Add automatic deprovisioning support, only enabled for openshift

* Implement a config watcher for service restarts
* If the configmap bind point changes then restart all services

awx/main/tasks.py

@@ -292,6 +292,10 @@ def cluster_node_heartbeat(self):
             other_inst.save(update_fields=['capacity'])
             logger.error("Host {} last checked in at {}, marked as lost.".format(
                 other_inst.hostname, other_inst.modified))
+            if settings.AWX_AUTO_DEPROVISION_INSTANCES:
+                deprovision_hostname = other_inst.hostname
+                other_inst.delete()
+                logger.info("Host {} Automatically Deprovisioned.".format(deprovision_hostname))
         except DatabaseError as e:
             if 'did not affect any rows' in str(e):
                 logger.debug('Another instance has marked {} as lost'.format(other_inst.hostname))

awx/settings/defaults.py

@@ -641,6 +641,9 @@ AWX_ANSIBLE_CALLBACK_PLUGINS = ""
 # Time at which an HA node is considered active
 AWX_ACTIVE_NODE_TIME = 7200
 
+# Automatically remove nodes that have missed their heartbeats after some time
+AWX_AUTO_DEPROVISION_INSTANCES = False
+
 # Enable Pendo on the UI, possible values are 'off', 'anonymous', and 'detailed'
 # Note: This setting may be overridden by database settings.
 PENDO_TRACKING_STATE = "off"

installer/image_build/files/supervisor.conf

@@ -41,6 +41,15 @@ priority=5
 
 # TODO: Exit Handler
 
+[eventlistener:awx-config-watcher]
+command=/usr/bin/config-watcher
+stderr_logfile=/dev/stdout
+stderr_logfile_maxbytes=0
+stdout_logfile=/dev/stdout
+stdout_logfile_maxbytes=0
+events=TICK_60
+priority=0
+
 [unix_http_server]
 file=/tmp/supervisor.sock
 

installer/image_build/files/supervisor_task.conf

@@ -43,6 +43,15 @@ priority=5
 
 # TODO: Exit Handler
 
+[eventlistener:awx-config-watcher]
+command=/usr/bin/config-watcher
+stderr_logfile=/dev/stdout
+stderr_logfile_maxbytes=0
+stdout_logfile=/dev/stdout
+stdout_logfile_maxbytes=0
+events=TICK_60
+priority=0
+
 [unix_http_server]
 file=/tmp/supervisor.sock
 

installer/image_build/tasks/main.yml

@@ -163,6 +163,12 @@
     dest: "{{ docker_base_path }}/requirements"
   delegate_to: localhost
 
+- name: Stage config watcher
+  copy:
+    src: ../tools/scripts/config-watcher
+    dest: "{{ docker_base_path }}/config-watcher"
+  delegate_to: localhost
+
 - name: Stage Makefile
   copy:
     src: ../Makefile

installer/image_build/templates/Dockerfile.j2

@@ -22,6 +22,7 @@ ADD requirements/requirements_ansible.txt \
     requirements/requirements_git.txt \
     /tmp/requirements/
 ADD ansible.repo /etc/yum.repos.d/ansible.repo
+ADD config-watcher /usr/bin/config-watcher
 ADD RPM-GPG-KEY-ansible-release /etc/pki/rpm-gpg/RPM-GPG-KEY-ansible-release
 # OS Dependencies
 WORKDIR /tmp
@@ -50,7 +51,7 @@ ADD supervisor.conf /supervisor.conf
 ADD supervisor_task.conf /supervisor_task.conf
 ADD launch_awx.sh /usr/bin/launch_awx.sh
 ADD launch_awx_task.sh /usr/bin/launch_awx_task.sh
-RUN chmod +rx /usr/bin/launch_awx.sh && chmod +rx /usr/bin/launch_awx_task.sh
+RUN chmod +rx /usr/bin/launch_awx.sh && chmod +rx /usr/bin/launch_awx_task.sh && chmod +rx /usr/bin/config-watcher
 ADD settings.py /etc/tower/settings.py
 RUN chmod g+w /etc/passwd
 RUN chmod -R 777 /var/log/nginx && chmod -R 777 /var/lib/nginx

installer/openshift/templates/configmap.yml.j2

@@ -13,6 +13,9 @@ data:
     # Container environments don't like chroots
     AWX_PROOT_ENABLED = False
 
+    # Automatically deprovision pods that go offline
+    AWX_AUTO_DEPROVISION_INSTANCES = True
+
     #Autoprovisioning should replace this
     CLUSTER_HOST_ID = socket.gethostname()
     SYSTEM_UUID = '00000000-0000-0000-0000-000000000000'

tools/scripts/config-watcher

@@ -0,0 +1,58 @@
+#!/usr/bin/env python
+
+import os
+import sys
+import hashlib
+from supervisor import childutils
+
+
+def hash(f):
+    s = hashlib.sha1()
+    with open(f, "rb") as fd:
+        for chunk in iter(lambda: fd.read(4096), b""):
+            s.update(chunk)
+    return s.hexdigest()
+
+
+def last_hash(f):
+    with open(f, "r") as fd:
+        return fd.read().strip()
+
+
+def write_hash(f, h):
+    with open(f, "w") as fd:
+        fd.write(h)
+
+
+def main():
+    while 1:
+        rpc = childutils.getRPCInterface(os.environ)
+        headers, payload = childutils.listener.wait(sys.stdin, sys.stdout)
+        if not headers['eventname'].startswith('TICK'):
+            childutils.listener.ok(sys.stdout)
+            continue
+        try:
+            current_hash = hash("/etc/tower/settings.py")
+        except:
+            sys.stderr.write("Could not open settings.py, skipping config watcher")
+            childutils.listener.ok(sys.stdout)
+            continue
+        try:
+            if current_hash == last_hash("/var/lib/awx/.configsha"):
+                childutils.listener.ok(sys.stdout)
+                continue
+            else:
+                sys.stderr.write("Config changed, reloading services")
+                for proc in rpc.supervisor.getAllProcessInfo():
+                    group = proc['group']
+                    name = proc['name']
+                    program = "{}:{}".format(group, name)
+                    if group == "tower-processes":
+                        sys.stderr.write('Restarting %s\n' % program)
+                        rpc.supervisor.stopProcess(program)
+                        rpc.supervisor.startProcess(program)
+                    
+        except:
+            sys.stderr.write("No previous hash found")
+        write_hash("/var/lib/awx/.configsha")
+        childutils.listener.ok(sys.stdout)