Install pytz library along with graphite.

It's now a requirement -
https://github.com/graphite-project/graphite-web/blob/master/docs/install.rst#dependencies

Related issue -
graphite-project/graphite-web#1019

manifests/init.pp

@@ -80,7 +80,10 @@
 #   Optional: Carbon package name
 #
 # [*graphite_web_pkg_name*]
-#   Optional: Grpahite-Web package name
+#   Optional: Graphite-Web package name
+#
+# [*pytz_pkg_name*]
+#   Optional: pytz package name
 #
 class graphite(
   $admin_password = $graphite::params::admin_password,
@@ -107,6 +110,7 @@
   $whisper_pkg_name = 'whisper',
   $carbon_pkg_name = 'carbon',
   $graphite_web_pkg_name = 'graphite-web',
+  $pytz_pkg_name = 'pytz',
 ) inherits graphite::params {
   validate_string(
     $admin_password,

manifests/install.pp

@@ -7,6 +7,7 @@
   $carbon = $::graphite::carbon_pkg_name
   $whisper = $::graphite::whisper_pkg_name
   $graphite_web = $::graphite::graphite_web_pkg_name
+  $pytz = $::graphite::pytz_pkg_name
   $ver = $::graphite::version
 
   if $::graphite::use_python_pip {
@@ -27,10 +28,21 @@
       environment  => ["PYTHONPATH=${root_dir}/lib:${root_dir}/webapp"],
       install_args => "--install-option=\"--prefix=${root_dir}\" --install-option=\"--install-lib=${root_dir}/webapp\""
     }
+    python::pip { [
+      $pytz,
+    ]:
+      ensure       => latest,
+      virtualenv   => $root_dir,
+      environment  => ["PYTHONPATH=${root_dir}/lib:${root_dir}/webapp"],
+      install_args => "--install-option=\"--prefix=${root_dir}\" --install-option=\"--install-lib=${root_dir}/lib\""
+    }
   }
   else {
-    package { [$carbon, $graphite_web, $whisper]:
-      ensure => $ver,
+    package {
+      [$carbon, $graphite_web, $whisper]:
+        ensure => $ver;
+      $pytz:
+        ensure => latest;
     }
   }
 

spec/classes/graphite/graphite__install_spec.rb

@@ -19,6 +19,12 @@
       it_should_behave_like "pip_package", "whisper"
       it_should_behave_like "pip_package", "carbon"
       it_should_behave_like "pip_package", "graphite-web"
+      it {
+        should contain_python__pip("pytz")
+          .with_ensure('latest')
+          .with_virtualenv('/this/is/root')
+          .with_environment(["PYTHONPATH=/this/is/root/lib:/this/is/root/webapp"])
+      }
     end
   end
 
@@ -29,11 +35,13 @@
       :whisper_pkg_name => 'python-whisper',
       :carbon_pkg_name => 'python-carbon',
       :graphite_web_pkg_name => 'python-graphite-web',
+      :pytz_package_name => 'python-pytz',
     }}
 
     it { should contain_package('python-whisper').with_ensure('1.2.3') }
     it { should contain_package('python-carbon').with_ensure('1.2.3') }
     it { should contain_package('python-graphite-web').with_ensure('1.2.3') }
+    it { should contain_package('python-pytz').with_ensure('latest') }
   end
 
 end