feat: extend craft_application.git module (#576)

Signed-off-by: Dariusz Duda <[email protected]>
Co-authored-by: Tiago Nobrega <[email protected]>
Co-authored-by: Michael DuBelko <[email protected]>

craft_application/git/__init__.py

@@ -14,18 +14,39 @@
 
 """Git repository utilities."""
 
-from ._consts import COMMIT_SHORT_SHA_LEN
+from ._consts import (
+    NO_PUSH_URL,
+    COMMIT_SHA_LEN,
+    COMMIT_SHORT_SHA_LEN,
+    CRAFTGIT_BINARY_NAME,
+    GIT_FALLBACK_BINARY_NAME,
+)
 from ._errors import GitError
-from ._models import GitType, short_commit_sha
-from ._git_repo import GitRepo, get_git_repo_type, is_repo, parse_describe
+from ._models import GitType, Commit, short_commit_sha
+
+from ._git_repo import (
+    GitRepo,
+    get_git_repo_type,
+    is_repo,
+    is_commit,
+    is_short_commit,
+    parse_describe,
+)
 
 __all__ = [
     "GitError",
     "GitRepo",
     "GitType",
+    "Commit",
     "get_git_repo_type",
     "is_repo",
     "parse_describe",
+    "is_commit",
+    "is_short_commit",
     "short_commit_sha",
+    "NO_PUSH_URL",
+    "COMMIT_SHA_LEN",
     "COMMIT_SHORT_SHA_LEN",
+    "CRAFTGIT_BINARY_NAME",
+    "GIT_FALLBACK_BINARY_NAME",
 ]

craft_application/git/_consts.py

@@ -16,4 +16,12 @@
 
 from typing import Final
 
+NO_PUSH_URL: Final[str] = "no_push"
+
+COMMIT_SHA_LEN: Final[int] = 40
+
 COMMIT_SHORT_SHA_LEN: Final[int] = 7
+
+CRAFTGIT_BINARY_NAME: Final[str] = "craft.git"
+
+GIT_FALLBACK_BINARY_NAME: Final[str] = "git"

craft_application/git/_git_repo.py

@@ -18,10 +18,14 @@
 
 import logging
 import os
+import re
+import shutil
 import subprocess
 import time
+from functools import lru_cache
 from pathlib import Path
 from shlex import quote
+from typing import Final, cast
 
 from craft_parts.utils import os_utils
 from typing_extensions import Self
@@ -45,11 +49,25 @@
     else:
         del os.environ["SSL_CERT_DIR"]
 
+from ._consts import CRAFTGIT_BINARY_NAME, GIT_FALLBACK_BINARY_NAME, NO_PUSH_URL
 from ._errors import GitError
-from ._models import GitType
+from ._models import Commit, GitType, short_commit_sha
 
 logger = logging.getLogger(__name__)
 
+COMMIT_REGEX: Final[re.Pattern[str]] = re.compile("[0-9a-f]{40}")
+SHORT_COMMIT_REGEX: Final[re.Pattern[str]] = re.compile("[0-9a-f]{7}")
+
+
+def is_commit(ref: str) -> bool:
+    """Check if given commit is a valid git commit sha."""
+    return bool(COMMIT_REGEX.fullmatch(ref))
+
+
+def is_short_commit(ref: str) -> bool:
+    """Check if given short commit is a valid git commit sha."""
+    return bool(SHORT_COMMIT_REGEX.fullmatch(ref))
+
 
 def is_repo(path: Path) -> bool:
     """Check if a directory is a git repo.
@@ -196,6 +214,68 @@ def commit(self, message: str = "auto commit") -> str:
                 f"in {str(self.path)!r}."
             ) from error
 
