Intiial utils push to ONAP

Issue-Id: DCAEGEN2-80
Change-Id: I1dc8f2d384b0af346fccb86e6767b7e3ca484078
Signed-off-by: Tommy Carpenter <tommy@research.att.com>

1 files changed, 269 insertions, 0 deletions

diff --git a/python-dockering/dockering/config_building.py b/python-dockering/dockering/config_building.py
new file mode 100644
index 0000000..d8e3c84
--- /dev/null
+++ b/python-dockering/dockering/config_building.py
@@ -0,0 +1,269 @@
+# org.onap.dcae
+# ================================================================================
+# Copyright (c) 2017 AT&T Intellectual Property. All rights reserved.
+# ================================================================================
+# 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.
+# ============LICENSE_END=========================================================
+#
+# ECOMP is a trademark and service mark of AT&T Intellectual Property.
+
+"""
+Abstraction in Docker container configuration
+"""
+from dockering import utils
+from dockering.exceptions import DockerConstructionError
+
+
+#
+# Methods to build container envs
+#
+
+def create_envs_healthcheck(docker_config, default_interval="15s",
+        default_timeout="1s"):
+    """Extract health check environment variables for Docker containers
+
+    Parameters
+    ----------
+    docker_config: dict where there's an entry called "healthcheck"
+
+    Returns
+    -------
+    dict of Docker envs for healthcheck
+    """
+    # TODO: This has been shamefully lifted from the dcae-cli and should probably
+    # shared as a library. The unit tests are there. The difference is that
+    # there are defaults that are passed in here but the defaults should really
+    # come from the component spec definition. The issue is that nothing forwards
+    # those defaults.
+
+    envs = dict()
+    hc = docker_config["healthcheck"]
+
+    # NOTE: For the multiple port, schema scenario, you can explicitly set port
+    # to schema. For example if image EXPOSE 8080, SERVICE_8080_CHECK_HTTP works.
+    # https://github.com/gliderlabs/registrator/issues/311
+
+    if hc["type"] == "http":
+        envs["SERVICE_CHECK_HTTP"] = hc["endpoint"]
+    elif hc["type"] == "https":
+        # WATCH: HTTPS health checks don't work. Seems like Registrator bug.
+        # Submitted issue https://github.com/gliderlabs/registrator/issues/516
+        envs["SERVICE_CHECK_HTTPS"] = hc["endpoint"]
+        utils.logger.warn("Https-based health checks may not work because Registrator issue #516")
+    elif hc["type"] == "script":
+        envs["SERVICE_CHECK_SCRIPT"] = hc["script"]
+    elif hc["type"] == "docker":
+        # Note this is only supported in the AT&T open source version of registrator
+        envs["SERVICE_CHECK_DOCKER_SCRIPT"] = hc["script"]
+    else:
+        # You should never get here but not having an else block feels weird
+        raise DockerConstructionError("Unexpected health check type: {0}".format(hc["type"]))
+
+    envs["SERVICE_CHECK_INTERVAL"] = hc.get("interval", default_interval)
+    envs["SERVICE_CHECK_TIMEOUT"] = hc.get("timeout", default_timeout)
+
+    return envs
+
+
+def create_envs(service_component_name, *envs):
+    """Merge all environment variables maps
+
+    Creates a complete environment variables map that is to be used for creating
+    the container.
+
+    Args:
+    -----
+    envs: Arbitrary list of dicts where each dict is of the structure:
+
+        {
+            <environment variable name>: <environment variable value>,
+            <environment variable name>: <environment variable value>,
+            ...
+        }
+
+    Returns:
+    --------
+    Dict of all environment variable name to environment variable value
+    """
+    master_envs = { "HOSTNAME": service_component_name,
+                    # For Registrator to register with generated name and not the
+                    # image name
+                    "SERVICE_NAME": service_component_name }
+    for envs_map in envs:
+        master_envs.update(envs_map)
+    return master_envs
+
+
+#
+# Methods for volume bindings
+#
+
+def _parse_volumes_param(volumes):
+    """Parse volumes details for Docker containers from blueprint
+
+    Takes in a list of dicts that contains Docker volume info and
+    transforms them into docker-py compliant (unflattened) data structures.
+    Look for the `volumes` parameters under the `run` method on
+    [this page](https://docker-py.readthedocs.io/en/stable/containers.html)
+
+    Args:
