(POOLER-123) Implement a max TTL (#349)

* (POOLER-123) Implement a max TTL

Before this change, we could checkout a vm and set the lifetime to a
very high number which would esssentially keep the vm running forever.
Now implementing a config setting max_lifetime_upper_limit which enforces
a maximum lifetime in hours both for initial checkout and extending a
running vm

* (POOLER-123) Improve PUT vm endpoint error messaging

Prior to this commit the PUT vm endpoint didn't give any useful
information about why a user's request failed.

This commit updates PUT to output a more helpful set of error messages
in the `failure` key that gets returned in the JSON response.

* (POOLER-123) Update max_lifetime_upper_limit key

This commit switches the max_lifetime_upper_limit key from being a
symbol to being a string, which is what the config hash seems to contain.

* (maint) Add option to disable Redis persistence in docker-compose

This commit is just a handy little command override to the redis
container to prevent persistence.

docker/docker-compose.yml

@@ -22,6 +22,8 @@ services:
       - redislocal
   redislocal:
     image: redis
+    # Uncomment this if you don't want the redis data to persist
+    #command: "redis-server --save '' --appendonly no"
     ports:
       - "6379:6379"
     networks:

lib/vmpooler/api/v1.rb

@@ -875,7 +875,7 @@ module Vmpooler
       status 404
       result = { 'ok' => false }
 
-      failure = false
+      failure = []
 
       params[:hostname] = hostname_shorten(params[:hostname], config['domain'])
 
@@ -892,24 +892,42 @@ module Vmpooler
             when 'lifetime'
               need_token! if Vmpooler::API.settings.config[:auth]
 
+              # in hours, defaults to one week
+              max_lifetime_upper_limit = config['max_lifetime_upper_limit']
+              if max_lifetime_upper_limit
+                max_lifetime_upper_limit = max_lifetime_upper_limit.to_i
+                if arg.to_i >= max_lifetime_upper_limit
+                  failure.push("You provided a lifetime (#{arg}) that exceeds the configured maximum of #{max_lifetime_upper_limit}.")
+                else
+                  # also make sure we do not extend past max_lifetime_upper_limit
+                  rdata = backend.hgetall('vmpooler__vm__' + params[:hostname])
+                  running = ((Time.now - Time.parse(rdata['checkout'])) / 60 / 60).round(2)
+                  unless running + arg.to_i < max_lifetime_upper_limit
+                    failure.push("You provided a lifetime (#{arg}) that will extend the current lifetime past the configured maximum of #{max_lifetime_upper_limit}.")
+                  end
+                end
+              end
+
+              # validate lifetime is within boundaries
               unless arg.to_i > 0
-                failure = true
+                failure.push("You provided a lifetime (#{arg}) but you must provide a positive number.")
               end
             when 'tags'
               unless arg.is_a?(Hash)
-                failure = true
+                failure.push("You provided tags (#{arg}) as something other than a hash.")
               end
 
               if config['allowed_tags']
-                failure = true if not (arg.keys - config['allowed_tags']).empty?
+                failure.push("You provided unsuppored tags (#{arg}).") if not (arg.keys - config['allowed_tags']).empty?
               end
             else
-              failure = true
+              failure.push("Unknown argument #{arg}.")
           end
         end
 
-        if failure
+        if failure.size > 0
           status 400
+          result['failure'] = failure
         else
           jdata.each do |param, arg|
             case param

spec/helpers.rb

@@ -99,6 +99,10 @@ def fetch_vm(vm)
   redis.hgetall("vmpooler__vm__#{vm}")
 end
 
+def set_vm_data(vm, key, value)
+  redis.hset("vmpooler__vm__#{vm}", key, value)
+end
+
 def snapshot_revert_vm(vm, snapshot = '12345678901234567890123456789012')
   redis.sadd('vmpooler__tasks__snapshot-revert', "#{vm}:#{snapshot}")
   redis.hset("vmpooler__vm__#{vm}", "snapshot:#{snapshot}", "1")

spec/integration/api/v1/vm_hostname_spec.rb

@@ -20,12 +20,14 @@ describe Vmpooler::API::V1 do
         config: {
           'site_name' => 'test pooler',
           'vm_lifetime_auth' => 2,
+
         },
         pools: [
           {'name' => 'pool1', 'size' => 5},
           {'name' => 'pool2', 'size' => 10}
         ],
         alias: { 'poolone' => 'pool1' },
+        auth: false
       }
     }
 
@@ -34,7 +36,6 @@ describe Vmpooler::API::V1 do
     before(:each) do
       app.settings.set :config, config
       app.settings.set :redis, redis
-      app.settings.set :config, auth: false
       create_token('abcdefghijklmnopqrstuvwxyz012345', 'jdoe', current_time)
     end
 
@@ -122,6 +123,41 @@ describe Vmpooler::API::V1 do
           vm = fetch_vm('testhost')
           expect(vm['lifetime']).to be_nil
         end
+
+        it 'does not enforce a lifetime' do
+          create_vm('testhost')
+
+          put "#{prefix}/vm/testhost", '{"lifetime":"20000"}'
+          expect_json(ok = true, http = 200)
+
+          vm = fetch_vm('testhost')
+          expect(vm['lifetime']).to eq("20000")
+        end
+
+        it 'does not allow a lifetime to be initially past config 168' do
+          app.settings.set :config,
+                           { :config => { 'max_lifetime_upper_limit' => 168 } }
+          create_vm('testhost')
+
+          put "#{prefix}/vm/testhost", '{"lifetime":"200"}'
+          expect_json(ok = false, http = 400)
+
+          vm = fetch_vm('testhost')
+          expect(vm['lifetime']).to be_nil
+        end
+
+        it 'does not allow a lifetime to be extended past config 168' do
+          app.settings.set :config,
+                           { :config => { 'max_lifetime_upper_limit' => 168 } }
+          create_vm('testhost')
+
+          set_vm_data('testhost', "checkout", (Time.now - (69*60*60)))
+          put "#{prefix}/vm/testhost", '{"lifetime":"100"}'
+          expect_json(ok = false, http = 400)
+
+          vm = fetch_vm('testhost')
+          expect(vm['lifetime']).to be_nil
+        end
       end
 
       context '(auth configured)' do

vmpooler.yaml.example

@@ -498,6 +498,12 @@
 #     Expects a boolean value
 #     (optional; default: false)
 #
+#   - max_lifetime_upper_limit
+#     Sets a lifetime upper limit (in hours) for how long the vm lifetime can be set via the API. Lifetime can be set and extended
+#     so this configuration is used to enforce an upper limit to both the initial lifetime request and/or the extended
+#     lifetime (by checking how long it has already been running).
+#     (optional; default: unlimited)
+#
 # Example:
 
 :config: