Use wrapper shell script for systems without a "/usr/bin/env python"

Some systems (Ubuntu 17.04+) have nothing for "/usr/bin/env python". The
have python3 instead. This commit introduces a wrapper script that finds
out which python binary to use. Instead of linking bin/ansible-cmdb
directly to lib/ansible-cmdb (the python script), we now link to the
wrapper script.

Author: fboender

src/ansible-cmdb

@@ -1,208 +1,34 @@
-#!/usr/bin/env python
+#!/bin/sh
 
-# ansible_cmd
 #
-# Generate host overview (configuration management database) from ansible fact
-# gathering output.
-#
-# Usage:
-#
-#   $ ansible -m setup --tree out all
-#   $ ansible-cmdb out > cmdb.html
+# Wrapper script to find python version to use.
 #
 
-import optparse
-import sys
-import os
-import logging
-from mako import exceptions
-import ansiblecmdb
-import ansiblecmdb.util as util
-import ansiblecmdb.render as render
-
+# Find python binary
+PY_BIN=$(which python)
+if [ -z "$PY_BIN" ]; then
+    PY_BIN=$(which python3)
+fi
 
 # Verify Python version
-if sys.version_info < (2, 7):
-    sys.stderr.write(
-        "Ansible-cmdb requires Python v2.7+. You are running {}. Support for "
-        "Python v2.6 supported ended October 2013. You should upgrade to a "
-        "newer version.\n".format(sys.version))
-    sys.exit(1)
-
-
-def get_logger():
-    """
-    Instantiate a logger.
-    """
-    root = logging.getLogger()
-    root.setLevel(logging.WARNING)
-    ch = logging.StreamHandler(sys.stderr)
-    ch.setLevel(logging.DEBUG)
-    formatter = logging.Formatter('%(message)s')
-    ch.setFormatter(formatter)
-    root.addHandler(ch)
-    return root
-
-
-def get_data_dir():
-    """
-    Find out our installation prefix and data directory. These can be in
-    different places depending on how ansible-cmdb was installed.
-    """
-    data_dir_paths = [
-        os.path.join(os.path.dirname(ansiblecmdb.__file__), 'data'),
-        os.path.join(os.path.dirname(sys.argv[0]), '..', 'lib', 'ansiblecmdb', 'data'),
-        '/usr/local/lib/ansiblecmdb/data',
-        '/usr/lib/ansiblecmdb/data',
-    ]
-
-    data_dir = util.find_path(data_dir_paths, 'tpl/html_fancy.tpl')
-    if not data_dir:
-        sys.stdout.write("Couldn't find the data dir for the templates. I tried: {0}\n".format(", ".join(data_dir_paths)))
-        sys.exit(1)
-
-    return data_dir
-
-
-def get_hosts_files(option):
-    """
-    Find out the location of the `hosts` file. This looks in multiple places
-    such as the `-i` option, current dir and ansible configuration files. The
-    first match is returned as a list.
-    """
-    if option is not None:
-        return option.split(',')
-
-    # Use hosts file from the current dir if it exists
-    if os.path.isfile('hosts'):
-        return ['hosts']
-
-    # Perhaps it's configured in a configuration file. Try to find a
-    # configuration file and see if it contains a `hostsfile` entry.
-    config_locations = [
-        '.',
-        '/etc/ansible/'
-    ]
-    config_dir = util.find_path(config_locations, 'ansible.cfg')
-    log.debug('config_dir = {0}'.format(config_dir))
-    if config_dir:
-        with open(os.path.join(config_dir, 'ansible.cfg'), 'r') as cf:
-            for line in cf:
-                if line.startswith('hostfile'):
-                    return [line.split('=', 1)[1].strip()]
-
-
-def parse_user_params(user_params):
-    """
-    Parse the user params (-p/--params) and them as a dict.
-    """
-    if user_params:
-        params = {}
-        try:
-            for param in options.params.split(','):
-                param_key, param_value = param.split('=', 1)
-                params[param_key] = param_value
-        except ValueError as e:
-            sys.stdout.write("Invalid params specified. Should be in format: <key=value>[,<key=value>..]\n")
-            sys.exit(1)
-        return params
-    else:
-        return {}
-
-
-if __name__ == "__main__":
-    log = get_logger()
-    data_dir = get_data_dir()
-    tpl_dir = os.path.join(data_dir, 'tpl')
-    static_dir = os.path.join(data_dir, 'static')
-    version = open(os.path.join(data_dir, 'VERSION')).read().strip()
-
-    parser = optparse.OptionParser(version="%prog v{0}".format(version))
-    parser.set_usage(sys.argv[0] + " [option] <dir> > output.html")
-    parser.add_option("-t", "--template", dest="template", action="store", default='html_fancy', help="Template to use. Default is 'html_fancy'")
-    parser.add_option("-i", "--inventory", dest="inventory", action="store", default=None, help="Inventory to read extra info from")
-    parser.add_option("-f", "--fact-cache", dest="fact_cache", action="store_true", default=False, help="<dir> contains fact-cache files")
