agent: extract dependency creation from New

With this change, Agent.New() accepts many of the dependencies instead
of creating them in New. Accepting fully constructed dependencies from
a constructor makes the type easier to test, and easier to change.

There are still a number of dependencies created in Start() which can
be addressed in a follow up.

agent/acl.go

@@ -59,7 +59,7 @@ func (a *Agent) aclAccessorID(secretID string) string {
 	return ident.ID()
 }
 
-func (a *Agent) initializeACLs() error {
+func initializeACLs(nodeName string) (acl.Authorizer, error) {
 	// Build a policy for the agent master token.
 	// The builtin agent master policy allows reading any node information
 	// and allows writes to the agent with the node name of the running agent
@@ -69,7 +69,7 @@ func (a *Agent) initializeACLs() error {
 		PolicyRules: acl.PolicyRules{
 			Agents: []*acl.AgentRule{
 				{
-					Node:   a.config.NodeName,
+					Node:   nodeName,
 					Policy: acl.PolicyWrite,
 				},
 			},
@@ -81,12 +81,7 @@ func (a *Agent) initializeACLs() error {
 			},
 		},
 	}
-	master, err := acl.NewPolicyAuthorizerWithDefaults(acl.DenyAll(), []*acl.Policy{policy}, nil)
+	return acl.NewPolicyAuthorizerWithDefaults(acl.DenyAll(), []*acl.Policy{policy}, nil)
-	if err != nil {
-		return err
-	}
-	a.aclMasterAuthorizer = master
-	return nil
 }
 
 // vetServiceRegister makes sure the service registration action is allowed by

agent/acl_test.go

@@ -35,37 +35,38 @@ type TestACLAgent struct {
 // Basically it needs a local state for some of the vet* functions, a logger and a delegate.
 // The key is that we are the delegate so we can control the ResolveToken responses
 func NewTestACLAgent(t *testing.T, name string, hcl string, resolveAuthz authzResolver, resolveIdent identResolver) *TestACLAgent {
+	t.Helper()
+
 	a := &TestACLAgent{resolveAuthzFn: resolveAuthz, resolveIdentFn: resolveIdent}
 
 	dataDir := testutil.TempDir(t, "acl-agent")
-	logger := hclog.NewInterceptLogger(&hclog.LoggerOptions{
-		Name:   name,
-		Level:  hclog.Debug,
-		Output: testutil.NewLogBuffer(t),
-	})
 
-	opts := []AgentOption{
+	logBuffer := testutil.NewLogBuffer(t)
-		WithLogger(logger),
+	loader := func(source config.Source) (cfg *config.RuntimeConfig, warnings []string, err error) {
-		WithBuilderOpts(config.BuilderOpts{
+		dataDir := fmt.Sprintf(`data_dir = "%s"`, dataDir)
-			HCL: []string{
+		opts := config.BuilderOpts{
-				TestConfigHCL(NodeID()),
+			HCL: []string{TestConfigHCL(NodeID()), hcl, dataDir},
-				hcl,
+		}
-				fmt.Sprintf(`data_dir = "%s"`, dataDir),
+		return config.Load(opts, source)
-			},
-		}),
 	}
-
+	bd, err := NewBaseDeps(loader, logBuffer)
-	agent, err := New(opts...)
 	require.NoError(t, err)
-	cfg := agent.GetConfig()
+
+	bd.Logger = hclog.NewInterceptLogger(&hclog.LoggerOptions{
+		Name:       name,
+		Level:      hclog.Debug,
+		Output:     logBuffer,
+		TimeFormat: "04:05.000",
+	})
+	bd.TelemetrySink = metrics.NewInmemSink(1*time.Second, time.Minute)
+
+	agent, err := New(bd)
+	require.NoError(t, err)
+
+	agent.delegate = a
+	agent.State = local.NewState(LocalConfig(bd.RuntimeConfig), bd.Logger, bd.Tokens)
+	agent.State.TriggerSyncChanges = func() {}
 	a.Agent = agent
-
-	agent.logger = logger
-	agent.MemSink = metrics.NewInmemSink(1*time.Second, time.Minute)
-
-	a.Agent.delegate = a
-	a.Agent.State = local.NewState(LocalConfig(cfg), logger, a.Agent.tokens)
-	a.Agent.State.TriggerSyncChanges = func() {}
 	return a
 }
 

