environmentpath only scan for production environment

Directory environment are configured at "/etc/puppet/environments" but there's only production environment shown when "puppet module list" is run. Is this normal behavior ?

my puppet.conf at puppet master
================
cat /etc/puppet/puppet.conf

[main]
logdir = /var/log/puppet
rundir = /var/run/puppet
ssldir = $vardir/ssl
## Allow services in the 'puppet' group to access key (Foreman + proxy)
privatekeydir = $ssldir/private_keys

{ group = service }

hostprivkey = $privatekeydir/$certname.pem

{ mode = 640 }

## Puppet 3.0.x requires this in both [main] and [master] - harmless on agents
autosign = $confdir/autosign.conf

{ mode = 664 }
show_diff = false

environmentpath = /etc/puppet/environments

[agent]

classfile = $vardir/classes.txt
localconfig = $vardir/localconfig
default_schedules = false
report = true
pluginsync = true
masterport = 8140
#environment = production
certname = server1
server = server1
listen = false
splay = false
runinterval = 1800
noop = false
configtimeout = 120

[master]
autosign = $confdir/autosign.conf { mode = 664 }

reports = foreman
external_nodes = /etc/puppet/node.rb
node_terminus = exec
ca = true
ssldir = /var/lib/puppet/ssl
certname = server1.truelife.th
strict_variables = false
environmentpath = /etc/puppet/environments
============================================\

# tree /etc/puppet/environments/
/etc/puppet/environments/
├── common
├── development
│   ├── environment.conf
│   ├── manifests
│   └── modules
├── example_env
│   ├── manifests
│   ├── modules
│   └── README.environment
├── production
│   ├── environment.conf
│   ├── manifests
│   └── modules
├── test
└── test2
├── environment.conf
├── manifests
└── modules
============================================

[root@server1 puppet]# puppet config print environmentpath
/etc/puppet/environments

[root@server1 puppet]# puppet config print environment
production

[root@server1 puppet]# puppet module list
/etc/puppet/environments/production/modules (no modules installed)
/etc/puppet/modules (no modules installed)
/usr/share/puppet/modules (no modules installed)