Skip to content

Latest commit

 

History

History

stock-con

README.md

The stock consumer

The stock consumer (stock-con) consumes data from the stock generator and performs various calculations on different endpoints on it.

Local development

Set it up locally (assumes npm installed, tested with version 5.7.1):

$ npm install express
$ npm install

Build and run in one terminal (note: make sure you've got the stock generator service running as well otherwise it won't work):

$ DOK_STOCKGEN_HOSTNAME=localhost DOK_STOCKGEN_PORT=9876 npm start

In another terminal (requires http installed, otherwise use curl):

$ while true; do \
   http localhost:9898/average/NYSE:RHT ; \
   sleep 2 ; \
  done

Endpoints

Basic stats

Usage:

/average/$SYMBOL

Behavior: If $SYMBOL is a valid and known one a response like below, otherwise a 404:

HTTP/1.1 200 OK
Connection: keep-alive
Content-Length: 114
Content-Type: application/json; charset=utf-8
Date: Tue, 13 Mar 2018 17:34:01 GMT
ETag: W/"72-vkOrThRnV1hPbp7xrmGe17qHb4I"
X-Powered-By: Express

{
    "current": 598.8333836078177,
    "forecast": 437.20974460845946,
    "moving_average": 599.5866511312555,
    "symbol": "NYSE:RHT"
}

Health check

Usage:

/healthz

Behavior: A 200 response like below, listing the number of known symbols and the symbol that has been queried for most recently (ignoring unknown symbols):

HTTP/1.1 200 OK
Connection: keep-alive
Content-Length: 38
Content-Type: application/json; charset=utf-8
Date: Tue, 13 Mar 2018 17:34:43 GMT
ETag: W/"26-rNuCWemdLty1c1TH7oAt5mn3q2U"
X-Powered-By: Express

{
    "lastseen": "NYSE:RHT",
    "numsymbols": 4
}

Containerized deployment

The stock-con app container image is defined in Dockerfile and publicly available via quay.io/mhausenblas/stock-con:0.3.

To deploy it as an Kubernetes application, use the provided manifest like so:

$ kubectl apply -f app.yaml
$ kubectl get deploy,svc,po

If you do have an Ingress controller running, you can use the following to expose stock-con to the public:

$ kubectl apply -f public-con.yaml

Once the Ingress resource is deployed (check with kubectl get ing) you can access it like so (assuming the public-facing IP is 192.168.99.100):

$ http --verify=no https://192.168.99.100/stock-con/average/NYSE:RHT

Visualization

Note: the following is WIP, no need to look at it now.

Idea: install Prometheus and Grafana, instrument stock-con with siimon/prom-client, and visualize the stocks over time.

Prometheus

TBD.

Grafana

The Grafana app requires an Ingress controller.

$ kubectl create -f grafana-app.yaml

Note: see also the NGINX Ingress user guide for more options.