Components

There are currently three components that make up a functioning sisock stack (in the context of live montioring, anyway). There’s the crossbar server, the intermediate web server, and then all the DataNodeServers. This page documents how to get containers of these components and configure them in your docker-config.yml.

sisock-crossbar

The crossbar server, an implementation of a WAMP router, serves as the communication channel between all the various components, as well as to parts of the Observatory Control System (OCS). This is provided by an image at grumpy.physics.yale.edu/sisock-crossbar.

Alongside this server runs the sisock Hub, which keeps track of all the running DataNodeSevers.

Configuration

Option	Description
container_name	sisock_crossbar - a currently hardcoded value in sisock, used for DNS resolution within Docker
ports	Exposes the crossbar container on localhost at port 8001, used for OCS communication. The 127.0.0.1 is critical if the computer you are running on is exposed to the internet.
volumes	We need the TLS certs bind mounted.
PYTHONBUFFERED	Force stdin, stdout, and stderr to be unbuffered. For logging in Docker.

sisock-crossbar:
  image: grumpy.physics.yale.edu/sisock-crossbar:0.1.0
  container_name: sisock_crossbar # required for proper name resolution in sisock code
  ports:
    - "127.0.0.1:8001:8001" # expose for OCS
  volumes:
    - ./.crossbar:/app/.crossbar
  environment:
       - PYTHONUNBUFFERED=1

sisock-http

Between Grafana and sisock sits an web server. This serves as a data source for Grafana, translating the queries from Grafana into data and field requests in sisock. The result is data from a DataNodeServer is passed through the crossbar server to the sisock-http server and then to Grafana over http, displaying in your browser.

Configuration

The image is provided at grumpy.physics.yale.edu/sisock-http, and depends on the crossbar server running to function. Since it communicates over the secure port on crossbar we need the TLS certificates mounted. The HTTP server defaultly runs on port 5000, but you can change this with the environment variable ‘PORT’, as shown in the example. There is also a ‘LOGLEVEL’ environment variable which can be used to set the log level. This is useful for debugging. txaio is used for logging.

sisock-http:
  image: grumpy.physics.yale.edu/sisock-http:0.1.0
  depends_on:
    - "sisock-crossbar"
  environment:
    PORT: "5001"
    LOGLEVEL: "info"
  volumes:
    - ./.crossbar:/app/.crossbar:ro

g3-file-scanner

This component will scan a directory for .g3 files, opening them and storing information about them required for the g3-reader DataNodeServer in a MySQL database. It scans at a given interval, defined as an environment variable. It also requires connection parameters for the SQL database, and a top level directory to scan.

Configuration

The image is provided at grumpy.physics.yale.edu/sisock-g3-file-scanner, and only depends on the database we store file information in.

g3-file-scanner:
  image: grumpy.physics.yale.edu/sisock-g3-file-scanner:0.2.0
  volumes:
    - /home/koopman/data/yale:/data:ro # has to match the mount in g3-reader
  environment:
      SQL_HOST: "database"
      SQL_USER: "development"
      SQL_PASSWD: "development"
      SQL_DB: "files"
      DATA_DIRECTORY: '/data/'
      SCAN_INTERVAL: 3600 # seconds
  depends_on:
    - "database"

Common Configuration

There are some environment variables which are common among all sisock components. These mostly relate to connection settings for the crossbar server. The defaults will work for a simple, single node, setup. However, moving to multiple nodes, in most cases, will require setting some of these.

Option	Description
WAMP_USER	The username configured for connecting to the crossbar server. This is the “role” in the crossbar config.
WAMP_SECRET	The associated secret for the WAMP_USER.
CROSSBAR_HOST	IP or domain name for the crossbar server.
CROSSBAR_TLS_PORT	The port configured for secure connection to the crossbar server. In default SO configurations this is 8080.
CROSSBAR_OCS_PORT	The port configured for open connection to the crossbar server. In default SO configurations this is 8001.

Warning

The default WAMP_SECRET is not secure. If you are deploying your crossbar server in a public manner, you should not use the default secret.