make packages

error. I can't get the rpm pkg (My system is CentOS7.4).Here is What I get.

[username@localhost osquery]$ make packages
-- Welcome to osquery's build -- thank you for your patience! :)
-- For a brief tutorial see: <http://osquery.readthedocs.io/en/stable/development/building/>
-- If at first you dont succeed, perhaps: make distclean; make depsclean
-- Building for platform CentOS (centos, centos7)
-- Building osquery version  3.3.1-1-g5188ce5 sdk 3.3.1
-- Cannot find fpm executable in path
-- Configuring done
-- Generating done
-- Build files have been written to: /home/username/osquery/build/centos7
Building linux packages (no custom config)


[username@localhost osquery]$ ls -all /home/username/osquery/build/centos7
total 1156
drwxrwxr-x. 10 username username   4096 Nov 19 04:44 .
drwxrwxr-x.  5 username username     86 Nov 19 04:44 ..
drwxrwx---.  2 username username  73728 Nov 19 04:28 cache
-rw-rw-r--.  1 username username  32171 Nov 19 04:31 CMakeCache.txt
drwxrwxr-x.  9 username username   4096 Nov 19 04:44 CMakeFiles
-rw-rw-r--.  1 username username   2039 Nov 19 04:12 cmake_install.cmake
-rw-rw-r--.  1 username username 970311 Nov 19 04:44 compile_commands.json
-rw-rw-r--.  1 username username    412 Nov 19 04:12 CTestTestfile.cmake
drwxrwxr-x.  3 username username     94 Nov 19 04:44 external
drwxrwxr-x.  7 username username    199 Nov 19 04:14 generated
-rw-rw-r--.  1 username username    271 Nov 19 04:12 gmock_main.pc
-rw-rw-r--.  1 username username    264 Nov 19 04:12 gmock.pc
-rw-rw-r--.  1 username username    287 Nov 19 04:12 gtest_main.pc
-rw-rw-r--.  1 username username    264 Nov 19 04:12 gtest.pc
-rw-rw-r--.  1 username username  40624 Nov 19 04:44 Makefile
drwxrwxr-x.  4 username username   4096 Nov 19 04:44 osquery
-rw-rw-r--.  1 username username     41 Nov 19 04:32 .provision
lrwxrwxrwx.  1 username username     33 Nov 19 04:44 test_data -> /home/username/osquery/tools/tests
drwxrwxr-x.  3 username username     23 Nov 19 04:28 Testing
drwxrwxr-x.  5 username username     59 Nov 19 04:12 third-party
drwxrwxr-x.  3 username username     19 Nov 19 04:12 tools