agent/agent.go

@@ -21,7 +21,6 @@ import (
 	"github.com/hashicorp/go-connlimit"
 	"github.com/hashicorp/go-hclog"
 	"github.com/hashicorp/go-memdb"
-	"github.com/mitchellh/cli"
 
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/grpclog"
@@ -312,85 +311,6 @@ type Agent struct {
 	enterpriseAgent
 }
 
-type agentOptions struct {
-	logger        hclog.InterceptLogger
-	builderOpts   config.BuilderOpts
-	ui            cli.Ui
-	config        *config.RuntimeConfig
-	overrides     []config.Source
-	writers       []io.Writer
-	initTelemetry bool
-}
-
-type AgentOption func(opt *agentOptions)
-
-// WithTelemetry is used to control whether the agent will
-// set up metrics.
-func WithTelemetry(initTelemetry bool) AgentOption {
-	return func(opt *agentOptions) {
-		opt.initTelemetry = initTelemetry
-	}
-}
-
-// WithLogger is used to override any automatic logger creation
-// and provide one already built instead. This is mostly useful
-// for testing.
-func WithLogger(logger hclog.InterceptLogger) AgentOption {
-	return func(opt *agentOptions) {
-		opt.logger = logger
-	}
-}
-
-// WithBuilderOpts specifies the command line config.BuilderOpts to use that the agent
-// is being started with
-func WithBuilderOpts(builderOpts config.BuilderOpts) AgentOption {
-	return func(opt *agentOptions) {
-		opt.builderOpts = builderOpts
-	}
-}
-
-// WithCLI provides a cli.Ui instance to use when emitting configuration
-// warnings during the first configuration parsing.
-func WithCLI(ui cli.Ui) AgentOption {
-	return func(opt *agentOptions) {
-		opt.ui = ui
-	}
-}
-
-// WithLogWriter will add an additional log output to the logger that gets
-// configured after configuration parsing
-func WithLogWriter(writer io.Writer) AgentOption {
-	return func(opt *agentOptions) {
-		opt.writers = append(opt.writers, writer)
-	}
-}
-
-// WithOverrides is used to provide a config source to append to the tail sources
-// during config building. It is really only useful for testing to tune non-user
-// configurable tunables to make various tests converge more quickly than they
-// could otherwise.
-func WithOverrides(overrides ...config.Source) AgentOption {
-	return func(opt *agentOptions) {
-		opt.overrides = overrides
-	}
-}
-
-// WithConfig provides an already parsed configuration to the Agent
-// Deprecated: Should allow the agent to parse the configuration.
-func WithConfig(config *config.RuntimeConfig) AgentOption {
-	return func(opt *agentOptions) {
-		opt.config = config
-	}
-}
-
-func flattenAgentOptions(options []AgentOption) agentOptions {
-	var flat agentOptions
-	for _, opt := range options {
-		opt(&flat)
-	}
-	return flat
-}
-
 // New process the desired options and creates a new Agent.
 // This process will
 //   * parse the config given the config Flags
@@ -406,10 +326,7 @@ func flattenAgentOptions(options []AgentOption) agentOptions {
 //   * setup the NodeID if one isn't provided in the configuration
 //   * create the AutoConfig object for future use in fully
 //     resolving the configuration
-func New(options ...AgentOption) (*Agent, error) {
+func New(bd BaseDeps) (*Agent, error) {
-	flat := flattenAgentOptions(options)
-
-	// Create most of the agent
 	a := Agent{
 		checkReapAfter:  make(map[structs.CheckID]time.Duration),
 		checkMonitors:   make(map[structs.CheckID]*checks.CheckMonitor),
@@ -425,94 +342,28 @@ func New(options ...AgentOption) (*Agent, error) {
 		retryJoinCh:     make(chan error),
 		shutdownCh:      make(chan struct{}),
 		endpoints:       make(map[string]string),
-		tokens:          new(token.Store),
+
-		logger:          flat.logger,
+		// TODO: store the BaseDeps instead of copying them over to Agent
+		tokens:          bd.Tokens,
+		logger:          bd.Logger,
+		tlsConfigurator: bd.TLSConfigurator,
+		config:          bd.RuntimeConfig,
+		cache:           bd.Cache,
+		MemSink:         bd.TelemetrySink,
+		connPool:        bd.ConnPool,
+		autoConf:        bd.AutoConfig,
 	}
 