+        volumes (list): List of
+
+            {
+              "host": {
+                "path": <target path on host>
+                },
+              "container": {
+                "bind": <target path in container>,
+                "mode": <read/write>
+              }
+            }
+
+    Returns:
+        dict of the form
+
+            {
+              <target path on host>: {
+                "bind": <target path in container>,
+                "mode": <read/write>
+              }
+            }
+
+        if volumes is None then returns None
+    """
+    if volumes:
+        return dict([ (vol["host"]["path"], vol["container"]) for vol in volumes ])
+    else:
+        return None
+
+
+#
+# Utility methods used to help build the inputs to create the host_config
+#
+
+def add_host_config_params_volumes(volumes=None, host_config_params=None):
+    """Add volumes input params
+
+    Args:
+    -----
+    volumes (list): List of
+
+            {
+              "host": {
+                "path": <target path on host>
+                },
+              "container": {
+                "bind": <target path in container>,
+                "mode": <read/write>
+              }
+            }
+
+    host_config_params (dict): Target dict to accumulate host config inputs
+
+    Returns:
+    --------
+    Updated host_config_params
+    """
+# TODO: USE parse_volumes_param here!
+    if host_config_params == None:
+        host_config_params = {}
+
+    host_config_params["binds"] = _parse_volumes_param(volumes)
+    return host_config_params
+
+def add_host_config_params_ports(ports=None, host_config_params=None):
+    """Add ports input params
+
+    Args:
+    -----
+    ports (list): Each port mapping entry is of the form
+
+        "<container ports>:<host port>"
+
+    host_config_params (dict): Target dict to accumulate host config inputs
+
+    Returns:
+    --------
+    Updated host_config_params
+    """
+    if host_config_params == None:
+        host_config_params = {}
+
+    if ports:
+        ports = [ port.split(":") for port in ports ]
+        port_bindings = { port[0]: { "HostPort": port[1] }  for port in ports }
+        host_config_params["port_bindings"] = port_bindings
+        host_config_params["publish_all_ports"] = False
+    else:
+        host_config_params["publish_all_ports"] = True
+
+    return host_config_params
+
+def add_host_config_params_dns(docker_host, host_config_params=None):
+    """Add dns input params
+
+    This is not a generic implementation. This method will setup dns with the
+    expectation that a local consul agent is running on the docker host and will
+    service the dns requests.
+
+    Args:
+    -----
+    docker_host (string): Docker host ip address which will be used as the dns server
+    host_config_params (dict): Target dict to accumulate host config inputs
+
+    Returns:
+    --------
+    Updated host_config_params
+    """
+    if host_config_params == None:
+        host_config_params = {}
+
+    host_config_params["dns"] = [docker_host]
+    host_config_params["dns_search"] = ["service.consul"]
+    host_config_params["extra_hosts"] = { "consul": docker_host }
+    return host_config_params
+
+
+def create_container_config(client, image, envs, host_config_params, tty=False):
+    """Create docker container config
+
+    Args:
+    -----
+    envs (dict): dict of environment variables to pass into the docker containers.
+        Gets passed into docker-py.create_container call
+    host_config_params (dict): Dict of input parameters to the docker-py
+        "create_host_config" method call
+    """
+    # This is the 1.10.6 approach to binding volumes
+    # http://docker-py.readthedocs.io/en/1.10.6/volumes.html
+    volumes = host_config_params.get("bind", None)
+    target_volumes = [ target["bind"] for target in volumes.values() ] \
+            if volumes else None
+
+    host_config = client.create_host_config(**host_config_params)
+
+    if "port_bindings" in host_config_params:
+        # TODO: Use six for creating the list of ports - six.iterkeys
+        ports = host_config_params["port_bindings"].keys()
+    else:
+        ports = None
+
+    command = "" # This is required...
+    config = client.create_container_config(image, command, detach=True, tty=tty,
+            host_config=host_config, ports=ports,
+            environment=envs, volumes=target_volumes)
+
+    utils.logger.info("Docker container config: {0}".format(config))
+
+    return config
+