Enable multiple threads, disabled muliple workers

This sets multiple threads in Deckhand's chart config (4)
and set workers to just 1.

Deckhand's database is not configured to work with multiprocessing.
Currently there is a data race on acquiring shared SQLAlchemy
engine pooled connection strings when workers > 1. As a
workaround, we use multiple threads but only 1 worker. For more
information, see:

https://github.com/att-comdev/deckhand/issues/20

Change-Id: I60adeffff5461fdda957124232bc5a606baae413

charts/deckhand/templates/deployment.yaml

@@ -47,10 +47,15 @@ spec:
           env:
             - name: 'DECKHAND_API_TIMEOUT'
               value: {{ .Values.conf.uwsgi.timeout | default 600 | quote }}
+            # NOTE(fmontei): Deckhand's database is not configured to work with
+            # multiprocessing. Currently there is a data race on acquiring shared
+            # SQLAlchemy engine pooled connection strings when workers > 1. As a
+            # workaround, we use multiple threads but only 1 worker. For more
+            # information, see: https://github.com/att-comdev/deckhand/issues/20
             - name: 'DECKHAND_API_WORKERS'
-              value: {{ .Values.conf.uwsgi.workers | default 4 | quote }}
+              value: {{ .Values.conf.uwsgi.workers | default 1 | quote }}
             - name: 'DECKHAND_API_THREADS'
-              value: {{ .Values.conf.uwsgi.threads | default 1 | quote }}
+              value: {{ .Values.conf.uwsgi.threads | default 4 | quote }}
           image: {{ .Values.images.tags.deckhand }}
           imagePullPolicy: {{ .Values.images.pull_policy }}
 {{ tuple $envAll $envAll.Values.pod.resources.api | include "helm-toolkit.snippets.kubernetes_resources" | indent 10 }}

charts/deckhand/values.yaml

@@ -179,8 +179,13 @@ secrets:
 
 conf:
   uwsgi:
-    threads: 1
-    workers: 4
+    # NOTE(fmontei): Deckhand's database is not configured to work with
+    # multiprocessing. Currently there is a data race on acquiring shared
+    # SQLAlchemy engine pooled connection strings when workers > 1. As a
+    # workaround, we use multiple threads but only 1 worker. For more
+    # information, see: https://github.com/att-comdev/deckhand/issues/20
+    threads: 4
+    workers: 1
   policy:
     admin_api: role:admin
     deckhand:create_cleartext_documents: rule:admin_api

deckhand/control/api.py

@@ -33,7 +33,7 @@ CONFIG_FILES = ['deckhand.conf', 'deckhand-paste.ini']
 def _get_config_files(env=None):
     if env is None:
         env = os.environ
-    dirname = env.get('OS_DECKHAND_CONFIG_DIR', '/etc/deckhand').strip()
+    dirname = env.get('DECKHAND_CONFIG_DIR', '/etc/deckhand').strip()
     return [os.path.join(dirname, config_file) for config_file in CONFIG_FILES]
 
 

docs/source/getting-started.rst

@@ -139,8 +139,8 @@ Create the directory ``/etc/deckhand`` and copy the config file there::
 
 To specify an alternative directory for the config file, run::
 
-    $ export OS_DECKHAND_CONFIG_DIR=<PATH>
-    $ [sudo] cp etc/deckhand/deckhand.conf.sample ${OS_DECKHAND_CONFIG_DIR}/deckhand.conf
+    $ export DECKHAND_CONFIG_DIR=<PATH>
+    $ [sudo] cp etc/deckhand/deckhand.conf.sample ${DECKHAND_CONFIG_DIR}/deckhand.conf
 
 To conveniently create an ephemeral PostgreSQL DB run::
 
@@ -152,7 +152,7 @@ Retrieve the environment variable which contains connection information::
     declare -x PIFPAF_POSTGRESQL_URL="postgresql://localhost/postgres?host=/tmp/tmpsg6tn3l9&port=9824"
 
 Substitute the connection information into the config file in
-``${OS_DECKHAND_CONFIG_DIR}``::
+``${DECKHAND_CONFIG_DIR}``::
 
     [database]
 

entrypoint.sh

@@ -20,10 +20,19 @@ set -ex
 PORT=${PORT:-9000}
 # How long uWSGI should wait for each deckhand response
 DECKHAND_API_TIMEOUT=${DECKHAND_API_TIMEOUT:-"600"}
+
+# NOTE(fmontei): Deckhand's database is not configured to work with
+# multiprocessing. Currently there is a data race on acquiring shared
+# SQLAlchemy engine pooled connection strings when workers > 1. As a
+# workaround, we use multiple threads but only 1 worker. For more
+# information, see: https://github.com/att-comdev/deckhand/issues/20
+
 # Number of uWSGI workers to handle API requests
-DECKHAND_API_WORKERS=${DECKHAND_API_WORKERS:-"4"}
+DECKHAND_API_WORKERS=${DECKHAND_API_WORKERS:-"1"}
 # Threads per worker
-DECKHAND_API_THREADS=${DECKHAND_API_THREADS:-"1"}
+DECKHAND_API_THREADS=${DECKHAND_API_THREADS:-"4"}
+# The Deckhand configuration directory containing deckhand.conf
+DECKHAND_CONFIG_DIR=${DECKHAND_CONFIG_DIR:-"/etc/deckhand/deckhand.conf"}
 
 # Start deckhand application
 exec uwsgi \

tools/functional-tests.sh

@@ -68,7 +68,7 @@ function gen_config {
     export DECKHAND_TEST_URL=http://localhost:9000
     export DATABASE_URL=postgresql+psycopg2://deckhand:password@$POSTGRES_IP:5432/deckhand
     # Used by Deckhand's initialization script to search for config files.
-    export OS_DECKHAND_CONFIG_DIR=$CONF_DIR
+    export DECKHAND_CONFIG_DIR=$CONF_DIR
 
     cp etc/deckhand/logging.conf.sample $CONF_DIR/logging.conf
 
@@ -198,19 +198,19 @@ gen_config
 gen_paste
 gen_policy
 
+ROOTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
 if [ -z "$DECKHAND_IMAGE" ]; then
     log_section "Running Deckhand via uwsgi"
-
-    # Set --workers 2, so that concurrency is always tested.
-    uwsgi \
-        --http :9000 \
-        -w deckhand.cmd \
-        --callable deckhand_callable \
-        --enable-threads \
-        --workers 2 \
-        --threads 1 \
-        -L \
-        --pyargv "--config-file $CONF_DIR/deckhand.conf" &
+    # NOTE(fmontei): Deckhand's database is not configured to work with
+    # multiprocessing. Currently there is a data race on acquiring shared
+    # SQLAlchemy engine pooled connection strings when workers > 1. As a
+    # workaround, we use multiple threads but only 1 worker. For more
+    # information, see: https://github.com/att-comdev/deckhand/issues/20
+    export DECKHAND_API_WORKERS=1
+    export DECKHAND_API_THREADS=4
+    source $ROOTDIR/../entrypoint.sh &
+    sleep 5
 else
     log_section "Running Deckhand via Docker"
     sudo docker run \
@@ -229,8 +229,6 @@ echo $DECKHAND_ID
 
 log_section Running tests
 
-ROOTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
-
 # Create folder for saving HTML test results.
 if [ ! -d $ROOTDIR/results ]; then
     mkdir $ROOTDIR/results