Alter agent install to detect installation from package (#30289)

* Alter agent install to detect installation from package

Alter the elastic-agent install command to not run the installation or
uninstall steps (on failure) when the agent has been installed via the
package manager of a Linux os. Instead the enroll command will be
executed.

* Check package manager by running which instead of looking for file

* Update Vagrantfile

Co-authored-by: Pier-Hugues Pellerin <phpellerin@gmail.com>

* Remove commented question

Co-authored-by: Pier-Hugues Pellerin <phpellerin@gmail.com>

Vagrantfile

@@ -53,6 +53,8 @@ TEST_BOXES = [
   {:name => "amazon2", :box => "bento/amazonlinux-2", :platform => "centos"},
 
   # Unsupported platforms
+  {:name => "opensuse153", :box => "bento/opensuse-leap-15.3", :platform => "opensuse"},
+  {:name => "sles12", :box => "elastic/sles-12-x86_64", :platform => "sles"},
   {:name => "solaris", :box => "https://s3.amazonaws.com/beats-files/vagrant/beats-solaris-11.2-virtualbox-2016-11-02_1603.box", :platform => "unix"},
   {:name => "freebsd", :box => "bento/freebsd-13", :platform => "freebsd", :extras => "pkg install -y -q bash && chsh -s bash vagrant"},
   {:name => "openbsd", :box => "generic/openbsd6", :platform => "openbsd", :extras => "sudo pkg_add go"},
@@ -103,14 +105,14 @@ Vagrant.configure("2") do |config|
         end
       end
 
-      # Freebsd 
+      # Freebsd
       if node[:platform] == "freebsd"
         nodeconfig.vm.provision "shell", path: "dev-tools/vagrant_scripts/unixProvision.sh", args: "gvm amd64 freebsd #{GO_VERSION}", privileged: false
         nodeconfig.vm.provision "shell", inline: "sudo mount -t linprocfs /dev/null /proc", privileged: false
       end
 
       # gvm install
-      if node[:platform] == "centos" or node[:platform] == "ubuntu" or node[:platform] == "debian" or node[:platorm] == "archlinux"
+      if [:centos, :ubuntu, :debian, :archlinux, :opensuse, :sles].include?(node[:platform].to_sym)
         nodeconfig.vm.provision "shell", type: "shell", path: "dev-tools/vagrant_scripts/unixProvision.sh", args: "gvm amd64 linux #{GO_VERSION}", privileged: false
       end
 

dev-tools/vagrant_scripts/unixProvision.sh

@@ -45,6 +45,11 @@ function archProvision () {
     pacman -Sy && pacman -S --noconfirm make gcc python python-pip git
 }
 
+function suseProvision() {
+    zypper refresh
+    zypper install -y make gcc git python3 python3-pip python3-virtualenv git rpm-devel
+}
+
 case "${PROVISION_TYPE}" in
     "gvm")
         gvmProvision $ARCH $OS $GO_VERSION
@@ -61,6 +66,9 @@ case "${PROVISION_TYPE}" in
     "debian" | "ubuntu")
         debProvision
     ;;
+    "opensuse" | "sles")
+        suseProvision
+    ;;
     *)
         echo "No Extra provisioning steps for this platform"
-esac
+esac

x-pack/elastic-agent/CHANGELOG.next.asciidoc

@@ -161,3 +161,4 @@
 - Discover changes in Kubernetes nodes metadata as soon as they happen. {pull}23139[23139]
 - Add results of inspect output command into archive produced by diagnostics collect. {pull}29902[29902]
 - Add support for loading input configuration from external configuration files in standalone mode. You can load inputs from YAML configuration files under the folder `{path.config}/inputs.d`. {pull}30087[30087]
+- Install command will skip install/uninstall steps when installation via package is detected on Linux distros. {pull}30289[30289]

x-pack/elastic-agent/pkg/agent/cmd/install.go

@@ -59,6 +59,10 @@ func installCmd(streams *cli.IOStreams, cmd *cobra.Command, args []string) error
 		return fmt.Errorf("already installed at: %s", paths.InstallPath)
 	}
 
+	if status == install.PackageInstall {
+		fmt.Fprintf(streams.Out, "Installed as a system package, installation will not be altered.\n")
+	}
+
 	// check the lock to ensure that elastic-agent is not already running in this directory
 	locker := filelock.NewAppLocker(paths.Data(), paths.AgentLockFileName)
 	if err := locker.TryLock(); err != nil {
@@ -80,7 +84,7 @@ func installCmd(streams *cli.IOStreams, cmd *cobra.Command, args []string) error
 				return fmt.Errorf("installation was cancelled by the user")
 			}
 		}
-	} else {
+	} else if status != install.PackageInstall {
 		if !force {
 			confirm, err := cli.Confirm(fmt.Sprintf("Elastic Agent will be installed at %s and will run as a service. Do you want to continue?", paths.InstallPath), true)
 			if err != nil {
@@ -141,30 +145,33 @@ func installCmd(streams *cli.IOStreams, cmd *cobra.Command, args []string) error
 			}
 		}
 	}
-	cfgFile := paths.ConfigFile()
-	err = install.Install(cfgFile)
-	if err != nil {
-		return err
-	}
 
