Run smart-reconfigure instead of HUP

We don't want to HUP all the processes in the container, we just
want zuul to reconfigure. Use the smart-reconfigure command.

Also - start the scheduler in the gate job.

Change-Id: I66754ed168165d2444930ab1110e95316f7307a7

playbooks/roles/zuul-scheduler/handlers/main.yaml

@@ -1,4 +1,6 @@
 - name: Reload Zuul Scheduler
   shell:
-    cmd: docker-compose kill -s HUP scheduler
+    cmd: docker-compose exec -T scheduler zuul-scheduler smart-reconfigure
     chdir: /etc/zuul-scheduler
+  # Don't run a restart if we're starting zuul with the playbook
+  when: not zuul_scheduler_start|bool

playbooks/roles/zuul-scheduler/tasks/main.yaml

@@ -68,6 +68,6 @@
     cmd: docker-compose pull
     chdir: /etc/zuul-scheduler
 
-- name: Run docker prune to cleanup unneeded images
-  shell:
-    cmd: docker image prune -f
+- name: Start containers
+  include_tasks: start.yaml
+  when: zuul_scheduler_start | bool

playbooks/roles/zuul-scheduler/tasks/start.yaml

@@ -0,0 +1,9 @@
+- name: Run docker-compose up
+  shell:
+    cmd: docker-compose up -d
+    chdir: /etc/zuul-scheduler
+
+# TODO: put this in a handler
+- name: Run docker prune to cleanup unneeded images
+  shell:
+    cmd: docker image prune -f

playbooks/zuul/templates/group_vars/zuul-scheduler.yaml.j2

@@ -1,3 +1,5 @@
+zuul_scheduler_start: true
+
 gearman_server_ssl_key: |
   -----BEGIN RSA PRIVATE KEY-----
   MIIJKAIBAAKCAgEAsma7rv193P35/Wg1Um3ARP66iLWc3Z3ZLAM6LVbr4AXo0Eww