debian-forge/tools/osbuild-depsolve-dnf

#!/usr/bin/python3
# pylint: disable=invalid-name

"""
A JSON-based interface for depsolving using DNF.

Reads a request through stdin and prints the result to stdout.
In case of error, a structured error is printed to stdout as well.
"""
import json
import os
import os.path
import sys
import tempfile

from osbuild.solver import GPGKeyReadError, MarkingError, DepsolveError, RepoError

# Load the solver configuration
config = {"use_dnf5": False}
config_path = os.environ.get("OSBUILD_SOLVER_CONFIG") or "/usr/lib/osbuild/solver.json"
try:
    with open(config_path, encoding="utf-8") as f:
        config = json.load(f)
except FileNotFoundError:
    pass

if config.get("use_dnf5", False):
    from osbuild.solver.dnf5 import DNF5 as Solver
else:
    from osbuild.solver.dnf import DNF as Solver


def get_string_option(option):
    # option.get_value() causes an error if it's unset for string values, so check if it's empty first
    if option.empty():
        return None
    return option.get_value()


def setup_cachedir(request):
    arch = request["arch"]
    # If dnf-json is run as a service, we don't want users to be able to set the cache
    cache_dir = os.environ.get("OVERWRITE_CACHE_DIR", "")
    if cache_dir:
        cache_dir = os.path.join(cache_dir, arch)
    else:
        cache_dir = request.get("cachedir", "")

    if not cache_dir:
        return "", {"kind": "Error", "reason": "No cache dir set"}

    return cache_dir, None


def solve(request, cache_dir):
    command = request["command"]
    arguments = request["arguments"]

    with tempfile.TemporaryDirectory() as persistdir:
        solver = Solver(request, persistdir, cache_dir)
        try:
            if command == "dump":
                result = solver.dump()
            elif command == "depsolve":
                result = solver.depsolve(arguments)
            elif command == "search":
                result = solver.search(arguments.get("search", {}))
        except GPGKeyReadError as e:
            printe("error reading gpgkey")
            return None, {
                "kind": type(e).__name__,
                "reason": str(e)
            }
        except RepoError as e:
            return None, {
                "kind": "RepoError",
                "reason": f"There was a problem reading a repository: {e}"
            }
        except MarkingError as e:
            printe("error install_specs")
            return None, {
                "kind": "MarkingErrors",
                "reason": f"Error occurred when marking packages for installation: {e}"
            }
        except DepsolveError as e:
            printe("error depsolve")
            # collect list of packages for error
            pkgs = []
            for t in arguments.get("transactions", []):
                pkgs.extend(t["package-specs"])
            return None, {
                "kind": "DepsolveError",
                "reason": f"There was a problem depsolving {', '.join(pkgs)}: {e}"
            }
        except Exception as e:  # pylint: disable=broad-exception-caught
            printe("error traceback")
            import traceback
            return None, {
                "kind": type(e).__name__,
                "reason": str(e),
                "traceback": traceback.format_exc()
            }

    return result, None


def printe(*msg):
    print(*msg, file=sys.stderr)


def fail(err):
    printe(f"{err['kind']}: {err['reason']}")
    print(json.dumps(err))
    sys.exit(1)


def respond(result):
    print(json.dumps(result))


# pylint: disable=too-many-return-statements
def validate_request(request):
    command = request.get("command")
    valid_cmds = ("depsolve", "dump", "search")
    if command not in valid_cmds:
        return {
            "kind": "InvalidRequest",
            "reason": f"invalid command '{command}': must be one of {', '.join(valid_cmds)}"
        }

    if not request.get("arch"):
        return {
            "kind": "InvalidRequest",
            "reason": "no 'arch' specified"
        }

    if not request.get("module_platform_id"):
        return {
            "kind": "InvalidRequest",
            "reason": "no 'module_platform_id' specified"
        }
    if not request.get("releasever"):
        return {
            "kind": "InvalidRequest",
            "reason": "no 'releasever' specified"
        }
    arguments = request.get("arguments")
    if not arguments:
        return {
            "kind": "InvalidRequest",
            "reason": "empty 'arguments'"
        }

    if not arguments.get("repos") and not arguments.get("root_dir"):
        return {
            "kind": "InvalidRequest",
            "reason": "no 'repos' or 'root_dir' specified"
        }

    return None


def main():
    request = json.load(sys.stdin)
    err = validate_request(request)
    if err:
        fail(err)

    cachedir, err = setup_cachedir(request)
    if err:
        fail(err)
    result, err = solve(request, cachedir)
    if err:
        fail(err)
    else:
        respond(result)


if __name__ == "__main__":
    main()