command line flags: dashes and underscores synonyms

go/flagutil/flagutil.go

@@ -21,6 +21,7 @@ package flagutil
 import (
 	"errors"
 	"flag"
+	"fmt"
 	"sort"
 	"strings"
 )
@@ -124,3 +125,58 @@ func (value StringMapValue) String() string {
 	sort.Strings(parts)
 	return strings.Join(parts, ",")
 }
+
+// DualFormatStringListVar creates a flag which supports both dashes and underscores
+func DualFormatStringListVar(p *[]string, name string, value []string, usage string) {
+	dashes := strings.Replace(name, "_", "-", -1)
+	underscores := strings.Replace(name, "-", "_", -1)
+
+	StringListVar(p, underscores, value, usage)
+	if dashes != underscores {
+		StringListVar(p, dashes, *p, fmt.Sprintf("Synonym to -%s", underscores))
+	}
+}
+
+// DualFormatStringVar creates a flag which supports both dashes and underscores
+func DualFormatStringVar(p *string, name string, value string, usage string) {
+	dashes := strings.Replace(name, "_", "-", -1)
+	underscores := strings.Replace(name, "-", "_", -1)
+
+	flag.StringVar(p, underscores, value, usage)
+	if dashes != underscores {
+		flag.StringVar(p, dashes, *p, fmt.Sprintf("Synonym to -%s", underscores))
+	}
+}
+
+// DualFormatInt64Var creates a flag which supports both dashes and underscores
+func DualFormatInt64Var(p *int64, name string, value int64, usage string) {
+	dashes := strings.Replace(name, "_", "-", -1)
+	underscores := strings.Replace(name, "-", "_", -1)
+
+	flag.Int64Var(p, underscores, value, usage)
+	if dashes != underscores {
+		flag.Int64Var(p, dashes, *p, fmt.Sprintf("Synonym to -%s", underscores))
+	}
+}
+
+// DualFormatIntVar creates a flag which supports both dashes and underscores
+func DualFormatIntVar(p *int, name string, value int, usage string) {
+	dashes := strings.Replace(name, "_", "-", -1)
+	underscores := strings.Replace(name, "-", "_", -1)
+
+	flag.IntVar(p, underscores, value, usage)
+	if dashes != underscores {
+		flag.IntVar(p, dashes, *p, fmt.Sprintf("Synonym to -%s", underscores))
+	}
+}
+
+// DualFormatBoolVar creates a flag which supports both dashes and underscores
+func DualFormatBoolVar(p *bool, name string, value bool, usage string) {
+	dashes := strings.Replace(name, "_", "-", -1)
+	underscores := strings.Replace(name, "-", "_", -1)
+
+	flag.BoolVar(p, underscores, value, usage)
+	if dashes != underscores {
+		flag.BoolVar(p, dashes, *p, fmt.Sprintf("Synonym to -%s", underscores))
+	}
+}

