feat: dockerize application [FC-0063] (#228)

Add docker support and set requirements to use base.in rather
than base.txt to make it easier to use this repo as part of
another package.

.dockerignore

@@ -0,0 +1,7 @@
+.git
+.github
+
+**/.coverage
+**/.pytest_cache
+**/__pycache__
+**/*.pyc

Dockerfile

@@ -0,0 +1,8 @@
+FROM python:3.8.20-alpine3.20
+
+WORKDIR /app
+
+COPY . .
+RUN pip install --no-cache-dir /app
+
+ENTRYPOINT ["cc2olx"]

MANIFEST.in

@@ -1,6 +1,7 @@
 include LICENSE
 include README.rst
 
+recursive-include requirements *
 recursive-include tests *
 recursive-exclude * __pycache__
 recursive-exclude * *.py[co]

README.rst

@@ -58,6 +58,23 @@ The link map file can be supplied using `-f` or `--link_file`::
 
     cc2olx -r zip -i <IMSCC_FILE> -f <CSV_FILE>
 
+Dockerization
+-------------
+
+To make the application platform-independent, it is dockerized. To run the
+application using Docker you need:
+
+1. Build the image::
+
+    docker build -t cc2olx .
+
+2. Run the conversion command in a container by mounting passed argument path
+directories/files and passing the corresponding arguments to the script::
+
+    docker run --rm -v /input/file/path/cc_course_dump.imscc:/data/input/cc_course_dump.imscc -v /output/file/path/output_dir:/data/output/ cc2olx -r zip -i /data/input/cc_course_dump.imscc -o /data/output/edx_dump
+
+It will convert Common Cartridge dump from */input/file/path/cc_course_dump.imscc*
+and save the OLX in */output/file/path/output_dir/edx_dump.zip* file.
 
 Test Data
 ---------

setup.py

@@ -1,27 +1,13 @@
-import os
-import re
-
 from glob import glob
 from os.path import basename, splitext
 
 from setuptools import setup, find_packages
 
+from utils import get_version, load_requirements
+
 with open("README.rst", encoding="utf-8") as readme_file:
     readme = readme_file.read()
 
-
-def get_version(*file_paths):
-    """
-    Extract the version string from the file at the given relative path fragments.
-    """
-    filename = os.path.join(os.path.dirname(__file__), *file_paths)
-    version_file = open(filename, encoding="utf-8").read()
-    version_match = re.search(r"^__version__ = ['\"]([^'\"]*)['\"]", version_file, re.M)
-    if version_match:
-        return version_match.group(1)
-    raise RuntimeError("Unable to find version string. ")
-
-
 VERSION = get_version("src", "cc2olx", "__init__.py")
 
 
@@ -41,7 +27,7 @@ def get_version(*file_paths):
     ],
     description=("Command line tool, that converts Common Cartridge " "courses to Open edX Studio imports."),
     entry_points={"console_scripts": ["cc2olx=cc2olx.main:main"]},
-    install_requires=["lxml"],
+    install_requires=load_requirements("requirements/base.in"),
     license="GNU Affero General Public License",
     long_description=readme,
     include_package_data=True,

utils.py

@@ -0,0 +1,104 @@
+import os
+import re
+
+
+def get_version(*file_paths):
+    """
+    Extract the version string from the file at the given relative path fragments.
+    """
+    filename = os.path.join(os.path.dirname(__file__), *file_paths)
+    version_file = open(filename, encoding="utf-8").read()
+    version_match = re.search(r"^__version__ = ['\"]([^'\"]*)['\"]", version_file, re.M)
+    if version_match:
+        return version_match.group(1)
+    raise RuntimeError("Unable to find version string. ")
+
+
+def is_requirement(line):
+    """
+    Return True if the requirement line is a package requirement.
+
+    That is, it is not blank, a comment, or editable.
+    """
+    # Remove whitespace at the start/end of the line
+    line = line.strip()
+
+    # Skip blank lines, comments, and editable installs
+    return bool(line) and not line.startswith(("-r", "#", "-e", "git+", "-c"))
+
+
+def load_requirements(*requirements_paths):
+    """
+    Load all requirements from the specified requirements files.
+
+    Requirements will include any constraints from files specified
+    with -c in the requirements files.
+    Returns a list of requirement strings.
+    """
+    def check_name_consistent(package):
+        """
+        Raise exception if package is named different ways.
+
+        This ensures that packages are named consistently so we can match
+        constraints to packages. It also ensures that if we require a package
+        with extras we don't constrain it without mentioning the extras (since
+        that too would interfere with matching constraints.)
+        """
+        canonical = package.lower().replace("_", "-").split("[")[0]
+        seen_spelling = by_canonical_name.get(canonical)
+        if seen_spelling is None:
+            by_canonical_name[canonical] = package
+        elif seen_spelling != package:
+            raise Exception(
+                f'Encountered both "{seen_spelling}" and "{package}" in requirements '
+                "and constraints files; please use just one or the other."
+            )
+
+    def add_version_constraint_or_raise(current_line, current_requirements, add_if_not_present):
+        if regex_match := requirement_line_regex.match(current_line):
+            package = regex_match.group(1)
+            version_constraints = regex_match.group(2)
+            check_name_consistent(package)
+            existing_version_constraints = current_requirements.get(package, None)
+            # It's fine to add constraints to an unconstrained package,
+            # but raise an error if there are already constraints in place.
+            if existing_version_constraints and existing_version_constraints != version_constraints:
+                raise Exception(
+                    f"Multiple constraint definitions found for {package}:"
+                    f' "{existing_version_constraints}" and "{version_constraints}".'
+                    f"Combine constraints into one location with {package}"
+                    f"{existing_version_constraints},{version_constraints}."
+                )
+            if add_if_not_present or package in current_requirements:
+                current_requirements[package] = version_constraints
+
+    by_canonical_name = {}  # e.g. {"django": "Django", "confluent-kafka": "confluent_kafka[avro]"}
+    requirements = {}
+    constraint_files = set()
+
+    # groups "pkg<=x.y.z,..." into ("pkg", "<=x.y.z,...")
+    re_package_name_base_chars = r"a-zA-Z0-9\-_."  # chars allowed in base package name
+    # Two groups: name[maybe,extras], and optionally a constraint
+    requirement_line_regex = re.compile(
+        rf"([{re_package_name_base_chars}]+(?:\[[{re_package_name_base_chars},\s]+\])?)([<>=][^#\s]+)?"
+    )
+
+    # Read requirements from .in files and store the path to any
+    # constraint files that are pulled in.
+    for path in requirements_paths:
+        with open(path) as reqs:
+            for line in reqs:
+                if is_requirement(line):
+                    add_version_constraint_or_raise(line, requirements, True)
+                if line and line.startswith("-c") and not line.startswith("-c http"):
+                    constraint_files.add(os.path.dirname(path) + "/" + line.split("#")[0].replace("-c", "").strip())
+
+    # process constraint files: add constraints to existing requirements
+    for constraint_file in constraint_files:
+        with open(constraint_file) as reader:
+            for line in reader:
+                if is_requirement(line):
+                    add_version_constraint_or_raise(line, requirements, False)
+
+    # process back into list of pkg><=constraints strings
+    return [f'{pkg}{version or ""}' for (pkg, version) in sorted(requirements.items())]