Zoidberg

The Mastermind

Prerequisites

On nodes that will be running Zoidberg commands:

• sudo apt-get install python3-pip
• sudo update-alternatives --config python and select Python 3
• pip install pyyaml

On nodes that will be receiveing Zoidberg commands:

• sudo apt-get install git python3-pip
• sudo update-alternatives --config python and select Python 3
• pip install pyyaml

Command spec

Assumes you have the zb symlink, and have symlinked the path to your zoidberg config file as ./zbc.

Each command takes the following structure:

./zb ./zbc <instruction> [services...]

For each command, you may optionally specify a subset of services that the command should apply to. Otherwise it will apply to all services in the specified config file.

Available instructions:

• install
  • Install the entire system, or the specified services
  • Deletes anything that currently exists for those services and starts from scratch
• update
  • Updates the whole system or the specified services
  • Assumes everything's in place already and does a git pull on the branch specified in the source
• start
• run
  • Start the whole system, or just the specified services
  • Assumes everything's in place already, doesn't make any installation changes
  • start and run are synonyms
• stop
  • Stops the whole system, or just the specified services
  • Assumes everything's in place already, doesn't make any installation changes
• restart
  • Restarts the whole system, or just the specified services
  • Assumes everything's in place already, doesn't make any installation changes
• install_prereqs
  • Installs the prerequisites for Zoidberg on the target nodes
  • Only needs to be done once per node
• shutdown
  • Shuts down the nodes
• ping
  • Does nothing other than try and copy the config to the nodes, as a rudimentary ping

Config file

The YAML file specifies:

• Which hosts are available
• Which sources are available, and where they are from
• Which services need to run on which host

It is possible for a single host to hold multiple sources and multiple services. It is possible for a single source to be used in multiple services, and those services to be on different machines.

Example YAML:

hosts:
    hostid1:
        ip: 0.0.0.1
    hostid2:
        ip: 0.0.0.2
source:
    source1:
        source: https://git.uri/svc1.git
        branch: dev-branch
    source2:
        source: https://git.uri/svc2.git
services:
    svc1:
        source: source1
        host: hostid1
    svc2:
        source: source2
        host: hostid2