# yosoy ![Go](https://github.com/lukaszbudnik/yosoy/workflows/Go/badge.svg) ![Docker](https://github.com/lukaszbudnik/yosoy/workflows/Docker%20Image%20CI/badge.svg)

yosoy is a HTTP service for stubbing and prototyping distributed applications. It is a service which will introduce itself to the caller and print some useful information about its environment. "Yo soy" in español means "I am".

yosoy is extremely useful when creating a distributed application stub and you need to see more meaningful responses than a default nginx welcome page.

Typical use cases include:

- testing HTTP routing & ingress
- testing HTTP load balancing
- testing HTTP caching
- stubbing and prototyping distributed applications

## API

yosoy responds to all requests with a JSON containing the information about:

- HTTP request:
  - Host
  - Request URI
  - Method
  - Scheme
  - Proto
  - URL
  - Remote IP
  - HTTP headers
  - HTTP proxy headers
- host:
  - Hostname
  - How many times it was called
  - Env variables if `YOSOY_SHOW_ENVS` is set to `true`, `yes`, `on`, or `1`
  - Files' contents if `YOSOY_SHOW_FILES` is set to a comma-separated list of (valid) files

Checkout out [Sample JSON response](#sample-json-response) below to see how useful yosoy is when troubleshooting/stubbing/prototyping distributed applications.

## Docker image

The docker image is available on docker hub:

```sh
docker pull lukasz/yosoy
```

and ghcr.io:

```sh
docker pull ghcr.io/lukaszbudnik/yosoy
```

It exposes HTTP service on port 80.

## Kubernetes example

There is a sample Kubernetes deployment file in the `test` folder. It uses both `YOSOY_SHOW_ENVS` and `YOSOY_SHOW_FILES`. The deployment uses Kubernetes Downward API to expose labels and annotations as volume files which are then returned by yosoy.

Deploy it to minikube and execute curl to the service a couple of times:

```bash
# start minikube
minikube start
# deploy test service
kubectl apply -f test/deployment.yaml
# tunnel to it and copy the URL as $URL variable
minikube service --url camarero
# simulate some HTTP requests
curl -H "Host: gateway.myapp.com" $URL/camarero/abc
curl -H "Host: gateway.myapp.com" $URL/camarero/abc
curl -H "Host: gateway.myapp.com" $URL/camarero/abc
curl -H "Host: gateway.myapp.com" $URL/camarero/abc
```

## Sample JSON response

A sample yosoy JSON response to a request made from a single page application (SPA) to a backend API deployed in Kubernetes behind nginx ingress and [haproxy-auth-gateway](https://github.com/lukaszbudnik/haproxy-auth-gateway) looks like this:

```json
{
  "host": "api.localtest.me",
  "proto": "HTTP/1.1",
  "method": "GET",
  "scheme": "https",
  "requestUri": "/camarero",
  "url": "https:///camarero",
  "remoteAddr": "192.168.65.3",
  "counter": 1,
  "headers": {
    "Accept": ["*/*"],
    "Accept-Encoding": ["gzip, deflate, br"],
    "Accept-Language": ["en-US,en;q=0.9,pl-PL;q=0.8,pl;q=0.7,es;q=0.6"],
    "Authorization": [
      "Bearer eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJXejFuaDNCWDI4UHMxVEMzSDRoOW52Q1VWRXpjVVBzQms4Z1NmeEp4ZS1JIn0.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.t5y3L4FzGxM0zwI3fskDI8Kemxz_izcvPPKciSEvNHnZWGQK-9AclGNFz_A9cLFSkpc6l6lBmt7WaC0i04c4h1a9G9AOFImmVXPMPDdTXOQ4aah4CvlN6Fy8ShvSHrQA-wMHEELBpIFsKFx2WP3QHiy27ycr3kqQzW4QymyU7J8tM4-qKR_H1_8aiNOrm5fIED-nEP096V2zvWXiGZX7ts6XE2-annhKphCABLdmIiwgDUnhlAz0hdiDrDbIjzr0ldW4AnUkSQxIZY0PnoEnGVuUvkOYvJpFx10gjORMnRgHSEj9Mk5dtyVGHcihZ5TntCL40WoymNxae6K4-FH3Lw"
    ],
    "Origin": ["https://lukaszbudnik.github.io"],
    "Referer": ["https://lukaszbudnik.github.io/"],
    "Sec-Ch-Ua": [
      "\" Not;A Brand\";v=\"99\", \"Google Chrome\";v=\"91\", \"Chromium\";v=\"91\""
    ],
    "Sec-Ch-Ua-Mobile": ["?0"],
    "Sec-Fetch-Dest": ["empty"],
    "Sec-Fetch-Mode": ["cors"],
    "Sec-Fetch-Site": ["cross-site"],
    "User-Agent": [
      "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36"
    ],
    "X-Forwarded-For": ["192.168.65.3", "10.1.3.9"],
    "X-Forwarded-Host": ["api.localtest.me"],
    "X-Forwarded-Port": ["443"],
    "X-Forwarded-Proto": ["https"],
    "X-Real-Ip": ["192.168.65.3"],
    "X-Request-Id": ["48a77564d88ca8a893610b9458bfd885"],
    "X-Scheme": ["https"]
  },
  "hostname": "camarero-cf7c95ccd-cz5lh",
  "envVariables": [
    "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
    "HOSTNAME=camarero-cf7c95ccd-cz5lh",
    "YOSOY_SHOW_FILES=/etc/podinfo/labels,/etc/podinfo/annotations",
    "YOSOY_SHOW_ENVS=true",
    "KUBERNETES_SERVICE_PORT=443",
    "KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443",
    "KUBERNETES_PORT=tcp://10.96.0.1:443",
    "KUBERNETES_PORT_443_TCP_PORT=443",
    "KUBERNETES_SERVICE_HOST=10.96.0.1",
    "KUBERNETES_PORT_443_TCP_PROTO=tcp",
    "KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1",
    "HOME=/root"
  ],
  "files": {
    "/etc/podinfo/annotations": "kubernetes.io/config.seen=\"2021-08-24T15:12:19.555374430Z\"\nkubernetes.io/config.source=\"api\"",
    "/etc/podinfo/labels": "app.kubernetes.io/component=\"api\"\napp.kubernetes.io/name=\"camarero\"\napp.kubernetes.io/part-of=\"hotel\"\napp.kubernetes.io/version=\"0.0.1\"\npod-template-hash=\"cf7c95ccd\""
  }
}
```