绝对路径？ models.FileFIeld 的 `upload_to`

Question

I have FileField in models.py

class DocFile(models.Model):
    document = models.FileField(upload_to='_mat/')

It works well for local(mac),and the file is stored under /Users/whitebear/myproj/_mat/

However I do the same thing on server (Ubuntu 20, using ENGINX-unit)

It shows the error PermissionError: [Errno 13] Permission denied: '/_mat'

But, /var/www/html/myproj/_mat/ permission is 777

So I guess, somehow it trys to make /_mat as absolute path ..???

If I set upload_to like this ,

document =  models.FileField(upload_to='/var/www/html/myproj_mat/')

It says to use 'relative path'

These are error stack trace.

    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
    return view_func(*args, **kwargs)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/views/generic/base.py", line 70, in view
    return self.dispatch(request, *args, **kwargs)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/rest_framework/views.py", line 509, in dispatch
    response = self.handle_exception(exc)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/rest_framework/views.py", line 469, in handle_exception
    self.raise_uncaught_exception(exc)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/rest_framework/views.py", line 480, in raise_uncaught_exception
    raise exc
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/rest_framework/views.py", line 506, in dispatch
    response = handler(request, *args, **kwargs)
  File "/var/www/html/aicomposer/current/defapp/views.py", line 350, in post
    entry.save()
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/base.py", line 726, in save
    self.save_base(using=using, force_insert=force_insert,
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/base.py", line 763, in save_base
    updated = self._save_table(
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/base.py", line 868, in _save_table
    results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/base.py", line 906, in _do_insert
    return manager._insert(
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/query.py", line 1270, in _insert
    return query.get_compiler(using=using).execute_sql(returning_fields)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/sql/compiler.py", line 1415, in execute_sql
    for sql, params in self.as_sql():
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/sql/compiler.py", line 1358, in as_sql
    value_rows = [
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/sql/compiler.py", line 1359, in <listcomp>
    [self.prepare_value(field, self.pre_save_val(field, obj)) for field in fields]
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/sql/compiler.py", line 1359, in <listcomp>
    [self.prepare_value(field, self.pre_save_val(field, obj)) for field in fields]
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/sql/compiler.py", line 1310, in pre_save_val
    return field.pre_save(obj, add=True)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/fields/files.py", line 302, in pre_save
    file.save(file.name, file.file, save=False)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/db/models/fields/files.py", line 89, in save
    self.name = self.storage.save(name, content, max_length=self.field.max_length)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/core/files/storage.py", line 54, in save
    return self._save(name, content)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/site-packages/django/core/files/storage.py", line 255, in _save
    os.makedirs(directory, exist_ok=True)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/os.py", line 213, in makedirs
    makedirs(head, exist_ok=exist_ok)
  File "/home/ubuntu/anaconda3/envs/aiwave/lib/python3.8/os.py", line 223, in makedirs
    mkdir(name, mode)
PermissionError: [Errno 13] Permission denied: '/_mat'

Answer 1

The MEDIA_ROOT setting [Django-doc] specifies the:

Absolute filesystem path to the directory that will hold user-uploaded files.

You thus should specify with this setting where you will store the media files. If MEDIA_ROOT is thus / , then it will store these in the /_mat/ directory of the server.

You thus can set the MEDIA_ROOT setting to:

# settings.py

# ⋮,

MEDIA_ROOT = '/var/www/html/myproj/'

# ⋮

Answer 2

permission denied i think come from ubuntu file system it self so you can run

sudo chmod -R 755 /var/www/html/myproj/_mat/

and it is better also to make user of Nginx is same as gunicorn and give this user access to your media as follow let your user is user1

sudo chown -R user1:user1 /var/www/html/myproj/_mat/