Share host info between packages

changelog/fragments/1730288427-shared-host.yaml

@@ -0,0 +1,32 @@
+# Kind can be one of:
+# - breaking-change: a change to previously-documented behavior
+# - deprecation: functionality that is being removed in a later release
+# - bug-fix: fixes a problem in a previous version
+# - enhancement: extends functionality but does not break or fix existing behavior
+# - feature: new functionality
+# - known-issue: problems that we are aware of in a given version
+# - security: impacts on the security of a product or a user’s deployment.
+# - upgrade: important information for someone upgrading from a prior version
+# - other: does not fit into any of the other categories
+kind: enhancement
+
+# Change summary; a 80ish characters long description of the change.
+summary: Collect host info exactly once on startup
+
+# Long description; in case the summary is not enough to describe the change
+# this field accommodate a description without length limits.
+# NOTE: This field will be rendered only for breaking-change and known-issue kinds at the moment.
+#description:
+
+# Affected component; usually one of "elastic-agent", "fleet-server", "filebeat", "metricbeat", "auditbeat", "all", etc.
+component: elastic-agent
+
+# PR URL; optional; the PR number that added the changeset.
+# If not present is automatically filled by the tooling finding the PR where this changelog fragment has been added.
+# NOTE: the tooling supports backports, so it's able to fill the original PR number instead of the backport PR number.
+# Please provide it if you are adding a fragment for a different PR.
+#pr: https://github.com/owner/repo/1234
+
+# Issue URL; optional; the GitHub issue related to this changeset (either closes or is part of).
+# If not present is automatically filled by the tooling with the issue linked to the PR number.
+#issue: https://github.com/owner/repo/1234

internal/pkg/agent/application/info/agent_metadata.go

@@ -18,7 +18,6 @@ import (
 	"github.com/elastic/elastic-agent/internal/pkg/util"
 	"github.com/elastic/elastic-agent/pkg/core/logger"
 
-	"github.com/elastic/go-sysinfo"
 	"github.com/elastic/go-sysinfo/types"
 )
 
@@ -146,7 +145,7 @@ func Metadata(ctx context.Context, l *logger.Logger) (*ECSMeta, error) {
 
 // ECSMetadata returns an agent ECS compliant metadata.
 func (i *AgentInfo) ECSMetadata(l *logger.Logger) (*ECSMeta, error) {
-	sysInfo, err := sysinfo.Host()
+	sysInfo, err := util.GetHost()
 	if err != nil {
 		return nil, err
 	}
@@ -195,7 +194,7 @@ func (i *AgentInfo) ECSMetadataFlatMap(l *logger.Logger) (map[string]interface{}
 	// TODO: remove these values when kibana migrates to ECS
 	meta := make(map[string]interface{})
 
-	sysInfo, err := sysinfo.Host()
+	sysInfo, err := util.GetHost()
 	if err != nil {
 		return nil, err
 	}

internal/pkg/agent/application/info/agent_metadata_test.go

@@ -11,8 +11,6 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/elastic/go-sysinfo"
-
 	"github.com/elastic/elastic-agent/internal/pkg/agent/application/paths"
 	"github.com/elastic/elastic-agent/internal/pkg/release"
 	"github.com/elastic/elastic-agent/internal/pkg/testutils"
@@ -34,7 +32,7 @@ func TestECSMetadata(t *testing.T) {
 		assert.NotNil(t, metadata.Elastic.Agent, "metadata.Elastic.Agent must not be nil")
 	}
 
-	sysInfo, err := sysinfo.Host()
+	sysInfo, err := util.GetHost()
 	require.NoError(t, err)
 
 	info := sysInfo.Info()

internal/pkg/agent/application/info/inject_config.go

@@ -7,10 +7,11 @@ package info
 import (
 	"runtime"
 
+	"github.com/elastic/elastic-agent/internal/pkg/util"
+
 	"github.com/elastic/elastic-agent/internal/pkg/agent/application/paths"
 	"github.com/elastic/elastic-agent/internal/pkg/agent/errors"
 	"github.com/elastic/elastic-agent/internal/pkg/config"
-	"github.com/elastic/go-sysinfo"
 )
 
 // InjectAgentConfig injects config to a provided configuration.
@@ -30,7 +31,7 @@ func InjectAgentConfig(c *config.Config) error {
 // agentGlobalConfig gets global config used for resolution of variables inside configuration
 // such as ${path.data}.
 func agentGlobalConfig() (map[string]interface{}, error) {
-	hostInfo, err := sysinfo.Host()
+	hostInfo, err := util.GetHost()
 	if err != nil {
 		return nil, err
 	}

internal/pkg/composable/providers/host/host.go

@@ -132,6 +132,7 @@ func ContextProviderBuilder(log *logger.Logger, c *config.Config, _ bool) (corec
 
 func getHostInfo(log *logger.Logger) func() (map[string]interface{}, error) {
 	return func() (map[string]interface{}, error) {
+		// We don't use the shared host info from util here, as we explicitly want the latest host information on every call.
 		sysInfo, err := sysinfo.Host()
 		if err != nil {
 			return nil, err

internal/pkg/util/host.go

@@ -6,9 +6,11 @@ package util
 
 import (
 	"context"
+	"sync"
 	"time"
 
