Merge "Adding the generic solver code"

14 files changed, 759 insertions, 0 deletions

diff --git a/runtime/__init__.py b/runtime/__init__.py
new file mode 100644
index 0000000..2aa67d8
--- /dev/null
+++ b/runtime/__init__.py
@@ -0,0 +1,17 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
diff --git a/runtime/model_api.py b/runtime/model_api.py
new file mode 100644
index 0000000..fd87333
--- /dev/null
+++ b/runtime/model_api.py
@@ -0,0 +1,215 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+import json
+import traceback
+
+import mysql.connector
+from flask import g, Flask, Response
+
+from osdf.config.base import osdf_config
+from osdf.logging.osdf_logging import debug_log, error_log
+from osdf.operation.exceptions import BusinessException
+
+
+def init_db():
+    if is_db_enabled():
+        get_db()
+
+
+def get_db():
+    """Opens a new database connection if there is none yet for the
+        current application context. 
+    """
+    if not hasattr(g, 'pg'):
+        properties = osdf_config['deployment']
+        host, db_port, db = properties["osdfDatabaseHost"], properties["osdfDatabasePort"], \
+                            properties.get("osdfDatabaseSchema")
+        user, password = properties["osdfDatabaseUsername"], properties["osdfDatabasePassword"]
+        g.pg = mysql.connector.connect(host=host, port=db_port, user=user, password=password, database=db)
+    return g.pg
+
+
+def close_db():
+    """Closes the database again at the end of the request."""
+    if hasattr(g, 'pg'):
+        g.pg.close()
+
+
+app = Flask(__name__)
+
+
+def create_model_data(model_api):
+    with app.app_context():
+        try:
+            model_info = model_api['modelInfo']
+            model_id = model_info['modelId']
+            debug_log.debug(
+                "persisting model_api {}".format(model_id))
+            connection = get_db()
+            cursor = connection.cursor(buffered=True)
+            query = "SELECT model_id FROM optim_model_data WHERE model_id = %s"
+            values = (model_id,)
+            cursor.execute(query, values)
+            if cursor.fetchone() is None:
+                query = "INSERT INTO optim_model_data (model_id, model_content, description, solver_type) VALUES " \
+                        "(%s, %s, %s, %s)"
+                values = (model_id, model_info['modelContent'], model_info.get('description'), model_info['solver'])
+                cursor.execute(query, values)
+                g.pg.commit()
+
+                debug_log.debug("A record successfully inserted for request_id: {}".format(model_id))
+                return retrieve_model_data(model_id)
+                close_db()
+            else:
+                query = "UPDATE optim_model_data SET model_content = %s, description = %s, solver_type = %s where " \
+                        "model_id = %s "
+                values = (model_info['modelContent'], model_info.get('description'), model_info['solver'], model_id)
+                cursor.execute(query, values)
+                g.pg.commit()
+
+                return retrieve_model_data(model_id)
+                close_db()
+        except Exception as err:
+            error_log.error("error for request_id: {} - {}".format(model_id, traceback.format_exc()))
+            close_db()
+            raise BusinessException(err)
+
+
+def retrieve_model_data(model_id):
+    status, resp_data = get_model_data(model_id)
+
+    if status == 200:
+        resp = json.dumps(build_model_dict(resp_data))
+        return build_response(resp, status)
+    else:
+        resp = json.dumps({
+            'modelId': model_id,
+            'statusMessage': "Error retrieving the model data for model {} due to {}".format(model_id, resp_data)
+        })
+        return build_response(resp, status)
+
+
+def build_model_dict(resp_data, content_needed=True):
+    resp = {'modelId': resp_data[0], 'description': resp_data[2] if resp_data[2] else '',
+            'solver': resp_data[3]}
+    if content_needed:
+        resp.update({'modelContent': resp_data[1]})
+    return resp
+
+
+def build_response(resp, status):
+    response = Response(resp, content_type='application/json; charset=utf-8')
+    response.headers.add('content-length', len(resp))
+    response.status_code = status
+    return response
+
+
+def delete_model_data(model_id):
+    with app.app_context():
+        try:
+            debug_log.debug("deleting model data given model_id = {}".format(model_id))
+            d = dict();
