From 1d2b71857bf57c5a4b9999321104b9f94e57d894 Mon Sep 17 00:00:00 2001
From: RachelElysia <71795832+RachelElysia@users.noreply.github.com>
Date: Tue, 17 Jun 2025 09:20:09 -0400
Subject: [PATCH] Host API: Return empty array instead of 404 for software
 filter not found (#30045)

---
 changes/29823-26258-empty-host          |  1 +
 server/service/hosts.go                 |  4 ++--
 server/service/integration_core_test.go | 14 +++++++++++---
 3 files changed, 14 insertions(+), 5 deletions(-)
 create mode 100644 changes/29823-26258-empty-host

diff --git a/changes/29823-26258-empty-host b/changes/29823-26258-empty-host
new file mode 100644
index 0000000000..d723f299d5
--- /dev/null
+++ b/changes/29823-26258-empty-host
@@ -0,0 +1 @@
+- Fixed host API to returns empty array (instead of 404) if software title or version is not found on hosts on that team consistent with other host filters
diff --git a/server/service/hosts.go b/server/service/hosts.go
index a66fb78d81..f1a47f53a3 100644
--- a/server/service/hosts.go
+++ b/server/service/hosts.go
@@ -102,7 +102,7 @@ func listHostsEndpoint(ctx context.Context, request interface{}, svc fleet.Servi
 			id = req.Opts.SoftwareIDFilter
 		}
 		software, err = svc.SoftwareByID(ctx, *id, req.Opts.TeamFilter, false)
-		if err != nil {
+		if err != nil && !fleet.IsNotFound(err) { // ignore not found, just return nil for the software in that case
 			return listHostsResponse{Err: err}, nil
 		}
 	}
@@ -112,7 +112,7 @@ func listHostsEndpoint(ctx context.Context, request interface{}, svc fleet.Servi
 		var err error
 
 		softwareTitle, err = svc.SoftwareTitleByID(ctx, *req.Opts.SoftwareTitleIDFilter, req.Opts.TeamFilter)
-		if err != nil {
+		if err != nil && !fleet.IsNotFound(err) { // ignore not found, just return nil for the software title in that case
 			return listHostsResponse{Err: err}, nil
 		}
 	}
diff --git a/server/service/integration_core_test.go b/server/service/integration_core_test.go
index 9184d6809b..b42aa2ba8b 100644
--- a/server/service/integration_core_test.go
+++ b/server/service/integration_core_test.go
@@ -1788,11 +1788,19 @@ func (s *integrationTestSuite) TestListHosts() {
 
 	// Filter by inexistent software.
 	resp = listHostsResponse{}
-	s.DoJSON("GET", "/api/latest/fleet/hosts", nil, http.StatusNotFound, &resp, "software_id", fmt.Sprint(9999))
+	s.DoJSON("GET", "/api/latest/fleet/hosts", nil, http.StatusOK, &resp, "software_id", fmt.Sprint(9999))
+	require.Len(t, resp.Hosts, 0)
+	assert.Nil(t, resp.Software)
+
 	resp = listHostsResponse{}
-	s.DoJSON("GET", "/api/latest/fleet/hosts", nil, http.StatusNotFound, &resp, "software_version_id", fmt.Sprint(9999))
+	s.DoJSON("GET", "/api/latest/fleet/hosts", nil, http.StatusOK, &resp, "software_version_id", fmt.Sprint(9999))
+	require.Len(t, resp.Hosts, 0)
+	assert.Nil(t, resp.Software)
+
 	resp = listHostsResponse{}
-	s.DoJSON("GET", "/api/latest/fleet/hosts", nil, http.StatusNotFound, &resp, "software_title_id", fmt.Sprint(9999))
+	s.DoJSON("GET", "/api/latest/fleet/hosts", nil, http.StatusOK, &resp, "software_title_id", fmt.Sprint(9999))
+	require.Len(t, resp.Hosts, 0)
+	assert.Nil(t, resp.SoftwareTitle)
 
 	// Filter by non-existent team.
 	resp = listHostsResponse{}