-	// parse the configuration and handle the error/warnings
+	// TODO: set globals somewhere else, not Agent.New
-	cfg, warnings, err := config.Load(flat.builderOpts, nil, flat.overrides...)
+	grpclog.SetLoggerV2(logging.NewGRPCLogger(bd.RuntimeConfig.LogLevel, bd.Logger))
-	if err != nil {
-		return nil, err
-	}
-	for _, w := range warnings {
-		if a.logger != nil {
-			a.logger.Warn(w)
-		} else if flat.ui != nil {
-			flat.ui.Warn(w)
-		} else {
-			fmt.Fprint(os.Stderr, w)
-		}
-	}
-
-	// set the config in the agent, this is just the preliminary configuration as we haven't
-	// loaded any auto-config sources yet.
-	a.config = cfg
-
-	// create the cache using the rate limiting settings from the config. Note that this means
-	// that these limits are not reloadable.
-	a.cache = cache.New(a.config.Cache)
-
-	if flat.logger == nil {
-		logConf := &logging.Config{
-			LogLevel:          cfg.LogLevel,
-			LogJSON:           cfg.LogJSON,
-			Name:              logging.Agent,
-			EnableSyslog:      cfg.EnableSyslog,
-			SyslogFacility:    cfg.SyslogFacility,
-			LogFilePath:       cfg.LogFile,
-			LogRotateDuration: cfg.LogRotateDuration,
-			LogRotateBytes:    cfg.LogRotateBytes,
-			LogRotateMaxFiles: cfg.LogRotateMaxFiles,
-		}
-
-		a.logger, err = logging.Setup(logConf, flat.writers)
-		if err != nil {
-			return nil, err
-		}
-
-		grpclog.SetLoggerV2(logging.NewGRPCLogger(logConf, a.logger))
-	}
-
-	if flat.initTelemetry {
-		memSink, err := lib.InitTelemetry(cfg.Telemetry)
-		if err != nil {
-			return nil, fmt.Errorf("Failed to initialize telemetry: %w", err)
-		}
-		a.MemSink = memSink
-	}
-
-	// TODO (autoconf) figure out how to let this setting be pushed down via autoconf
-	// right now it gets defaulted if unset so this check actually doesn't do much
-	// for a normal running agent.
-	if a.config.Datacenter == "" {
-		return nil, fmt.Errorf("Must configure a Datacenter")
-	}
-	if a.config.DataDir == "" && !a.config.DevMode {
-		return nil, fmt.Errorf("Must configure a DataDir")
-	}
-
-	tlsConfigurator, err := tlsutil.NewConfigurator(a.config.ToTLSUtilConfig(), a.logger)
-	if err != nil {
-		return nil, err
-	}
-	a.tlsConfigurator = tlsConfigurator
-
-	err = a.initializeConnectionPool()
-	if err != nil {
-		return nil, fmt.Errorf("Failed to initialize the connection pool: %w", err)
-	}
 
 	a.serviceManager = NewServiceManager(&a)
 
