set exit_code = -1 for scripts that are pending before upgrade to 4.44.0 (#16581)

for https://github.com/fleetdm/fleet/issues/16547

# Checklist for submitter

If some of the following don't apply, delete the relevant line.

<!-- Note that API documentation changes are now addressed by the
product design team. -->

- [x] Added/updated tests
- [x] Manual QA for all new/changed functionality

server/datastore/mysql/migrations/tables/20240126020643_AddHostActivities.go

@@ -49,23 +49,23 @@ func Up_20240126020643(tx *sql.Tx) error {
 		return errors.Wrap(err, "create host_activities table")
 	}
 
-	// Prior to this update, the database didn't differentiate between
-	// "async" and "sync" requests. With Fleet v4.44.0, all async requests
-	// will execute regardless of their pending duration. To avoid
-	// unintended execution of old requests upon server upgrade, these are
-	// now marked as "sync", reflecting their original 5-minute execution
-	// limit.
+	// Force an exit_code for scripts that didn't run previous to this update.
+	// In previous releases, scripts were allowed to be queued only for 5
+	// minutes, since we're removing that restriction, any scripts with a
+	// null exit_code would be unexpectedly sent to the host unless we do
+	// this.
 	const setOldScriptsAsSyncStmt = `
             UPDATE host_script_results hsr
             SET
-                sync_request = 1,
+                exit_code = -1,
                 updated_at = hsr.updated_at
             WHERE
-                user_id IS NULL
+	        exit_code IS NULL
+                AND user_id IS NULL
                 AND created_at < CURRENT_TIMESTAMP
 	`
 	if _, err := tx.Exec(setOldScriptsAsSyncStmt); err != nil {
-		return errors.Wrap(err, "set sync_request = 1 for old scripts")
+		return errors.Wrap(err, "set exit_code = -1 for old scripts")
 	}
 
 	return nil

server/datastore/mysql/migrations/tables/20240126020643_AddHostActivities_test.go

@@ -32,24 +32,24 @@ func TestUp_20240126020643(t *testing.T) {
 	// existing host execution request's timestamp hasn't changed (despite
 	// added column, and modified sync_request)
 	type scriptResults struct {
-		CreatedAt   time.Time `db:"created_at"`
-		UpdatedAt   time.Time `db:"updated_at"`
-		SyncRequest bool      `db:"sync_request"`
+		CreatedAt time.Time `db:"created_at"`
+		UpdatedAt time.Time `db:"updated_at"`
+		ExitCode  *int      `db:"exit_code"`
 	}
 
 	var sr scriptResults
-	err := db.Get(&sr, `SELECT created_at, updated_at, sync_request FROM host_script_results WHERE id = ?`, hsr1)
+	err := db.Get(&sr, `SELECT created_at, updated_at, exit_code FROM host_script_results WHERE id = ?`, hsr1)
 	require.NoError(t, err)
 	assert.Equal(t, minutesAgo, sr.CreatedAt)
 	assert.Equal(t, minutesAgo, sr.UpdatedAt)
-	assert.True(t, sr.SyncRequest)
+	assert.Equal(t, -1, *sr.ExitCode)
 
 	sr = scriptResults{}
-	err = db.Get(&sr, `SELECT created_at, updated_at, sync_request FROM host_script_results WHERE id = ?`, hsr2)
+	err = db.Get(&sr, `SELECT created_at, updated_at, exit_code FROM host_script_results WHERE id = ?`, hsr2)
 	require.NoError(t, err)
 	assert.Equal(t, minutesAgo, sr.CreatedAt)
 	assert.Equal(t, minutesAgo, sr.UpdatedAt)
-	assert.True(t, sr.SyncRequest)
+	assert.Equal(t, 1, *sr.ExitCode)
 
 	// create a new host execution request with user u1 and one with u2
 	hsr3 := execNoErrLastID(t, db, `INSERT INTO host_script_results (host_id, execution_id, script_contents, output, user_id) VALUES (?, ?, ?, ?, ?)`, 1, uuid.NewString(), "echo 'hello'", "", u1)