+    def get_last_commit(self) -> Commit:
+        """Get the last Commit on the current head."""
+        try:
+            last_commit = self._repo[self._repo.head.target]
+        except pygit2.GitError as error:
+            raise GitError("could not retrieve last commit") from error
+        else:
+            commit_message = cast(
+                str,
+                last_commit.message,  # pyright: ignore[reportAttributeAccessIssue,reportUnknownMemberType]
+            )
+            return Commit(
+                sha=str(last_commit.id),
+                message=commit_message,
+            )
+
+    def get_last_commit_on_branch_or_tag(
+        self,
+        branch_or_tag: str,
+        *,
+        remote: str | None = None,
+        fetch: bool = False,
+    ) -> Commit:
+        """Find last commit corresponding to given branch or tag."""
+        if fetch and remote is not None:
+            self.fetch(remote=remote, tags=True)
+        rev_list_output = [
+            self.get_git_command(),
+            "rev-list",
+            "-n",
+            "1",
+            branch_or_tag,
+        ]
+        try:
+            rev_parse_output = subprocess.check_output(
+                rev_list_output,
+                text=True,
+                stderr=subprocess.STDOUT,
+            )
+        except subprocess.CalledProcessError as error:
+            error_details = (
+                f"cannot find ref: {branch_or_tag!r}.\nCommand output:\n{error.stdout}"
+            )
+            raise GitError(error_details) from error
+
+        commit_sha = rev_parse_output.strip()
+        try:
+            commit_obj = self._repo.get(commit_sha)
+        except (pygit2.GitError, ValueError) as error:
+            raise GitError(
+                f"cannot find commit: {short_commit_sha(commit_sha)!r}"
+            ) from error
+        else:
+            commit_message = cast(
+                str,
+                commit_obj.message,  # pyright: ignore[reportOptionalMemberAccess,reportAttributeAccessIssue,reportUnknownMemberType]
+            )
+            return Commit(
+                sha=commit_sha,
+                message=commit_message,
+            )
+
     def is_clean(self) -> bool:
         """Check if the repo is clean.
 
@@ -286,6 +366,76 @@ def rename_remote(
                 f"cannot rename '{remote_name}' to '{new_remote_name}'"
             ) from error
 
+    def get_remote_url(self, remote_name: str) -> str:
+        """Get URL associated with the given remote.
+
+        Equivalent of git remote get-url <name>
+
+
+        :param remote_name: the remote repository name
+
+        :raises GitError: if remote does not exist
+        """
+        if not self.remote_exists(remote_name=remote_name):
+            raise GitError(f"cannot get URL for non-existing remote '{remote_name}'")
+        return cast(str, self._repo.remotes[remote_name].url)
+
+    def set_remote_url(self, remote_name: str, remote_url: str) -> None:
+        """Set new URL for the existing remote.
+
+        Equivalent of git remote set-url <name> <url>
+
+
+        :param remote_name: the remote repository name
+        :param remote_url: URL to be associated with the given remote
+
+        :raises GitError: if remote does not exist
+        """
+        if not self.remote_exists(remote_name=remote_name):
+            raise GitError(f"cannot set URL for non-existing remote: {remote_name!r}")
+        self._repo.remotes.set_url(remote_name, remote_url)
+
+    def get_remote_push_url(self, remote_name: str) -> str:
+        """Get push-only URL associated with the given remote.
+
+        Equivalent of git remote get-url --push <name>
+
+        :param remote_name: the remote repository name
+
+        :raises GitError: if remote does not exist
+        """
+        if not self.remote_exists(remote_name=remote_name):
+            raise GitError(
+                f"cannot get push URL for non-existing remote: {remote_name!r}"
+            )
+        return cast(str, self._repo.remotes[remote_name].push_url)
+
+    def set_remote_push_url(self, remote_name: str, remote_push_url: str) -> None:
+        """Set new push-only URL for the existing remote.
+
+        Equivalent of git remote set-url --push <name> <url>
+
+
+        :param remote_name: the remote repository name
+        :param remote_url: push URL to be associated with the given remote
+
+        :raises GitError: if remote does not exist
+        """
+        if not self.remote_exists(remote_name=remote_name):
+            raise GitError(
+                f"cannot set push URL for non-existing remote: {remote_name!r}"
+            )
+        self._repo.remotes.set_push_url(remote_name, remote_push_url)
+
+    def set_no_push(self, remote_name: str) -> None:
+        """Disable pushing to the selected remote.
+
+        :param remote_name: the remote repository name
+
+        :raises GitError: if remote does not exist
+        """
+        self.set_remote_push_url(remote_name, NO_PUSH_URL)
+
     def push_url(  # noqa: PLR0912 (too-many-branches)
         self,
         remote_url: str,
@@ -321,7 +471,14 @@ def push_url(  # noqa: PLR0912 (too-many-branches)
         # Force push in case this repository already exists. The repository is always
         # going to exist solely for remote builds, so the only potential issue here is a
         # race condition with multiple remote builds on the same machine.
-        cmd: list[str] = ["git", "push", "--force", remote_url, refspec, "--progress"]
+        cmd: list[str] = [
+            self.get_git_command(),
+            "push",
+            "--force",
+            remote_url,
+            refspec,
+            "--progress",
+        ]
         if push_tags:
             cmd.append("--tags")
 
