allocrunner: allow option to use real Nomad allocrunner.

internal/config/config.go

@@ -36,10 +36,26 @@ type Config struct {
 	// to allocate 0.8MHz of CPU and 0.7MiB of memory per client instance.
 	NodeNum int `hcl:"node_num,optional"`
 
+	// AllocRunnerType defines what alloc-runner nodesim will build. It
+	// supports either the basic simulated runner included within this
+	// application, or the "real" one pulled directly from Nomad.
+	AllocRunnerType string `hcl:"alloc_runner_type,optional"`
+
 	Log  *Log  `hcl:"log,block"`
 	Node *Node `hcl:"node,block"`
 }
 
+const (
+	// AllocRunnerTypeSim is the simulated alloc runner included within nodesim
+	// under the package allocrunnersim.
+	AllocRunnerTypeSim = "sim"
+
+	// AllocRunnerTypeReal is the alloc runner which is set up from the Nomad
+	// codebase directly. This implements the task runner and hooks for a real
+	// client experience.
+	AllocRunnerTypeReal = "real"
+)
+
 // Node is the configuration object that is used to configure the Nomad clients
 // that are instantiated by simnode. It contains a small subset of parameters
 // which allow for useful configuration to account for environment specific
@@ -64,10 +80,11 @@ type Node struct {
 // merging user supplied data.
 func Default() *Config {
 	return &Config{
-		WorkDir:        fmt.Sprintf("nomad-nodesim-%d", os.Getpid()),
-		NodeNamePrefix: fmt.Sprintf("node-%s", uuid.Short()),
-		ServerAddr:     []string{"127.0.0.1:4647"},
-		NodeNum:        1,
+		WorkDir:         fmt.Sprintf("nomad-nodesim-%d", os.Getpid()),
+		NodeNamePrefix:  fmt.Sprintf("node-%s", uuid.Short()),
+		ServerAddr:      []string{"127.0.0.1:4647"},
+		NodeNum:         1,
+		AllocRunnerType: AllocRunnerTypeSim,
 		Log: &Log{
 			Level:           "debug",
 			JSON:            false,
@@ -102,6 +119,9 @@ func (c *Config) Merge(z *Config) *Config {
 	if z.NodeNum > 0 {
 		result.NodeNum = z.NodeNum
 	}
+	if z.AllocRunnerType != "" {
+		result.AllocRunnerType = z.AllocRunnerType
+	}
 	if z.Log != nil {
 		result.Log = c.Log.merge(z.Log)
 	}

main.go

@@ -21,6 +21,7 @@ import (
 	"github.com/hashicorp-forge/nomad-nodesim/simnode"
 	"github.com/hashicorp/go-hclog"
 	"github.com/hashicorp/nomad/client"
+	"github.com/hashicorp/nomad/client/allocrunner"
 	"github.com/hashicorp/nomad/client/config"
 	"github.com/hashicorp/nomad/client/consul"
 	"github.com/hashicorp/nomad/client/state"
@@ -44,6 +45,7 @@ func main() {
 	flag.Var(&flagConfig.ServerAddr, "server-addr", "address of server's rpc port; can be specified multiple times")
 	flag.StringVar(&flagConfig.NodeNamePrefix, "node-name-prefix", "", "nodes will be named [prefix]-[i]")
 	flag.IntVar(&flagConfig.NodeNum, "node-num", 0, "number of client nodes")
+	flag.StringVar(&flagConfig.AllocRunnerType, "alloc-runner-type", "", "the type of Nomad client alloc runner to use")
 
 	// The CLI flags for the HCL Logger.
 	flag.StringVar(&flagConfig.Log.Level, "log-level", "", "the verbosity level of logs")
@@ -281,7 +283,7 @@ func startClient(logger hclog.Logger, buildInfo *internalSimnode.BuildInfo, cfg
 	clientCfg.DisableRemoteExec = true
 	clientCfg.RPCHoldTimeout = 5 * time.Second
 
-	pluginLoader := pluginsim.New(clientCfg.Logger, "loader")
+	pluginLoader := pluginsim.New(clientCfg.Logger)
 	clientCfg.PluginLoader = pluginLoader
 	clientCfg.PluginSingletonLoader = singleton.NewSingletonLoader(clientCfg.Logger, pluginLoader)
 
@@ -296,8 +298,25 @@ func startClient(logger hclog.Logger, buildInfo *internalSimnode.BuildInfo, cfg
 		S3Timeout:       5 * time.Second,
 	}
 
+	// This config parameter is used by the taskrunner API hook. The hook will
+	// panic when triggered if this is not set.
+	clientCfg.APIListenerRegistrar = config.NoopAPIListenerRegistrar{}
+
 	clientCfg.Node.Canonicalize()
-	clientCfg.AllocRunnerFactory = allocrunnersim.NewEmptyAllocRunnerFunc
+
+	// Build the allocation runner factory based on whether we want the
+	// simulated (light) or real version.
+	var allocRunnerFactory config.AllocRunnerFactory
+	switch cfg.AllocRunnerType {
+	case internalConfig.AllocRunnerTypeSim:
+		allocRunnerFactory = allocrunnersim.NewEmptyAllocRunnerFunc
+	case internalConfig.AllocRunnerTypeReal:
+		allocRunnerFactory = allocrunner.NewAllocRunner
+	default:
+		return nil, fmt.Errorf("unsupported alloc-runner type: %s", cfg.AllocRunnerType)
+	}
+
+	clientCfg.AllocRunnerFactory = allocRunnerFactory
 
 	// Consul support is disabled
 	capi := simconsul.NoopCatalogAPI{}

pluginsim/pluginsim.go

@@ -12,7 +12,7 @@ import (
 	"github.com/hashicorp/nomad/helper/pluginutils/loader"
 )
 
-func New(logger hclog.Logger, name string) *loader.PluginLoader {
+func New(logger hclog.Logger) *loader.PluginLoader {
 
 	loader, err := setupPluginLoader(logger)
 	if err != nil {