2019-04-08

[limnh]

Attempting to parse the json output from nomad alloc status. can get DesiredState with open('alloc-json.json') { |f| f.grep(/DesiredStatus/) } but have not figured out how to add ID

[limnh]

Have set an ENV VAR for $NOMAD_ADDR to run and create file from the nomad alloc status. command here: curl \ $NOMAD_ADDR/v1/allocations | jq '.' > alloc-json.json

[limnh]

may have to just do a secondary grep command like open('alloc-json.json') { |f| f.grep(/ID/) }

[limnh]

Daily To-Do List:

Questions/Issues:

• How do I pull nomad API output, and where do I put it?
  • include?
  • how do I only find nodes with mismatching corresponding statuses? -each_line & select
• How do I use the Nomad API?
  • How do I ensure that local/public are communicating with the correct node?
• I've got the right curl command, but how does that transpose to Ruby?

Solutions:

• alloc-json.txt.each_line.select do |line| (line.include?("run") && str.include?("pending")) || (line.include?("stop") && str.include?("running")) end

  • It was decided that this method is too brittle, and the Nomad API should be used instead.

• curl \ https://localhost:4646/v1/allocations from these Nomad docs

  • Created an ENV VAR $NOMAD_ADDR that can be used in this curl command.

require 'uri'
require 'json'

uri = URI.parse("http://#{ENV['NOMAD_ADDR']}/v1/allocations")
response = Net::HTTP.get(uri)

allocs = []
body = JSON.parse(response)
body.each do |alloc|
  allocs << {
    "DesiredStatus" => alloc["DesiredStatus"],
    "ID" => alloc["ID"],
    "ClientStatus" => alloc["ClientStatus"]
  }
end

puts allocs

• Requires:
  • Net::HTTP provides a rich library which can be used to build HTTP user-agents.
  • JSON is a lightweight data-interchange format.
  • URI is a module providing classes to handle Uniform Resource Identifiers
• allocs is creating a new empty array for the hashes
• body is an object(array) that the command will iterate over
  • .each is the module that goes over each object within the array
• << Append—Pushes the given object on to the end of this array.
• Three keys that we are searching for within this new array:
  • DesiredStatus
  • ClientStatus
  • ID
• Will spit out the relevant values from the keys we're searching.