Adds canary support for signals. (#3785)

* clean pr

* Add revision

src/dispatch/database/revisions/tenant/versions/2023-09-13_e875e9544048.py

@@ -0,0 +1,26 @@
+"""Adds canary column to signal_instance
+
+Revision ID: e875e9544048
+Revises: 0560fab4537f
+Create Date: 2023-09-13 09:31:24.223488
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = "e875e9544048"
+down_revision = "0560fab4537f"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column("signal_instance", sa.Column("canary", sa.Boolean(), nullable=True))
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column("signal_instance", "canary")

src/dispatch/signal/flows.py

@@ -90,6 +90,10 @@ def signal_instance_create_flow(
             )
         return signal_instance
 
+    # limited support for canary signals, just store the instance and return
+    if signal_instance.canary:
+        return signal_instance
+
     if not signal_instance.signal.create_case:
         return signal_instance
 

src/dispatch/signal/models.py

@@ -231,6 +231,7 @@ class SignalInstance(Base, TimeStampMixin, ProjectMixin):
     case_priority = relationship("CasePriority", backref="signal_instances")
     fingerprint = Column(String)
     filter_action = Column(String)
+    canary = Column(Boolean, default=False)
     raw = Column(JSONB)
     signal = relationship("Signal", backref="instances")
     signal_id = Column(Integer, ForeignKey("signal.id"))
@@ -364,6 +365,7 @@ class AdditionalMetadata(DispatchBase):
 class SignalInstanceBase(DispatchBase):
     project: ProjectRead
     case: Optional[CaseReadMinimal]
+    canary: Optional[bool] = False
     entities: Optional[List[EntityRead]] = []
     raw: dict[str, Any]
     filter_action: SignalFilterAction = None