+            connection = get_db()
+            cursor = connection.cursor(buffered=True)
+            query = "delete from optim_model_data WHERE model_id = %s"
+            values = (model_id,)
+            cursor.execute(query, values)
+            g.pg.commit()
+            close_db()
+            resp = {
+                "statusMessage": "model data for modelId {} deleted".format(model_id)
+            }
+            return build_response(json.dumps(resp), 200)
+        except Exception as err:
+            error_log.error("error deleting model_id: {} - {}".format(model_id, traceback.format_exc()))
+            close_db()
+            raise BusinessException(err)
+
+
+def get_model_data(model_id):
+    with app.app_context():
+        try:
+            debug_log.debug("getting model data given model_id = {}".format(model_id))
+            d = dict();
+            connection = get_db()
+            cursor = connection.cursor(buffered=True)
+            query = "SELECT model_id, model_content, description, solver_type  FROM optim_model_data WHERE model_id = %s"
+            values = (model_id,)
+            cursor.execute(query, values)
+            if cursor is None:
+                return 400, "FAILED"
+            else:
+                rows = cursor.fetchone()
+                if rows is not None:
+                    index = 0
+                    for row in rows:
+                        d[index] = row
+                        index = index + 1
+                    return 200, d
+                else:
+                    close_db()
+                    return 500, "NOT_FOUND"
+        except Exception:
+            error_log.error("error for request_id: {} - {}".format(model_id, traceback.format_exc()))
+            close_db()
+            return 500, "FAILED"
+
+
+def retrieve_all_models():
+    status, resp_data = get_all_models()
+    model_list = []
+    if status == 200:
+        for r in resp_data:
+            model_list.append(build_model_dict(r, False))
+        resp = json.dumps(model_list)
+        return build_response(resp, status)
+
+    else:
+        resp = json.dumps({
+            'statusMessage': "Error retrieving all the model data due to {}".format(resp_data)
+        })
+        return build_response(resp, status)
+
+
+def get_all_models():
+    with app.app_context():
+        try:
+            debug_log.debug("getting all model data".format())
+            connection = get_db()
+            cursor = connection.cursor(buffered=True)
+            query = "SELECT model_id, model_content, description, solver_type  FROM optim_model_data"
+    
+            cursor.execute(query)
+            if cursor is None:
+                return 400, "FAILED"
+            else:
+                rows = cursor.fetchall()
+                if rows is not None:
+                    return 200, rows
+                else:
+                    close_db()
+                    return 500, "NOT_FOUND"
+        except Exception:
+            error_log.error("error for request_id:  {}".format(traceback.format_exc()))
+            close_db()
+            return 500, "FAILED"
+
+
+def is_db_enabled():
+    return osdf_config['deployment'].get('isDatabaseEnabled', False)
diff --git a/runtime/models/__init__.py b/runtime/models/__init__.py
new file mode 100644
index 0000000..2aa67d8
--- /dev/null
+++ b/runtime/models/__init__.py
@@ -0,0 +1,17 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
diff --git a/runtime/models/api/__init__.py b/runtime/models/api/__init__.py
new file mode 100644
index 0000000..2aa67d8
--- /dev/null
+++ b/runtime/models/api/__init__.py
@@ -0,0 +1,17 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
diff --git a/runtime/models/api/model_request.py b/runtime/models/api/model_request.py
new file mode 100644
index 0000000..710da4b
--- /dev/null
+++ b/runtime/models/api/model_request.py
@@ -0,0 +1,48 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+from schematics.types import StringType
+from schematics.types.compound import ModelType
+
+from osdf.models.api.common import OSDFModel
+
+
+class RequestInfo(OSDFModel):
+    """Info for northbound request from client such as PCI-mS Handler"""
+    transactionId = StringType(required=True)
+    requestID = StringType(required=True)
+    sourceId = StringType(required=True)
+
+
+class OptimModelInfo(OSDFModel):
+    """Optimizer request info details."""
+    # ModelId from the database
+    modelId = StringType()
+    # type of solver (mzn, or-tools, etc.)