-	if err := a.initializeACLs(); err != nil {
+	// TODO: do this somewhere else, maybe move to newBaseDeps
-		return nil, err
+	var err error
-	}
+	a.aclMasterAuthorizer, err = initializeACLs(bd.RuntimeConfig.NodeName)
-
-	// Retrieve or generate the node ID before setting up the rest of the
-	// agent, which depends on it.
-	cfg.NodeID, err = newNodeIDFromConfig(a.config, a.logger)
 	if err != nil {
-		return nil, fmt.Errorf("failed to setup node ID: %w", err)
+		return nil, err
 	}
 
 	// We used to do this in the Start method. However it doesn't need to go
@@ -521,48 +372,9 @@ func New(options ...AgentOption) (*Agent, error) {
 	// pass the agent itself so its safe to move here.
 	a.registerCache()
 
-	cmConf := new(certmon.Config).
-		WithCache(a.cache).
-		WithTLSConfigurator(a.tlsConfigurator).
-		WithDNSSANs(a.config.AutoConfig.DNSSANs).
-		WithIPSANs(a.config.AutoConfig.IPSANs).
-		WithDatacenter(a.config.Datacenter).
-		WithNodeName(a.config.NodeName).
-		WithFallback(a.autoConfigFallbackTLS).
-		WithLogger(a.logger.Named(logging.AutoConfig)).
-		WithTokens(a.tokens).
-		WithPersistence(a.autoConfigPersist)
-	acCertMon, err := certmon.New(cmConf)
-	if err != nil {
-		return nil, err
-	}
-
-	acConf := autoconf.Config{
-		DirectRPC:   a.connPool,
-		Logger:      a.logger,
-		CertMonitor: acCertMon,
-		Loader: func(source config.Source) (*config.RuntimeConfig, []string, error) {
-			return config.Load(flat.builderOpts, source, flat.overrides...)
-		},
-	}
-	ac, err := autoconf.New(acConf)
-	if err != nil {
-		return nil, err
-	}
-
-	a.autoConf = ac
-
 	return &a, nil
 }
 
-// GetLogger retrieves the agents logger
-// TODO make export the logger field and get rid of this method
-// This is here for now to simplify the work I am doing and make
-// reviewing the final PR easier.
-func (a *Agent) GetLogger() hclog.InterceptLogger {
-	return a.logger
-}
-
 // GetConfig retrieves the agents config
 // TODO make export the config field and get rid of this method
 // This is here for now to simplify the work I am doing and make
@@ -573,31 +385,6 @@ func (a *Agent) GetConfig() *config.RuntimeConfig {
 	return a.config
 }
 
-func (a *Agent) initializeConnectionPool() error {
-	var rpcSrcAddr *net.TCPAddr
-	if !ipaddr.IsAny(a.config.RPCBindAddr) {
-		rpcSrcAddr = &net.TCPAddr{IP: a.config.RPCBindAddr.IP}
-	}
-
-	pool := &pool.ConnPool{
-		Server:          a.config.ServerMode,
-		SrcAddr:         rpcSrcAddr,
-		Logger:          a.logger.StandardLogger(&hclog.StandardLoggerOptions{InferLevels: true}),
-		TLSConfigurator: a.tlsConfigurator,
-		Datacenter:      a.config.Datacenter,
-	}
-	if a.config.ServerMode {
-		pool.MaxTime = 2 * time.Minute
-		pool.MaxStreams = 64
-	} else {
-		pool.MaxTime = 127 * time.Second
-		pool.MaxStreams = 32
-	}
-
-	a.connPool = pool
-	return nil
-}
-
 // LocalConfig takes a config.RuntimeConfig and maps the fields to a local.Config
 func LocalConfig(cfg *config.RuntimeConfig) local.Config {
 	lc := local.Config{
@@ -638,8 +425,8 @@ func (a *Agent) Start(ctx context.Context) error {
 		return fmt.Errorf("Failed to load TLS configurations after applying auto-config settings: %w", err)
 	}
 