@@ -382,6 +539,72 @@ def push_url(  # noqa: PLR0912 (too-many-branches)
             f"for the git repository in {str(self.path)!r}."
         )
 
+    def fetch(
+        self,
+        *,
+        remote: str,
+        tags: bool = False,
+        ref: str | None = None,
+        depth: int | None = None,
+    ) -> None:
+        """Fetch the contents of the given remote.
+
+        :param remote: The name of the remote.
+        :param tags: Whether to fetch tags.
+        :param ref: Optional reference to the specific object to fetch.
+        :param depth: Maximum number of commits to fetch (all by default).
+        """
+        fetch_command = [self.get_git_command(), "fetch"]
+
+        if not self.remote_exists(remote):
+            raise GitError(f"cannot fetch undefined remote: {remote!r}")
+
+        if tags:
+            fetch_command.append("--tags")
+        if depth is not None:
+            fetch_command.extend(["--depth", f"{depth}"])
+
+        fetch_command.append(remote)
+        if ref is not None:
+            fetch_command.append(ref)
+
+        try:
+            os_utils.process_run(fetch_command, logger.debug)
+        except FileNotFoundError as error:
+            raise GitError("git command not found in the system") from error
+        except subprocess.CalledProcessError as error:
+            raise GitError(f"cannot fetch remote: {remote!r}") from error
+
+    def remote_contains(
+        self,
+        *,
+        remote: str,
+        commit_sha: str,
+    ) -> bool:
+        """Check if the given commit is pushed to the remote repository."""
+        logger.debug(
+            "Checking if %r was pushed to %r", short_commit_sha(commit_sha), remote
+        )
+        checking_command = [
+            self.get_git_command(),
+            "branch",
+            "--remotes",
+            "--contains",
+            commit_sha,
+        ]
+        try:
+            remotes_that_has_given_commit = subprocess.check_output(
+                checking_command,
+                text=True,
+            )
+        except subprocess.CalledProcessError as error:
+            raise GitError("incorrect commit provided, cannot check") from error
+        else:
+            for line in remotes_that_has_given_commit.splitlines():
+                if line.strip().startswith(f"{remote}/"):
+                    return True
+        return False
+
     def describe(
         self,
         *,
@@ -461,7 +684,7 @@ def clone_repository(
             raise GitError("Cannot clone to existing repository")
 
         logger.debug("Cloning %s to %s", url, path)
-        clone_cmd = ["git", "clone"]
+        clone_cmd = [cls.get_git_command(), "clone"]
         if checkout_branch is not None:
             logger.debug("Checking out to branch: %s", checkout_branch)
             clone_cmd.extend(["--branch", quote(checkout_branch)])
@@ -482,3 +705,21 @@ def clone_repository(
                 f"cannot clone repository: {url} to {str(path)!r}"
             ) from error
         return cls(path)
+
+    @classmethod
+    @lru_cache(maxsize=1)
+    def get_git_command(cls) -> str:
+        """Get name of the git executable that may be used in subprocesses.
+
+        Fallback to the previous behavior in case of non-snap / local installation or
+        if snap does not provide expected binary.
+        """
+        craftgit_binary = CRAFTGIT_BINARY_NAME
+        if shutil.which(craftgit_binary):
+            return craftgit_binary
+        logger.warning(
+            "Cannot find craftgit binary: %r. Is it a part of snap package?",
+            craftgit_binary,
+        )
+        logger.warning("Falling back to: %r", GIT_FALLBACK_BINARY_NAME)
+        return GIT_FALLBACK_BINARY_NAME

craft_application/git/_models.py

@@ -14,6 +14,7 @@
 
 """Git repository models."""
 
+from dataclasses import dataclass
 from enum import Enum
 
 from ._consts import COMMIT_SHORT_SHA_LEN
@@ -30,3 +31,16 @@ class GitType(Enum):
     INVALID = 0
     NORMAL = 1
     SHALLOW = 2
+
+
+@dataclass
+class Commit:
+    """Model representing a commit."""
+
+    sha: str
+    message: str
+
+    @property
+    def short_sha(self) -> str:
+        """Get short commit sha."""
+        return short_commit_sha(self.sha)