The Docker Image Script

Simple example

The next example demonstrates one way on how to create a docker image for Python 3.6.

- docker(image):
    name: python
    tag: "3.6"
    unique: no
    script: |
      FROM centos:7
      RUN yum -y install yum-utils git
      RUN yum -y install
      RUN yum -y install python36u python36u-pip
      RUN pip3.6 install tox

When you run this (see examples folder for docker-image.yaml) then last lines should look like following:

2017-12-22 09:20:15,179 - spline.components.tasks -  | Installing collected packages: py, six, pluggy, virtualenv, tox
2017-12-22 09:20:15,339 - spline.components.tasks -  |   Running install for pluggy: started
2017-12-22 09:20:15,665 - spline.components.tasks -  |     Running install for pluggy: finished with status 'done'
2017-12-22 09:20:15,800 - spline.components.tasks -  | Successfully installed pluggy-0.6.0 py-1.5.2 six-1.11.0 tox-2.9.1 virtualenv-15.1.0
2017-12-22 09:20:16,588 - spline.components.tasks -  |  ---> 29abbe7ec073
2017-12-22 09:20:16,601 - spline.components.tasks -  | Removing intermediate container 5ceeb0cf5b89
2017-12-22 09:20:16,601 - spline.components.tasks -  | Successfully built 29abbe7ec073
2017-12-22 09:20:16,608 - spline.components.tasks -  | Successfully tagged python:3.6
2017-12-22 09:20:16,610 - spline.components.bash - Exit code has been 0
2017-12-22 09:20:16,611 - spline.components.tasks - Processing Bash code: finished

You can verify afterwards:

$ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
python              3.6                 29abbe7ec073        9 minutes ago       605MB
$ docker run --rm -i python:3.6 bash -c "python3.6 -V"
Python 3.6.3

The option “unique”

In the example above unique has been set to no. The default is yes which injects the pid of the spline tool into the name. The idea is to allow multiple images generated in parallel without conflicts.


The script field represents the Dockerfile and please refer to the official Documentation if you need to know more. However Jinja2 templating is supported:

- docker(image):
    name: python
    tag: "3.6"
    unique: no
    script: "{{ model.templates.dockerfiles.py36 }}"

Please note: you also can use jinja templaring in the tag.

The compete example - as already mentioned - in the examples folder.

Conditional tasks

The field when allows you to define a condition; when evaluated as true then the task is executed otherwise not. More details you can read in the separate section Conditional Tasks.