Using a proxy server

This topic describes how to use a proxy server with buildpacks for your application.

Using a proxy server

You can assign proxy servers to environment variables. Proxy servers can be used to monitor your application’s traffic or to fetch your application’s dependencies.

A buildpack uses a proxy server if that buildpack contacts the internet during staging.

Note: The binary buildpack does not use a proxy server because it does not access the internet during staging.

Setting environment variables

Note: If you are using a Java buildpack, the http_proxy and https_proxy environment variables are not supported at runtime. The Java buildpack does not add the functionality to make proxies work at runtime.

To set your environment variables:

Add the following to the env block of your application manifest YAML file:
```
---
env:
  http_proxy: http://YOUR-HTTP-PROXY:PORT
  https_proxy: https://YOUR-HTTPS-PROXY:PORT
```
Where:
- YOUR-HTTP-PROXY is the address of your proxy server for HTTP requests.
- YOUR-HTTPS-PROXY is the address of your proxy server for HTTPS requests.
- PORT is the port number you are using for your proxy server.
Set the environment variables with the Cloud Foundry Command Line Interface (cf CLI) cf set-env command:
```
cf set-env YOUR-APP http_proxy "http://YOUR-HTTP-PROXY:PORT"
```
```
cf set-env YOUR-APP https_proxy "https://YOUR-HTTPS-PROXY:PORT"
```
Where:
- YOUR-APP is the name of your application.
- YOUR-HTTP-PROXY is the address of your proxy server for HTTP requests.
- YOUR-HTTPS-PROXY is the address of your proxy server for HTTPS requests.
- PORT is the port number you are using for your proxy server.

Un-setting environment variables

Removing an environment variable from the application manifest YAML file is not sufficient to un-set the environment variable.

You must also un-set the environment variables with the Cloud Foundry Command Line Interface (cf CLI) cf unset-env command:

```console
cf unset-env YOUR-APP ENV_VAR_NAME
```

For example:

```console
cf unset-env YOUR-APP https_proxy
```

Where:
<ul>
  <li><code>YOUR-APP</code> is the name of your application.</li>
  <li><code>ENV_VAR_NAME</code> is the name of the environment variable.</li>
</ul>