(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.

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