Write md5sum for service config directories

The configuration generated by docker-puppet may change on update,
so checksum the combined files from the config-data directories,
to enable detecting those that have changed and restarting the
appropriate containers - we need to merge this checksum into
the environment passed to the containters, as this will cause
paunch to correctly restart containers when the configuration
generated changes, even if the rest of the json definition
provided by heat does not.

Change-Id: I40d9080cf3ad708ef4ed91e46d2b2ae1138bb9c3

2 files changed, 59 insertions, 3 deletions

diff --git a/docker/deploy-steps-playbook.yaml b/docker/deploy-steps-playbook.yaml
index a0beaa2c..b3cb500f 100644
--- a/docker/deploy-steps-playbook.yaml
+++ b/docker/deploy-steps-playbook.yaml
@@ -23,12 +23,15 @@
     ##################################################
     # Per step starting of the containers using paunch
     ##################################################
-    - name: Check if /var/lib/tripleo-config/docker-container-startup-config-step_{{step}}.json exists
+    - name: Check if /var/lib/hashed-tripleo-config/docker-container-startup-config-step_{{step}}.json exists
       stat:
-        path: /var/lib/tripleo-config/docker-container-startup-config-step_{{step}}.json
+        path: /var/lib/tripleo-config/hashed-docker-container-startup-config-step_{{step}}.json
       register: docker_config_json
+    # Note docker-puppet.py generates the hashed-*.json file, which is a copy of
+    # the *step_n.json with a hash of the generated external config added
+    # This acts as a salt to enable restarting the container if config changes
     - name: Start containers for step {{step}}
-      command: paunch --debug apply --file /var/lib/tripleo-config/docker-container-startup-config-step_{{step}}.json --config-id tripleo_step{{step}} --managed-by tripleo-{{role_name}}
+      command: paunch --debug apply --file /var/lib/tripleo-config/hashed-docker-container-startup-config-step_{{step}}.json --config-id tripleo_step{{step}} --managed-by tripleo-{{role_name}}
       when: docker_config_json.stat.exists
       changed_when: false
       check_mode: no
diff --git a/docker/docker-puppet.py b/docker/docker-puppet.py
index d9d0c255..340a9e9f 100755
--- a/docker/docker-puppet.py
+++ b/docker/docker-puppet.py
@@ -18,9 +18,11 @@
 # that can be used to generate config files or run ad-hoc puppet modules
 # inside of a container.
 
+import glob
 import json
 import logging
 import os
+import sys
 import subprocess
 import sys
 import tempfile
@@ -55,6 +57,28 @@ def pull_image(name):
         log.debug(cmd_stderr)
 
 
+def match_config_volume(prefix, config):
+    # Match the mounted config volume - we can't just use the
+    # key as e.g "novacomute" consumes config-data/nova
+    volumes = config.get('volumes', [])
+    config_volume=None
+    for v in volumes:
+        if v.startswith(prefix):
+            config_volume =  os.path.relpath(
+                v.split(":")[0], prefix).split("/")[0]
+            break
+    return config_volume
+
+
+def get_config_hash(prefix, config_volume):
+    hashfile = os.path.join(prefix, "%s.md5sum" % config_volume)
+    hash_data = None
+    if os.path.isfile(hashfile):
+        with open(hashfile) as f:
+            hash_data = f.read().rstrip()
+    return hash_data
+
+
 def rm_container(name):
     if os.environ.get('SHOW_DIFF', None):
         log.info('Diffing container: %s' % name)
@@ -197,6 +221,10 @@ def mp_puppet_config((config_volume, puppet_tags, manifest, config_image, volume
              mkdir -p /var/lib/config-data/${NAME}/var/www
              cp -a /var/www/* /var/lib/config-data/${NAME}/var/www/
             fi
+
+            # Write a checksum of the config-data dir, this is used as a
+            # salt to trigger container restart when the config changes
+            tar cf - /var/lib/config-data/${NAME} | md5sum | awk '{print $1}' > /var/lib/config-data/${NAME}.md5sum
         fi
         """)
 
@@ -297,5 +325,30 @@ for returncode, config_volume in zip(returncodes, config_volumes):
         log.error('ERROR configuring %s' % config_volume)
         success = False
 
+
+# Update the startup configs with the config hash we generated above
+config_volume_prefix = os.environ.get('CONFIG_VOLUME_PREFIX', '/var/lib/config-data')
+log.debug('CONFIG_VOLUME_PREFIX: %s' % config_volume_prefix)
+startup_configs = os.environ.get('STARTUP_CONFIG_PATTERN', '/var/lib/tripleo-config/docker-container-startup-config-step_*.json')
+log.debug('STARTUP_CONFIG_PATTERN: %s' % startup_configs)
+infiles = glob.glob('/var/lib/tripleo-config/docker-container-startup-config-step_*.json')
+for infile in infiles:
+    with open(infile) as f:
+        infile_data = json.load(f)
+
+    for k, v in infile_data.iteritems():
+        config_volume = match_config_volume(config_volume_prefix, v)
+        if config_volume:
+            config_hash = get_config_hash(config_volume_prefix, config_volume)
+            if config_hash:
+                env = v.get('environment', [])
+                env.append("TRIPLEO_CONFIG_HASH=%s" % config_hash)
+                log.debug("Updating config hash for %s, config_volume=%s hash=%s" % (k, config_volume, config_hash))
+                infile_data[k]['environment'] = env
+
+    outfile = os.path.join(os.path.dirname(infile), "hashed-" + os.path.basename(infile))
+    with open(outfile, 'w') as out_f:
+        json.dump(infile_data, out_f)
+
 if not success:
     sys.exit(1)