Remove eventing & experimental subsystems

The eventing subsystem was the only pre-release experiment present in
upstream's 1.14.x branch; this wasn't stabilized and more widely used
until later release (1.15.x and the upcoming 1.16.x); and so makes
little sense to keep in its partial form. Additionally, no existing
plugins within this distribution currently emit such events.

By removing eventing, we can also remove the experiments subsystem; this
was only used for enabling the eventing subsystem in this release.

See also: https://developer.hashicorp.com/vault/docs/concepts/events

Signed-off-by: Alexander Scheel <alexander.m.scheel@gmail.com>

command/commands.go

@@ -56,12 +56,6 @@ const (
 	// EnvVaultLogLevel is used to specify the log level applied to logging
 	// Supported log levels: Trace, Debug, Error, Warn, Info
 	EnvVaultLogLevel = "BAO_LOG_LEVEL"
-	// EnvVaultExperiments defines the experiments to enable for a server as a
-	// comma separated list. See experiments.ValidExperiments() for the list of
-	// valid experiments. Not mutable or persisted in storage, only read and
-	// logged at startup _per node_. This was initially introduced for the events
-	// system being developed over multiple release cycles.
-	EnvVaultExperiments = "BAO_EXPERIMENTS"
 
 	// flagNameAddress is the flag used in the base command to read in the
 	// address of the Vault server.
@@ -273,11 +267,6 @@ func initCommands(ui, serverCmdUi cli.Ui, runOpts *RunOptions) map[string]cli.Co
 				BaseCommand: getBaseCommand(),
 			}, nil
 		},
-		"events subscribe": func() (cli.Command, error) {
-			return &EventsSubscribeCommands{
-				BaseCommand: getBaseCommand(),
-			}, nil
-		},
 		"lease": func() (cli.Command, error) {
 			return &LeaseCommand{
 				BaseCommand: getBaseCommand(),

command/server.go

@@ -41,7 +41,6 @@ import (
 	config2 "github.com/openbao/openbao/command/config"
 	"github.com/openbao/openbao/command/server"
 	"github.com/openbao/openbao/helper/builtinplugins"
-	"github.com/openbao/openbao/helper/experiments"
 	loghelper "github.com/openbao/openbao/helper/logging"
 	"github.com/openbao/openbao/helper/metricsutil"
 	"github.com/openbao/openbao/helper/namespace"
@@ -122,7 +121,6 @@ type ServerCommand struct {
 
 	flagConfigs            []string
 	flagRecovery           bool
-	flagExperiments        []string
 	flagDev                bool
 	flagDevTLS             bool
 	flagDevTLSCertDir      string
@@ -212,17 +210,6 @@ func (c *ServerCommand) Flags() *FlagSets {
 			"Using a recovery operation token, \"sys/raw\" API can be used to manipulate the storage.",
 	})
 
-	f.StringSliceVar(&StringSliceVar{
-		Name:       "experiment",
-		Target:     &c.flagExperiments,
-		Completion: complete.PredictSet(experiments.ValidExperiments()...),
-		Usage: "Name of an experiment to enable. Experiments should NOT be used in production, and " +
-			"the associated APIs may have backwards incompatible changes between releases. This " +
-			"flag can be specified multiple times to specify multiple experiments. This can also be " +
-			fmt.Sprintf("specified via the %s environment variable as a comma-separated list. ", EnvVaultExperiments) +
-			"Valid experiments are: " + strings.Join(experiments.ValidExperiments(), ", "),
-	})
-
 	f = set.NewFlagSet("Dev Options")
 
 	f.BoolVar(&BoolVar{
@@ -1128,11 +1115,6 @@ func (c *ServerCommand) Run(args []string) int {
 		}
 	}
 
-	if err := server.ExperimentsFromEnvAndCLI(config, EnvVaultExperiments, c.flagExperiments); err != nil {
-		c.UI.Error(err.Error())
-		return 1
-	}
-
 	// If mlockall(2) isn't supported, show a warning. We disable this in dev
 	// because it is quite scary to see when first using Vault. We also disable
 	// this if the user has explicitly disabled mlock in configuration.
@@ -1203,12 +1185,6 @@ func (c *ServerCommand) Run(args []string) int {
 	info[key] = strings.Join(envVarKeys, ", ")
 	infoKeys = append(infoKeys, key)
 
-	if len(config.Experiments) != 0 {
-		expKey := "experiments"
-		info[expKey] = strings.Join(config.Experiments, ", ")
-		infoKeys = append(infoKeys, expKey)
-	}
-
 	barrierSeal, barrierWrapper, unwrapSeal, seals, sealConfigError, err := setSeal(c, config, infoKeys, info)
 	// Check error here
 	if err != nil {
@@ -2720,7 +2696,6 @@ func createCoreConfig(c *ServerCommand, config *server.Config, backend physical.
 		EnableResponseHeaderHostname:   config.EnableResponseHeaderHostname,
 		EnableResponseHeaderRaftNodeID: config.EnableResponseHeaderRaftNodeID,
 		DisableSSCTokens:               config.DisableSSCTokens,
-		Experiments:                    config.Experiments,
 		AdministrativeNamespacePath:    config.AdministrativeNamespacePath,
 	}