pkgs/development/libraries/ndi/update.py

   1 #!/usr/bin/env nix-shell
   2 #! nix-shell -i python -p "python3.withPackages (ps: with ps; [ ps.absl-py ps.requests ])"
   3
   4 import hashlib
   5 import io
   6 import json
   7 import os.path
   8 import tarfile
   9
  10 import requests
  11 from absl import app, flags
  12
  13 BASE_NAME = "Install_NDI_SDK_v5_Linux"
  14 NDI_SDK_URL = f"https://downloads.ndi.tv/SDK/NDI_SDK_Linux/{BASE_NAME}.tar.gz"
  15 NDI_EXEC = f"{BASE_NAME}.sh"
  16
  17 NDI_ARCHIVE_MAGIC = b"__NDI_ARCHIVE_BEGIN__\n"
  18
  19 FLAG_out = flags.DEFINE_string("out", None, "Path to read/write version.json from/to.")
  20
  21
  22 def find_version_json() -> str:
  23     if FLAG_out.value:
  24         return FLAG_out.value
  25     try_paths = ["pkgs/development/libraries/ndi/version.json", "version.json"]
  26     for path in try_paths:
  27         if os.path.exists(path):
  28             return path
  29     raise Exception(
  30         "Couldn't figure out where to write version.json; try specifying --out"
  31     )
  32
  33
  34 def fetch_tarball() -> bytes:
  35     r = requests.get(NDI_SDK_URL)
  36     r.raise_for_status()
  37     return r.content
  38
  39
  40 def read_version(tarball: bytes) -> str:
  41     # Find the inner script.
  42     outer_tarfile = tarfile.open(fileobj=io.BytesIO(tarball), mode="r:gz")
  43     eula_script = outer_tarfile.extractfile(NDI_EXEC).read()
  44
  45     # Now find the archive embedded within the script.
  46     archive_start = eula_script.find(NDI_ARCHIVE_MAGIC) + len(NDI_ARCHIVE_MAGIC)
  47     inner_tarfile = tarfile.open(
  48         fileobj=io.BytesIO(eula_script[archive_start:]), mode="r:gz"
  49     )
  50
  51     # Now find Version.txt...
  52     version_txt = (
  53         inner_tarfile.extractfile("NDI SDK for Linux/Version.txt")
  54         .read()
  55         .decode("utf-8")
  56     )
  57     _, _, version = version_txt.strip().partition(" v")
  58     return version
  59
  60
  61 def main(argv):
  62     tarball = fetch_tarball()
  63
  64     sha256 = hashlib.sha256(tarball).hexdigest()
  65     version = {
  66         "hash": f"sha256:{sha256}",
  67         "version": read_version(tarball),
  68     }
  69
  70     out_path = find_version_json()
  71     with open(out_path, "w") as f:
  72         json.dump(version, f)
  73         f.write("\n")
  74
  75
  76 if __name__ == "__main__":
  77     app.run(main)