[build] Trigger the downstream CI and get the status back

Allows triggering a pipeline at any other repository
passing parameters.

scripts/ci-circleci-start-pipeline.py

@@ -0,0 +1,71 @@
+#!/usr/bin/env python3
+
+# Implements https://circleci.com/docs/api/v2/#trigger-a-new-pipeline
+
+import argparse
+import os
+import requests
+import sys
+
+
+def TriggerPiperline(slug, token, branch, params):
+    url = "https://circleci.com/api/v2/project/github/%s/pipeline" % (slug)
+
+    headers = {
+        "Content-Type": "application/json",
+        "Accept": "application/json",
+    }
+
+    data = {
+        "parameters": params
+    }
+
+    if branch:
+        data["branch"] = branch
+
+    r = requests.post(url, auth=(token, ""), headers=headers, json=data)
+
+    if r.status_code != 201:
+        print("Error triggering the CircleCI: %s." % r.json()["message"])
+        sys.exit(1)
+
+
+def Main():
+    token = os.getenv("CIRCLE_API_TOKEN")
+    hash = os.getenv("CIRCLE_SHA1", default="1234567890")
+    username = os.getenv("CIRCLE_PROJECT_USERNAME", default="username")
+    project = os.getenv("CIRCLE_PROJECT_REPONAME", default="repository")
+
+    parser = argparse.ArgumentParser(
+        description="Creates CircleCI jobs and waits for the result.")
+
+    parser.add_argument("--token", default=token,
+            help="CircleCI token, otherwise environment CIRCLE_API_TOKEN.")
+    parser.add_argument("--origin-slug", default="mapbox/mapbox-gl-native",
+            help="Origin repository, otherwise CIRCLE_PROJECT_USERNAME/CIRCLE_PROJECT_REPONAME.")
+    parser.add_argument("--target-slug", default="".join((username, '/', project)),
+            help="Repository to trigger the pipeline, example: mapbox/mapbox-gl-native-internal.")
+    parser.add_argument("--hash", default=hash,
+            help="Commit git hash that triggered the pipeline, otherwise environment CIRCLE_SHA1.")
+    parser.add_argument("--branch",
+            help="Build a specific branch, otherwise it will build the default branch.")
+
+    args = parser.parse_args()
+
+    if not args.token:
+        print("CircleCI token not set. Use --token or set CIRCLE_API_TOKEN.")
+        sys.exit(1)
+
+    params = {
+        "mapbox_upstream": True,
+        "mapbox_slug": args.origin_slug,
+        "mapbox_hash": args.hash
+    }
+
+    TriggerPiperline(args.target_slug, args.token, args.branch, params)
+
+    return 0
+
+
+if __name__ == "__main__":
+    Main()