From 0d6e74cfc7041a55b08e0b5f7a73769af10ce632 Mon Sep 17 00:00:00 2001
From: vrde <agranzot@gmail.com>
Date: Wed, 27 Apr 2016 17:00:21 +0200
Subject: [PATCH] Use .wait to check when the database is ready

---
 bigchaindb/commands/bigchain.py |  9 ++++++--
 bigchaindb/commands/utils.py    | 37 ++++++++++++++++++++++++++++-----
 bigchaindb/exceptions.py        |  3 ++-
 3 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/bigchaindb/commands/bigchain.py b/bigchaindb/commands/bigchain.py
index 8065834a..d23f99fc 100644
--- a/bigchaindb/commands/bigchain.py
+++ b/bigchaindb/commands/bigchain.py
@@ -19,7 +19,9 @@ import bigchaindb.config_utils
 from bigchaindb.util import ProcessGroup
 from bigchaindb.client import temp_client
 from bigchaindb import db
-from bigchaindb.exceptions import DatabaseAlreadyExists, KeypairNotFoundException
+from bigchaindb.exceptions import (StartupError,
+                                   DatabaseAlreadyExists,
+                                   KeypairNotFoundException)
 from bigchaindb.commands import utils
 from bigchaindb.processes import Processes
 from bigchaindb import crypto
@@ -149,7 +151,10 @@ def run_start(args):
     bigchaindb.config_utils.autoconfigure(filename=args.config, force=True)
 
     if args.start_rethinkdb:
-        proc = utils.start_rethinkdb()
+        try:
+            proc = utils.start_rethinkdb()
+        except StartupError as e:
+            sys.exit('Error starting RethinkDB, reason is: {}'.format(e))
         logger.info('RethinkDB started with PID %s' % proc.pid)
 
     try:
diff --git a/bigchaindb/commands/utils.py b/bigchaindb/commands/utils.py
index 99b6b4cb..b3cc356c 100644
--- a/bigchaindb/commands/utils.py
+++ b/bigchaindb/commands/utils.py
@@ -2,31 +2,58 @@
 for ``argparse.ArgumentParser``.
 """
 
-import time
 import argparse
 import multiprocessing as mp
 import subprocess
 
+import rethinkdb as r
+
+import bigchaindb
+from bigchaindb.exceptions import StartupError
+from bigchaindb import db
 from bigchaindb.version import __version__
 
 
 def start_rethinkdb():
+    """Start RethinkDB as a child process and wait for it to be
+    available.
+
+    Raises:
+        ``bigchaindb.exceptions.StartupError`` if RethinkDB cannot
+        be started.
+    """
+
     proc = subprocess.Popen(['rethinkdb', '--bind', 'all'],
                             stdout=subprocess.PIPE,
                             stderr=subprocess.STDOUT,
                             universal_newlines=True)
 
+    dbname = bigchaindb.config['database']['name']
     line = ''
 
     for line in proc.stdout:
         if line.startswith('Server ready'):
             # FIXME: seems like tables are not ready when the server is ready,
-            #        that's why we need to sleep a bit before returning.
-            #        Not the optimal solution. Happy to see the right one :)
-            time.sleep(1)
+            #        that's why we need to query RethinkDB to know the state
+            #        of the database. This code assumes the tables are ready
+            #        when the database is ready. This seems a valid assumption.
+
+            try:
+                conn = db.get_conn()
+                # Before checking if the db is ready, we need to query
+                # the server to check if it contains that db
+                if r.db_list().contains(dbname).run(conn):
+                    r.db(dbname).wait().run(conn)
+            except (r.ReqlOpFailedError, r.ReqlDriverError) as exc:
+                raise StartupError('Error waiting for the database `{}` '
+                                   'to be ready'.format(dbname)) from exc
+
             return proc
 
-    exit('Error starting RethinkDB, reason is: {}'.format(line))
+    # We are here when we exhaust the stdout of the process.
+    # The last `line` contains info about the error.
+    raise StartupError(line)
+
     proc.kill()
 
 
diff --git a/bigchaindb/exceptions.py b/bigchaindb/exceptions.py
index 0baa4ad2..8abfaaf7 100644
--- a/bigchaindb/exceptions.py
+++ b/bigchaindb/exceptions.py
@@ -28,4 +28,5 @@ class DatabaseDoesNotExist(Exception):
 class KeypairNotFoundException(Exception):
     """Raised if operation cannot proceed because the keypair was not given"""
 
-
+class StartupError(Exception):
+    """Raised when there is an error starting up the system"""