Packages

•  package root

  glngn server is a low-code business process as a service rapid development system.

  glngn server is a low-code business process as a service rapid development system. Conceptually similar to a programmable Microsoft Access or Apple FileMaker for scalable event sourced business services. In addition to a library, a standalone application is provided that is useful with minimal ceremony. This can be customized with a simple API. As well as deployed to a kubernetes cluster should those advantages be required.

  A deployment is cluster of glngn.server.node.AppNodes serving a dynamic composition of glngn.server.ServiceFragments. Deployments are designed to be fully usable as a standalone local application or a kubernetes service.

  • User Manual
  • Developer Manual
  • If your goal is to extend the application service's then see glngn.server.ServiceFragment.
  • If your goal is to restrict the configuration or prelude to better suite a business domain then see glngn.server.host.HostApp.
  • If you are debugging a failure of a glngn server process and have the exit code then see glngn.server.host.ExitCodes$

  Contact support@dogheadbone.com for support and licensing.

  Definition Classes

  root

•  package glngn

  Definition Classes

  root

•  package server
  • User Manual
  • Developer Manual
  • If your goal is to extend a service with business specific components then see glngn.server.ServiceFragment.
  • If your goal is to customize the configuration or prelude to better suite a business domain then see glngn.server.host.HostApp.
  • If you are debugging a failure of a glngn server process and have the exit code then see glngn.server.host.ExitCodes$

  Definition Classes

  glngn

•  abstract class ServiceFragment extends ActorService with ServiceEndpoints

  A service fragment is an object defining a logical service.

  A service fragment is an object defining a logical service. Service fragments must be instantiated under a group with a name to use. This scopes all endpoints, authorization, and entity data to that group and name.

  An object extending this class declares a new service fragment. A service has a protocol of commands, queries and events. Operators can use the protocol directly. Users can only use the protocol through the declared endpoints.

  The usability focus is on rapid development and data acquisition:

  • easy declaration of the commands, queries and events
  • automatic auditing
  • components for common business as a service activities

  A service is three declarations:

  • A protocol consisting of commands and queries
  • A mapping from protocol messages to implementations
  • an interface exported to users as endpoints

  This is implemented in this EDSL as:

  • Types in the Proto hierarchy. Commands extend Command and Queries extend Query.
  • Implementations defined by (partial) functions from messages in this protocol to a handler. Handlers can delegate to akka actors, event source entities, ZIO actions, or plain functions.
  • the exports of commands and queries are REST endpoints. These consist of explicit (verb, path components, data) and implicit (auth token, session token, csrf token, origin) data plus a mapping to the Proto.

  Definition Classes

  server

  Examples:

  1. Scopes If services.IntegerCounters was instantiated under a group doors with the service name entrances and exits then these would not share data. The entity /doors/entrances/front would have a different state than /doors/exits/front. Even though the object, IntegerCounters, is the same.

  ,

  2. Minimal service fragment definition

     import glngn.prelude._
     
     object MinimalServiceFragment extends ServiceFragment {
       sealed trait Proto extends Message
     }

  ,

  3. A hypothetical service fragment definition

     // a hypothetical service for account balances
     final object ClientBalanceFragment extends ServiceFragment {
       type AccountId = EntityId
       type CurrencyValue = Int // fractions of currency unit
     
       // messages in the protocol
       sealed trait Proto extends Message
       // a command to increase the balance of an account
       case class IncBalanceForAccount(account: AccountId, amount: CurrencyValue)
         extends Command[CurrencyValue] with Proto
       // a command to decrease the balance of an account
       case class DecBalanceForAccount(account: AccountId, amount: CurrencyValue)
         extends Command[CurrencyValue] with Proto
       // a query to retrieve the account balance
       case class GetBalanceForAccount(account: AccountId)
         extends Query[CurrencyValue] with Proto
       // an event outside of the command/query model.
       case class RequestAudit(account: AccountId) extends Proto
     
       override def instantiate(env: InstanceEnv) = new Instance(env) {
         import Bindings.{delegate, entity, async}
     
         // the service protocol is implemented using...
         val bindings = bindingsChain(
           // ... a akka typed Behavior[Envelope] delegate
           delegate {
             Behaviors.receiveMessagePartial
               case Event(RequestAudit) => ???
             }
             // Note the use of a partial function: unhandled messages will propagate to the
             // next binding. (Even if the delegate behavior above changes)
           },
           // ... operations on a named counter entity
           entity(NamedValue) {
             case IncBalanceForAccount(accountId, amount) => CounterEntity.Inc(amount) -> accountId
             case DecBalanceForAccount(accountId, amount) => CounterEntity.Dec(amount) -> accountId
             case GetBalanceForAccount(accountId)         => CounterEntity.Get         -> accountId
           },
           // ... a daemon sending Proto messages back to this service
           async(OrdersOverSMSBehavior) // where OrdersOverSMSBehavior being a [[ServiceActorDaemon]]
         )
     
         import Endpoints.{query, command}
     
         // The protocol is exported to users with the endpoints
         def endpoints: Endpoints[_] = endpointsChain(
           // results in the REST interface:
           //
           // GET $accountName
           // POST $accountName/inc
           // POST $accountName/dec
           //
           // once instantiated this is schema can be viewed under /openapi.json
           query.entityId { accountName =>
             GetBalanceForAccount(accountName)
           },
           command.entityId.slug("inc").value[CurrencyValue] { (accountId, amount) =>
             IncBalanceForAccount(accountId, amount)
           },
           command.entityId.slug("dec").value[CurrencyValue] { (accountId, amount) =>
             DecBalanceForAccount(accountId, amount)
           }
         )
       }
     }

• Bindings
• BindingsInstance
• Command
• DelegateOps
• Endpoints
• EndpointsInstance
• EndpointsOp
• Envelope
• Event
• Instance
• InstanceEnv
• Proto
• Query
• Request
• ServiceInstance
• StopEnvelope

glngn.server.ServiceFragment

Instance 

Companion class Instance