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Diffstat (limited to 'src/debputy/packaging/alternatives.py')
| -rw-r--r-- | src/debputy/packaging/alternatives.py | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/src/debputy/packaging/alternatives.py b/src/debputy/packaging/alternatives.py new file mode 100644 index 0000000..249fa9e --- /dev/null +++ b/src/debputy/packaging/alternatives.py @@ -0,0 +1,225 @@ +import textwrap +from typing import List, Dict, Tuple, Mapping + +from debian.deb822 import Deb822 + +from debputy.maintscript_snippet import MaintscriptSnippetContainer, MaintscriptSnippet +from debputy.packager_provided_files import PackagerProvidedFile +from debputy.packages import BinaryPackage +from debputy.packaging.makeshlibs import resolve_reserved_provided_file +from debputy.plugin.api import VirtualPath +from debputy.util import _error, escape_shell, POSTINST_DEFAULT_CONDITION + +# Match debhelper (minus one space in each end, which comes +# via join). +LINE_PREFIX = "\\\n " + + +def process_alternatives( + binary_package: BinaryPackage, + fs_root: VirtualPath, + reserved_packager_provided_files: Dict[str, List[PackagerProvidedFile]], + maintscript_snippets: Dict[str, MaintscriptSnippetContainer], +) -> None: + if binary_package.is_udeb: + return + + provided_alternatives_file = resolve_reserved_provided_file( + "alternatives", + reserved_packager_provided_files, + ) + if provided_alternatives_file is None: + return + + with provided_alternatives_file.open() as fd: + alternatives = list(Deb822.iter_paragraphs(fd)) + + for no, alternative in enumerate(alternatives): + process_alternative( + provided_alternatives_file.fs_path, + fs_root, + alternative, + no, + maintscript_snippets, + ) + + +def process_alternative( + provided_alternatives_fs_path: str, + fs_root: VirtualPath, + alternative_deb822: Deb822, + no: int, + maintscript_snippets: Dict[str, MaintscriptSnippetContainer], +) -> None: + name = _mandatory_key( + "Name", + alternative_deb822, + provided_alternatives_fs_path, + f"Stanza number {no}", + ) + error_context = f"Alternative named {name}" + link_path = _mandatory_key( + "Link", + alternative_deb822, + provided_alternatives_fs_path, + error_context, + ) + impl_path = _mandatory_key( + "Alternative", + alternative_deb822, + provided_alternatives_fs_path, + error_context, + ) + priority = _mandatory_key( + "Priority", + alternative_deb822, + provided_alternatives_fs_path, + error_context, + ) + if "/" in name: + _error( + f'The "Name" ({link_path}) key must be a basename and cannot contain slashes' + f" ({error_context} in {provided_alternatives_fs_path})" + ) + if link_path == impl_path: + _error( + f'The "Link" key and the "Alternative" key must not have the same value' + f" ({error_context} in {provided_alternatives_fs_path})" + ) + impl = fs_root.lookup(impl_path) + if impl is None or impl.is_dir: + _error( + f'The path listed in "Alternative" ("{impl_path}") does not exist' + f" in the package. ({error_context} in {provided_alternatives_fs_path})" + ) + for key in ["Slave", "Slaves", "Slave-Links"]: + if key in alternative_deb822: + _error( + f'Please use "Dependents" instead of "{key}".' + f" ({error_context} in {provided_alternatives_fs_path})" + ) + dependents = alternative_deb822.get("Dependents") + install_command = [ + escape_shell( + "update-alternatives", + "--install", + link_path, + name, + impl_path, + priority, + ) + ] + remove_command = [ + escape_shell( + "update-alternatives", + "--remove", + link_path, + impl_path, + ) + ] + if dependents: + seen_link_path = set() + for line in dependents.splitlines(): + line = line.strip() + if not line: # First line is usually empty + continue + dlink_path, dlink_name, dimpl_path = parse_dependent_link( + line, + error_context, + provided_alternatives_fs_path, + ) + if dlink_path in seen_link_path: + _error( + f'The Dependent link path "{dlink_path}" was used twice.' + f" ({error_context} in {provided_alternatives_fs_path})" + ) + dimpl = fs_root.lookup(dimpl_path) + if dimpl is None or dimpl.is_dir: + _error( + f'The path listed in "Dependents" ("{dimpl_path}") does not exist' + f" in the package. ({error_context} in {provided_alternatives_fs_path})" + ) + seen_link_path.add(dlink_path) + install_command.append(LINE_PREFIX) + install_command.append( + escape_shell( + # update-alternatives still uses this old option name :-/ + "--slave", + dlink_path, + dlink_name, + dimpl_path, + ) + ) + postinst = textwrap.dedent( + """\ + if {CONDITION}; then + {COMMAND} + fi + """ + ).format( + CONDITION=POSTINST_DEFAULT_CONDITION, + COMMAND=" ".join(install_command), + ) + + prerm = textwrap.dedent( + """\ + if [ "$1" = "remove" ]; then + {COMMAND} + fi + """ + ).format(COMMAND=" ".join(remove_command)) + maintscript_snippets["postinst"].append( + MaintscriptSnippet( + f"debputy (via {provided_alternatives_fs_path})", + snippet=postinst, + ) + ) + maintscript_snippets["prerm"].append( + MaintscriptSnippet( + f"debputy (via {provided_alternatives_fs_path})", + snippet=prerm, + ) + ) + + +def parse_dependent_link( + line: str, + error_context: str, + provided_alternatives_file: str, +) -> Tuple[str, str, str]: + parts = line.split() + if len(parts) != 3: + if len(parts) > 1: + pass + _error( + f"The each line in Dependents links must have exactly 3 space separated parts." + f' The "{line}" split into {len(parts)} part(s).' + f" ({error_context} in {provided_alternatives_file})" + ) + + dlink_path, dlink_name, dimpl_path = parts + if "/" in dlink_name: + _error( + f'The Dependent link name "{dlink_path}" must be a basename and cannot contain slashes' + f" ({error_context} in {provided_alternatives_file})" + ) + if dlink_path == dimpl_path: + _error( + f'The Dependent Link path and Alternative must not have the same value ["{dlink_path}"]' + f" ({error_context} in {provided_alternatives_file})" + ) + return dlink_path, dlink_name, dimpl_path + + +def _mandatory_key( + key: str, + alternative_deb822: Mapping[str, str], + provided_alternatives_file: str, + error_context: str, +) -> str: + try: + return alternative_deb822[key] + except KeyError: + _error( + f'Missing mandatory key "{key}" in {provided_alternatives_file} ({error_context})' + ) |