New audiogen: script

closes #9

larigira/audioform_script.py

@@ -0,0 +1,21 @@
+from flask_wtf import Form
+from wtforms import StringField, validators, SubmitField
+
+
+class ScriptAudioForm(Form):
+    nick = StringField(u'Audio nick', validators=[validators.required()],
+                       description='A simple name to recognize this audio')
+    name = StringField(u'Name', validators=[validators.required()],
+                       description='filename (NOT path) of the script')
+    args = StringField(u'Arguments',
+                       description='arguments, separated by spaces')
+    submit = SubmitField(u'Submit')
+
+
+def scriptaudio_receive(form):
+    return {
+        'kind': 'script',
+        'nick': form.nick.data,
+        'name': form.name.data,
+        'args': form.args.data
+    }

larigira/audiogen_script.py

@@ -0,0 +1,47 @@
+import logging
+import os
+import subprocess
+
+from config import get_conf
+log = logging.getLogger('audioscript')
+
+
+def generate(spec):
+    '''
+    Recognized arguments (fields in spec):
+        - name [mandatory]            script name
+        - args [default=empty]   arguments, space-separated
+    '''
+    conf = get_conf()
+    spec.setdefault('args', '')
+    args = spec['args'].split()
+    for attr in ('name', ):
+        if attr not in spec:
+            raise ValueError("Malformed audiospec: missing '%s'" % attr)
+
+    scriptpath = os.path.join(conf['SCRIPTS_PATH'], spec['name'])
+    if not os.path.exists(scriptpath):
+        raise ValueError("Script %s not found", spec['name'])
+    if not os.access(scriptpath, os.R_OK | os.X_OK):
+        raise ValueError("Insufficient privileges for script %s" % scriptpath)
+    if os.stat(scriptpath).st_uid != os.getuid():
+        raise ValueError("Script %s owned by %d, should be owned by %d"
+                         % (spec['name'], os.stat(scriptpath).st_uid,
+                            os.getuid()))
+    try:
+        log.info('Going to run {}'.format([scriptpath] + args))
+        out = subprocess.check_output([scriptpath] + args,
+                                      env=dict(
+                                          HOME=os.environ['HOME'],
+                                          PATH=os.environ['PATH'],
+                                          MPD_HOST=conf['MPD_HOST'],
+                                          MPD_PORT=str(conf['MPD_PORT'])),
+                                      cwd='/')
+    except subprocess.CalledProcessError as exc:
+        log.error("Error %d when running script %s" %
+                  (exc.returncode, spec['name']))
+        return []
+
+    out = [p for p in out.split('\n') if p]
+    logging.debug('Script %s produced %d files' % (spec['name'], len(out)))
+    return out

larigira/config.py

@@ -18,6 +18,7 @@ def get_conf(prefix='LARIGIRA_'):
     conf['MPD_PORT'] = int(os.getenv('MPD_PORT', '6600'))
     conf['CACHING_TIME'] = 10
     conf['DB_URI'] = os.path.join(conf_dir, 'db.json')
+    conf['SCRIPTS_PATH'] = os.path.join(conf_dir, 'scripts')
     conf['BOOTSTRAP_SERVE_LOCAL'] = True
     conf['SECRET_KEY'] = 'Please replace me!'
     conf['MPD_WAIT_START'] = True

setup.py

@@ -58,7 +58,8 @@ setup(name='larigira',
           'larigira.audiogenerators': [
               'mpd = larigira.audiogen_mpdrandom:generate_by_artist',
               'static = larigira.audiogen_static:generate',
-              'randomdir = larigira.audiogen_randomdir:generate'
+              'randomdir = larigira.audiogen_randomdir:generate',
+              'script = larigira.audiogen_script:generate',
           ],
           'larigira.timegenerators': [
               'frequency = larigira.timegen_every:FrequencyAlarm',
@@ -72,9 +73,11 @@ setup(name='larigira',
           ],
           'larigira.audioform_create': [
               'static = larigira.audioform_static:StaticAudioForm',
+              'script = larigira.audioform_script:ScriptAudioForm',
           ],
           'larigira.audioform_receive': [
               'static = larigira.audioform_static:staticaudio_receive',
+              'script = larigira.audioform_script:scriptaudio_receive',
           ],
       }
       )