Add validation check to module name (#49)

Add validation check to module name

changelog/49.feature

@@ -0,0 +1 @@
+Module name is now validated against available modules on host. Can be skipped with `--skip-validation`.

mdbenchmark/generate.py

@@ -19,20 +19,82 @@
 # along with MDBenchmark.  If not, see <http://www.gnu.org/licenses/>.
 import click
 import datreant.core as dtr
-from jinja2.exceptions import TemplateNotFound
 
-from . import console
+from . import console, mdengines, utils
 from .cli import cli
-from .mdengines import detect_md_engine, namd
-from .utils import ENV, normalize_host, print_possible_hosts
+
+
+def validate_name(ctx, param, name=None):
+    """Validate that we are given a name argument."""
+    if name is None:
+        raise click.BadParameter(
+            'Please specify the base name of your input files.',
+            param_hint='"-n" / "--name"')
+
+    return name
+
+
+def validate_module(ctx, param, module=None):
+    """Validate that we are given a module argument."""
+    if module is None or not module:
+        raise click.BadParameter(
+            'Please specify which MD engine module to use for the benchmarks.',
+            param_hint='"-m" / "--module"')
+    return module
+
+
+def validate_number_of_nodes(min_nodes, max_nodes):
+    """Validate that the minimal number of nodes is smaller than the maximal
+       number.
+    """
+    if min_nodes > max_nodes:
+        raise click.BadParameter(
+            'The minimal number of nodes needs to be smaller than the maximal number.',
+            param_hint='"--min-nodes"')
+
+
+def print_known_hosts(ctx, param, value):
+    """Callback to print all available hosts to the user."""
+    if not value or ctx.resilient_parsing:
+        return
+    utils.print_possible_hosts()
+    ctx.exit()
+
+
+def validate_hosts(ctx, param, host=None):
+    """Callback to validate the hostname received as input.
+
+    If we were not given a hostname, we first try to guess it via
+    `utils.guess_host`. If this fails, we give up and throw an error.
+
+    Otherwise we compare the provided/guessed host with the list of available
+    templates. If the hostname matches the template name, we continue by
+    returning the hostname.
+    """
+    if host is None:
+        host = utils.guess_host()
+        if host is None:
+            raise click.BadParameter(
+                'Could not guess host. Please provide a value explicitly.',
+                param_hint='"--host"')
+
+    known_hosts = utils.get_possible_hosts()
+    if host not in known_hosts:
+        console.info('Could not find template for host \'{}\'.', host)
+        utils.print_possible_hosts()
+        # TODO: Raise some appropriate error here
+        ctx.exit()
+        return
+
+    return host
 
 
 @cli.command()
 @click.option(
     '-n',
     '--name',
     help='Name of input files. All files must have the same base name.',
-    show_default=True)
+    callback=validate_name)
 @click.option(
     '-g',
     '--gpu',
@@ -43,8 +105,13 @@
     '-m',
     '--module',
     help='Name of the MD engine module to use.',
-    multiple=True)
-@click.option('--host', help='Name of the job template.', default=None)
+    multiple=True,
+    callback=validate_module)
+@click.option(
+    '--host',
+    help='Name of the job template.',
+    default=None,
+    callback=validate_hosts)
 @click.option(
     '--min-nodes',
     help='Minimal number of nodes to request.',
@@ -64,48 +131,46 @@
     show_default=True,
     type=click.IntRange(1, 1440))
 @click.option(
-    '--list-hosts', help='Show available job templates.', is_flag=True)
-def generate(name, gpu, module, host, min_nodes, max_nodes, time, list_hosts):
-    """Generate benchmarks."""
-    if list_hosts:
-        print_possible_hosts()
-        return
-
-    if not name:
-        raise click.BadParameter(
-            'Please specify the base name of your input files.',
-            param_hint='"-n" / "--name"')
-
-    if not module:
-        raise click.BadParameter(
-            'Please specify which mdengine module to use for the benchmarks.',
-            param_hint='"-m" / "--module"')
-
-    if min_nodes > max_nodes:
-        raise click.BadParameter(
-            'The minimal number of nodes needs to be smaller than the maximal number.',
-            param_hint='"--min-nodes"')
+    '--list-hosts',
+    help='Show available job templates.',
+    is_flag=True,
+    is_eager=True,
+    callback=print_known_hosts,
+    expose_value=False)
+@click.option(
+    '--skip-validation',
+    help='Skip the validation of module names.',
+    default=False,
+    is_flag=True)
+def generate(name, gpu, module, host, min_nodes, max_nodes, time,
+             skip_validation):
+    """Generate benchmarks simulations from the CLI."""
+    # Validate the number of nodes
+    validate_number_of_nodes(min_nodes=min_nodes, max_nodes=max_nodes)
 
-    host = normalize_host(host)
-    try:
-        tmpl = ENV.get_template(host)
-    except TemplateNotFound:
-        raise click.BadParameter(
-            'Could not find template for host \'{}\'.'.format(host),
-            param_hint='"--host"')
+    # Grab the template name for the host. This should always work because
+    # click does the validation for us
+    tmpl = utils.retrieve_host_template(host)
 
-    # Make sure we only warn the user once, if they are using NAMD.
+    # Warn the user that NAMD support is still experimental.
     if any(['namd' in m for m in module]):
         console.warn(
             'NAMD support is experimental. '
             'All input files must be in the current directory. '
-            'Parameter paths must be absolute. Only crude file checks are performed!'
+            'Parameter paths must be absolute. Only crude file checks are performed! '
             'If you use the {} option make sure you use the GPU compatible NAMD module!',
             '--gpu')
 
