First stab

migrations/versions/838230f05aa0_.py

@@ -1,8 +1,8 @@
 """empty message
 
-Revision ID: 8fca9cdfb5be
+Revision ID: 838230f05aa0
 Revises: 
-Create Date: 2022-09-26 10:38:30.015462
+Create Date: 2022-09-26 12:12:48.657804
 
 """
 from alembic import op
@@ -10,7 +10,7 @@ import sqlalchemy as sa
 
 
 # revision identifiers, used by Alembic.
-revision = '8fca9cdfb5be'
+revision = '838230f05aa0'
 down_revision = None
 branch_labels = None
 depends_on = None
@@ -105,6 +105,8 @@ def upgrade():
     sa.Column('updated_at_in_seconds', sa.Integer(), nullable=True),
     sa.Column('created_at_in_seconds', sa.Integer(), nullable=True),
     sa.Column('status', sa.String(length=50), nullable=True),
+    sa.Column('bpmn_version_control_type', sa.String(length=50), nullable=True),
+    sa.Column('bpmn_version_control_identifier', sa.String(length=255), nullable=True),
     sa.ForeignKeyConstraint(['process_initiator_id'], ['user.id'], ),
     sa.PrimaryKeyConstraint('id')
     )

src/spiffworkflow_backend/models/process_instance.py

@@ -106,6 +106,8 @@ class ProcessInstanceModel(SpiffworkflowBaseDBModel):
     status: str = db.Column(db.String(50))
 
     bpmn_xml_file_contents: bytes | None = None
+    bpmn_version_control_type: str = db.Column(db.String(50))
+    bpmn_version_control_identifier: str = db.Column(db.String(255))
 
     @property
     def serialized(self) -> dict[str, Any]:
@@ -159,6 +161,7 @@ class ProcessInstanceModelSchema(Schema):
             "updated_at_in_seconds",
             "created_at_in_seconds",
             "status",
+            "bpmn_version_control_identifier"
         ]
 
     status = marshmallow.fields.Method("get_status", dump_only=True)

src/spiffworkflow_backend/routes/process_api_blueprint.py

@@ -49,6 +49,7 @@ from spiffworkflow_backend.models.spiff_logging import SpiffLoggingModel
 from spiffworkflow_backend.models.user import UserModel
 from spiffworkflow_backend.services.error_handling_service import ErrorHandlingService
 from spiffworkflow_backend.services.file_system_service import FileSystemService
+from spiffworkflow_backend.services.git_service import GitService
 from spiffworkflow_backend.services.message_service import MessageService
 from spiffworkflow_backend.services.process_instance_processor import (
     ProcessInstanceProcessor,
@@ -609,12 +610,18 @@ def process_instance_show(
 ) -> flask.wrappers.Response:
     """Create_process_instance."""
     process_instance = find_process_instance_by_id_or_raise(process_instance_id)
+    current_version_control_revision = GitService.get_current_revision()
     process_model = get_process_model(process_model_id, process_group_id)
 
     if process_model.primary_file_name:
+        if process_instance.bpmn_version_control_identifier == current_version_control_revision:
             bpmn_xml_file_contents = SpecFileService.get_data(
                 process_model, process_model.primary_file_name
             )
+        else:
+            bpmn_xml_file_contents = GitService.get_instance_file_contents_for_revision(
+                process_model, process_instance.bpmn_version_control_identifier
+            )
         process_instance.bpmn_xml_file_contents = bpmn_xml_file_contents
 
     return make_response(jsonify(process_instance), 200)

src/spiffworkflow_backend/services/git_service.py

@@ -0,0 +1,24 @@
+import os
+from flask import current_app
+
+from spiffworkflow_backend.models.process_model import ProcessModelInfo
+from spiffworkflow_backend.services.file_system_service import FileSystemService
+
+
+class GitService:
+
+    @staticmethod
+    def get_current_revision() -> str:
+        bpmn_spec_absolute_dir = current_app.config["BPMN_SPEC_ABSOLUTE_DIR"]
+        # The value includes a carriage return character at the end, so we don't grab the last character
+        current_git_revision = os.popen(f"cd {bpmn_spec_absolute_dir} && git rev-parse --short HEAD").read()[:-1]
+        return current_git_revision
+
+    @staticmethod
+    def get_instance_file_contents_for_revision(process_model: ProcessModelInfo, revision: str) -> str:
+        bpmn_spec_absolute_dir = current_app.config["BPMN_SPEC_ABSOLUTE_DIR"]
+        process_model_relative_path = FileSystemService.process_model_relative_path(process_model)
+        shell_command = f"cd {bpmn_spec_absolute_dir} && git show {revision}:{process_model_relative_path}/{process_model.primary_file_name}"
+        # git show 78ae5eb:category_number_one/script-task/script-task.bpmn
+        file_contents = os.popen(shell_command).read()[:-1]
+        return file_contents

src/spiffworkflow_backend/services/process_instance_service.py

@@ -1,4 +1,5 @@
 """Process_instance_service."""
+import os
 import time
 from typing import Any
 from typing import Dict
@@ -27,6 +28,7 @@ from spiffworkflow_backend.models.task import Task
 from spiffworkflow_backend.models.task_event import TaskAction
 from spiffworkflow_backend.models.task_event import TaskEventModel
 from spiffworkflow_backend.models.user import UserModel
+from spiffworkflow_backend.services.git_service import GitService
 from spiffworkflow_backend.services.process_instance_processor import (
     ProcessInstanceProcessor,
 )
@@ -47,12 +49,15 @@ class ProcessInstanceService:
         process_group_identifier: Optional[str] = None,
     ) -> ProcessInstanceModel:
         """Get_process_instance_from_spec."""
+        current_git_revision = GitService.get_current_revision()
         process_instance_model = ProcessInstanceModel(
             status=ProcessInstanceStatus.not_started.value,
             process_initiator=user,
             process_model_identifier=process_model_identifier,
             process_group_identifier=process_group_identifier,
             start_in_seconds=round(time.time()),
+            bpmn_version_control_type='git',
+            bpmn_version_control_identifier=current_git_revision,
         )
         db.session.add(process_instance_model)
         db.session.commit()

tests/spiffworkflow_backend/integration/test_process_api.py

@@ -25,6 +25,7 @@ from spiffworkflow_backend.models.process_model import NotificationType
 from spiffworkflow_backend.models.process_model import ProcessModelInfoSchema
 from spiffworkflow_backend.models.task_event import TaskEventModel
 from spiffworkflow_backend.models.user import UserModel
+from spiffworkflow_backend.services.git_service import GitService
 from spiffworkflow_backend.services.process_instance_processor import (
     ProcessInstanceProcessor,
 )
@@ -689,6 +690,9 @@ class TestProcessApi(BaseTest):
         assert response.json["updated_at_in_seconds"] is not None
         assert response.json["status"] == "not_started"
         assert response.json["process_model_identifier"] == test_process_model_id
+        # TODO: mock out the responses for the git service so we can do something like this
+        # current_revision = GitService.get_current_revision()
+        # assert response.json["bpmn_version_control_identifier"] == current_revision
 
     def test_process_instance_run(
         self, app: Flask, client: FlaskClient, with_db_and_bpmn_file_cleanup: None