eccodes: new package for encoding and decoding meteorological data (#3900)

* eccodes: new package for encoding and decoding meteorological data

* eccodes: remove line breaks from package docstring

* eccodes: simplify names of variants

* eccodes: give a description for each variant

* eccodes: use succinct code for cmake_args

* eccodes: found extra dependency for python variant

* eccodes: add URL for a list of available releases

var/spack/repos/builtin/packages/eccodes/package.py

+##############################################################################
+# Copyright (c) 2013-2016, Lawrence Livermore National Security, LLC.
+# Produced at the Lawrence Livermore National Laboratory.
+#
+# This file is part of Spack.
+# Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
+# LLNL-CODE-647188
+#
+# For details, see https://github.com/llnl/spack
+# Please also see the LICENSE file for our notice and the LGPL.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License (as
+# published by the Free Software Foundation) version 2.1, February 1999.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
+# conditions of the GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+##############################################################################
+#
+from spack import *
+
+
+class Eccodes(CMakePackage):
+    """ecCodes is a package developed by ECMWF for processing meteorological
+    data in GRIB (1/2), BUFR (3/4) and GTS header formats."""
+
+    homepage = "https://software.ecmwf.int/wiki/display/ECC/ecCodes+Home"
+    url      = "https://software.ecmwf.int/wiki/download/attachments/45757960/eccodes-2.2.0-Source.tar.gz?api=v2"
+    list_url = "https://software.ecmwf.int/wiki/display/ECC/Releases"
+
+    version('2.2.0', 'b27e6f0a3eea5b92dac37372e4c45a62')
+
+    variant('netcdf', default=True,
+            description="Support GRIB to NetCDF conversion")
+    variant('jpeg', default=True,
+            description="Support JPEG2000 encoding/decoding")
+    variant('png', default=True,
+            description="Support PNG encoding/decoding")
+    variant('python', default=False,
+            description="Build the eccodes Python interface")
+    variant('pthreads', default=False,
+            description="Enable POSIX threads")
+    variant('openmp', default=False,
+            description="Enable OpenMP threads")
+    variant('memfs', default=False,
+            description="Memory based access to definitions/samples")
+
+    depends_on('netcdf', when='+netcdf')
+    depends_on('openjpeg', when='+jpeg')
+    depends_on('libpng', when='+png')
+    depends_on('py-numpy', when='+python')
+    extends('python', when='+python')
+
+    def cmake_args(self):
+        variants = ['+netcdf', '+jpeg', '+png', '+python',
+                    '+pthreads', '+openmp', '+memfs']
+        options = ['NETCDF', 'JPG', 'PNG', 'PYTHON',
+                   'ECCODES_THREADS', 'ECCODES_OMP_THREADS', 'MEMFS']
+        return map(lambda variant, option: "-DENABLE_%s=%s" %
+                   (option, 'YES' if variant in self.spec else 'NO'),
+                   variants, options)