isolated ramparts: replace systemd unit with a tower-expect binary

instead of launching isolated tasks via `systemctl`, treat
`awx.main.isolated.run` as an executable that knows how to daemonize

additionally, add `setup.py isolated_build` for isolated Tower source
distribution

tools/docker-isolated/Dockerfile

@@ -17,7 +17,7 @@ ENV LANGUAGE en_US:en
 ENV LC_ALL en_US.UTF-8
 WORKDIR /
 EXPOSE 22
-ADD tools/docker-isolated/playbook@.service /lib/systemd/system/playbook@.service
+ADD tools/docker-isolated/tower-expect /usr/local/bin/tower-expect
 
 RUN rm -f /etc/ssh/ssh_host_ecdsa_key /etc/ssh/ssh_host_rsa_key
 RUN ssh-keygen -q -N "" -t dsa -f /etc/ssh/ssh_host_ecdsa_key

tools/docker-isolated/README.md

@@ -66,6 +66,6 @@ This should give a shell to the `tools_isolated_1` container, as the
 The following command would run the playbook for job 57.
 
 ```bash
-systemctl start playbook@57.service
+tower-expect start 57
 ```
 

tools/docker-isolated/playbook@.service

@@ -1,7 +0,0 @@
-[Unit]
-Description=Run of Ansible Tower job %I
-
-[Service]
-ExecStart=/venv/tower_isolated/bin/python /tower_isolated/run.py %I
-Restart=no
-Environment=TOWER_LIB_DIRECTORY=/tower_lib

tools/docker-isolated/tower-expect

@@ -0,0 +1,3 @@
+#!/bin/bash
+. /venv/tower_isolated/bin/activate
+exec env TOWER_LIB_DIRECTORY=/tower_lib /tower_isolated/run.py "$@"