+    solver = StringType(required=True)
+    # Description of the model
+    description = StringType()
+    # a large blob string containing the model (which is not that
+    # problematic since models are fairly small).
+    modelContent = StringType()
+
+
+class OptimModelRequestAPI(OSDFModel):
+    """Request for Optimizer API (specific to optimization and additional metadata"""
+    requestInfo = ModelType(RequestInfo, required=True)
+    modelInfo = ModelType(OptimModelInfo, required=True)
diff --git a/runtime/models/api/model_response.py b/runtime/models/api/model_response.py
new file mode 100644
index 0000000..e4a41a5
--- /dev/null
+++ b/runtime/models/api/model_response.py
@@ -0,0 +1,31 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+from schematics.types import StringType
+
+from osdf.models.api.common import OSDFModel
+
+
+class OptimModelResponse(OSDFModel):
+    modelId = StringType()
+    # type of solver (mzn, or-tools, etc.)
+    solver = StringType()
+    # a large blob string containing the model
+    modelContent = StringType()
+    # statusMessage
+    statusMessage = StringType()
diff --git a/runtime/models/api/optim_request.py b/runtime/models/api/optim_request.py
new file mode 100644
index 0000000..4a046d2
--- /dev/null
+++ b/runtime/models/api/optim_request.py
@@ -0,0 +1,60 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+from schematics.types import BaseType, DictType, StringType, IntType
+from schematics.types.compound import ModelType
+
+from osdf.models.api.common import OSDFModel
+
+"""
+"""
+class RequestInfo(OSDFModel):
+    """Info for northbound request from client """
+    transactionId = StringType(required=True)
+    requestID = StringType(required=True)
+    callbackUrl = StringType()
+    sourceId = StringType(required=True)
+    timeout = IntType()
+
+
+class DataInfo(OSDFModel):
+    """Optimization data info"""
+    text = StringType()
+    json = DictType(BaseType)
+
+
+class OptimInfo(OSDFModel):
+    """Optimizer request info details."""
+    # ModelId from the database, if its not populated,
+    # assume that solverModel will be populated.
+    modelId = StringType()
+    # type of solver (mzn, or-tools, etc.)
+    solver = StringType()
+    # Arguments for solver
+    solverArgs = DictType(BaseType)
+    # NOTE: a large blob string containing the model (which is not that
+    # problematic since models are fairly small).
+    modelContent = StringType()
+    # Data Payload, input data for the solver
+    optData = ModelType(DataInfo)
+
+
+class OptimizationAPI(OSDFModel):
+    """Request for Optimizer API (specific to optimization and additional metadata"""
+    requestInfo = ModelType(RequestInfo, required=True)
+    optimInfo = ModelType(OptimInfo, required=True)
diff --git a/runtime/models/api/optim_response.py b/runtime/models/api/optim_response.py
new file mode 100644
index 0000000..6fd0f6b
--- /dev/null
+++ b/runtime/models/api/optim_response.py
@@ -0,0 +1,30 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+from schematics.types import StringType, BaseType
+from schematics.types.compound import DictType
+
+from osdf.models.api.common import OSDFModel
+
+
+class OptimResponse(OSDFModel):
+    transactionId = StringType(required=True)
+    requestID = StringType(required=True)
+    requestStatus = StringType(required=True)
+    statusMessage = StringType()
+    solutions = DictType(BaseType)
diff --git a/runtime/optim_engine.py b/runtime/optim_engine.py
new file mode 100644
index 0000000..4a8788e
--- /dev/null
+++ b/runtime/optim_engine.py
@@ -0,0 +1,79 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+from flask import Response
+
+from osdf.operation.exceptions import BusinessException
+from .model_api import get_model_data
+from .models.api.optim_request import OptimizationAPI
+from .solvers.mzn.mzn_solver import solve as mzn_solve
+from .solvers.py.py_solver import solve as py_solve
+
+
+def is_valid_optim_request(request_json):
+    # Method to check whether the requestinfo/optimizer value is valid.
