Add git info to context

.changes/unreleased/Features-20230925-182237.yaml

@@ -0,0 +1,6 @@
+kind: Features
+body: Add git_branch and git_sha to the Jinja context
+time: 2023-09-25T18:22:37.142445+02:00
+custom:
+  Author: b-per
+  Issue: "8690"

core/dbt/context/base.py

@@ -26,6 +26,8 @@
 from dbt.events.contextvars import get_node_info
 from dbt.version import __version__ as dbt_version
 
+from pygit2 import Repository, GitError  # type: ignore
+
 # These modules are added to the context. Consider alternative
 # approaches which will extend well to potentially many modules
 import pytz
@@ -204,6 +206,45 @@ def to_dict(self) -> Dict[str, Any]:
         self._ctx.update(builtins)
         return self._ctx
 
+    @contextproperty()
+    def git_branch(self) -> str:
+        """The `git_branch` variable returns the current branch name if the
+        code is version controlled by git.
+        Otherwise it returns an empty string.
+        """
+
+        if hasattr(get_flags(), "PROJECT_DIR"):
+            project_dir = get_flags().PROJECT_DIR
+        else:
+            project_dir = "."
+
+        try:
+            branch_name = Repository(project_dir).head.shorthand
+        except GitError:
+            branch_name = ""
+
+        return branch_name
+
+    @contextproperty()
+    def git_sha(self) -> str:
+        """The `git_sha` variable returns the sha of the last commit
+        if the dbt code is version controlled in git.
+        Otherwise it returns an empty string.
+        """
+
+        if hasattr(get_flags(), "PROJECT_DIR"):
+            project_dir = get_flags().PROJECT_DIR
+        else:
+            project_dir = "."
+
+        try:
+            repo = Repository(project_dir)
+            sha = repo.head.target.hex
+        except GitError:
+            sha = ""
+
+        return sha
+
     @contextproperty()
     def dbt_version(self) -> str:
         """The `dbt_version` variable returns the installed version of dbt that

core/setup.py

@@ -83,6 +83,7 @@
         "pytz>=2015.7",
         "pyyaml>=6.0",
         "typing-extensions>=3.7.4",
+        "pygit2 >= 1.0.0",
         # ----
         # Match snowflake-connector-python, to ensure compatibility in dbt-snowflake
         "cffi>=1.9,<2.0.0",

tests/functional/context_values/test_git.py

@@ -0,0 +1,39 @@
+import os
+import subprocess
+import pytest
+
+from dbt.tests.util import run_dbt_and_capture
+
+# we use a macro to print the value and check the logs when testing
+on_run_start_macro_assert_git_branch = """
+{% macro assert_git_branch_name() %}
+    {{ log("git branch name: " ~ git_branch, 1) }}
+{% endmacro %}
+"""
+
+
+class TestContextGitValues:
+    @pytest.fixture(scope="class")
+    def macros(self):
+        return {
+            "assert_git_branch_name.sql": on_run_start_macro_assert_git_branch,
+        }
+
+    @pytest.fixture(scope="class")
+    def project_config_update(self):
+        return {
+            "on-run-start": "{{ assert_git_branch_name() }}",
+        }
+
+    def test_git_values(self, project):
+        os.chdir(project.project_root)
+        # Initialize a new git repository
+        subprocess.run(["git", "init"], check=True)
+        subprocess.run(["git", "config", "user.email", "[email protected]"], check=True)
+        subprocess.run(["git", "config", "user.name", "dbt Labs"], check=True)
+        subprocess.run(["git", "checkout", "-b" "new_branch_for_testing"], check=True)
+        subprocess.run(["git", "add", "*"], check=True)
+        subprocess.run(["git", "commit", "-m", "commit to git"], check=True)
+
+        _, run_logs = run_dbt_and_capture(["run"])
+        assert "git branch name: new_branch_for_testing" in run_logs

tests/unit/test_context.py

@@ -188,6 +188,8 @@ def assert_has_keys(required_keys: Set[str], maybe_keys: Set[str], ctx: Dict[str
         "print",
         "diff_of_two_dicts",
         "local_md5",
+        "git_branch",
+        "git_sha",
     }
 )