roles/zabbix-server: Deploy Zabbix server, web UI

The *zabbix-server* role deploys the Zabbix server database, daemon, and
web interface. It requires the *apache* role to configure Apache HTTPD
to serve the web UI.

roles/zabbix-server/library/zabbix_db_schema

@@ -0,0 +1,69 @@
+#!/usr/bin/python
+import os
+import psycopg2
+
+
+SCHEMA_DIRECTORY = '/usr/share/zabbix-postgresql'
+SCHEMA_FILES = [
+    'schema.sql',
+]
+DATA_FILES = [
+    'images.sql',
+    'data.sql',
+]
+
+def main():
+    module = AnsibleModule(
+        argument_spec=dict(
+            database=dict(required=True),
+            username=dict(required=True),
+            password=dict(no_log=True),
+            host=dict(),
+            schema_only=dict(type='bool', default=False),
+        ),
+        supports_check_mode=True,
+    )
+
+    database = module.params['database']
+    username = module.params['username']
+    password = module.params['password']
+    host = module.params['host']
+    schema_only = module.params['schema_only']
+
+    dsn = {
+        'dbname': database,
+        'user': username,
+    }
+    if password:
+        dsn['password'] = password
+    if host:
+        dsn['host'] = host
+
+    conn = psycopg2.connect(**dsn)
+    with conn.cursor() as cur:
+        cur.execute('SELECT tablename FROM pg_tables '
+                    "WHERE schemaname = 'public'")
+        changed = cur.rowcount == 0
+
+    if changed and not module.check_mode:
+        psql = module.get_bin_path('psql')
+        if password:
+            os.environ['PGPASSWORD'] = password
+        if schema_only:
+            scripts = SCHEMA_FILES
+        else:
+            scripts = SCHEMA_FILES + DATA_FILES
+        for filename in scripts:
+            path = os.path.join(SCHEMA_DIRECTORY, filename)
+            cmd = ['psql', '-U', username, '-f', path]
+            if host:
+                cmd.extend(('-h', host))
+            cmd.append(database)
+            module.run_command(cmd, check_rc=True)
+
+    module.exit_json(changed=changed)
+
+
+from ansible.module_utils.basic import *
+
+main()