dasher.rb

#!/usr/bin/env ruby

require 'yaml'

#
# dasher
# This script takes a configmap yaml file and a JSON grafana dashboard file,
# and replaces the JSON in the configmap with the JSON from the file.  This 
# is useful for updating the telemeter-lts dashboard config maps with JSON
# expoerted from a modified Grafana dashboard.

if ARGV.length != 2
  raise "Usage: dasher /path/to/grafana-dash.configmap.yaml /path/to/dashboard.json"
end
puts "Loading configmap from #{ARGV.first}, JSON dashboard from #{ARGV.last}"
configmap = YAML.load_file(ARGV.first)
raise "Expected a single key, found #{configmap["data"].keys}" unless configmap["data"].length == 1
key = configmap["data"].keys.first
configmap["data"][key] = File.open(ARGV.last).read
File.open(ARGV.first, "w") { |file| file.write(configmap.to_yaml) }
puts "Done!"