upgrade(installer): Add APM injector package installation support (#2…

…4372)

* fix(errors): Clearer errors

* upgrade(updater): Add injector support

* fix(updater): Use privileged command to write

* fix(updater): Update catalog and support ld.so.preload not existing

* upgrade(updater): Add injector docker support

* chore(updater): Make writing to ld.so.preload safer and remove experiment

* remove catalog changes for less conflicts

* fix(installer): Cleanup APM injector on setup failure

* fix(updater): Remove APM injector on purge

* test(installer): Add E2E test for injector installation

* fix(installer): Add agent config support for apm injector & fix test

* fix(installer): Add error message to helper commands and tentatively fix e2e

* fix(installer): Fix e2e tests

* refactor(installer): Refactor injector installation

* refactor(installer): Manipulate files in go instead of string manipulation

* feat(updater): Add lock to package installation commands

* fix(tests): Version is not resolved anymore in docker's daemon.json

* fix(installer): Allow installation of the injector before the agent

* address part of the review

* chore(installer): Add more tests

* fix(tests): Skip some tests to be able to merge

pkg/updater/install.go

@@ -13,6 +13,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 
 	oci "github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/types"
@@ -27,11 +28,15 @@ const (
 	datadogPackageConfigLayerMediaType types.MediaType = "application/vnd.datadog.package.config.layer.v1.tar+zstd"
 	datadogPackageMaxSize                              = 3 << 30 // 3GiB
 	defaultConfigsDir                                  = "/etc"
+
+	packageDatadogAgent = "datadog-agent"
+	packageAPMInjector  = "datadog-apm-inject"
 )
 
 type installer struct {
 	repositories *repository.Repositories
 	configsDir   string
+	installLock  sync.Mutex
 }
 
 func newInstaller(repositories *repository.Repositories) *installer {
@@ -56,10 +61,17 @@ func (i *installer) installStable(pkg string, version string, image oci.Image) e
 	if err != nil {
 		return fmt.Errorf("could not create repository: %w", err)
 	}
-	if pkg == "datadog-agent" {
+
+	i.installLock.Lock()
+	defer i.installLock.Unlock()
+	switch pkg {
+	case packageDatadogAgent:
 		return service.SetupAgentUnits()
+	case packageAPMInjector:
+		return service.SetupAPMInjector()
+	default:
+		return nil
 	}
-	return nil
 }
 
 func (i *installer) installExperiment(pkg string, version string, image oci.Image) error {
@@ -100,19 +112,25 @@ func (i *installer) uninstallExperiment(pkg string) error {
 }
 
 func (i *installer) startExperiment(pkg string) error {
-	// TODO(arthur): currently we only support the datadog-agent package
-	if pkg != "datadog-agent" {
+	i.installLock.Lock()
+	defer i.installLock.Unlock()
+	switch pkg {
+	case packageDatadogAgent:
+		return service.StartAgentExperiment()
+	default:
 		return nil
 	}
-	return service.StartAgentExperiment()
 }
 
 func (i *installer) stopExperiment(pkg string) error {
-	// TODO(arthur): currently we only support the datadog-agent package
-	if pkg != "datadog-agent" {
+	i.installLock.Lock()
+	defer i.installLock.Unlock()
+	switch pkg {
+	case packageDatadogAgent:
+		return service.StopAgentExperiment()
+	default:
 		return nil
 	}
-	return service.StopAgentExperiment()
 }
 
 func extractPackageLayers(image oci.Image, configDir string, packageDir string) error {