sisock

Brief Overview

Sisock is a suite of software for serving Simons Observatory data over websockets.

The key components are:

• A WAMP server — This runs on just one computer; all data are routed through it.
• Data node servers — These can be spread across the internet, located on machines from which data are to be served (data nodes).
• A hub — The hub keeps track of which data node servers are online. Only one hub is run, by default on the computer running the WAMP server).
• Consumers — These are clients that request data from data node servers. They connect to the hub in order to know which data node servers are available and how to access them.
  • The components/grafana_server is an example of a consumer. It reads data via sisock and then passes it to Grafana over HTTP.

The following diagram illustrates the above:

Installing and Running

1. Setting Up Crossbar

First, we need to set up the crossbar configuration. For this, you need access to the ocs-site-configs repository.

Everything you need to do to run sisock can be done from the templates directory of this ocs-site-configs repo; if you are modifying anything for local development, you can make a copy of this directory elsewhere.

Important: if you make a copy of these files, for security reasons do not do it in the root directory of your sisock clone, since it will put the encryption certificates in your docker image. This is not necessarily a problem on your local machine, but would compromise security if the image gets pushed to the public DockerHub.

A default configuration can be found in the templates directory. You will need first to run setup_tls.py to generate encryption certificates in templates/.crossbar

Important: the ‘common name’ (CN) of the certificate should be localhost if you are doing local development, or else the hostname of your server if you are in production mode and will be serving over the internet. The certificates will be rejected if their CN does not match the real-life hostname. You will have to modify the above script if you do not want localhost. See templates/.crossbar/README.md for instructions on manually generating the certificates.

The .crossbar/config.json file should work out of the box, but advanced users can tweak settings as they see fit.

2. Setting up to use docker

Get Dependencies

You will need to have docker and docker-compose installed on your system. There are plenty of websites online that give instructions on how to do so, but

$ pip install docker docker-compose

should do the trick.

Create docker-compose.yaml

We will presume that you want to do local development in the following instructions.

If not, instead of using templates/docker-compose_dev-mode.yaml from ocs-site-configs, you could use templates/docker-compose.yaml. In this case, you actually don't need any of the sisock code locally, since it pulls all the docker images from grumpy.physics.yale.edu: see below for how to access images from this computer.

Sisock is normally run in docker containers using docker-compose. You will need to create a YAML file for configuring this. Again, you can find an example in the ocs-site-configs in templates/docker-compose_dev-mode.yaml.

If you want to use this file ‘out of the box’, define the following environment variable:

• SISOCK_DIR to point to the root of your sisock clone.

You can also customise which ports are used for various services, though the default values are probably fine on most machines.

• SISOCK_SQL_PORT (default = 3308; chosen in order not to conflict with 3306 if you are already running an SQL server).
• SISOCK_HTTP_PORT (default = 5000)
• SISOCK_GRAFANA_PORT (default = 3000)

Additionally, if you want to use certain data node servers that read data from your local disc, you should also define:

• For g3-reader, define ${SISOCK_HK_DIR}.
• For radiometer-server, define ${SISOCK_RADIOMETER_DIR}.
• For apex-weather-server, define ${SISOCK_APEX_DIR}.

Make Sure You Have Access to the so3g Docker Image

The g3_reader data node server uses the so3g library, whose image is pulled by components/g3_file_scanner/Dockerfile. By default, this image is pulled from grumpy at Yale. You will need to do the following to enable this:

$ docker login grumpy.physics.yale.edu

The username/password is a SO standard: ask Brian Koopman if you don't know it.

Alternatively, you can create your own image locally and alter components/g3file_scanner/Dockerfile as appropriate.

3. Go!

Firing Things Up

If it doesn't yet exist, create the overarching network for the system:

$ docker network create --driver bridge sisock-net

To run all the services, simply do:

$ docker-compose up

Note that this and all subsequent docker-compose commands assume your YAML file is named docker-compose.yaml. If you are using the out-of-the-box configuration from ocs-site-configs, use the -f flag to specify the filename.

Or, you can select which services listed in docker-compose.yaml you want to run. For instance, the following is a nice, minimal check that things are working:

$ docker-compose up grafana sisock-http sensors-server

The commands above attach the stdout of all the containers to your terminal; you can terminate with good ol' ctrl-c. This mode is helpful for debugging. However, if you'd like to background this, throw the -d flag.

Grafana should now be running: access it at localhost:3000. You'll need to configure the Grafana data source as the SimpleJson type with a URL of http://sisock-http:5000. (The user defined bridge network, sisock-net, enables DNS resolution by container name, in this case sisock-http, as is defined in the docker-compose.yaml file.)

Rebuilding

If you make modifications to the code, docker-compose up won't automatically update the images. You will need to do this yourself with docker-compose build. For instance, if you were working on the code in components/data_node_servers/sensors/, you would do:

$ docker-compose build sensors-server

To rebuild all the images (normally not necessary), just do:

$ docker-compose build

Clean-up

To shutdown and cleanup, run:

$ docker-compose down

If you'd like to remove the images as well run:

$ docker-compose down --rmi all

This will not remove sisock-net. To do so:

$ docker network rm sisock-net

Furthermore, if you really don't want your saved grafana configuration, you can remove the grafana-storage container:

$ docker volume rm grafana-storage

License

This project is licensed under the BSD 2-Clause License - see the LICENSE.txt file for details.