(POOLER-81) Add time remaining information (#280)

* (POOLER-81) Add time_remaining information

Before, the only time calculation displayed for a given VM was the
lifetime parameter. Added the remaining parameter which will
display time until the VM is destroyed as a float.

Additionally, start_time and end_time were added to api to return
as UTC based times (e.g. 2018-07-10 11:01:03 -0700).

* Remove abs eval from GET, rework spec tests to check each field.
This allows us to account for "flakiness" of the remaining return.

* Change datetime to RFC3339 for start_time and end_time

lib/vmpooler/api/v1.rb

@@ -645,6 +645,9 @@ module Vmpooler
           result[params[:hostname]]['state'] = 'destroyed'
         elsif rdata['checkout']
           result[params[:hostname]]['running'] = ((Time.now - Time.parse(rdata['checkout'])) / 60 / 60).round(2)
+          result[params[:hostname]]['remaining'] = ((Time.parse(rdata['checkout']) + rdata['lifetime'].to_i*60*60 - Time.now) / 60 / 60).round(2)
+          result[params[:hostname]]['start_time'] = Time.parse(rdata['checkout']).to_datetime.rfc3339
+          result[params[:hostname]]['end_time'] = (Time.parse(rdata['checkout']) + rdata['lifetime'].to_i*60*60).to_datetime.rfc3339
           result[params[:hostname]]['state'] = 'running'
         elsif rdata['check']
           result[params[:hostname]]['state'] = 'ready'

spec/integration/api/v1/vm_spec.rb

@@ -39,6 +39,24 @@ describe Vmpooler::API::V1 do
       create_token('abcdefghijklmnopqrstuvwxyz012345', 'jdoe', current_time)
     end
 
+    describe 'GET /vm/:hostname' do
+      it 'returns correct information on a running vm' do
+        create_running_vm 'pool1', 'abcdefghijklmnop'
+        get "#{prefix}/vm/abcdefghijklmnop"
+        expect_json(ok = true, http = 200)
+        response_body = (JSON.parse(last_response.body)["abcdefghijklmnop"])
+
+        expect(response_body["template"]).to eq("pool1")
+        expect(response_body["lifetime"]).to eq(0)
+        expect(response_body["running"]).to be >= 0
+        expect(response_body["remaining"]).to be <= 0
+        expect(response_body["start_time"]).to eq(current_time.to_datetime.rfc3339)
+        expect(response_body["end_time"]).to eq(current_time.to_datetime.rfc3339)
+        expect(response_body["state"]).to eq("running")
+        expect(response_body["ip"]).to eq("")
+      end
+    end
+
     describe 'POST /vm' do
       it 'returns a single VM' do
         create_ready_vm 'pool1', 'abcdefghijklmnop'