https://github.com/verizon/helm
A native Scala client for interacting with Consul
https://github.com/verizon/helm
consul infrastructure reasonable
Last synced: 5 months ago
JSON representation
A native Scala client for interacting with Consul
- Host: GitHub
- URL: https://github.com/verizon/helm
- Owner: Verizon
- License: apache-2.0
- Archived: true
- Created: 2017-02-27T17:06:46.000Z (over 9 years ago)
- Default Branch: master
- Last Pushed: 2019-08-11T15:03:04.000Z (almost 7 years ago)
- Last Synced: 2024-12-11T09:20:28.665Z (over 1 year ago)
- Topics: consul, infrastructure, reasonable
- Language: Scala
- Size: 161 KB
- Stars: 81
- Watchers: 9
- Forks: 24
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Helm
[](https://travis-ci.org/Verizon/helm)
[](https://maven-badges.herokuapp.com/maven-central/io.verizon.helm/core_2.11)
[](https://codecov.io/gh/Verizon/helm)
A native [Scala](http://scala-lang.org) client for interacting with [Consul](https://www.consul.io/). There is currently one supported client, which uses [http4s](http://http4s.org) to make HTTP calls to Consul. Alternative implementations could be added with relative ease by providing an additional free interpreter for the `ConsulOp` algebra.
## Getting Started
Add the following to your `build.sbt`:
libraryDependencies += "io.verizon.helm" %% "http4s" % "1.4.78-scalaz-7.1"
The *Helm* binaries are located on maven central, so no additional resolvers are needed.
### Algebra
Consul operations are specified by the `ConsulOp` algebra. Two
examples are `get` and `set`:
```
import helm._
import ConsulOp.ConsulOpF
val s: ConsulOpF[Unit] = : ConsulOp.kvSet("key", "value")
val g: ConsulOpF[Option[String]] = : ConsulOp.kvGet("key")
```
These are however just descriptions of what operations the program might perform in the future, just creating these operations does not
actually execute the operations. In order to perform the gets and sets, we need to use the [http4s](http://http4s.org) interpreter.
### The http4s interpreter
First we create an interpreter, which requires an http4s client and
a base url for consul:
```
import cats.effect.IO
import helm.http4s._
import org.http4s.Uri.uri
import org.http4s.client.blaze.Http1Client
val client = Http1Client[IO]().unsafeRunSync
val baseUrl = uri("http://127.0.0.1:8500")
val interpreter = new Http4sConsulClient(baseUrl, client)
```
Now we can apply commands to our http4s client to get back IOs
which actually interact with consul.
```
import cats.effect.IO
val s: IO[Unit] = helm.run(interpreter, ConsulOp.kvSet("testkey", "testvalue"))
val g: IO[Option[String]] = helm.run(interpreter, ConsulOp.kvGet("testkey"))
// actually execute the calls
s.unsafeRunSync
g.unsafeRunSync
```
Typically, the *Helm* algebra would be a part of a `Coproduct` with other algebras in a larger program, so running the `IO` immediately after `helm.run` is not typical.
## Contributing
Contributions are welcome; particularly to expand the algebra with additional operations that are supported by Consul but not yet supported by *Helm*.