-	// load the tokens - this requires the logger to be setup
+	// TODO: move to newBaseDeps
-	// which is why we can't do this in New
+	// TODO: handle error
 	a.loadTokens(a.config)
 	a.loadEnterpriseTokens(a.config)
 
@@ -858,20 +645,6 @@ func (a *Agent) autoEncryptInitialCertificate(ctx context.Context) (*structs.Sig
 	return client.RequestAutoEncryptCerts(ctx, addrs, a.config.ServerPort, a.tokens.AgentToken(), a.config.AutoEncryptDNSSAN, a.config.AutoEncryptIPSAN)
 }
 
-func (a *Agent) autoConfigFallbackTLS(ctx context.Context) (*structs.SignedResponse, error) {
-	if a.autoConf == nil {
-		return nil, fmt.Errorf("AutoConfig manager has not been created yet")
-	}
-	return a.autoConf.FallbackTLS(ctx)
-}
-
-func (a *Agent) autoConfigPersist(resp *structs.SignedResponse) error {
-	if a.autoConf == nil {
-		return fmt.Errorf("AutoConfig manager has not been created yet")
-	}
-	return a.autoConf.RecordUpdatedCerts(resp)
-}
-
 func (a *Agent) listenAndServeGRPC() error {
 	if len(a.config.GRPCAddrs) < 1 {
 		return nil

agent/config/builder.go

@@ -35,11 +35,11 @@ import (
 	"golang.org/x/time/rate"
 )
 
-// LoadConfig will build the configuration including the extraHead source injected
+// Load will build the configuration including the extraHead source injected
 // after all other defaults but before any user supplied configuration and the overrides
 // source injected as the final source in the configuration parsing chain.
-func Load(builderOpts BuilderOpts, extraHead Source, overrides ...Source) (*RuntimeConfig, []string, error) {
+func Load(opts BuilderOpts, extraHead Source, overrides ...Source) (*RuntimeConfig, []string, error) {
-	b, err := NewBuilder(builderOpts)
+	b, err := NewBuilder(opts)
 	if err != nil {
 		return nil, nil, err
 	}

