Prevent installing on pending host+installer (#21722)

#21428

Figma:
https://www.figma.com/design/4pfUOYy7IyMIrjMH2fuCdU/%2319551-Policy-automations%3A-install-software?node-id=5871-12100&t=pKh926u8a30iYFBA-4


- [X] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/Committing-Changes.md#changes-files)
for more information.
- [X] Added/updated tests
- [X] Manual QA for all new/changed functionality

changes/21428-prevent-install-when-already-pending

@@ -0,0 +1 @@
+* Added validation to `POST /api/_version_/fleet/hosts/{host_id}/software/install/{software_title_id}` to prevent installing on a host that already has a pending installation for that software title.

ee/server/service/software_installers.go

@@ -385,6 +385,24 @@ func (svc *Service) InstallSoftwareTitle(ctx context.Context, hostID uint, softw
 
 		// if we found an installer, use that
 		if installer != nil {
+			lastInstallRequest, err := svc.ds.GetHostLastInstallData(ctx, host.ID, installer.InstallerID)
+			if err != nil {
+				return ctxerr.Wrapf(ctx, err, "getting last install data for host %d and installer %d", host.ID, installer.InstallerID)
+			}
+			if lastInstallRequest != nil && lastInstallRequest.Status != nil && *lastInstallRequest.Status == fleet.SoftwareInstallerPending {
+				return &fleet.BadRequestError{
+					Message: "Couldn't install software. Host has a pending install request.",
+					InternalErr: ctxerr.WrapWithData(
+						ctx, err, "host already has a pending install for this installer",
+						map[string]any{
+							"host_id":               host.ID,
+							"software_installer_id": installer.InstallerID,
+							"team_id":               host.TeamID,
+							"title_id":              softwareTitleID,
+						},
+					),
+				}
+			}
 			return svc.installSoftwareTitleUsingInstaller(ctx, host, installer)
 		}
 	}

server/service/integration_enterprise_test.go

@@ -11117,7 +11117,7 @@ func (s *integrationEnterpriseTestSuite) TestHostSoftwareInstallResult() {
 
 	host := createOrbitEnrolledHost(t, "linux", "", s.ds)
 
-	// create a software installer and some host install requests
+	// Create software installers and corresponding host install requests.
 	payload := &fleet.UploadSoftwareInstallerPayload{
 		InstallScript:     "install script",
 		PreInstallQuery:   "pre install query",
@@ -11127,6 +11127,24 @@ func (s *integrationEnterpriseTestSuite) TestHostSoftwareInstallResult() {
 	}
 	s.uploadSoftwareInstaller(payload, http.StatusOK, "")
 	titleID := getSoftwareTitleID(t, s.ds, payload.Title, "deb_packages")
+	payload2 := &fleet.UploadSoftwareInstallerPayload{
+		InstallScript:     "install script 2",
+		PreInstallQuery:   "pre install query 2",
+		PostInstallScript: "post install script 2",
+		Filename:          "vim.deb",
+		Title:             "vim",
+	}
+	s.uploadSoftwareInstaller(payload2, http.StatusOK, "")
+	titleID2 := getSoftwareTitleID(t, s.ds, payload2.Title, "deb_packages")
+	payload3 := &fleet.UploadSoftwareInstallerPayload{
+		InstallScript:     "install script 3",
+		PreInstallQuery:   "pre install query 3",
+		PostInstallScript: "post install script 3",
+		Filename:          "emacs.deb",
+		Title:             "emacs",
+	}
+	s.uploadSoftwareInstaller(payload3, http.StatusOK, "")
+	titleID3 := getSoftwareTitleID(t, s.ds, payload3.Title, "deb_packages")
 
 	latestInstallUUID := func() string {
 		var id string
@@ -11138,9 +11156,10 @@ func (s *integrationEnterpriseTestSuite) TestHostSoftwareInstallResult() {
 
 	// create some install requests for the host
 	installUUIDs := make([]string, 3)
+	titleIDs := []uint{titleID, titleID2, titleID3}
 	for i := 0; i < len(installUUIDs); i++ {
 		resp := installSoftwareResponse{}
-		s.DoJSON("POST", fmt.Sprintf("/api/v1/fleet/hosts/%d/software/install/%d", host.ID, titleID), nil, http.StatusAccepted, &resp)
+		s.DoJSON("POST", fmt.Sprintf("/api/v1/fleet/hosts/%d/software/install/%d", host.ID, titleIDs[i]), nil, http.StatusAccepted, &resp)
 		installUUIDs[i] = latestInstallUUID()
 	}
 
@@ -11203,7 +11222,14 @@ func (s *integrationEnterpriseTestSuite) TestHostSoftwareInstallResult() {
 		Status:                fleet.SoftwareInstallerFailed,
 		PreInstallQueryOutput: ptr.String(fleet.SoftwareInstallerQueryFailCopy),
 	})
-	wantAct.InstallUUID = installUUIDs[1]
+	wantAct = fleet.ActivityTypeInstalledSoftware{
+		HostID:          host.ID,
+		HostDisplayName: host.DisplayName(),
+		SoftwareTitle:   payload2.Title,
+		SoftwarePackage: payload2.Filename,
+		InstallUUID:     installUUIDs[1],
+		Status:          string(fleet.SoftwareInstallerFailed),
+	}
 	s.lastActivityOfTypeMatches(wantAct.ActivityName(), string(jsonMustMarshal(t, wantAct)), 0)
 
 	s.Do("POST", "/api/fleet/orbit/software_install/result",
@@ -11225,8 +11251,14 @@ func (s *integrationEnterpriseTestSuite) TestHostSoftwareInstallResult() {
 		Output:                  ptr.String(fmt.Sprintf(fleet.SoftwareInstallerInstallSuccessCopy, "success")),
 		PostInstallScriptOutput: ptr.String(fmt.Sprintf(fleet.SoftwareInstallerPostInstallSuccessCopy, "ok")),
 	})
-	wantAct.InstallUUID = installUUIDs[2]
-	wantAct.Status = string(fleet.SoftwareInstallerInstalled)
+	wantAct = fleet.ActivityTypeInstalledSoftware{
+		HostID:          host.ID,
+		HostDisplayName: host.DisplayName(),
+		SoftwareTitle:   payload3.Title,
+		SoftwarePackage: payload3.Filename,
+		InstallUUID:     installUUIDs[2],
+		Status:          string(fleet.SoftwareInstallerInstalled),
+	}
 	lastActID := s.lastActivityOfTypeMatches(wantAct.ActivityName(), string(jsonMustMarshal(t, wantAct)), 0)
 
 	// non-existing installation uuid
@@ -13073,6 +13105,11 @@ func (s *integrationEnterpriseTestSuite) TestPolicyAutomationsSoftwareInstallers
 	require.Equal(t, fleet.SoftwareInstallerPending, *host1LastInstall.Status)
 	prevExecutionID := host1LastInstall.ExecutionID
 
+	// Request a manual installation on the host for the same installer, which should fail.
+	var installResp installSoftwareResponse
+	s.DoJSON("POST", fmt.Sprintf("/api/latest/fleet/hosts/%d/software/install/%d",
+		host1Team1.ID, dummyInstallerPkgTitleID), nil, http.StatusBadRequest, &installResp)
+
 	// Submit same results as before, which should not trigger a installation because the policy is already failing.
 	distributedResp = submitDistributedQueryResultsResponse{}
 	s.DoJSONWithoutAuth("POST", "/api/osquery/distributed/write", genDistributedReqWithPolicyResults(