[Bioc-devel] bioconductor AMI & shiny app

hi,

i'm trying to use a shiny app through AWS and the bioconductor AMI, but 
i cannot make it work.

i have created a security group in AWS that has open the 8787 and 6219 
ports, the former for RStudio and the latter to access the shiny app. 
this is the command-line output from my desktop interrogating how the 
security group is configured:

$ aws ec2 describe-security-groups --group-names test | ./JSON.sh -b
["SecurityGroups",0,"Description"]      "test"
["SecurityGroups",0,"IpPermissions",0,"ToPort"] 22
["SecurityGroups",0,"IpPermissions",0,"IpProtocol"]     "tcp"
["SecurityGroups",0,"IpPermissions",0,"IpRanges",0,"CidrIp"]    "0.0.0.0/0"
["SecurityGroups",0,"IpPermissions",0,"FromPort"]       22
["SecurityGroups",0,"IpPermissions",1,"ToPort"] 3838
["SecurityGroups",0,"IpPermissions",1,"IpProtocol"]     "tcp"
["SecurityGroups",0,"IpPermissions",1,"IpRanges",0,"CidrIp"]    "0.0.0.0/0"
["SecurityGroups",0,"IpPermissions",1,"FromPort"]       3838
["SecurityGroups",0,"IpPermissions",2,"ToPort"] 6219
["SecurityGroups",0,"IpPermissions",2,"IpProtocol"]     "tcp"
["SecurityGroups",0,"IpPermissions",2,"IpRanges",0,"CidrIp"]    "0.0.0.0/0"
["SecurityGroups",0,"IpPermissions",2,"FromPort"]       6219
["SecurityGroups",0,"IpPermissions",3,"ToPort"] 8787
["SecurityGroups",0,"IpPermissions",3,"IpProtocol"]     "tcp"
["SecurityGroups",0,"IpPermissions",3,"IpRanges",0,"CidrIp"]    "0.0.0.0/0"
["SecurityGroups",0,"IpPermissions",3,"FromPort"]       8787

i have updated the shiny-server in the bioc AMI to the lastest version. 
this is the command-line output from the AWS instance running the bioc AMI:

$ tail -n 5 /var/log/shiny-server.log
0[2014-05-21 13:37:59.867] [INFO] shiny-server - Shiny Server 
v1.1.0.10000 (Node.js v0.10.21)
[2014-05-21 13:37:59.888] [INFO] shiny-server - Using pidfile 
/var/run/shiny-server.pid
[2014-05-21 13:37:59.891] [INFO] shiny-server - Using config file 
"/etc/shiny-server/shiny-server.conf"
[2014-05-21 13:37:59.950] [WARN] shiny-server - Running as root 
unnecessarily is a security risk! You could be running more securely as 
non-root.
[2014-05-21 13:37:59.954] [INFO] shiny-server - Starting listener on 
0.0.0.0:3838

i connect to R studio through the 8787 port and then i do the following 
using the code from the example of the 'runApp()' man page:

library(shiny)

runApp(list(
        ui = bootstrapPage(
          numericInput('n', 'Number of obs', 100),
          plotOutput('plot')
        ),
        server = function(input, output) {
          output$plot <- renderPlot({ hist(runif(input$n)) })
        }
      ), host="ec2-xx-xx-xx-xx.compute-1.amazonaws.com", port=6219)

where "ec2-xx-xx-xx-xx.compute-1.amazonaws.com is the public DNS of my 
instance.

the server starts fine with the message "Listening on http://ec2-xx 
..etc", however, the window opens directly with the error message "The 
system returned: (111) Connection refused"

if instead of using the public DNS as host i use the IP address in the 
"inet addr" field from the eht0 entry of the 'ifconfig' unix command it 
gives a "timeout" after a few minutes and if i use the IP address 
resulting from concatenating xx.xx.xx.xx in the public DNS name then it 
says "Failed to create server".

to make it more puzzling if i connect with the browser to the port 3838 
of the public DNS server, i.e., 
ec2-xx-xx-xx-xx.compute-1.amazonaws.com:3838 then it says "Welcome to 
Shiny Server!" and the example app works perfectly.

so it seems that i'm doing something wrong when starting the server from 
RStudio via runApp().

i've been googling a lot and i think i have everything in place so i 
wonder whether something might be wrong in how the bioc AMI is 
configured. before i updated the shiny-server even the last option 
wasn't working, but i don't know what else could i do system-wide to try 
to fix this problem.

any hint will be very much appreciated,

thanks!!
robert.