pulumi/halloumi

halloumi

Pulumi + Heroku = Halloumi

You write your application, we run it in the cloud.

halloumi is a prototype and not under active development.

Summary

The halloumi SDK defines an application model where you simply write your http handler, and we take care of the rest.

The node version is independently runnable via yarn start, and the go version has a small binary CLI to orchestrate execution.

All you have to do is define HTTP handlers, and halloumi takes care of running it in the cloud:

Node.js

// this application will deploy multiple services publicly available int the cloud
const application = new App();

const svc1 = new WebService("hello", (expressApp: express.Express) => {
    // a simple static handler
    expressApp.get('/', (req, res) => res.send("omg i'm alive\n"));
});
application.addService(svc1);


const svc2 = new WebService("world", (expressApp: express.Express) => {
    expressApp.get('/', async (req, res) => {
        // track dependencies across services and make them available at runtime
        const svc1Url = svc1.discover();
        // this handler calls svc1 and passes the result through
        const result = await (await fetch(svc1Url)).text()
        
        res.send(`this is the world. With a window from hello:\n${result} \n`);
    });
});
application.addService(svc2);

application.run().catch(err => { console.error(err) });

Go

app := app.NewApp("petStore")

// a cloud web service that returns a number [0-100)
randomNumberService := web.NewWebService("randomNumber", func() http.Handler {
    // a normal HTTP handler, halloumi takes care of running this in the cloud
    r := mux.NewRouter()
    handler := func(w http.ResponseWriter, r *http.Request) {
        rand.Seed(time.Now().UnixNano())
        fmt.Fprintf(w, "%d", rand.Intn(100))
    }
    r.HandleFunc("/", handler)
    return r
})

app.Register(randomNumberService)

Cross-service Dependencies

Halloumi allows consuming services from other services:

// a cloud web service that returns N of a random animal.
// this service takes a dependency on the URLs of the previously defined services
nAnimalsService := web.NewWebService("nAnimals", func() http.Handler {
    r := mux.NewRouter()
    var num string
    var animal string
    handler := func(w http.ResponseWriter, r *http.Request) {
        // Notice how we have the URL of randomNumberService
        // available to consume here!
        numResp, err := http.Get(randomNumberService.URL())
        if err != nil {
            fmt.Fprintf(w, err.Error())
        }
        defer numResp.Body.Close()

        if numResp.StatusCode == http.StatusOK {
            bodyBytes, err := ioutil.ReadAll(numResp.Body)
            if err != nil {
                log.Fatal(err)
            }
            num = string(bodyBytes)
        }

        // Notice how we have the URL of randomAnimalService
        // available to consume here!
        animalResp, err := http.Get(randomAnimalService.URL())
        if err != nil {
            fmt.Fprintf(w, err.Error())
        }
        defer numResp.Body.Close()

        if animalResp.StatusCode == http.StatusOK {
            bodyBytes, err := ioutil.ReadAll(animalResp.Body)
            if err != nil {
                log.Fatal(err)
            }
            animal = string(bodyBytes)
        }

        fmt.Fprintf(w, "Wow, you got %s %ss!", num, animal)
    }
    r.HandleFunc("/", handler)
    return r
})