-    parser.add_option("-p", "--params", dest="params", action="store", default=None, help="Params to send to template")
-    parser.add_option("-d", "--debug", dest="debug", action="store_true", default=False, help="Show debug output")
-    parser.add_option("-q", "--quiet", dest="quiet", action="store_true", default=False, help="Don't report warnings")
-    parser.add_option("-c", "--columns", dest="columns", action="store", default=None, help="Show only given columns")
-    parser.add_option("--exclude-cols", dest="exclude_columns", action="store", default=None, help="Exclude cols from output")
-    (options, args) = parser.parse_args()
-
-    if len(args) < 1:
-        parser.print_usage()
-        sys.stderr.write("The <dir> argument is mandatory\n")
-        sys.exit(1)
-
-    if options.quiet:
-        log.setLevel(logging.ERROR)
-    elif options.debug:
-        log.setLevel(logging.DEBUG)
-
-    hosts_files = get_hosts_files(options.inventory)
-
-    # Handle template params
-    params = {
-        'lib_dir': data_dir,  # Backwards compatibility for custom templates < ansible-cmdb v1.7
-        'data_dir': data_dir,
-        'version': version,
-        'log': log,
-        'columns': None,
-        'exclude_columns': None,
-    }
-    params.update(parse_user_params(options.params))
-    if options.columns is not None:
-        params['columns'] = options.columns.split(',')
-    if options.exclude_columns is not None:
-        params['exclude_columns'] = options.exclude_columns.split(',')
-
-    # Log some debug information
-    log.debug('data_dir = {0}'.format(data_dir))
-    log.debug('tpl_dir = {0}'.format(tpl_dir))
-    log.debug('static_dir = {0}'.format(static_dir))
-    log.debug('inventory files = {0}'.format(hosts_files))
-    log.debug('template params = {0}'.format(params))
-
-    ansible = ansiblecmdb.Ansible(args, hosts_files, options.fact_cache, debug=options.debug)
-
-    # Render a template with the gathered host info
-    renderer = render.Render(options.template, ['.', tpl_dir])
-    if renderer.tpl_file is None:
-        sys.stderr.write("Template '{0}' not found at any of \n  {1}\n".format(options.template, "\n  ".join(renderer.tpl_possibilities)))
-        sys.exit(1)
-
-    # Make sure we always output in UTF-8, regardless of the user's locale /
-    # terminal encoding. This is different in Python 2 and 3.
-    try:
-        output = renderer.render(ansible.hosts, params)
-        if output:
-            if sys.version_info[0] == 3:
-                sys.stdout.buffer.write(output.lstrip())
-            else:
-                sys.stdout.write(output.lstrip())
-    except Exception as err:
-        full_err = exceptions.text_error_template().render().replace("\n", "\n    ")
-        debug_cmd = "{0} -d {1}".format(sys.argv[0], ' '.join(sys.argv[1:]))
-        debug_txt = ("Whoops, it looks like something went wrong while rendering the template.\n\n"
-                     "The reported error was: {0}: {1}\n\nThe full error was:{2}\n"
-                     "The output is probably not correct.\n\n".format(err.__class__.__name__, err, full_err))
-        if err.__class__.__name__ == "KeyError":
-            debug_txt += "!!! This is probably a problem with missing information in your host facts\n\n"
-        if not options.debug:
-            debug_txt += ("You can re-run ansible-cmdb with the -d switch to turn on debugging\n"
-                          "to get an insight in what might be going wrong:\n\n"
-                          "  {0}\n\n".format(debug_cmd))
-        debug_txt += \
-"""\
-You can report a bug on the issue tracker:
-
-  https://github.com/fboender/ansible-cmdb/issues
-
-Please include the debugging output (-d switch) in the report!
-
-If you can, also include the hosts file and the facts file for the last host
-that rendered properly ('Rendering host...' in the output. If these files must
-remain confidential, you can send them to ferry.boender@gmail.com instead.
-"""
-        sys.stderr.write(debug_txt)
-        sys.exit(1)
+PY_VMAJOR=$($PY_BIN -c "import sys; print(sys.version_info.major)")
+PY_VMINOR=$($PY_BIN -c "import sys; print(sys.version_info.minor)")
+
+if [ "$PY_VMAJOR" -eq 2 -a "$PY_VMINOR" -lt 7 ]; then
+    echo "Python v2.7 or v3.0 or higher is required" >&2
+    exit 1
+fi
+
+# Find path to the real ansible-cmdb python script
+BIN_DIR=$(dirname $0)
+if [ -f "$BIN_DIR/ansible-cmdb.py" ]; then
+    ANSIBLE_CMDB="$BIN_DIR/ansible-cmdb.py"
+elif [ -f "$BIN_DIR/../lib/ansible-cmdb/ansible-cmdb.py" ]; then
+    ANSIBLE_CMDB="$BIN_DIR/../lib/ansible-cmdb/ansible-cmdb.py"
+else
+    echo "Couldn't find $BIN_DIR/ansible-cmdb.py in . or $BIN_DIR/../lib/ansible-cmdb (cwd=$PWD)" >&2
+    exit 2
+fi
+
+# Run it
+$PY_BIN $ANSIBLE_CMDB "$@"