Reduce memory footprint by reordering struct elements

internal/pkg/agent/application/pipeline/actions/handlers/handler_action_unenroll.go

@@ -26,11 +26,11 @@ type stateStore interface {
 // Unenroll results in  running agent entering idle state, non managed non standalone.
 // For it to be operational again it needs to be either enrolled or reconfigured.
 type Unenroll struct {
+	dispatcher pipeline.Router
+	stateStore stateStore
 	log        *logger.Logger
 	emitter    pipeline.EmitterFunc
-	dispatcher pipeline.Router
 	closers    []context.CancelFunc
-	stateStore stateStore
 }
 
 // NewUnenroll creates a new Unenroll handler.
@@ -75,6 +75,7 @@ func (h *Unenroll) Handle(ctx context.Context, a fleetapi.Action, acker store.Fl
 	} else if h.stateStore != nil {
 		// backup action for future start to avoid starting fleet gateway loop
 		h.stateStore.Add(a)
+		// nolint: errcheck // Ignore the error at this point.
 		h.stateStore.Save()
 	}
 

internal/pkg/agent/application/upgrade/upgrade.go

@@ -44,15 +44,15 @@ var (
 
 // Upgrader performs an upgrade
 type Upgrader struct {
-	agentInfo   *info.AgentInfo
+	reporter    stateReporter
+	caps        capabilities.Capability
+	reexec      reexecManager
+	acker       acker
 	settings    *artifact.Config
+	agentInfo   *info.AgentInfo
 	log         *logger.Logger
 	closers     []context.CancelFunc
-	reexec      reexecManager
-	acker       acker
-	reporter    stateReporter
 	upgradeable bool
-	caps        capabilities.Capability
 }
 
 // Action is the upgrade action state.

internal/pkg/agent/operation/operation_retryable.go

@@ -18,8 +18,8 @@ import (
 // if nth operation fails all preceding are retried as well
 type retryableOperations struct {
 	logger      *logger.Logger
-	operations  []operation
 	retryConfig *retry.Config
+	operations  []operation
 }
 
 func newRetryableOperations(

internal/pkg/agent/stateresolver/resolve.go

@@ -60,10 +60,10 @@ func (s *state) String() string {
 }
 
 type active struct {
-	LastChange   stateChange
+	Program      program.Program
 	LastModified time.Time
 	Identifier   string
-	Program      program.Program
+	LastChange   stateChange
 }
 
 func (s *active) String() string {

internal/pkg/composable/providers/kubernetes/pod.go

@@ -23,15 +23,15 @@ import (
 )
 
 type pod struct {
-	logger           *logp.Logger
-	cleanupTimeout   time.Duration
-	comm             composable.DynamicProviderComm
-	scope            string
-	config           *Config
-	metagen          metadata.MetaGen
 	watcher          kubernetes.Watcher
 	nodeWatcher      kubernetes.Watcher
+	comm             composable.DynamicProviderComm
+	metagen          metadata.MetaGen
 	namespaceWatcher kubernetes.Watcher
+	config           *Config
+	logger           *logp.Logger
+	scope            string
+	cleanupTimeout   time.Duration
 
 	// Mutex used by configuration updates not triggered by the main watcher,
 	// to avoid race conditions between cross updates and deletions.

internal/pkg/composable/providers/kubernetesleaderelection/config.go

@@ -8,10 +8,12 @@ import "github.com/elastic/elastic-agent-autodiscover/kubernetes"
 
 // Config for kubernetes_leaderelection provider
 type Config struct {
-	KubeConfig        string                       `config:"kube_config"`
-	KubeClientOptions kubernetes.KubeClientOptions `config:"kube_client_options"`
+	KubeConfig string `config:"kube_config"`
+
 	// Name of the leaderelection lease
 	LeaderLease string `config:"leader_lease"`
+
+	KubeClientOptions kubernetes.KubeClientOptions `config:"kube_client_options"`
 }
 
 // InitDefaults initializes the default values for the config.

