1 files changed, 162 insertions, 0 deletions
diff --git a/comm/taskcluster/comm_taskgraph/decision.py b/comm/taskcluster/comm_taskgraph/decision.py
new file mode 100644
index 0000000000..a075b47cf5
--- /dev/null
+++ b/comm/taskcluster/comm_taskgraph/decision.py
@@ -0,0 +1,162 @@
+#  This Source Code Form is subject to the terms of the Mozilla Public
+#  License, v. 2.0. If a copy of the MPL was not distributed with this
+#  file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import logging
+import os
+import sys
+
+from redo import retry
+from taskgraph.decision import (
+    _determine_more_accurate_base_ref,
+    _determine_more_accurate_base_rev,
+    _get_env_prefix,
+)
+from taskgraph.taskgraph import TaskGraph
+from taskgraph.util.taskcluster import get_artifact
+from taskgraph.util.vcs import get_repository
+
+from gecko_taskgraph.util.backstop import is_backstop
+from gecko_taskgraph.util.partials import populate_release_history
+from gecko_taskgraph.util.taskgraph import (
+    find_decision_task,
+    find_existing_tasks_from_previous_kinds,
+)
+
+from . import COMM
+from comm_taskgraph.parameters import get_defaults
+
+logger = logging.getLogger(__name__)
+
+BALROG_PRODUCT = "Thunderbird"
+
+# Backstop defaults
+BACKSTOP_TIME_INTERVAL = 60 * 22  # minutes
+INTEGRATION_PROJECTS = {"comm-central"}
+
+PER_PROJECT_PARAMETERS = {
+    "ash": {
+        "target_tasks_method": "ash_tasks",
+    },
+    "jamun": {
+        "target_tasks_method": "nightly_desktop",
+        "release_type": "nightly",
+    },
+    "try-comm-central": {
+        "enable_always_target": True,
+        "target_tasks_method": "try_cc_tasks",
+    },
+    "comm-central": {
+        "target_tasks_method": "comm_central_tasks",
+        "release_type": "nightly",
+    },
+    "comm-beta": {
+        "target_tasks_method": "mozilla_beta_tasks",
+        "release_type": "beta",
+    },
+    "comm-esr115": {
+        "target_tasks_method": "mozilla_esr115_tasks",
+        "release_type": "release",
+    },
+}
+
+CRON_OPTIONS = {
+    "nightly_desktop": {
+        "existing_tasks": lambda parameters, graph_config: get_existing_tasks(
+            parameters, graph_config
+        ),
+        "release_history": lambda parameters, graph_config: populate_release_history(
+            BALROG_PRODUCT, parameters["project"]
+        ),
+    }
+}
+
+
+def get_decision_parameters(graph_config, parameters):
+    logger.info("{}.get_decision_parameters called".format(__name__))
+
+    # Apply default values for all Thunderbird CI projects
+    parameters.update(get_defaults(graph_config.vcs_root))
+
+    # If the target method is nightly, we should build partials. This means
+    # knowing what has been released previously.
+    # An empty release_history is fine, it just means no partials will be built
+    project = parameters["project"]
+
+    if project in PER_PROJECT_PARAMETERS:
+        # Upstream will set target_tasks_method to "default" when nothing is set
+        if parameters["target_tasks_method"] == "default":
+            del parameters["target_tasks_method"]
+
+        # If running from .cron.yml, do not overwrite existing parameters
+        update_parameters = [
+            (_k, _v)
+            for _k, _v in PER_PROJECT_PARAMETERS[project].items()
+            if _k not in parameters or not parameters[_k]
+        ]
+        parameters.update(update_parameters)
+        logger.info("project parameters set for project {} from {}.".format(project, __file__))
+    else:
+        # Projects without a target_tasks_method should not exist for Thunderbird CI
+        raise Exception("No target_tasks_method is defined for project {}.".format(project))
+
+    del parameters["backstop"]
+    parameters["backstop"] = is_backstop(
+        parameters,
+        trust_domain="comm",
+        time_interval=BACKSTOP_TIME_INTERVAL,
+        integration_projects=INTEGRATION_PROJECTS,
+    )
+    for n in (
+        "COMM_BASE_REPOSITORY",
+        "COMM_BASE_REV",
+        "COMM_HEAD_REPOSITORY",
+        "COMM_HEAD_REV",
+        "COMM_HEAD_REF",
+    ):
+        val = os.environ.get(n, "")
+        parameters[n.lower()] = val
+
+    repo_path = COMM
+    repo = get_repository(repo_path)
+    logger.info("Determining comm_base_ref...")
+    parameters["comm_base_ref"] = _determine_more_accurate_base_ref(
+        repo,
+        candidate_base_ref="",
+        head_ref=parameters.get("comm_head_ref"),
+        base_rev=parameters.get("comm_base_rev"),
+    )
+    logger.info("Determining comm_base_rev...")
+    parameters["comm_base_rev"] = _determine_more_accurate_base_rev(
+        repo,
+        base_ref=parameters["comm_base_ref"],
+        candidate_base_rev=parameters.get("comm_base_rev"),
+        head_rev=parameters.get("comm_head_rev"),
+        env_prefix=_get_env_prefix(graph_config),
+    )
+
+    parameters.setdefault("release_history", dict())
+    if parameters.get("tasks_for", "") == "cron":
+        for key, _callable in CRON_OPTIONS.get(parameters["target_tasks_method"], {}).items():
+            result = _callable(parameters, graph_config)
+            parameters[key] = result
+
+
+def get_existing_tasks(parameters, graph_config):
+    """
+    Find the decision task corresponding to the on-push graph, and return
+    a mapping of labels to task-ids from it.
+    """
+    try:
+        decision_task = retry(
+            find_decision_task,
+            args=(parameters, graph_config),
+            attempts=4,
+            sleeptime=5 * 60,
+        )
+    except Exception:
+        logger.exception("Didn't find existing push task.")
+        sys.exit(1)
+
+    _, task_graph = TaskGraph.from_json(get_artifact(decision_task, "public/full-task-graph.json"))
+    return find_existing_tasks_from_previous_kinds(task_graph, [decision_task], [])