__package_pip: add optional dependencies

This is a poor implementation of optional dependencies for pip packages.
It ensures to install them if the package will be installed, but does
not take into account if they must be added/removed after the package is
already installed. Also, it will not be autoremoved, as all dependencies
will not be removed.

cdist/conf/type/__package_pip/gencode-remote

@@ -56,6 +56,19 @@ fi
 
 case "$state_should" in
     present)
+        if [ -f "$__object/parameter/extra" ]
+        then
+            while read extra
+            do
+                if [ "$extras" ]; then
+                    extras="$extras,$extra"
+                else
+                    extras="$extra"
+                fi
+            done < "$__object/parameter/extra"
+            name="${name}[${extras}]"
+        fi
+
         if [ "$runas" ]
         then
             echo "su -c '$pip install -q $name' $runas"

cdist/conf/type/__package_pip/man.rst

@@ -22,6 +22,11 @@ OPTIONAL PARAMETERS
 name
     If supplied, use the name and not the object id as the package name.
 
+extra
+    Extra optional dependencies which should be installed along the selected
+    package. Can be specified multiple times. Will only be applied if the
+    package actually will be installed, but will not explicitly checked.
+
 pip
     Instead of using pip from PATH, use the specific pip path.
 
@@ -46,6 +51,14 @@ EXAMPLES
     # Use pip in a virtualenv located at /foo/shinken_virtualenv as user foo
     __package_pip pyro --state present --pip /foo/shinken_virtualenv/bin/pip --runas foo
 
+    # Install package with optional dependencies
+    __package_pip mautrix-telegram --extra speedups --extra webp_convert --extra hq_thumbnails
+    # or do a little cheating
+    __package_pip mautrix-telegram --extra speedups,webp_convert,hq_thumbnails
+
+    # or take all extras
+    __package_pip mautrix-telegram --extra all
+
 
 SEE ALSO
 --------

cdist/conf/type/__package_pip/parameter/optional_multiple

@@ -0,0 +1 @@
+extra