Why don't I have permission to install psycopg2 in a virtualenv

Question

My goal is to serve a hello world Django app that uses postgres on an EC2 instance running Ubuntu. I logged in via ssh and cloned a git repo containing a Django project with this requirements.txt:

Django==1.8.2  
djangorestframework==3.1.2  
psycopg2==2.6

I created a virtualenv and then, when I ran (ec2_deploy_test)ubuntu@ip-172-31-22-100:~/ec2-deploy-test$ pip install -r requirements.txt, this exception was thrown:

Collecting psycopg2==2.6 (from -r requirements.txt (line 3)) /home/ubuntu/Envs/ec2_deploy_test/local/lib/python2.7/site-packages/pip/vendor/requests/packages/urllib3/util/ssl.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning. InsecurePlatformWarning Downloading psycopg2-2.6.tar.gz (367kB) 100% |████████████████████████████████| 368kB 785kB/s Building wheels for collected packages: psycopg2 Exception: Traceback (most recent call last): File "/home/ubuntu/Envs/ec2_deploy_test/local/lib/python2.7/site-packages/pip/basecommand.py", line 223, in main status = self.run(options, args) File "/home/ubuntu/Envs/ec2_deploy_test/local/lib/python2.7/site-packages/pip/commands/install.py", line 291, in run wb.build(autobuilding=True) File "/home/ubuntu/Envs/ec2_deploy_test/local/lib/python2.7/site-packages/pip/wheel.py", line 753, in build ensure_dir(output_dir) File "/home/ubuntu/Envs/ec2_deploy_test/local/lib/python2.7/site-packages/pip/utils/init.py", line 70, in ensure_dir os.makedirs(path) File "/home/ubuntu/Envs/ec2_deploy_test/lib/python2.7/os.py", line 150, in makedirs makedirs(head, mode) File "/home/ubuntu/Envs/ec2_deploy_test/lib/python2.7/os.py", line 150, in makedirs makedirs(head, mode) File "/home/ubuntu/Envs/ec2_deploy_test/lib/python2.7/os.py", line 150, in makedirs makedirs(head, mode) File "/home/ubuntu/Envs/ec2_deploy_test/lib/python2.7/os.py", line 157, in makedirs mkdir(name, mode) OSError: [Errno 13] Permission denied: '/home/ubuntu/.cache/pip/wheels/ab'

Then I ran (ec2_deploy_test)ubuntu@ip-172-31-22-100:~/ec2-deploy-test$ sudo pip install -r requirements.txt and psycopg2 installed successfully.

Why would I need root permissions to install a python package in my virtual environment? I am new to Linux and sysadmin in general so all advice is welcome. Thanks in advance.

Answer 1

For some reason you don't have an access to create a directory inside the /home/ubuntu/.cache/pip/wheels/ab. Normally this problem shouldn't appear; anyway, since it happened, just change the rights of the .cache directory recursively. I guess that the problem is an ownership, so try to launch the command sudo chown -R <USERNAME> ~/.cache/pip, where the <USERNAME> supposed to be the name of your user.

An advice — try to not launch an apps from root without a real need in this. Most probably that the directory to which you have no an access was created by some application being run with root rights — and now an ownership messed.