storage: simplified use of df to get disk information

- Use df --block-size=1 instead --human-readable to fix locale issue #1043.
- Code cleanup: get available space directly, better variable/module names.

Signed-off-by: Johannes Keyser <johanneskeyser@posteo.de>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/storage/__init__.py

@@ -64,8 +64,8 @@ def get_disks():
 def _get_disks_from_df():
     """Return the list of disks and free space available using 'df'."""
     command = ['df', '--exclude-type=tmpfs', '--exclude-type=devtmpfs',
-               '--output=source,target,fstype,size,used,pcent',
+               '--block-size=1',
-               '--human-readable']
+               '--output=source,target,fstype,size,used,avail,pcent']
     try:
         process = subprocess.run(command, stdout=subprocess.PIPE, check=True)
     except subprocess.CalledProcessError as exception:
@@ -78,9 +78,15 @@ def _get_disks_from_df():
     for line in output.splitlines()[1:]:
         parts = line.split()
         keys = ('device', 'mount_point', 'file_system_type', 'size', 'used',
-                'percentage_used')
+                'free', 'percent_used')
         disk = dict(zip(keys, parts))
-        disk['percentage_used'] = int(disk['percentage_used'].rstrip('%'))
+        disk['percent_used'] = int(disk['percent_used'].rstrip('%'))
+        disk['size'] = int(disk['size'])
+        disk['used'] = int(disk['used'])
+        disk['free'] = int(disk['free'])
+        disk['size_str'] = format_bytes(disk['size'])
+        disk['used_str'] = format_bytes(disk['used'])
+        disk['free_str'] = format_bytes(disk['free'])
         disks.append(disk)
 
     return disks
@@ -130,3 +136,27 @@ def is_expandable(device):
 def expand_partition(device):
     """Expand a partition."""
     actions.superuser_run('storage', ['expand-partition', device])
+
+
+def format_bytes(size):
+    """Return human readable disk size from bytes."""
+    if not size:
+        return size
+
+    if size < 1024:
+        return _('{disk_size:.1f} bytes').format(disk_size=size)
+
+    if size < 1024 ** 2:
+        size /= 1024
+        return _('{disk_size:.1f} KiB').format(disk_size=size)
+
+    if size < 1024 ** 3:
+        size /= 1024 ** 2
+        return _('{disk_size:.1f} MiB').format(disk_size=size)
+
+    if size < 1024 ** 4:
+        size /= 1024 ** 3
+        return _('{disk_size:.1f} GiB').format(disk_size=size)
+
+    size /= 1024 ** 4
+    return _('{disk_size:.1f} TiB').format(disk_size=size)

plinth/modules/storage/templates/storage.html

@@ -52,20 +52,20 @@
               <td>{{ disk.file_system_type }}</td>
               <td>
                 <div class="progress">
-                  {% if disk.percentage_used < 75 %}
+                  {% if disk.percent_used < 75 %}
                     <div class="progress-bar progress-bar-striped progress-bar-success"
-                  {% elif disk.percentage_used < 90 %}
+                  {% elif disk.percent_used < 90 %}
                     <div class="progress-bar progress-bar-striped progress-bar-warning"
                   {% else %}
                     <div class="progress-bar progress-bar-striped progress-bar-danger"
                   {% endif %}
-                         role="progressbar" aria-valuenow="disk.percentage_used"
+                         role="progressbar" aria-valuenow="disk.percent_used"
                          aria-valuemin="0" aria-valuemax="100"
-                         style="width: {{ disk.percentage_used }}%;">
+                         style="width: {{ disk.percent_used }}%;">
-                      {{ disk.percentage_used }}%
+                      {{ disk.percent_used }}%
                     </div>
                 </div>
-                <div>{{ disk.used }} / {{ disk.size }}</div>
+                <div>{{ disk.used_str }} / {{ disk.size_str }}</div>
               </td>
             </tr>
           {% endfor %}

plinth/modules/storage/views.py

@@ -25,7 +25,7 @@ from django.shortcuts import redirect
 from django.template.response import TemplateResponse
 from django.urls import reverse
 from django.utils.translation import ugettext as _
-from plinth.modules import storage as storage_module
+from plinth.modules import storage
 from plinth.utils import format_lazy, is_user_admin
 