agent/setup.go

@@ -0,0 +1,163 @@
+package agent
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net"
+	"time"
+
+	"github.com/armon/go-metrics"
+	autoconf "github.com/hashicorp/consul/agent/auto-config"
+	"github.com/hashicorp/consul/agent/cache"
+	certmon "github.com/hashicorp/consul/agent/cert-monitor"
+	"github.com/hashicorp/consul/agent/config"
+	"github.com/hashicorp/consul/agent/pool"
+	"github.com/hashicorp/consul/agent/structs"
+	"github.com/hashicorp/consul/agent/token"
+	"github.com/hashicorp/consul/ipaddr"
+	"github.com/hashicorp/consul/lib"
+	"github.com/hashicorp/consul/logging"
+	"github.com/hashicorp/consul/tlsutil"
+	"github.com/hashicorp/go-hclog"
+)
+
+// TODO: BaseDeps should be renamed in the future once more of Agent.Start
+// has been moved out in front of Agent.New, and we can better see the setup
+// dependencies.
+type BaseDeps struct {
+	Logger          hclog.InterceptLogger
+	TLSConfigurator *tlsutil.Configurator // TODO: use an interface
+	TelemetrySink   *metrics.InmemSink    // TODO: use an interface
+	RuntimeConfig   *config.RuntimeConfig
+	Tokens          *token.Store
+	Cache           *cache.Cache
+	AutoConfig      *autoconf.AutoConfig // TODO: use an interface
+	ConnPool        *pool.ConnPool       // TODO: use an interface
+}
+
+type ConfigLoader func(source config.Source) (cfg *config.RuntimeConfig, warnings []string, err error)
+
+func NewBaseDeps(configLoader ConfigLoader, logOut io.Writer) (BaseDeps, error) {
+	d := BaseDeps{}
+	cfg, warnings, err := configLoader(nil)
+	if err != nil {
+		return d, err
+	}
+
+	// TODO: use logging.Config in RuntimeConfig instead of separate fields
+	logConf := &logging.Config{
+		LogLevel:          cfg.LogLevel,
+		LogJSON:           cfg.LogJSON,
+		Name:              logging.Agent,
+		EnableSyslog:      cfg.EnableSyslog,
+		SyslogFacility:    cfg.SyslogFacility,
+		LogFilePath:       cfg.LogFile,
+		LogRotateDuration: cfg.LogRotateDuration,
+		LogRotateBytes:    cfg.LogRotateBytes,
+		LogRotateMaxFiles: cfg.LogRotateMaxFiles,
+	}
+	d.Logger, err = logging.Setup(logConf, []io.Writer{logOut})
+	if err != nil {
+		return d, err
+	}
+
+	for _, w := range warnings {
+		d.Logger.Warn(w)
+	}
+
+	cfg.NodeID, err = newNodeIDFromConfig(cfg, d.Logger)
+	if err != nil {
+		return d, fmt.Errorf("failed to setup node ID: %w", err)
+	}
+
+	d.TelemetrySink, err = lib.InitTelemetry(cfg.Telemetry)
+	if err != nil {
+		return d, fmt.Errorf("failed to initialize telemetry: %w", err)
+	}
+
+	d.TLSConfigurator, err = tlsutil.NewConfigurator(cfg.ToTLSUtilConfig(), d.Logger)
+	if err != nil {
+		return d, err
+	}
+
+	d.RuntimeConfig = cfg
+	d.Tokens = new(token.Store)
+	// cache-types are not registered yet, but they won't be used until the components are started.
+	d.Cache = cache.New(cfg.Cache)
+	d.ConnPool = newConnPool(cfg, d.Logger, d.TLSConfigurator)
+
+	deferredAC := &deferredAutoConfig{}
+
+	cmConf := new(certmon.Config).
+		WithCache(d.Cache).
+		WithTLSConfigurator(d.TLSConfigurator).
+		WithDNSSANs(cfg.AutoConfig.DNSSANs).
+		WithIPSANs(cfg.AutoConfig.IPSANs).
+		WithDatacenter(cfg.Datacenter).
+		WithNodeName(cfg.NodeName).
+		WithFallback(deferredAC.autoConfigFallbackTLS).
+		WithLogger(d.Logger.Named(logging.AutoConfig)).
+		WithTokens(d.Tokens).
+		WithPersistence(deferredAC.autoConfigPersist)
+	acCertMon, err := certmon.New(cmConf)
+	if err != nil {
+		return d, err
+	}
+
+	acConf := autoconf.Config{
+		DirectRPC:   d.ConnPool,
+		Logger:      d.Logger,
+		CertMonitor: acCertMon,
+		Loader:      configLoader,
+	}
+	d.AutoConfig, err = autoconf.New(acConf)
+	if err != nil {
+		return d, err
+	}
+	// TODO: can this cyclic dependency be un-cycled?
+	deferredAC.autoConf = d.AutoConfig
+
+	return d, nil
+}
+
+func newConnPool(config *config.RuntimeConfig, logger hclog.Logger, tls *tlsutil.Configurator) *pool.ConnPool {
+	var rpcSrcAddr *net.TCPAddr
+	if !ipaddr.IsAny(config.RPCBindAddr) {
+		rpcSrcAddr = &net.TCPAddr{IP: config.RPCBindAddr.IP}
+	}
+
+	pool := &pool.ConnPool{
+		Server:          config.ServerMode,
+		SrcAddr:         rpcSrcAddr,
+		Logger:          logger.StandardLogger(&hclog.StandardLoggerOptions{InferLevels: true}),
+		TLSConfigurator: tls,
+		Datacenter:      config.Datacenter,
+	}
+	if config.ServerMode {
+		pool.MaxTime = 2 * time.Minute
+		pool.MaxStreams = 64
+	} else {
+		pool.MaxTime = 127 * time.Second
+		pool.MaxStreams = 32
+	}
+	return pool
+}
+
+type deferredAutoConfig struct {
+	autoConf *autoconf.AutoConfig // TODO: use an interface
+}
+
+func (a *deferredAutoConfig) autoConfigFallbackTLS(ctx context.Context) (*structs.SignedResponse, error) {
+	if a.autoConf == nil {
+		return nil, fmt.Errorf("AutoConfig manager has not been created yet")
+	}
+	return a.autoConf.FallbackTLS(ctx)
+}
+
+func (a *deferredAutoConfig) autoConfigPersist(resp *structs.SignedResponse) error {
+	if a.autoConf == nil {
+		return fmt.Errorf("AutoConfig manager has not been created yet")
+	}
+	return a.autoConf.RecordUpdatedCerts(resp)
+}

