[thin + apache2] server_url/appname responds "Not Found: /"

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I'm trying to deploy the rails sample project with thin and apache 2. I followed the tutorials mentioned on the question above, but I'm still getting nowhere.

if I put the url server_name/sample i get this message

Not Found: /index.html

thin.yml

chdir: /opt/bitnami/projects/sample
environment: production
address: 0.0.0.0
port: 3000
timeout: 30
log: log/thin.log
pid: tmp/pids/thin.pid
max_conns: 1024
max_persistent_conns: 512
require: []
wait: 30
servers: 2
prefix: /sample
daemonize: true

sample/config/httpd.conf

Alias /sample "/opt/bitnami/projects/sample/public"
<Directory "/opt/bitnami/projects/sample/public">
  AllowOverride None
  Order allow,deny
  Allow from all
</Directory>

ProxyPass /sample/public  balancer://appcluster
ProxyPass /sample balancer://appcluster
ProxyPassReverse /sample balancer://appcluster<Proxy balancer://appcluster>
  BalancerMember http://0.0.0.0:3000 max=1 retry=2
  BalancerMember http://0.0.0.0:3001 max=1 retry=2
  Order allow,deny
  Allow from all
</Proxy>

Thank you in for your help and time