Add connector manifest builder runtime

runtime/lib/build_manifest.py

@@ -0,0 +1,120 @@
+#!/usr/bin/env python3
+"""Resolve Nextcloud view rows through explicitly configured storage mounts."""
+
+from __future__ import annotations
+
+import argparse
+import csv
+import json
+import os
+import subprocess
+import sys
+import tempfile
+from pathlib import Path, PurePosixPath
+
+
+def read_config(path: Path) -> dict[str, tuple[str, Path]]:
+    result: dict[str, tuple[str, Path]] = {}
+    with path.open(encoding="utf-8") as handle:
+        for number, line in enumerate(handle, 1):
+            line = line.rstrip("\n")
+            if not line or line.startswith("#"):
+                continue
+            fields = line.split("\t")
+            if len(fields) != 3:
+                raise ValueError(f"{path}:{number}: expected storage_id, source_prefix and local_mount")
+            storage_id, prefix, mount = fields
+            result[storage_id] = (prefix.strip("/"), Path(mount))
+    return result
+
+
+def query_rows(args: argparse.Namespace) -> list[list[str]]:
+    password = args.password_file.read_text(encoding="utf-8").strip()
+    env = os.environ.copy()
+    env["PGPASSWORD"] = password
+    sql = f"SELECT share_id, display_name, storage_id, source_path FROM {args.view} ORDER BY share_id"
+    command = [
+        "psql", "-X", "-A", "-F", "\t", "-t",
+        "-h", args.host, "-p", str(args.port), "-U", args.user, "-d", args.database,
+        "-c", sql,
+    ]
+    completed = subprocess.run(command, env=env, check=True, text=True, capture_output=True)
+    return list(csv.reader(completed.stdout.splitlines(), delimiter="\t"))
+
+
+def contained_join(root: Path, relative: str) -> Path:
+    parts = PurePosixPath(relative).parts
+    if relative.startswith("/") or ".." in parts:
+        raise ValueError(f"unsafe source path: {relative}")
+    return root.joinpath(*parts)
+
+
+def build(args: argparse.Namespace) -> dict[str, object]:
+    adapters = read_config(args.storage_config)
+    rows = query_rows(args)
+    if not rows and not args.allow_empty:
+        raise RuntimeError("Nextcloud returned no Showcase shares; refusing an empty manifest")
+
+    manifest: list[str] = []
+    errors: list[str] = []
+    for row in rows:
+        if len(row) != 4:
+            errors.append(f"invalid database row with {len(row)} columns")
+            continue
+        share_id, display_name, storage_id, source_path = row
+        adapter = adapters.get(storage_id)
+        if not adapter:
+            errors.append(f"share {share_id}: unknown storage {storage_id}")
+            continue
+        prefix, mount = adapter
+        relative = source_path.strip("/")
+        if prefix:
+            expected = prefix + "/"
+            if relative != prefix and not relative.startswith(expected):
+                errors.append(f"share {share_id}: path does not match configured prefix")
+                continue
+            relative = relative[len(prefix):].lstrip("/")
+        source = contained_join(mount, relative)
+        if not mount.is_mount():
+            errors.append(f"share {share_id}: storage mount unavailable: {mount}")
+            continue
+        if not source.is_dir():
+            errors.append(f"share {share_id}: source directory unavailable: {source}")
+            continue
+        manifest.append(f"{share_id}\t{display_name.lstrip('/')}\t{source}")
+
+    if errors:
+        raise RuntimeError("; ".join(errors))
+    if len(manifest) != len(rows):
+        raise RuntimeError("not all Showcase shares could be resolved")
+
+    args.output.parent.mkdir(parents=True, exist_ok=True)
+    with tempfile.NamedTemporaryFile("w", encoding="utf-8", dir=args.output.parent, delete=False) as handle:
+        handle.write("\n".join(manifest) + ("\n" if manifest else ""))
+        temporary = Path(handle.name)
+    temporary.replace(args.output)
+    return {"shares": len(manifest), "manifest": str(args.output)}
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--host", required=True)
+    parser.add_argument("--port", type=int, default=5432)
+    parser.add_argument("--database", required=True)
+    parser.add_argument("--user", required=True)
+    parser.add_argument("--password-file", required=True, type=Path)
+    parser.add_argument("--view", default="piwigo_showcase_sources")
+    parser.add_argument("--storage-config", required=True, type=Path)
+    parser.add_argument("--output", required=True, type=Path)
+    parser.add_argument("--allow-empty", action="store_true")
+    args = parser.parse_args()
+    try:
+        print(json.dumps(build(args), ensure_ascii=False))
+    except Exception as error:
+        print(f"manifest: {error}", file=sys.stderr)
+        return 1
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())