---
title: HTTP Health Checks
sidebar_label: HTTP Health Checks
sidebar_position: 30
---

As of `v1.0.7` the zrok Agent supports health checks for `proxy` backend shares. Backend health checks are not yet implemented for other backend modes.

## Local Agent Health Checks

With an Agent running in your environment, create a share:

```
$ zrok share public http://127.0.0.1:18080
token:"8rvjpmeeyvwc"  frontendEndpoints:"http://8rvjpmeeyvwc.zrok.example.com:8080"
```

Then the new `zrok agent share http-healthcheck` command can be used to validate that the Agent is able to communicate with the backend target:

```
$ zrok agent share http-healthcheck 8rvjpmeeyvwc GET / 200
healthy
```

A non-existent endpoint will return a non-`200` response:
```
$ zrok agent share http-healthcheck 8rvjpmeeyvwc GET /non-existent 200
unhealthy; unexpected status code; got '202', want '200'
```

### Detecting Communications Errors

This health check infrastructure will report any issue communicating with the underlying backend target, including low-level communication errors:

```
$ zrok share public http://127.1.1.1:9090
token:"2bfvnne6kb3c"  frontendEndpoints:"http://2bfvnne6kb3c.zrok.quigley.com:8080"

$ zrok agent share http-healthcheck 2bfvnne6kb3c GET / 200
unhealthy; failed to execute request: Get "http://127.1.1.1:9090/": dial tcp 127.1.1.1:9090: connect: connection refused
```

## Remoted Agent Health Checks

When your Agent is remoted and accessible through the zrok API, you can use the `/agent/share/http-healthcheck` endpoint to remotely check your Agent's connectivity to the backend target:

```
$ curl -H "X-TOKEN: 5hLXj48Bmn11" -XPOST -H "Content-Type: application/zrok.v1+json" -d '{"envZId": "MxMbUXSANU", "shareToken": "8rvjpmeeyvwc", "httpVerb": "GET", "endpoint": "/", "expectedHttpResponse": 200}' http://localhost:18080/api/v1/agent/share/http-healthcheck | jq
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   136  100    17  100   119    267   1870 --:--:-- --:--:-- --:--:--  2158
{
  "healthy": true
}
```

A non-existent health check URL will return a non-`200` response:
```
$ curl -H "X-TOKEN: 5hLXj48Bmn11" -XPOST -H "Content-Type: application/zrok.v1+json" -d '{"envZId": "MxMbUXSANU", "shareToken": "8rvjpmeeyvwc", "httpVerb": "GET", "endpoint": "/non-existent", "expectedHttpResponse": 200}' http://localhost:18080/api/v1/agent/share/http-healthcheck | jq  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   189  100    58  100   131    866   1956 --:--:-- --:--:-- --:--:--  2863
{
  "error": "unexpected status code; got '202', want '200'"
}
```