go/vt/vttablet/tabletserver/tabletenv/config.go

@@ -123,9 +123,9 @@ func init() {
 	flag.BoolVar(&currentConfig.TwoPCEnable, "twopc_enable", defaultConfig.TwoPCEnable, "if the flag is on, 2pc is enabled. Other 2pc flags must be supplied.")
 	flag.StringVar(&currentConfig.TwoPCCoordinatorAddress, "twopc_coordinator_address", defaultConfig.TwoPCCoordinatorAddress, "address of the (VTGate) process(es) that will be used to notify of abandoned transactions.")
 	SecondsVar(&currentConfig.TwoPCAbandonAge, "twopc_abandon_age", defaultConfig.TwoPCAbandonAge, "time in seconds. Any unresolved transaction older than this time will be sent to the coordinator to be resolved.")
-	flag.BoolVar(&currentConfig.EnableTxThrottler, "enable-tx-throttler", defaultConfig.EnableTxThrottler, "If true replication-lag-based throttling on transactions will be enabled.")
-	flag.StringVar(&currentConfig.TxThrottlerConfig, "tx-throttler-config", defaultConfig.TxThrottlerConfig, "The configuration of the transaction throttler as a text formatted throttlerdata.Configuration protocol buffer message")
-	flagutil.StringListVar(&currentConfig.TxThrottlerHealthCheckCells, "tx-throttler-healthcheck-cells", defaultConfig.TxThrottlerHealthCheckCells, "A comma-separated list of cells. Only tabletservers running in these cells will be monitored for replication lag by the transaction throttler.")
+	flagutil.DualFormatBoolVar(&currentConfig.EnableTxThrottler, "enable_tx_throttler", defaultConfig.EnableTxThrottler, "If true replication-lag-based throttling on transactions will be enabled.")
+	flagutil.DualFormatStringVar(&currentConfig.TxThrottlerConfig, "tx_throttler_config", defaultConfig.TxThrottlerConfig, "The configuration of the transaction throttler as a text formatted throttlerdata.Configuration protocol buffer message")
+	flagutil.DualFormatStringListVar(&currentConfig.TxThrottlerHealthCheckCells, "tx_throttler_healthcheck_cells", defaultConfig.TxThrottlerHealthCheckCells, "A comma-separated list of cells. Only tabletservers running in these cells will be monitored for replication lag by the transaction throttler.")
 
 	flag.BoolVar(&enableHotRowProtection, "enable_hot_row_protection", false, "If true, incoming transactions for the same row (range) will be queued and cannot consume all txpool slots.")
 	flag.BoolVar(&enableHotRowProtectionDryRun, "enable_hot_row_protection_dry_run", false, "If true, hot row protection is not enforced but logs if transactions would have been queued.")
@@ -143,12 +143,12 @@ func init() {
 
 	flag.BoolVar(&enableHeartbeat, "heartbeat_enable", false, "If true, vttablet records (if master) or checks (if replica) the current time of a replication heartbeat in the table _vt.heartbeat. The result is used to inform the serving state of the vttablet via healthchecks.")
 	flag.DurationVar(&heartbeatInterval, "heartbeat_interval", 1*time.Second, "How frequently to read and write replication heartbeat.")
-	flag.BoolVar(&currentConfig.EnableLagThrottler, "enable-lag-throttler", defaultConfig.EnableLagThrottler, "If true, vttablet will run a throttler service, and will implicitly enable heartbeats")
+	flagutil.DualFormatBoolVar(&currentConfig.EnableLagThrottler, "enable_lag_throttler", defaultConfig.EnableLagThrottler, "If true, vttablet will run a throttler service, and will implicitly enable heartbeats")
 
 	flag.BoolVar(&currentConfig.EnforceStrictTransTables, "enforce_strict_trans_tables", defaultConfig.EnforceStrictTransTables, "If true, vttablet requires MySQL to run with STRICT_TRANS_TABLES or STRICT_ALL_TABLES on. It is recommended to not turn this flag off. Otherwise MySQL may alter your supplied values before saving them to the database.")
-	flag.BoolVar(&enableConsolidator, "enable-consolidator", true, "This option enables the query consolidator.")
-	flag.BoolVar(&enableConsolidatorReplicas, "enable-consolidator-replicas", false, "This option enables the query consolidator only on replicas.")
-	flag.BoolVar(&currentConfig.CacheResultFields, "enable-query-plan-field-caching", defaultConfig.CacheResultFields, "This option fetches & caches fields (columns) when storing query plans")
+	flagutil.DualFormatBoolVar(&enableConsolidator, "enable_consolidator", true, "This option enables the query consolidator.")
+	flagutil.DualFormatBoolVar(&enableConsolidatorReplicas, "enable_consolidator_replicas", false, "This option enables the query consolidator only on replicas.")
+	flagutil.DualFormatBoolVar(&currentConfig.CacheResultFields, "enable_query_plan_field_caching", defaultConfig.CacheResultFields, "This option fetches & caches fields (columns) when storing query plans")
 
 	flag.DurationVar(&healthCheckInterval, "health_check_interval", 20*time.Second, "Interval between health checks")
 	flag.DurationVar(&degradedThreshold, "degraded_threshold", 30*time.Second, "replication lag after which a replica is considered degraded")