Adding a Dockerfile and helper scripts for tests

Now we can propperly test python-mode in an environment with a very well
defined python version and a vim built/compiled for this specific
version as well.

The best way is to use the `build_docker_images.sh` file in order to
create the docker image with all python versions you desire.

Also, in order to run the container you just have to do:

docker run --rm -it python-mode:<version>

Related to python-mode#977

.dockerignore

@@ -0,0 +1,2 @@
+Dockerfile
+.dockerignore

Dockerfile

@@ -0,0 +1,48 @@
+# VERSION 1.0.0
+# AUTHOR: Diego Rabatone Oliveira (@diraol)
+# DESCRIPTION: Image used to test python-mode
+# BUILD: Use the build_docker_images.sh file
+#   docker build -t python-mode:<VER> -f Dockerfile --build-arg PYTHON=<VER> .
+# SOURCE: https://github.com/python-mode/python-mode
+ARG PYTHON
+FROM python:$PYTHON
+
+# Passing arg inside the build stage
+ARG PYTHON
+
+# Never prompts the user for choices on installation/configuration of packages
+ENV DEBIAN_FRONTEND noninteractive
+ENV TERM linux
+
+# https://docs.python.org/3.6/using/cmdline.html#envvar-PYTHONUNBUFFERED
+# https://github.com/sclorg/s2i-python-container/issues/157
+ENV PYTHONUNBUFFERED 1
+
+# Clonning and building VIM for the specific python version
+COPY ./tests/utils/build_vim.sh /opt/build_vim.sh
+RUN set -ex \
+    && cd /opt \
+    && chmod +x build_vim.sh \
+    && git clone https://github.com/vim/vim.git \
+    && ./build_vim.sh ${PYTHON} \
+    && rm -rf vim build_vim.sh
+
+ENV PYTHON_MODE_HOME /root/.vim/pack/foo/start/python-mode/
+ENV VIM_RC /root/.vimrc
+ENV PYMODE_RC /root/.pymoderc
+ENV TEST_FILE /root/test.py
+
+COPY . ${PYTHON_MODE_HOME}
+RUN set -ex \
+    && cd ${PYTHON_MODE_HOME} \
+    && find . -type f -name '*.pyc' -delete \
+    && find . -type d -name '__pycache__' -delete \
+    && ln -s ${PYTHON_MODE_HOME}tests/utils/test.py ${TEST_FILE} \
+    && ln -s ${PYTHON_MODE_HOME}tests/utils/pymoderc ${PYMODE_RC} \
+    && ln -s ${PYTHON_MODE_HOME}tests/utils/vimrc ${VIM_RC} \
+    && touch /root/.vimrc.before /root/.vimrc.after
+
+RUN set -ex && vim -e -s -c ':exec ":helptags ALL" | exec ":qall!"'
+
+WORKDIR /root
+ENTRYPOINT ["/bin/bash"]

build_docker_images.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+for VER in 2.7 3.5 3.6 3.7 3.7.1
+do
+    docker build -t python-mode:${VER} --build-arg PYTHON=${VER} -f Dockerfile .
+done

readme.md

@@ -188,6 +188,22 @@ Please, also provide more contextual information such as:
 * `git status` (under your _python-mode_ directory)
 * `tree <python-mode-directory>` or something similar (such as `ls -lR`)
 
+## Docker environment
+Now you can try python-mode within a docker container, with a python-version
+from your choice and a vim built for that python version.
+
+To build the docker images you should use the script `build_docker_images.sh`
+that is located on the root of this repo.
+
+To run the container for a specific version, after building it, you can do:
+
+`docker run --rm -it python-mode:<PYTHON_VERSION>`
+
+* PYTHON\_VERSION can be 2.7, 3.7, etc.
+
+If you do not want the container to be removed after you exit it, just remove
+the `--rm` from the command above.
+
 # Frequent problems
 
 Read this section before opening an issue on the tracker.

tests/utils/build_vim.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+set -e
+SPACER="#####################################################################"
+
+PYTHON=$1
+echo "Python version: ${PYTHON}"
+
+cd /opt/vim
+
+args=(  )
+# args+=( --with-features=huge )
+args+=( --enable-multibyte )
+args+=( --enable-cscope )
+
+PYTHON_CONFIG_DIR=$(find /usr -type d -name 'config*' | grep python | grep -v dist-packages)
+
+if [[ ${PYTHON} =~ ^2 ]]; then
+    args+=( --enable-pythoninterp=yes )
+    args+=( --with-python-config-dir=${PYTHON_CONFIG_DIR} )
+else
+    args+=( --enable-python3interp=yes )
+    args+=( --with-python3-config-dir=${PYTHON_CONFIG_DIR} )
+fi
+
+args+=( --prefix=/usr/local )
+
+echo ${SPACER}
+echo Starting build with args: ${args[@]}
+echo ${SPACER}
+
+./configure ${args[@]}
+
+make
+
+make install
+
+echo ${SPACER}
+echo vim installed with config args: ${args[@]}
+echo ${SPACER}

tests/utils/reset_update_repo.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+git reset --hard HEAD
+git checkout origin develop
+git pull origin develop
+git submodule sync --recursive
+git submodule update --init --recursive