+    opt_info = request_json['optimInfo']
+    if not opt_info.get('modelId'):
+        if not opt_info.get('modelContent') or not opt_info.get('solver'):
+            raise BusinessException('modelContent and solver needs to be populated if model_id is not set')
+    if not opt_info.get('optData'):
+        raise BusinessException('optimInfo.optData needs to be populated to solve for a problem')
+
+    return True
+
+
+def validate_request(request_json):
+    OptimizationAPI(request_json).validate()
+    if not is_valid_optim_request(request_json):
+        raise BusinessException('Invalid optim request ')
+    return True
+
+
+def process_request(request_json):
+    response_code, response_message = run_optimizer(request_json)
+    response = Response(response_message, content_type='application/json; charset=utf-8')
+    response.headers.add('content-length', len(response_message))
+    response.status_code = response_code
+    return response
+
+
+def run_optimizer(request_json):
+    validate_request(request_json)
+
+    model_content, solver = get_model_content(request_json)
+
+    if solver == 'mzn':
+        return mzn_solve(request_json, model_content)
+    elif solver == 'py':
+        return py_solve(request_json, model_content)
+    raise BusinessException('Unsupported optimization solver requested {} '.format(solver))
+
+
+def get_model_content(request_json):
+    model_id = request_json['optimInfo'].get('modelId')
+    if model_id:
+        status, data = get_model_data(model_id)
+        if status == 200:
+            model_content = data[1]
+            solver = data[3]
+        else:
+            raise BusinessException('model_id [{}] not found in the model database'.format(model_id))
+    else:
+        model_content = request_json['optimInfo']['modelContent']
+        solver = request_json['optimInfo']['solver']
+    return model_content, solver
diff --git a/runtime/solvers/__init__.py b/runtime/solvers/__init__.py
new file mode 100644
index 0000000..2aa67d8
--- /dev/null
+++ b/runtime/solvers/__init__.py
@@ -0,0 +1,17 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
diff --git a/runtime/solvers/mzn/__init__.py b/runtime/solvers/mzn/__init__.py
new file mode 100644
index 0000000..2aa67d8
--- /dev/null
+++ b/runtime/solvers/mzn/__init__.py
@@ -0,0 +1,17 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
diff --git a/runtime/solvers/mzn/mzn_solver.py b/runtime/solvers/mzn/mzn_solver.py
new file mode 100644
index 0000000..cf002e7
--- /dev/null
+++ b/runtime/solvers/mzn/mzn_solver.py
@@ -0,0 +1,102 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+import json
+from datetime import datetime
+
+from pymzn import Status, minizinc, cbc, gecode, chuffed, or_tools
+
+from osdf.utils.file_utils import delete_file_folder
+
+error_status_map = {
+    Status.INCOMPLETE: "incomplete",
+    Status.COMPLETE: "complete",
+    Status.UNSATISFIABLE: "unsatisfiable",
+    Status.UNKNOWN: "unknown",
+    Status.UNBOUNDED: "unbounded",
+    Status.UNSATorUNBOUNDED: "unsat_or_unbounded",
+    Status.ERROR: "error"
+}
+
+solver_dict = {
+    'cbc': cbc,
+    'geocode': gecode,
+    'chuffed': chuffed,
+    'cp': chuffed,
+    'or_tools': or_tools
+}
+
+
+def map_status(status):
+    return error_status_map.get(status, "failed")
+
+
+def solve(request_json, mzn_content):
+    req_info = request_json['requestInfo']
+    opt_info = request_json['optimInfo']
+    try:
+        mzn_solution = mzn_solver(mzn_content, opt_info)
+
+        response = {
+            'transactionId': req_info['transactionId'],
+            'requestID': req_info['requestID'],
+            'requestStatus': 'done',
+            'statusMessage': map_status(mzn_solution.status),
+            'solutions': mzn_solution[0] if mzn_solution else {}
+        }
+        return 200, json.dumps(response)
+    except Exception as e:
+        response = {
+            'transactionId': req_info['transactionId'],
+            'requestID': req_info['requestID'],
+            'requestStatus': 'failed',
+            'statusMessage': 'Failed due to {}'.format(e)
+        }
+        return 400, json.dumps(response)
+
+
+def mzn_solver(mzn_content, opt_info):
