Add ADDITIONAL_REQS config option

- Define requirements packages in settings.
   - Add COLLECTD_ADDITIONAL_PACKAGES variable.
   - User can define requirements to be installed by using the above
     variable in local.conf
   - Install system requirements and user defined requirements in
     libs/collectd.

Change-Id: If5883aa585be4c6a42e8ffbee9a59ad80de765ae
Closes-Bug: #1675120

devstack/libs/collectd

@@ -21,17 +21,8 @@ function stop_collectd {
 function install_requirements {
     echo "Installing pre-resquisites"
 
-    if is_ubuntu; then
-        install_package libvirt-bin libvirt-dev python-libvirt
-        if [[ "$COLLECTD_INSTALL_TYPE" == "source" ]]; then
-            install_package byacc flex bison build-essential automake libgcrypt20 libtool
-        fi
-
-    elif is_fedora; then
-        install_package libvirt libvirt-devel libvirt-python
-        if [[ "$COLLECTD_INSTALL_TYPE" == "source" ]]; then
-            install_package flex bison automake autoconf libtool
-        fi
+    if [[ ! -z "$COLLECTD_REQUIREMENTS" ]]; then
+        install_package $COLLECTD_REQUIREMENTS $COLLECTD_ADDITIONAL_PACKAGES
     else
         echo "Unsupported distros"
     fi

devstack/settings

@@ -43,3 +43,27 @@ fi
 #Custom units feature
 COLLECTD_CEILOMETER_UNITS=${COLLECTD_CEILOMETER_CUSTOM_UNITS:-none}
 COLLECTD_GNOCCHI_UNITS=${COLLECTD_GNOCCHI_CUSTOM_UNITS:-none}
+
+# User defined requirements
+COLLECTD_ADDITIONAL_PACKAGES=${COLLECTD_ADDITIONAL_PACKAGES:-''}
+COLLECTD_REQUIREMENTS=''
+
+# Definition for requirements
+ubuntu_bin_requirements="libvirt-bin libvirt-dev python-libvirt"
+ubuntu_src_requirements="$ubuntu_bin_requirements byacc flex bison build-essential automake libgcrypt20 libtool"
+centos_bin_requirements="libvirt libvirt-devel libvirt-python"
+centos_src_requirements="$centos_bin_requirements flex bison automake autoconf libtool"
+
+if is_ubuntu; then
+   if [[ "$COLLECTD_INSTALL_TYPE" == "source" ]]; then
+        COLLECTD_REQUIREMENTS="$ubuntu_src_requirements"
+   else
+        COLLECTD_REQUIREMENTS="$ubuntu_bin_requirements"
+   fi
+elif is_fedora; then
+  if [[ "$COLLECTD_INSTALL_TYPE" == "source" ]]; then
+        COLLECTD_REQUIREMENTS="$centos_src_requirements"
+  else
+        COLLECTD_REQUIREMENTS="$centos_bin_requirements"
+  fi
+fi

doc/source/devstackGSG.rst

@@ -78,6 +78,17 @@ To enable this feature execute the following instructions:
 
 | COLLECTD_CUSTOM_UNITS="<meter> <unit>,<meter> <unit>"
 
+Custom Packages Feature
+------------------------
+
+This feature enables users to define new packages to be installed when building
+collectd.
+
+* To include your new packages, add the following line with your chosen
+  packages to your local.conf file.
+
+| COLLECTD_ADDITIONAL_PACKAGES="package1 package2 package3"
+
 Gnocchi
 =======
 

doc/source/usage.rst

@@ -130,6 +130,15 @@ COLLECTD_PREFIX
 
     Default: /usr/
 
+COLLECTD_ADDITIONAL_PACKAGES
+    Specify additional packages to be installed before collectd is
+    built/installed. This is useful when building collectd from source it
+    will make sure the packages are installed. Collectd plugins are
+    automatically installed/built if requirements are met, so there is no need
+    for manual installation. A space separates packages.
+
+    Example: COLLECTD_ADDITIONAL_PACKAGES="package1 package2 package3"
+
 
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