agent/testagent.go

@@ -21,6 +21,7 @@ import (
 	"github.com/hashicorp/errwrap"
 	"github.com/hashicorp/go-hclog"
 	uuid "github.com/hashicorp/go-uuid"
+	"github.com/stretchr/testify/require"
 
 	"github.com/hashicorp/consul/acl"
 	"github.com/hashicorp/consul/agent/config"
@@ -167,38 +168,35 @@ func (a *TestAgent) Start(t *testing.T) (err error) {
 	portsConfig, returnPortsFn := randomPortsSource(a.UseTLS)
 	t.Cleanup(returnPortsFn)
 
-	nodeID := NodeID()
+	// Create NodeID outside the closure, so that it does not change
-
+	testHCLConfig := TestConfigHCL(NodeID())
-	opts := []AgentOption{
+	loader := func(source config.Source) (cfg *config.RuntimeConfig, warnings []string, err error) {
-		WithLogger(logger),
+		opts := config.BuilderOpts{
-		WithBuilderOpts(config.BuilderOpts{
+			HCL: []string{testHCLConfig, portsConfig, a.HCL, hclDataDir},
-			HCL: []string{
+		}
-				TestConfigHCL(nodeID),
+		overrides := []config.Source{
-				portsConfig,
+			config.FileSource{
-				a.HCL,
+				Name:   "test-overrides",
-				hclDataDir,
+				Format: "hcl",
-			},
+				Data:   a.Overrides},
-		}),
-		WithOverrides(config.FileSource{
-			Name:   "test-overrides",
-			Format: "hcl",
-			Data:   a.Overrides},
 			config.DefaultConsulSource(),
 			config.DevConsulSource(),
-		),
+		}
+		return config.Load(opts, source, overrides...)
 	}
+	bd, err := NewBaseDeps(loader, logOutput)
+	require.NoError(t, err)
 
-	agent, err := New(opts...)
+	bd.Logger = logger
+	bd.TelemetrySink = metrics.NewInmemSink(1*time.Second, time.Minute)
+	a.Config = bd.RuntimeConfig
+
+	agent, err := New(bd)
 	if err != nil {
 		return fmt.Errorf("Error creating agent: %s", err)
 	}
 
-	a.Config = agent.GetConfig()
-
-	agent.MemSink = metrics.NewInmemSink(1*time.Second, time.Minute)
-
 	id := string(a.Config.NodeID)
-
 	if err := agent.Start(context.Background()); err != nil {
 		agent.ShutdownAgent()
 		agent.ShutdownEndpoints()

command/agent/agent.go

@@ -60,11 +60,6 @@ type cmd struct {
 	logger            hclog.InterceptLogger
 }
 
-type GatedUi struct {
-	JSONoutput bool
-	ui         cli.Ui
-}
-
 func (c *cmd) init() {
 	c.flags = flag.NewFlagSet("", flag.ContinueOnError)
 	config.AddFlags(c.flags, &c.flagArgs)
@@ -165,25 +160,26 @@ func (c *cmd) run(args []string) int {
 		return 1
 	}
 
