runtime adr

docs/ocis/adr/0014-microservices-runtime.md

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+---
+title: "14. Microservices Runtime"
+weight: 14
+date: 2022-01-21T12:56:53+01:00
+geekdocRepo: https://github.com/owncloud/ocis
+geekdocEditPath: edit/master/docs/ocis/adr
+geekdocFilePath: 0014-microservices-runtime.md
+---
+
+* Status: proposed
+* Deciders: @butonic, @micbar, @dragotin, @mstingl, @pmaier1, @fschade
+* Date: 2022-01-21
+
+## Context and Problem Statement
+
+In an environment where shipping a single binary beats the deployment wars, framing a whole family of microservices within a package and running it using Go language mechanisms has plenty of value. In such environment, a runtime is necessary to orchestrate the services that run within it.
+
+## Decision Drivers
+
+- Start oCIS microservices with a single command (`ocis server`)
+- Clear separation of concerns
+
+## Considered Options
+
+1.The use of frameworks such as:
+  - asim/go-micro
+  - go-kit/kit
+2. Build and synchronize all services in-house.
+3. A hybrid solution between framework and in-house.
+
+## Options
+
+### go-kit/kit
+
+Pros
+- Large community behind
+- The creator is a maintainer of Go, so the code quality is quite high.
+
+Cons
+- Too verbose. Ultimately too slow to make progress.
+- Implementing a service would require defining interfaces and a lot of boilerplate.
+
+### asim/go-micro
+
+Pros
+- Implementation based in swappable interfaces.
+- Multiple implementations, either in-memory or through external services
+- Production ready
+
+## Decision Outcome
+
+Number 3: A hybrid solution between framework and in-house.
+
+### Design
+
+First of, every ocis service IS a go-micro service, and because go-micro makes use of urfave/cli, a service can be conveniently wrapped inside a subcommand. Writing a supervisor is then a choice. We do use a supervisor to ensure long-running processes and embrace the "let it crash" mentality. The piece we use for this end is called [Suture](https://github.com/thejerf/suture).
+
+The code regarding the runtime can be found pretty isolated [here](https://github.com/owncloud/ocis/blob/d6adb7bee83b58aa3524951ed55872a5f3105568/ocis/pkg/runtime/service/service.go). The runtime itself runs as a service. This is done so messages can be sent to it using the oCIS single binary to control the lifecycle of its services.