uwsgi and Pyramid

[Myles English]

Hello,

I have defined some packages to install Pyramid (a Python web
framework) here:
https://gist.github.com/mylese/861b4765e9f533bafa2cb2b305974caa

Now I am trying to get my python app (my_app), served by uwsgi
but get the infamous "no app loaded" error from uwsgi:


$ /gnu/store/y83n9b6zl76pq1v7qb0npl7p7gd0hgd7-profile/bin/uwsgi --need-app 
--ini production.ini

[uWSGI] getting INI configuration from production.ini
*** Starting uWSGI 2.0.12 (64bit) on [Mon Jun 20 22:45:02 2016] ***
compiled with version: 4.9.3 on 20 June 2016 21:04:07
os: Linux-4.5.4-1-ARCH #1 SMP PREEMPT Wed May 11 22:21:28 CEST 2016
nodename: bill
machine: x86_64
clock source: unix
pcre jit disabled
detected number of CPU cores: 2
current working directory: /home/myles/srv/my_app
detected binary path: 
/gnu/store/q3s2v62vqp288pfkswggcxjxfx1qii38-uwsgi-dev-2.0.12/bin/uwsgi
your processes number limit is 15779
your memory page size is 4096 bytes
detected max file descriptor number: 1024
lock engine: pthread robust mutexes
thunder lock: disabled (you can enable it with --thunder-lock)
uwsgi socket 0 bound to UNIX address /tmp/uwsgi-my_app.sock fd 3
Python version: 3.4.3 (default, Jan  1 1970, 00:00:01)  [GCC 4.9.3]
*** Python threads support is disabled. You can enable it with --enable-threads 
***
Python main interpreter initialized at 0x16487d0
your server socket listen backlog is limited to 100 connections
your mercy for graceful operations on workers is 60 seconds
mapped 145536 bytes (142 KB) for 1 cores
*** Operational MODE: single process ***
*** no app loaded. GAME OVER ***


If started with strace it gives slightly more info, it seems to
be looking for /home/myles/srv/my_app/uwsgi, but why?:


$ strace /gnu/store/y83n9b6zl76pq1v7qb0npl7p7gd0hgd7-profile/bin/uwsgi 
--need-app --ini production.ini

write(2, "*** Operational MODE: single pro"..., 41*** Operational MODE: single 
process ***
) = 41
readlink("uwsgi", 0x7ffc5954be10, 4096) = -1 ENOENT (No such file or directory)
getcwd("/home/myles/srv/my_app", 4096) = 25
lstat("/home/myles/srv/my_app/uwsgi", 0x7ffc5954bd30) = -1 ENOENT (No such file 
or directory)
fstat(2, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 3), ...}) = 0
fstat(2, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 3), ...}) = 0
ioctl(2, TCGETS, {B38400 opost isig icanon echo ...}) = 0
fstat(2, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 3), ...}) = 0
lseek(2, 0, SEEK_CUR)                   = -1 ESPIPE (Illegal seek)
ioctl(2, TCGETS, {B38400 opost isig icanon echo ...}) = 0
lseek(2, 0, SEEK_CUR)                   = -1 ESPIPE (Illegal seek)
write(2, "*** no app loaded. GAME OVER ***"..., 33*** no app loaded. GAME OVER 
***
) = 33
exit_group(22)                          = ?
+++ exited with 22 +++


I have been trying the above commands from an environment started
like this:

$ guix environment --ad-hoc my_app


Where my_site.scm is:

(define-module (my-local-packages mysite)
  #:use-module (guix packages)
  #:use-module (guix download)
  #:use-module (guix build-system python)
  #:use-module (guix licenses)
  #:use-module (gnu packages python)
  #:use-module (gnu packages web)
  #:use-module (my-packages python-pyramid))

(define-public my_app
  (package
  (name "my_app")
  (version "0.0.1")
  (source
    (origin
      (method url-fetch)
      (uri (string-append
            "file:///home/myles/srv/my_app/dist/my_app-"
            version
            ".tar.gz"))
      (sha256
       (base32
        "0sfyk45qgl51gi0cq5idg07zgb8qq1bn7pf9pxj8na0hyw9k6by3"))))
  (build-system python-build-system)
  (inputs
   `(("python-setuptools" ,python-setuptools)
     ("python-pyramid" ,python-pyramid)
     ("python-pyramid-mako" ,python-pyramid-mako)
     ("python-pyramid-chameleon" ,python-pyramid-chameleon)
     ("python-pygments" ,python-pygments)
     ("python-pyramid-debugtoolbar" ,python-pyramid-debugtoolbar)))
  (propagated-inputs
   `(("uwsgi" ,uwsgi "python")
     ("uwsgi" ,uwsgi "out")
     ("python" ,python)))
  (arguments
   `(#:tests? #f))  ;; ImportError: cannot import name 'my_view'
  (home-page "http://my_app.com";)
  (synopsis
    "Development of my site")
  (description
    "Development of my site")
  (license expat)))


The above installs my_site from a Python tarball distribution
made like this:

my_app$ python3 setup.py sdist

In setup.py in the list "install_requires", if I add 'uwsgi' it
gives this error upon running the above "guix environment"
command:

Adding my_app 0.0.1 to easy-install.pth file

Installed 
/gnu/store/bc38r7nrn4p20fpvb1p9v8w9zgqplpqf-my_app-0.0.1/lib/python3.4/site-packages/my_app-0.0.1-py3.4.egg
Processing dependencies for my_app==0.0.1
Searching foAdding my_app 0.0.1 to easy-install.pth file

Installed 
/gnu/store/bc38r7nrn4p20fpvb1p9v8w9zgqplpqf-my_app-0.0.1/lib/python3.4/site-packages/my_app-0.0.1-py3.4.egg
Processing dependencies for my_app==0.0.1
Searching for uwsgi
Reading https://pypi.python.org/simple/uwsgi/
Download error on https://pypi.python.org/simple/uwsgi/: [Errno -2] Name or 
service not known -- Some packages may not be found!
Couldn't find index page for 'uwsgi' (maybe misspelled?)
Scanning index of all packages (this may take a while)
Reading https://pypi.python.org/simple/
Download error on https://pypi.python.org/simple/: [Errno -2] Name or service 
not known -- Some packages may not be found!
No local packages or download links found for uwsgi
error: Could not find suitable distribution for Requirement.parse('uwsgi')
phase `install' failed after 2.9 seconds
builder for `/gnu/store/cb22aarjscjl7bfq0lw72hirs2cx1yir-my_app-0.0.1.drv' 
failed with exit code 1
guix environment: error: build failed: build of 
`/gnu/store/cb22aarjscjl7bfq0lw72hirs2cx1yir-my_app-0.0.1.drv' failed
guix environment --ad-hoc my_app  6.83s user 0.55s system 40% cpu 18.375 total


Does anybody use uwsgi to serve a Python app successfully?  Do I
need to add 'uwsgi' to my setup.py?  Why can't uwsgi find my app?
What else can I try?

Thanks,
Myles