internal/pkg/core/plugin/process/app.go

@@ -35,34 +35,32 @@ var (
 
 // Application encapsulates a concrete application ran by elastic-agent e.g Beat.
 type Application struct {
-	bgContext    context.Context
-	id           string
-	name         string
-	pipelineID   string
-	logLevel     string
-	desc         *app.Descriptor
-	srv          *server.Server
-	srvState     *server.ApplicationState
-	limiter      *tokenbucket.Bucket
-	startContext context.Context
-	tag          app.Taggable
-	state        state.State
-	reporter     state.Reporter
-	watchClosers map[int]context.CancelFunc
+	state            state.State
+	startContext     context.Context
+	statusReporter   status.Reporter
+	monitor          monitoring.Monitor
+	reporter         state.Reporter
+	tag              app.Taggable
+	bgContext        context.Context
+	srvState         *server.ApplicationState
+	limiter          *tokenbucket.Bucket
+	srv              *server.Server
+	desc             *app.Descriptor
+	restartCanceller context.CancelFunc
+	logger           *logger.Logger
+	watchClosers     map[int]context.CancelFunc
+	processConfig    *process.Config
+	restartConfig    map[string]interface{}
+
+	name       string
+	id         string
+	pipelineID string
+	logLevel   string
 
 	uid int
 	gid int
 
-	monitor        monitoring.Monitor
-	statusReporter status.Reporter
-
-	processConfig *process.Config
-
-	logger *logger.Logger
-
-	appLock          sync.Mutex
-	restartCanceller context.CancelFunc
-	restartConfig    map[string]interface{}
+	appLock sync.Mutex
 }
 
 // ArgsDecorator decorates arguments before calling an application
@@ -79,8 +77,8 @@ func NewApplication(
 	logger *logger.Logger,
 	reporter state.Reporter,
 	monitor monitoring.Monitor,
-	statusController status.Controller) (*Application, error) {
-
+	statusController status.Controller,
+) (*Application, error) {
 	s := desc.ProcessSpec()
 	uid, gid, err := s.UserGroup()
 	if err != nil {
@@ -157,7 +155,6 @@ func (a *Application) Stop() {
 
 			a.logger.Error(err)
 		}
-
 	}
 
 	a.appLock.Lock()
@@ -231,6 +228,7 @@ func (a *Application) watch(ctx context.Context, p app.Taggable, proc *process.I
 		a.setState(state.Restarting, msg, nil)
 
 		// it was a crash
+		// nolint: errcheck // Ignore the error at this point.
 		a.start(ctx, p, cfg, true)
 	}()
 }
@@ -277,6 +275,7 @@ func (a *Application) setState(s state.Status, msg string, payload map[string]in
 }
 
 func (a *Application) cleanUp() {
+	// nolint: errcheck // Ignore the error at this point.
 	a.monitor.Cleanup(a.desc.Spec(), a.pipelineID)
 }
 

internal/pkg/core/state/state.go

@@ -76,9 +76,9 @@ func FromProto(s proto.StateObserved_Status) Status {
 // State wraps the process state and application status.
 type State struct {
 	ProcessInfo *process.Info
-	Status      Status
-	Message     string
 	Payload     map[string]interface{}
+	Message     string
+	Status      Status
 }
 
 // Reporter is interface that is called when a state is changed.

internal/pkg/core/status/reporter.go

@@ -39,19 +39,19 @@ func (s AgentStatusCode) String() string {
 
 // AgentApplicationStatus returns the status of specific application.
 type AgentApplicationStatus struct {
+	Payload map[string]interface{}
 	ID      string
 	Name    string
-	Status  state.Status
 	Message string
-	Payload map[string]interface{}
+	Status  state.Status
 }
 
 // AgentStatus returns the overall status of the Elastic Agent.
 type AgentStatus struct {
-	Status       AgentStatusCode
+	UpdateTime   time.Time
 	Message      string
 	Applications []AgentApplicationStatus
-	UpdateTime   time.Time
+	Status       AgentStatusCode
 }
 
 // Controller takes track of component statuses.
@@ -68,15 +68,15 @@ type Controller interface {
 }
 
 type controller struct {
-	mx           sync.Mutex
-	status       AgentStatusCode
-	message      string
 	updateTime   time.Time
+	log          *logger.Logger
 	reporters    map[string]*reporter
 	appReporters map[string]*reporter
-	log          *logger.Logger
 	stateID      string
+	message      string
 	agentID      string
+	status       AgentStatusCode
+	mx           sync.Mutex
 }
 
