add JSON file + Python script to keep track of software licenses

Author: boegel

Diff for: licenses/README.md

@@ -0,0 +1,3 @@
+see https://spdx.org/licenses
+
+Python function to download SPDX list of licenses is available in `spdx.py`

Diff for: licenses/licenses.json

@@ -0,0 +1,10 @@
+{
+    "EasyBuild": {
+        "spdx": "GPL-2.0-only",
+        "license_url": "https://easybuild.io"
+    },
+    "GCCcore": {
+        "spdx": "GPL-2.0-with-GCC-exception",
+        "license_url": "https://github.com/gcc-mirror/gcc/blob/master/COPYING"
+    }
+}

Diff for: licenses/spdx.py

@@ -0,0 +1,100 @@
+import json
+import logging
+import sys
+import urllib.request
+
+SPDX_LICENSE_LIST_URL = 'https://raw.githubusercontent.com/spdx/license-list-data/main/json/licenses.json'
+
+LICENSE_URL = 'license_url'
+SPDX = 'spdx'
+
+spdx_license_list = None
+
+# Configure the logging module
+logging.basicConfig(level=logging.INFO, format="%(asctime)s - %(levelname)s - %(message)s")
+
+
+def get_spdx_license_list():
+    """
+    Download JSON file with current list of SPDX licenses, parse it, and return it as a Python dictionary.
+    """
+    global spdx_license_list
+
+    if spdx_license_list is None:
+        with urllib.request.urlopen(SPDX_LICENSE_LIST_URL) as fp:
+            spdx_license_list = json.load(fp)
+        version, release_date = spdx_license_list['licenseListVersion'], spdx_license_list['releaseDate']
+        logging.info(f"Downloaded version {version} of SPDX license list (release date: {release_date})")
+        licenses = spdx_license_list['licenses']
+        logging.info(f"Found info on {len(licenses)} licenses!")
+
+    return spdx_license_list
+
+
+def license_info(spdx_id):
+    """Find license with specified SPDX identifier."""
+ 
+    spdx_license_list = get_spdx_license_list()
+
+    licenses = spdx_license_list['licenses']
+    for lic in licenses:
+        if lic['licenseId'] == spdx_id:
+            return lic
+
+    # if no match is found, return None as result
+    return None
+
+
+def read_licenses(path):
+    """
+    Read software project to license mapping from specified path
+    """
+    with open(path) as fp:
+        licenses = json.loads(fp.read())
+
+    return licenses
+
+
+def check_licenses(licenses):
+    """
+    Check mapping of software licenses: make sure SPDX identifiers are valid.
+    """
+    faulty_licenses = {}
+
+    for software_name in licenses:
+        spdx_lic_id = licenses[software_name][SPDX]
+        lic_info = license_info(spdx_lic_id)
+        if lic_info:
+            lic_url = licenses[software_name][LICENSE_URL]
+            logging.info(f"License for software '{software_name}': {lic_info['name']} (see {lic_url})")
+        else:
+            logging.warning(f"Found faulty SPDX license ID for {software_name}: {spdx_lic_id}")
+            faulty_licenses[software_name] = spdx_lic_id
+
+    if faulty_licenses:
+        logging.warning(f"Found {len(faulty_licenses)} faulty SPDIX license IDs (out of {len(licenses)})!")
+        result = False
+    else:
+        logging.info(f"License check passed for {len(licenses)} licenses!")
+        result = True
+
+    return result
+
+
+def main(args):
+    if len(args) == 1:
+        licenses_path = args[0]
+    else:
+        logging.error("Usage: python spdx.py <path to licenses.json>")
+        sys.exit(1)
+
+    licenses = read_licenses(licenses_path)
+    if check_licenses(licenses):
+        logging.info("All license checks PASSED!")
+    else:
+        logging.error("One or more licence checks failed!")
+        sys.exit(2)
+
+
+if __name__ == '__main__':
+    main(sys.argv[1:])