---
layout: default
navsection: installguide
title: Install the download server
...

The keep-web server provides read-only HTTP access to files stored in Keep. It serves public data to unauthenticated clients, and serves private data to clients that supply Arvados API tokens. It can be installed anywhere with access to Keep services, typically behind a web proxy that provides SSL support. See the "godoc page":http://godoc.org/github.com/curoverse/arvados/services/keep-web for more detail.

By convention, we use the following hostname for the download service:

<notextile>
<pre><code>dl.<span class="userinput">uuid_prefix</span>.your.domain
</code></pre>
</notextile>

This hostname should resolve from anywhere on the internet.

h2. Install keep-web

On Debian-based systems:

<notextile>
<pre><code>~$ <span class="userinput">sudo apt-get install keep-web</span>
</code></pre>
</notextile>

On Red Hat-based systems:

<notextile>
<pre><code>~$ <span class="userinput">sudo yum install keep-web</span>
</code></pre>
</notextile>

Verify that @keep-web@ is functional:

<notextile>
<pre><code>~$ <span class="userinput">keep-web -h</span>
Usage of keep-web:
  -address string
        Address to listen on: "host:port", or ":port" to listen on all interfaces. (default ":80")
  -anonymous-token value
        API token to try when none of the tokens provided in an HTTP request succeed in reading the desired collection. If this flag is used more than once, each token will be attempted in turn until one works. (default [])
</code></pre>
</notextile>

If you intend to use Keep-web to serve public data to anonymous clients, configure it with an anonymous token. You can use the same one you used when you set up your Keepproxy server, or use the following command on the <strong>API server</strong> to create another:

<notextile>
<pre><code>/var/www/arvados-api/current/script$ <span class="userinput">RAILS_ENV=production bundle exec ./get_anonymous_user_token.rb</span>
hoShoomoo2bai3Ju1xahg6aeng1siquuaZ1yae2gi2Uhaeng2r
</code></pre></notextile>

We recommend running @keep-web@ under "runit":https://packages.debian.org/search?keywords=runit or a similar supervisor. The basic command to start @keep-web@ is:

<notextile>
<pre><code>export ARVADOS_API_HOST=<span class="userinput">uuid_prefix</span>.your.domain
exec sudo -u nobody keep-web -address=<span class="userinput">:9002</span> -anonymous-token=<span class="userinput">hoShoomoo2bai3Ju1xahg6aeng1siquuaZ1yae2gi2Uhaeng2r</span> 2&gt;&amp;1
</code></pre>
</notextile>

Omit the @-anonymous-token@ arguments if you do not want to serve public data.

Set @ARVADOS_API_HOST_INSECURE=1@ if your API server's SSL certificate is not signed by a recognized CA.

h3. Set up a reverse proxy with SSL support

The keep-web service will be accessible from anywhere on the internet, so we recommend using SSL for transport encryption.

This is best achieved by putting a reverse proxy with SSL support in front of keep-web, running on port 443 and passing requests to keep-web on port 9002 (or whatever port you chose in your run script).

Note: A wildcard SSL certificate is required in order to proxy keep-web effectively.

For example, using Nginx:

<notextile><pre>
upstream keep-web {
  server                127.0.0.1:<span class="userinput">9002</span>;
}

server {
  listen                <span class="userinput">[your public IP address]</span>:443 ssl;
  server_name           dl.<span class="userinput">uuid_prefix</span>.your.domain *.dl.<span class="userinput">uuid_prefix</span>.your.domain ~.*--dl.<span class="userinput">uuid_prefix</span>.your.domain;

  proxy_connect_timeout 90s;
  proxy_read_timeout    300s;

  ssl                   on;
  ssl_certificate       <span class="userinput"/>YOUR/PATH/TO/cert.pem</span>;
  ssl_certificate_key   <span class="userinput"/>YOUR/PATH/TO/cert.key</span>;

  location / {
    proxy_pass          http://keep-web;
    proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;
  }
}
</pre></notextile>

h3. Tell the API server about the keep-web service

If your wildcard certificate is valid for <code>*.dl.<span class="userinput">uuid_prefix</span>.your.domain</code>, add the following entry to your API server's @config/application.yml@ file:

<notextile>
<pre><code>keep-web: https://%{uuid_or_pdh}.dl.<span class="userinput">uuid_prefix</span>.your.domain
</code></pre>
</notextile>

If your wildcard certificate is valid for <code>*.<span class="userinput">uuid_prefix</span>.your.domain</code>, add the following entry to your API server's @config/application.yml@ file. This approach requires a wildcard DNS entry covering <code>*--dl.<span class="userinput">uuid_prefix</span>.your.domain</code>, which might be difficult to do without affecting other services, depending on your DNS server software.

<notextile>
<pre><code>keep-web: https://%{uuid_or_pdh}--dl.<span class="userinput">uuid_prefix</span>.your.domain
</code></pre>
</notextile>

h3. Configure DNS

Configure your DNS servers so <code>*--dl.<span class="userinput">uuid_prefix</span>.your.domain</code> or <code>*.dl.<span class="userinput">uuid_prefix</span>.your.domain</code> (according to the way you configured Workbench), as well as <code>dl.<span class="userinput">uuid_prefix</span>.your.domain</code>, resolve to your Nginx proxy's public IP address.