+    module = mdengines.normalize_modules(module, skip_validation)
+
+    # If several modules were given and we only cannot find one of them, we
+    # continue.
+    if not module:
+        console.error('No requested modules available!')
+
     for m in module:
-        # Here we detect the mdengine (GROMACS or NAMD).
-        engine = detect_md_engine(m)
+        # Here we detect the MD engine (supported: GROMACS and NAMD).
+        engine = mdengines.detect_md_engine(m)
 
         directory = '{}_{}'.format(host, m)
         gpu_string = ''

mdbenchmark/mdengines/__init__.py

@@ -17,22 +17,153 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with MDBenchmark.  If not, see <http://www.gnu.org/licenses/>.
+import os
+from collections import defaultdict
+
 import six
 
 from . import gromacs, namd
 from .. import console
 
+SUPPORTED_ENGINES = {'gromacs': gromacs, 'namd': namd}
+
 
 def detect_md_engine(modulename):
     """Detects the MD engine based on the available modules.
-        Any newly implemented mdengines must be added here.
-        Returns the python module."""
-    _engines = {'gromacs': gromacs, 'namd': namd}
 
-    for name, engine in six.iteritems(_engines):
+    Any newly implemented MD engines must be added here.
+
+    Returns
+    -------
+
+    The corresponding MD engine module or `None` if the requested module is not
+    supported.
+    """
+
+    for name, engine in six.iteritems(SUPPORTED_ENGINES):
         if name in modulename:
             return engine
 
-    console.error(
-        "No suitable engine detected for '{}'. Known engines are: {}.",
-        modulename, ', '.join(sorted(_engines.keys())))
+    return None
+
+
+def prepare_module_name(module):
+    """Split the provided module name into its base MD engine and version.
+
+    Currently we only try to split via the delimiter `/`, but this could be
+    changed upon request or made configurable on a per-host basis.
+    """
+    try:
+        basename, version = module.split('/')
+    except (ValueError, AttributeError) as e:
+        console.error('We were not able to determine the module name.')
+
+    return basename, version
+
+
+def get_available_modules():
+    """Return all available module versions for a given MD engine.
+
+    Returns
+    -------
+    If we cannot access the `MODULEPATH` environment variable, we return `None`.
+
+    available_modules : dict
+        Dictionary containing all available engines as keys and their versions as a list.
+    """
+
+    MODULE_PATHS = os.environ.get('MODULEPATH', None)
+    available_modules = dict((mdengine, []) for mdengine in SUPPORTED_ENGINES)
+
+    # Return `None` if the environment variable `MODULEPATH` does not exist.
+    if not MODULE_PATHS:
+        return None
+
+    # Go through the directory structure and grab all version of modules that we support.
+    for paths in MODULE_PATHS.split(':'):
+        for path, subdirs, files in os.walk(paths):
+            for mdengine in SUPPORTED_ENGINES:
+                if mdengine in path:
+                    for name in files:
+                        if not name.startswith('.'):
+                            available_modules[mdengine].append(name)
+
+    return available_modules
+
+
+def normalize_modules(modules, skip_validation):
+    """Validate that the provided module names are available.
+
+    We first check whether the requested MD engine is supported by the package.
+    Next we try to discover all available modules on the host. If this is not
+    possible, or if the user has used the `--skip-validation` option, we skip
+    the check and notify the user.
+
+    If the user requested modules that were not found on the system, we inform
+    the user and show all modules for that corresponding MD engine that were
+    found.
+    """
+    # Check if modules are from supported md engines
+    d = defaultdict(list)
+    for m in modules:
+        engine, version = prepare_module_name(m)
+        d[engine] = version
+    for engine in d.keys():
+        if detect_md_engine(engine) is None:
+            console.error("There is currently no support for '{}'. "
+                          "Supported MD engines are: gromacs, namd.", engine)
+
+    if skip_validation:
+        console.warn('Not performing module name validation.')
+        return modules
+
+    available_modules = get_available_modules()
+    if available_modules is None:
+        console.warn(
+            'Cannot locate modules available on this host. Not performing module name validation.'
+        )
+        return modules
+
+    good_modules = [
+        m for m in modules if validate_module_name(m, available_modules)
+    ]
+
+    # Prepare to warn the user about missing modules
+    missing_modules = set(modules).difference(good_modules)
+    if missing_modules:
+        d = defaultdict(list)
+        for mm in sorted(missing_modules):
+            engine, version = mm.split('/')
+            d[engine].append(version)
+
+        err = 'We have problems finding all of your requested modules on this host.\n'
+        args = []
+        for engine in sorted(d.keys()):
+            err += 'We were not able to find the following modules for MD engine {}: {}.\n'
+            args.append(engine)
+            args.extend(d[engine])
+            # Show all available modules that we found for the requested MD engine
+            err += 'Available modules are:\n{}\n'
+            args.extend([
+                '\n'.join([
+                    '{}/{}'.format(engine, mde)
+                    for mde in sorted(available_modules[engine])
+                ])
+            ])
+        console.warn(err, bold=True, *args)
+
+    return good_modules
+
+
+def validate_module_name(module, available_modules=None):
+    """Validates that the specified module version is available on the host.
+
+    Returns
+    -------
+
+    Returns True or False, indicating whether the specified version is
+    available on the host.
+    """
+    basename, version = prepare_module_name(module)
+
+    return version in available_modules[basename]