL = SSL{Mode: sslDisabledMode}
+		return
+	}
+
+	if user.SSL.Mode == sslRequireMode || user.SSL.Mode == sslAllowMode || user.SSL.Mode == sslPreferMode {
+		return
+	}
+
+	if user.SSL.RootCert == "" {
+		logging.WithFields(
+			"cert set", user.SSL.Cert != "",
+			"key set", user.SSL.Key != "",
+			"rootCert set", user.SSL.RootCert != "",
+		).Fatal("at least ssl root cert has to be set")
+	}
+}
+
+func (c Config) String(useAdmin bool, appName string) string {
+	user := c.User
+	if useAdmin {
+		user = c.Admin
+	}
+	c.checkSSL(user)
+	fields := []string{
+		"host=" + c.Host,
+		"port=" + strconv.Itoa(int(c.Port)),
+		"user=" + user.Username,
+		"dbname=" + c.Database,
+		"application_name=" + appName,
+		"sslmode=" + user.SSL.Mode,
+	}
+	if c.Options != "" {
+		fields = append(fields, "options="+c.Options)
+	}
+	if !useAdmin {
+		fields = append(fields, "dbname="+c.Database)
+	}
+	if user.Password != "" {
+		fields = append(fields, "password="+user.Password)
+	}
+	if user.SSL.Mode != sslDisabledMode {
+		fields = append(fields, "sslrootcert="+user.SSL.RootCert)
+		if user.SSL.Cert != "" {
+			fields = append(fields, "sslcert="+user.SSL.Cert)
+		}
+		if user.SSL.Key != "" {
+			fields = append(fields, "sslkey="+user.SSL.Key)
+		}
+	}
+
+	return strings.Join(fields, " ")
+}