 // NewController creates a new reporter.
@@ -272,15 +272,15 @@ type Reporter interface {
 }
 
 type reporter struct {
-	name             string
-	mx               sync.Mutex
-	isPersistent     bool
-	isRegistered     bool
-	status           state.Status
-	message          string
 	payload          map[string]interface{}
 	unregisterFunc   func()
 	notifyChangeFunc func()
+	message          string
+	name             string
+	status           state.Status
+	mx               sync.Mutex
+	isRegistered     bool
+	isPersistent     bool
 }
 
 // Update updates the status of a component.

internal/pkg/crypto/io.go

@@ -21,11 +21,11 @@ import (
 // Option is the default options used to generate the encrypt and decrypt writer.
 // NOTE: the defined options need to be same for both the Reader and the writer.
 type Option struct {
+	Generator       bytesGen
 	IterationsCount int
 	KeyLength       int
 	SaltLength      int
 	IVLength        int
-	Generator       bytesGen
 
 	// BlockSize must be a factor of aes.BlockSize
 	BlockSize int
@@ -180,7 +180,6 @@ func (w *Writer) Write(b []byte) (int, error) {
 }
 
 func (w *Writer) writeBlock(b []byte) error {
-
 	// randomly generate the salt and the initialization vector, this information will be saved
 	// on disk in the file as part of the header
 	iv, err := w.generator(w.option.IVLength)
@@ -189,12 +188,14 @@ func (w *Writer) writeBlock(b []byte) error {
 		return w.err
 	}
 
+	// nolint: errcheck // Ignore the error at this point.
 	w.writer.Write(iv)
 
 	encodedBytes := w.gcm.Seal(nil, iv, b, nil)
 
 	l := make([]byte, 4)
 	binary.LittleEndian.PutUint32(l, uint32(len(encodedBytes)))
+	// nolint: errcheck // Ignore the error at this point.
 	w.writer.Write(l)
 
 	_, err = w.writer.Write(encodedBytes)
@@ -325,7 +326,7 @@ func (r *Reader) consumeBlock() error {
 	}
 
 	encodedBytes := make([]byte, l)
-	_, err = io.ReadAtLeast(r.reader, encodedBytes, int(l))
+	_, err = io.ReadAtLeast(r.reader, encodedBytes, l)
 	if err != nil {
 		r.err = errors.Wrapf(err, "fail read the block of %d bytes", l)
 	}
@@ -364,7 +365,6 @@ func (r *Reader) Close() error {
 func randomBytes(length int) ([]byte, error) {
 	r := make([]byte, length)
 	_, err := rand.Read(r)
-
 	if err != nil {
 		return nil, err
 	}

internal/pkg/fleetapi/acker/retrier/retrier.go

@@ -32,19 +32,19 @@ type Option func(*Retrier)
 
 // Retrier implements retrier for actions acks
 type Retrier struct {
-	log   *logger.Logger
 	acker BatchAcker // AckBatch provider
+	log   *logger.Logger
 
-	initialRetryInterval time.Duration // initial retry interval
-	maxRetryInterval     time.Duration // max retry interval
-	maxRetries           int           // configurable maxNumber of retries per action
+	doneCh chan struct{} // signal channel to kickoff retry loop if not running
+	kickCh chan struct{} // signal channel when retry loop is done
 
 	actions []fleetapi.Action // pending actions
-	mx      sync.Mutex
 
-	kickCh chan struct{} // signal channel to kickoff retry loop if not running
+	maxRetryInterval     time.Duration // max retry interval
+	maxRetries           int           // configurable maxNumber of retries per action
+	initialRetryInterval time.Duration // initial retry interval
 
-	doneCh chan struct{} // signal channel when retry loop is done
+	mx sync.Mutex
 }
 
 // New creates new instance of retrier
@@ -173,7 +173,6 @@ func (r *Retrier) runRetries(ctx context.Context) {
 	default:
 	}
 	r.log.Debug("ack retrier: exit retry loop")
-
 }
 
 func (r *Retrier) updateRetriesMap(retries map[string]int, actions []fleetapi.Action, resp *fleetapi.AckResponse) (failed []fleetapi.Action) {