-	defer func() {
-		if err != nil {
-			install.Uninstall(cfgFile)
-		}
-	}()
-
-	if !delayEnroll {
-		err = install.StartService()
+	cfgFile := paths.ConfigFile()
+	if status != install.PackageInstall {
+		err = install.Install(cfgFile)
 		if err != nil {
-			fmt.Fprintf(streams.Out, "Installation failed to start Elastic Agent service.\n")
 			return err
 		}
 
 		defer func() {
 			if err != nil {
-				install.StopService()
+				install.Uninstall(cfgFile)
 			}
 		}()
+
+		if !delayEnroll {
+			err = install.StartService()
+			if err != nil {
+				fmt.Fprintf(streams.Out, "Installation failed to start Elastic Agent service.\n")
+				return err
+			}
+
+			defer func() {
+				if err != nil {
+					install.StopService()
+				}
+			}()
+		}
 	}
 
 	if enroll {
@@ -180,10 +187,12 @@ func installCmd(streams *cli.IOStreams, cmd *cobra.Command, args []string) error
 		}
 		err = enrollCmd.Wait()
 		if err != nil {
-			install.Uninstall(cfgFile)
-			exitErr, ok := err.(*exec.ExitError)
-			if ok {
-				return fmt.Errorf("enroll command failed with exit code: %d", exitErr.ExitCode())
+			if status != install.PackageInstall {
+				install.Uninstall(cfgFile)
+				exitErr, ok := err.(*exec.ExitError)
+				if ok {
+					return fmt.Errorf("enroll command failed with exit code: %d", exitErr.ExitCode())
+				}
 			}
 			return fmt.Errorf("enroll command failed for unknown reason: %s", err)
 		}

x-pack/elastic-agent/pkg/agent/install/install_unix.go

@@ -7,8 +7,58 @@
 
 package install
 
+import (
+	"os/exec"
+	"runtime"
+	"strings"
+
+	"github.com/elastic/beats/v7/x-pack/elastic-agent/pkg/agent/application/paths"
+)
+
 // postInstall performs post installation for unix-based systems.
 func postInstall() error {
 	// do nothing
 	return nil
 }
+
+func checkPackageInstall() bool {
+	if runtime.GOOS != "linux" {
+		return false
+	}
+
+	// NOTE searching for english words might not be a great idea as far as portability goes.
+	// list all installed packages then search for paths.BinaryName?
+	// dpkg is strange as the remove and purge processes leads to the package bing isted after a remove, but not after a purge
+
+	// check debian based systems (or systems that use dpkg)
+	// If the package has been installed, the status starts with "install"
+	// If the package has been removed (but not pruged) status starts with "deinstall"
+	// If purged or never installed, rc is 1
+	if _, err := exec.Command("which", "dpkg-query").Output(); err == nil {
+		out, err := exec.Command("dpkg-query", "-W", "-f", "${Status}", paths.BinaryName).Output()
+		if err != nil {
+			return false
+		}
+		if strings.HasPrefix(string(out), "deinstall") {
+			return false
+		}
+		return true
+	}
+
+	// check rhel and sles based systems (or systems that use rpm)
+	// if package has been installed query retuns with a list of associated files.
+	// otherwise if uninstalled, or has never been installled status ends with "not installed"
+	if _, err := exec.Command("which", "rpm").Output(); err == nil {
+		out, err := exec.Command("rpm", "-q", paths.BinaryName, "--state").Output()
+		if err != nil {
+			return false
+		}
+		if strings.HasSuffix(string(out), "not installed") {
+			return false
+		}
+		return true
+
+	}
+
+	return false
+}

x-pack/elastic-agent/pkg/agent/install/install_windows.go

@@ -35,3 +35,9 @@ func postInstall() error {
 
 	return nil
 }
+
+// checkPackageInstall is used for unix based systems to see if the Elastic-Agent was installed through a package manager.
+// returns false
+func checkPackageInstall() bool {
+	return false
+}

x-pack/elastic-agent/pkg/agent/install/installed.go

@@ -19,16 +19,24 @@ type StatusType int
 const (
 	// NotInstalled returned when Elastic Agent is not installed.
 	NotInstalled StatusType = iota
-	// Installed returned when Elastic Agent is installed currectly.
+	// Installed returned when Elastic Agent is installed correctly.
 	Installed
 	// Broken returned when Elastic Agent is installed but broken.
 	Broken
+	// PackageInstall returned when the Elastic agent has been installed through a package manager (deb/rpm)
+	PackageInstall
 )
 
 // Status returns the installation status of Agent.
 func Status() (StatusType, string) {
 	expected := filepath.Join(paths.InstallPath, paths.BinaryName)
 	status, reason := checkService()
+	if checkPackageInstall() {
+		if status == Installed {
+			return PackageInstall, "service running"
+		}
+		return PackageInstall, "service not running"
+	}
 	_, err := os.Stat(expected)
 	if os.IsNotExist(err) {
 		if status == Installed {