File size: 5,340 Bytes
2ee40b0 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 | #!/usr/bin/env python3
from __future__ import annotations
import argparse
import os
import subprocess
import sys
from dataclasses import dataclass
from pathlib import Path
DEFAULT_MAX_BYTES = 500 * 1024
@dataclass(frozen=True)
class ChangedBlob:
path: str
size_bytes: int
is_allowlisted: bool
is_binary: bool
def run_git(*args: str) -> str:
result = subprocess.run(
["git", *args],
check=True,
capture_output=True,
text=True,
)
return result.stdout
def load_allowlist(path: Path) -> set[str]:
allowlist: set[str] = set()
for raw_line in path.read_text(encoding="utf-8").splitlines():
line = raw_line.split("#", 1)[0].strip()
if line:
allowlist.add(line)
return allowlist
def get_changed_paths(base: str, head: str) -> list[str]:
output = run_git(
"diff",
"--name-only",
"--diff-filter=AM",
"--no-renames",
"-z",
base,
head,
)
return [path for path in output.split("\0") if path]
def is_binary_change(base: str, head: str, path: str) -> bool:
output = run_git(
"diff",
"--numstat",
"--diff-filter=AM",
"--no-renames",
base,
head,
"--",
path,
).strip()
if not output:
return False
added, deleted, _ = output.split("\t", 2)
return added == "-" and deleted == "-"
def blob_size(commit: str, path: str) -> int:
return int(run_git("cat-file", "-s", f"{commit}:{path}").strip())
def collect_changed_blobs(
base: str, head: str, allowlist: set[str]
) -> list[ChangedBlob]:
blobs: list[ChangedBlob] = []
for path in get_changed_paths(base, head):
blobs.append(
ChangedBlob(
path=path,
size_bytes=blob_size(head, path),
is_allowlisted=path in allowlist,
is_binary=is_binary_change(base, head, path),
)
)
return blobs
def format_kib(size_bytes: int) -> str:
return f"{size_bytes / 1024:.1f} KiB"
def write_step_summary(
max_bytes: int,
blobs: list[ChangedBlob],
violations: list[ChangedBlob],
) -> None:
summary_path = os.environ.get("GITHUB_STEP_SUMMARY")
if not summary_path:
return
lines = [
"## Blob Size Policy",
"",
f"Default max: `{max_bytes}` bytes ({format_kib(max_bytes)})",
f"Changed files checked: `{len(blobs)}`",
f"Violations: `{len(violations)}`",
"",
]
if blobs:
lines.extend(
[
"| Path | Kind | Size | Status |",
"| --- | --- | ---: | --- |",
]
)
for blob in blobs:
status = "allowlisted" if blob.is_allowlisted else "ok"
if blob in violations:
status = "blocked"
kind = "binary" if blob.is_binary else "non-binary"
lines.append(
f"| `{blob.path}` | {kind} | `{blob.size_bytes}` bytes ({format_kib(blob.size_bytes)}) | {status} |"
)
else:
lines.append("No changed files were detected.")
lines.append("")
Path(summary_path).write_text("\n".join(lines), encoding="utf-8")
def main() -> int:
parser = argparse.ArgumentParser(
description="Fail if changed blobs exceed the configured size budget."
)
parser.add_argument(
"--base", required=True, help="Base git revision to diff against."
)
parser.add_argument("--head", required=True, help="Head git revision to inspect.")
parser.add_argument(
"--max-bytes",
type=int,
default=DEFAULT_MAX_BYTES,
help=f"Maximum allowed blob size in bytes. Default: {DEFAULT_MAX_BYTES}.",
)
parser.add_argument(
"--allowlist",
type=Path,
required=True,
help="Path to the newline-delimited allowlist file.",
)
args = parser.parse_args()
allowlist = load_allowlist(args.allowlist)
blobs = collect_changed_blobs(args.base, args.head, allowlist)
violations = [
blob
for blob in blobs
if blob.size_bytes > args.max_bytes and not blob.is_allowlisted
]
write_step_summary(args.max_bytes, blobs, violations)
if not blobs:
print("No changed files were detected.")
return 0
print(
f"Checked {len(blobs)} changed file(s) against the {args.max_bytes}-byte limit."
)
for blob in blobs:
status = "allowlisted" if blob.is_allowlisted else "ok"
if blob in violations:
status = "blocked"
kind = "binary" if blob.is_binary else "non-binary"
print(
f"- {blob.path}: {blob.size_bytes} bytes ({format_kib(blob.size_bytes)}) [{kind}, {status}]"
)
if violations:
print("\nFile(s) exceed the configured limit:")
for blob in violations:
print(f"- {blob.path}: {blob.size_bytes} bytes > {args.max_bytes} bytes")
print(
"\nIf one of these is a real checked-in asset we want to keep, add its "
"repo-relative path to .github/blob-size-allowlist.txt. Otherwise, "
"shrink it or keep it out of git."
)
return 1
return 0
if __name__ == "__main__":
sys.exit(main())
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