 
@@ -34,10 +34,10 @@ logger = logging.getLogger(__name__)
 
 def index(request):
     """Show connection list."""
-    disks = storage_module.get_disks()
+    disks = storage.get_disks()
-    root_device = storage_module.get_root_device(disks)
+    root_device = storage.get_root_device(disks)
-    expandable_root_size = storage_module.is_expandable(root_device)
+    expandable_root_size = storage.is_expandable(root_device)
-    expandable_root_size = _format_bytes(expandable_root_size)
+    expandable_root_size = storage.format_bytes(expandable_root_size)
 
     warn_about_low_disk_space(request)
 
@@ -49,15 +49,15 @@ def index(request):
 
 def expand(request):
     """Warn and expand the root partition."""
-    disks = storage_module.get_disks()
+    disks = storage.get_disks()
-    root_device = storage_module.get_root_device(disks)
+    root_device = storage.get_root_device(disks)
 
     if request.method == 'POST':
         expand_partition(request, root_device)
         return redirect(reverse('storage:index'))
 
-    expandable_root_size = storage_module.is_expandable(root_device)
+    expandable_root_size = storage.is_expandable(root_device)
-    expandable_root_size = _format_bytes(expandable_root_size)
+    expandable_root_size = storage.format_bytes(expandable_root_size)
     return TemplateResponse(request, 'storage_expand.html',
                             {'title': _('Expand Root Partition'),
                              'expandable_root_size': expandable_root_size})
@@ -66,7 +66,7 @@ def expand(request):
 def expand_partition(request, device):
     """Expand the partition."""
     try:
-        storage_module.expand_partition(device)
+        storage.expand_partition(device)
     except Exception as exception:
         messages.error(request, _('Error expanding partition: {exception}')
                        .format(exception=exception))
@@ -79,71 +79,26 @@ def warn_about_low_disk_space(request):
     if not is_user_admin(request, cached=True):
         return
 
-    disks = storage_module.get_disks()
+    disks = storage.get_disks()
     list_root = [disk for disk in disks if disk['mountpoint'] == '/']
     if not list_root:
         logger.error('Error getting information about root partition.')
         return
 
-    perc_used = list_root[0]['percentage_used']
+    percent_used = list_root[0]['percent_used']
-    size_bytes = _interpret_size_string(list_root[0]['size'])
+    size_bytes = list_root[0]['size']
-    free_bytes = size_bytes * (100 - perc_used) / 100
+    free_bytes = list_root[0]['free']
+    free_gib = free_bytes / (1024 ** 3)
 
     message = format_lazy(
         # Translators: xgettext:no-python-format
         _('Warning: Low space on system partition ({percent_used}% used, '
           '{free_space} free).'),
-        percent_used=perc_used, free_space=_format_bytes(free_bytes))
+        percent_used=percent_used,
+        free_space=storage.format_bytes(free_bytes))
 
-    free_gib = free_bytes / (1024 ** 3)
+    if percent_used > 90 or free_gib < 1:
-    if perc_used > 90 or free_gib < 1:
         messages.error(request, message)
-    elif perc_used > 75 or free_gib < 2:
+    elif percent_used > 75 or free_gib < 2:
         messages.warning(request, message)
 
-
-def _interpret_size_string(size_str):
-    """Convert size string to number of bytes."""
-    # TODO: Drop --human-readable from df command (github issue #1043)
-    size_str = size_str.replace(',', '.')  # some locales use commas
-    size_str = size_str.replace('٫', '.')  # arabic decimal separator
-    if size_str[-1] in '0123456789':
-        return float(size_str[:-1])
-
-    if size_str[-1] == 'K':
-        return float(size_str[:-1]) * 1024
-
-    if size_str[-1] == 'M':
-        return float(size_str[:-1]) * 1024 ** 2
-
-    if size_str[-1] == 'G':
-        return float(size_str[:-1]) * 1024 ** 3
-
-    if size_str[-1] == 'T':
-        return float(size_str[:-1]) * 1024 ** 4
-
-    return -1
-
-
-def _format_bytes(size):
-    """Return human readable disk size from bytes."""
-    if not size:
-        return size
-
-    if size < 1024:
-        return _('{disk_size:.1f} bytes').format(disk_size=size)
-
-    if size < 1024 ** 2:
-        size /= 1024
-        return _('{disk_size:.1f} KiB').format(disk_size=size)
-
-    if size < 1024 ** 3:
-        size /= 1024 ** 2
-        return _('{disk_size:.1f} MiB').format(disk_size=size)
-
-    if size < 1024 ** 4:
-        size /= 1024 ** 3
-        return _('{disk_size:.1f} GiB').format(disk_size=size)
-
-    size /= 1024 ** 4
-    return _('{disk_size:.1f} TiB').format(disk_size=size)