-	logGate := logging.GatedWriter{Writer: &cli.UiWriter{Ui: c.UI}}
+	logGate := &logging.GatedWriter{Writer: &cli.UiWriter{Ui: c.UI}}
-
+	loader := func(source config.Source) (cfg *config.RuntimeConfig, warnings []string, err error) {
-	agentOptions := []agent.AgentOption{
+		return config.Load(c.flagArgs, source)
-		agent.WithBuilderOpts(c.flagArgs),
-		agent.WithCLI(c.UI),
-		agent.WithLogWriter(&logGate),
-		agent.WithTelemetry(true),
 	}
-
+	bd, err := agent.NewBaseDeps(loader, logGate)
-	agent, err := agent.New(agentOptions...)
 	if err != nil {
 		c.UI.Error(err.Error())
 		return 1
 	}
 
-	config := agent.GetConfig()
+	c.logger = bd.Logger
-	c.logger = agent.GetLogger()
+	agent, err := agent.New(bd)
+	if err != nil {
+		c.UI.Error(err.Error())
+		return 1
+	}
 
-	//Setup gate to check if we should output CLI information
+	config := bd.RuntimeConfig
+
+	// Setup gate to check if we should output CLI information
 	cli := GatedUi{
 		JSONoutput: config.LogJSON,
 		ui:         c.UI,
@@ -344,6 +340,11 @@ func (c *cmd) run(args []string) int {
 	}
 }
 
+type GatedUi struct {
+	JSONoutput bool
+	ui         cli.Ui
+}
+
 func (g *GatedUi) output(s string) {
 	if !g.JSONoutput {
 		g.ui.Output(s)

logging/grpc.go

@@ -19,9 +19,9 @@ type GRPCLogger struct {
 // Note that grpclog has Info, Warning, Error, Fatal severity levels AND integer
 // verbosity levels for additional info. Verbose logs in glog are always INFO
 // severity so we map Info,V0 to INFO, Info,V1 to DEBUG, and Info,V>1 to TRACE.
-func NewGRPCLogger(config *Config, logger hclog.Logger) *GRPCLogger {
+func NewGRPCLogger(logLevel string, logger hclog.Logger) *GRPCLogger {
 	return &GRPCLogger{
-		level:  config.LogLevel,
+		level:  logLevel,
 		logger: logger,
 	}
 }

logging/grpc_test.go

@@ -20,7 +20,7 @@ func TestGRPCLogger(t *testing.T) {
 		Output:     &out,
 		TimeFormat: "timeformat",
 	})
-	grpclog.SetLoggerV2(NewGRPCLogger(&Config{LogLevel: "TRACE"}, logger))
+	grpclog.SetLoggerV2(NewGRPCLogger("TRACE", logger))
 
 	// All of these should output something
 	grpclog.Info("Info,")
@@ -92,7 +92,7 @@ func TestGRPCLogger_V(t *testing.T) {
 				Level:  hclog.Trace,
 				Output: &out,
 			})
-			grpclog.SetLoggerV2(NewGRPCLogger(&Config{LogLevel: tt.level}, logger))
+			grpclog.SetLoggerV2(NewGRPCLogger(tt.level, logger))
 
 			assert.Equal(t, tt.want, grpclog.V(tt.v))
 		})

logging/logger.go

@@ -63,6 +63,7 @@ type LogSetupErrorFn func(string)
 // The provided ui object will get any log messages related to setting up
 // logging itself, and will also be hooked up to the gated logger. The final bool
 // parameter indicates if logging was set up successfully.
+// TODO: accept a single io.Writer
 func Setup(config *Config, writers []io.Writer) (hclog.InterceptLogger, error) {
 	if !ValidateLogLevel(config.LogLevel) {
 		return nil, fmt.Errorf("Invalid log level: %s. Valid log levels are: %v",