1 files changed, 90 insertions, 0 deletions
diff --git a/render_pkgbuild.py b/render_pkgbuild.py
new file mode 100755
index 000000000000..cd10e8f3093b
--- /dev/null
+++ b/render_pkgbuild.py
@@ -0,0 +1,90 @@
+#!/usr/bin/env python3
+import hashlib
+import json
+import pathlib
+import re
+import sys
+import typing
+
+import jinja2
+import requests
+from github import Github
+
+
+REPO_NAME = "fleetdm/fleet"
+VERSION_PATTERN = re.compile(r"orbit-v([0-9]+\.[0-9]+\.[0-9]+)")
+
+REPO = Github().get_repo(REPO_NAME)
+METADATA_PATH = pathlib.Path("./metadata.json")
+
+
+class TagInfo(typing.TypedDict):
+    name: str
+    pkgver: str
+    commit_sha: str
+    tarball_url: str
+
+
+class Metadata(typing.TypedDict):
+    tag_info: TagInfo
+    release_sha512sum: str
+
+
+def query_latest_tag_info() -> TagInfo:
+    for tag in REPO.get_tags():
+        match = VERSION_PATTERN.match(tag.name)
+        if match is not None:
+            return {
+                "name": tag.name,
+                "pkgver": match.group(1),
+                "commit_sha": tag.commit.sha,
+                "tarball_url": f"https://github.com/{REPO_NAME}/archive/refs/tags/{tag.name}.tar.gz",
+            }
+
+    raise RuntimeError("No tag matching pattern found.")
+
+
+def refresh_metadata(tag_info: TagInfo) -> Metadata:
+    release_sha512sum: typing.Optional[str] = None
+    if METADATA_PATH.exists():
+        old_metadata: Metadata = json.loads(METADATA_PATH.read_text())
+        if tag_info == old_metadata["tag_info"]:
+            release_sha512sum = old_metadata["release_sha512sum"]
+
+    metadata: Metadata = {
+        "tag_info": tag_info,
+        "release_sha512sum": release_sha512sum
+        or compute_remote_checksum(tag_info["tarball_url"]),
+    }
+
+    METADATA_PATH.write_text(json.dumps(metadata, sort_keys=True, indent=2))
+    return metadata
+
+
+def compute_remote_checksum(url: str, sumfunc=hashlib.sha512, chunk_size=1024) -> str:
+    s = sumfunc()
+    with requests.get(url, stream=True) as resp:
+        for content in resp.iter_content(chunk_size=chunk_size):
+            s.update(content)
+    return s.hexdigest()
+
+
+def render_pkgbuild(metadata: Metadata) -> None:
+    env = jinja2.Environment(loader=jinja2.FileSystemLoader("."))
+    env.globals["sha512sum"] = lambda path: hashlib.sha512(
+        pathlib.Path(path).read_bytes()
+    ).hexdigest()
+    template = env.get_template("./PKGBUILD.jinja")
+    result = template.render(metadata=metadata)
+    pathlib.Path("./PKGBUILD").write_text(result)
+
+
+def main() -> bool:
+    tag_info = query_latest_tag_info()
+    metadata = refresh_metadata(tag_info)
+    render_pkgbuild(metadata)
+    return True
+
+
+if __name__ == "__main__":
+    sys.exit(not bool(main()))