Add tool that helps with maintenance in Fedora

Most likely there are some missing checks for None and the program may
segfault, but this can be fixed in future.

Signed-off-by: Igor Raits <ignatenkobrain@fedoraproject.org>

tools/fedora-helper.py

@@ -0,0 +1,176 @@
+#!/usr/bin/python3
+
+import collections
+import os
+from pathlib import Path
+import sys
+import tempfile
+
+import click
+import requests
+from requests.compat import urljoin
+import solv
+
+XDG_CACHE_HOME = Path(os.getenv("XDG_CACHE_HOME", os.path.expanduser("~/.cache")))
+CACHEDIR = XDG_CACHE_HOME / "rust2rpm"
+
+# Arch that is used for resolving dependencies and such
+ARCH = "x86_64"
+# The repo that contains crates
+REPO_URL = f"https://kojipkgs.fedoraproject.org/repos/f33-build/latest/{ARCH}/"
+# Just some sane chunk size
+CHUNK_SIZE = 8192
+
+
+def _download(fname, chksum=None, uncompress=False):
+    url = urljoin(REPO_URL, fname)
+    with requests.get(urljoin(REPO_URL, fname), stream=True) as r:
+        tmp = tempfile.TemporaryFile()
+        total = int(r.headers["Content-Length"])
+        with click.progressbar(
+            length=total, label=f"Downloading {url}", file=sys.stderr
+        ) as pb:
+            for chunk in r.iter_content(chunk_size=CHUNK_SIZE):
+                pb.update(tmp.write(chunk))
+    tmp.seek(0)
+
+    if chksum is not None:
+        fchksum = solv.Chksum(chksum.type)
+        fchksum.add_fd(tmp.fileno())
+        if chksum != fchksum:
+            raise Exception(f"Checksums do not match: {fchksum} != {chksum}")
+
+    return solv.xfopen_fd(os.path.basename(url) if uncompress else None, tmp.fileno())
+
+
+@click.group()
+def cli():
+    pass
+
+
+@cli.command()
+@click.pass_context
+@click.argument("source", type=click.Path(exists=True))
+@click.option(
+    "-a",
+    "--add",
+    multiple=True,
+    type=click.Path(exists=True),
+    help="Add local RPMs to the pool that is used in dependency resolution.",
+)
+@click.option(
+    "-v", "--verbose", is_flag=True, help="Enable verbose mode.",
+)
+def get_binary_license(ctx, source, add, verbose):
+    """Get the resulting license of a binary.
+
+    Since all crates (aka `rust-*-devel`) are linked statically, the resulting
+    binary license should be result of combining source license and all used
+    crates.
+
+    This command resolves dependencies and outputs final license(s).
+    """
+    os.makedirs(CACHEDIR, exist_ok=True)
+
+    pool = solv.Pool()
+    pool.setarch(ARCH)
+
+    repo = pool.add_repo("upstream")
+    fd = _download("repodata/repomd.xml")
+    chksum = solv.Chksum(solv.REPOKEY_TYPE_SHA256)
+    chksum.add("1.1")
+    chksum.add_fd(fd.fileno())
+    cookie = chksum.raw()
+    repo.add_repomdxml(fd)
+    fd.close()
+
+    # Find "primary"
+    di = repo.Dataiterator_meta(
+        solv.REPOSITORY_REPOMD_TYPE, "primary", solv.Dataiterator.SEARCH_STRING
+    )
+    di.prepend_keyname(solv.REPOSITORY_REPOMD)
+    for d in di:
+        dp = d.parentpos()
+        filename = dp.lookup_str(solv.REPOSITORY_REPOMD_LOCATION)
+        checksum = dp.lookup_checksum(solv.REPOSITORY_REPOMD_CHECKSUM)
+        # FIXME: Can filename be None?
+
+    cache_file = CACHEDIR / "upstream.solv"
+    try:
+        with open(cache_file, "rb") as f:
+            clen = len(cookie)
+            f.seek(-clen, os.SEEK_END)
+            fcookie = f.read(clen)
+            if fcookie != cookie:
+                raise IOError("repomd.xml has changed")
+            f.seek(0)
+            fd = solv.xfopen_fd(None, f.fileno())
+            repo.add_solv(fd)
+            fd.close()
+        cached = True
+    except IOError:
+        # Failed to load from cache
+        cached = False
+
+    if not cached:
+        fd = _download(filename, chksum=checksum, uncompress=True)
+        repo.add_rpmmd(fd, None)
+        fd.close()
+
+        os.makedirs(CACHEDIR, exist_ok=True)
+        with tempfile.NamedTemporaryFile(prefix=".newsolv-", dir=CACHEDIR) as tmp:
+            fd = solv.xfopen_fd(None, tmp.fileno())
+            repo.write(fd)
+            fd.flush()
+            fd.write(cookie)
+            fd.close()
+            if repo.iscontiguous():
+                repo.empty()
+                repo.add_solv(tmp.name)
+            os.unlink(cache_file)
+            os.link(tmp.name, cache_file)
+
+    repo_local = pool.add_repo("local")
+    repo_local.priority = 99
+    s = repo.add_rpm(source)
+    for f in add:
+        repo.add_rpm(f)
+
+    pool.addfileprovides()
+    pool.createwhatprovides()
+
+    solver = pool.Solver()
+    solver.set_flag(solv.Solver.SOLVER_FLAG_IGNORE_RECOMMENDED, True)
+    problems = solver.solve(
+        [pool.Job(solv.Job.SOLVER_SOLVABLE | solv.Job.SOLVER_INSTALL, s.id)]
+    )
+    if problems:
+        click.echo("Failed to resolve dependencies:", err=True)
+        for problem in problems:
+            for rule in problem.findallproblemrules():
+                for info in rule.allinfos():
+                    click.echo(f"  - ", nl=False)
+                    click.secho(info.problemstr(), fg="red")
+        ctx.abort()
+
+    licenses = collections.defaultdict(set)
+    for p in solver.transaction().newsolvables():
+        if (
+            not (p.name.startswith("rust-") and p.name.endswith("-devel"))
+            and not p == s
+        ):
+            continue
+        licenses[p.lookup_str(solv.SOLVABLE_LICENSE)].add(p)
+    # XXX: This is pure hack and we should optimize license license in much better way
+    if "MIT or ASL 2.0" in licenses and "ASL 2.0 or MIT" in licenses:
+        licenses["MIT or ASL 2.0"].update(licenses.pop("ASL 2.0 or MIT"))
+
+    for license, packages in sorted(licenses.items()):
+        click.echo(f"# {license}")
+        if verbose:
+            for package in packages:
+                click.secho(f"#   * {package}", fg="white")
+
+
+if __name__ == "__main__":
+    cli()