 	"github.com/elastic/elastic-agent/pkg/core/logger"
+	"github.com/elastic/go-sysinfo"
 	"github.com/elastic/go-sysinfo/types"
 )
 
@@ -31,3 +33,61 @@ func GetHostName(isFqdnFeatureEnabled bool, hostInfo types.HostInfo, host types.
 
 	return fqdn
 }
+
+var _ types.Host = &threadSafeHost{}
+
+// threadSafeHost is a thread-safe wrapper around types.Host.
+// It exists so we can only create it once, as some of the setup it does is relatively expensive.
+type threadSafeHost struct {
+	sync.Mutex
+	inner types.Host
+}
+
+func newThreadSafeHost(inner types.Host) *threadSafeHost {
+	return &threadSafeHost{inner: inner}
+}
+
+func (s *threadSafeHost) CPUTime() (types.CPUTimes, error) {
+	s.Lock()
+	defer s.Unlock()
+	return s.inner.CPUTime()
+}
+
+func (s *threadSafeHost) Info() types.HostInfo {
+	s.Lock()
+	defer s.Unlock()
+	return s.inner.Info()
+}
+
+func (s *threadSafeHost) Memory() (*types.HostMemoryInfo, error) {
+	s.Lock()
+	defer s.Unlock()
+	return s.inner.Memory()
+}
+
+func (s *threadSafeHost) FQDNWithContext(ctx context.Context) (string, error) {
+	s.Lock()
+	defer s.Unlock()
+	return s.inner.FQDNWithContext(ctx)
+}
+
+func (s *threadSafeHost) FQDN() (string, error) {
+	s.Lock()
+	defer s.Unlock()
+	return s.inner.FQDN()
+}
+
+var (
+	sharedHost types.Host
+	once       sync.Once
+	hostErr    error
+)
+
+func GetHost() (types.Host, error) {
+	once.Do(func() {
+		var innerHost types.Host
+		innerHost, hostErr = sysinfo.Host()
+		sharedHost = newThreadSafeHost(innerHost)
+	})
+	return sharedHost, hostErr
+}

internal/pkg/util/host_test.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/elastic/elastic-agent-libs/logp"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
 	"github.com/elastic/go-sysinfo/types"
@@ -59,6 +60,25 @@ func TestGetHostName(t *testing.T) {
 	}
 }
 
+func TestSharedHost(t *testing.T) {
+	innerHost := &mockHost{}
+	shared := newThreadSafeHost(innerHost)
+
+	innerCpuTime, _ := innerHost.CPUTime()
+	sharedCpuTime, _ := shared.CPUTime()
+	assert.Equal(t, innerCpuTime, sharedCpuTime)
+
+	assert.Equal(t, innerHost.Info(), shared.Info())
+
+	innerMemoryInfo, _ := innerHost.Memory()
+	sharedMemoryInfo, _ := shared.Memory()
+	assert.Equal(t, innerMemoryInfo, sharedMemoryInfo)
+
+	innerFQDN, _ := innerHost.FQDN()
+	sharedFQDN, _ := shared.FQDN()
+	assert.Equal(t, innerFQDN, sharedFQDN)
+}
+
 type mockHost struct {
 	fqdn    string
 	fqdnErr error

pkg/component/platforms.go

@@ -9,8 +9,7 @@ import (
 	goruntime "runtime"
 	"strings"
 
-	"github.com/elastic/go-sysinfo"
-
+	"github.com/elastic/elastic-agent/internal/pkg/util"
 	"github.com/elastic/elastic-agent/pkg/utils"
 )
 
@@ -126,7 +125,7 @@ func LoadPlatformDetail(modifiers ...PlatformModifier) (PlatformDetail, error) {
 	if err != nil {
 		return PlatformDetail{}, err
 	}
-	info, err := sysinfo.Host()
+	info, err := util.GetHost()
 	if err != nil {
 		return PlatformDetail{}, err
 	}

pkg/testing/define/define.go

@@ -21,9 +21,9 @@ import (
 
 	"github.com/elastic/elastic-agent-libs/kibana"
 	"github.com/elastic/go-elasticsearch/v8"
-	"github.com/elastic/go-sysinfo"
 	"github.com/elastic/go-sysinfo/types"
 
+	"github.com/elastic/elastic-agent/internal/pkg/util"
 	atesting "github.com/elastic/elastic-agent/pkg/testing"
 	"github.com/elastic/elastic-agent/pkg/utils"
 	semver "github.com/elastic/elastic-agent/pkg/version"
@@ -205,7 +205,7 @@ func runOrSkip(t *testing.T, req Requirements, local bool, kubernetes bool) *Inf
 
 func getOSInfo() (*types.OSInfo, error) {
 	osInfoOnce.Do(func() {
-		sysInfo, err := sysinfo.Host()
+		sysInfo, err := util.GetHost()
 		if err != nil {
 			osInfoErr = err
 		} else {