+    args = opt_info['solverArgs']
+    solver = get_mzn_solver(args.pop('solver'))
+    mzn_opts = dict()
+
+    try:
+        file_name = persist_opt_data(opt_info)
+        mzn_opts.update(args)
+        return minizinc(mzn_content, file_name, **mzn_opts, solver=solver)
+
+    finally:
+        delete_file_folder(file_name)
+
+
+def persist_opt_data(opt_info):
+
+    if opt_info['optData'].get('json'):
+        data_content = json.dumps(opt_info['optData']['json'])
+        file_name = '/tmp/optim_engine_{}.json'.format(datetime.timestamp(datetime.now()))
+    elif opt_info['optData'].get('text'):
+        data_content = opt_info['optData']['text']
+        file_name = '/tmp/optim_engine_{}.dzn'.format(datetime.timestamp(datetime.now()))
+
+    with open(file_name, "wt") as data:
+        data.write(data_content)
+    return file_name
+
+
+def get_mzn_solver(solver):
+    return solver_dict.get(solver)
diff --git a/runtime/solvers/py/__init__.py b/runtime/solvers/py/__init__.py
new file mode 100644
index 0000000..a8aa582
--- /dev/null
+++ b/runtime/solvers/py/__init__.py
@@ -0,0 +1,17 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
\ No newline at end of file
diff --git a/runtime/solvers/py/py_solver.py b/runtime/solvers/py/py_solver.py
new file mode 100644
index 0000000..6b200ab
--- /dev/null
+++ b/runtime/solvers/py/py_solver.py
@@ -0,0 +1,92 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2020 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+import json
+import subprocess
+import traceback
+from datetime import datetime
+
+from osdf.logging.osdf_logging import error_log, debug_log
+from osdf.utils.file_utils import delete_file_folder
+
+
+def py_solver(py_content, opt_info):
+    py_file = '/tmp/custom_heuristics_{}.py'.format(datetime.timestamp(datetime.now()))
+    with open(py_file, "wt") as f:
+        f.write(py_content)
+    if opt_info['optData'].get('json'):
+        data_content = json.dumps(opt_info['optData']['json'])
+        input_file = '/tmp/optim_engine_{}.json'.format(datetime.timestamp(datetime.now()))
+    elif opt_info['optData'].get('text'):
+        data_content = opt_info['optData']['text']
+        input_file = '/tmp/optim_engine_{}.txt'.format(datetime.timestamp(datetime.now()))
+    with open(input_file, "wt") as f:
+        f.write(data_content)
+
+    output_file = '/tmp/opteng_output_{}.json'.format(datetime.timestamp(datetime.now()))
+
+    command = ['python', py_file, input_file, output_file]
+
+    try:
+        p = subprocess.run(command, stderr=subprocess.STDOUT, stdout=subprocess.PIPE)
+
+        debug_log.debug('Process return code {}'.format(p.returncode))
+        if p.returncode > 0:
+            error_log.error('Process return code {} {}'.format(p.returncode, p.stdout))
+            return 'error', {}
+        with open(output_file) as file:
+            data = file.read()
+            return 'success', json.loads(data)
+
+    except Exception as e:
+        error_log.error("Error running optimizer {}".format(traceback.format_exc()))
+        return 'error', {}
+    finally:
+        cleanup((input_file, output_file, py_file))
+
+
+def cleanup(file_tup):
+    for f in file_tup:
+        try:
+            delete_file_folder(f)
+        except Exception as e:
+            error_log.error("Failed deleting the file {} - {}".format(f, traceback.format_exc()))
+
+
+def solve(request_json, py_content):
+    req_info = request_json['requestInfo']
+    opt_info = request_json['optimInfo']
+    try:
+        status, solution = py_solver(py_content, opt_info)
+
+        response = {
+            'transactionId': req_info['transactionId'],
+            'requestID': req_info['requestID'],
+            'requestStatus': status,
+            'statusMessage': "completed",
+            'solutions': solution if solution else {}
+        }
+        return 200, json.dumps(response)
+    except Exception as e:
+        response = {
+            'transactionId': req_info['transactionId'],
+            'requestID': req_info['requestID'],
+            'requestStatus': 'failed',
+            'statusMessage': 'Failed due to {}'.format(e)
+        }
+        return 400, json.dumps(response)