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pythonamazon-web-servicesdockerpython-3.4

Docker Build can't find pip


Trying to follow a few[1][2] simple Docker tutorials via AWS am and getting the following error:

> docker build -t my-app-image .                                         
Sending build context to Docker daemon 94.49 MB
Step 1 : FROM amazon/aws-eb-python:3.4.2-onbuild-3.5.1
# Executing 2 build triggers...
Step 1 : ADD . /var/app
 ---> Using cache
Step 1 : RUN if [ -f /var/app/requirements.txt ]; then /var/app/bin/pip install -r /var/app/requirements.txt; fi
 ---> Running in d48860787e63
/bin/sh: 1: /var/app/bin/pip: not found
The command '/bin/sh -c if [ -f /var/app/requirements.txt ]; then /var/app/bin/pip install -r /var/app/requirements.txt; fi' returned a non-zero code: 127

Dockerfile:

# For Python 3.4
FROM amazon/aws-eb-python:3.4.2-onbuild-3.5.1

Which pip returns the following:

> which pip                                                             
./bin/pip

Relevant file structure:

.
├── Dockerfile
├── bin
│   ├── activate
│   ├── pip
│   ├── pip3
│   ├── pip3.5
│   ├── python -> python3
│   ├── python-config
│   ├── python3
│   ├── python3.5 -> python3
│   .
.

Again, noob in all things Docker so I'm not sure what troubleshooting steps to take. Please let me know what other helpful information I can provide.


Solution

  • Something is very odd here. Why do you have the virtualenv content next to your Dockerfile? The image you are building from creates the virtualenv on /var/app (within the container, yes?) for you. I believe that the ONBUILD command copies it (or parts of it) over and corrupt the rest of the process, making the /var/app/bin/pip inoperable.

    FROM       python:3.4.2 <-- this is the base image, on top of which the following command will be applied
    
    WORKDIR    /var/app <-- this is the working dir (a la 'cd /var/app')
    
    RUN        pip3 install virtualenv <-- using pip3 (installed using base image I presume) to install the virtualenv package
    RUN        virtualenv /var/app <-- creating a virtual env on /var/app
    RUN        /var/app/bin/pip install --download-cache /src uwsgi <-- using the recently install virtualenv pip to install uwsgi
    
    ...
    
    ONBUILD    ADD . /var/app <-- add the contents of the directory where the Dockerfile is built from, I think this is where the corruption happen 
    ONBUILD    RUN if [ -f /var/app/requirements.txt ]; then /var/app/bin/pip install -r /var/app/requirements.txt; fi <-- /var/app/bin/pip has beed corrupted
    

    You should not care about externally having /var/app available on the host. You just need (based on the Dockerbuild file) have the "requirements.txt" available on the host, to be copied into the container (or not, if not, it will skip).