R/ip_external.r

In getip: 'IP' Address 'Lookup'

get_external = function(url)
{
  ip = tryCatch(readLines(url, warn=FALSE), warning=identity)
  
  if (inherits(ip, "simpleWarning"))
    return(-1L)
  else
    return(ip)
}



### Services
ip_external_amazonaws = function()
{
  url = "http://checkip.amazonaws.com/"
  ip = get_external(url)
  
  return(ip)
}

ip_external_httpbin = function()
{
  url = "http://httpbin.org/ip"
  ip = get_external(url)
  
  if (identical(ip, -1L))
    return(ip)
  
  ip = gsub("(  \"origin\": \"|\")", "", ip[2L])
  return(ip)
}

ip_external_ipify = function()
{
  url = "https://api.ipify.org/?format=json"
  ip = get_external(url)
  
  if (identical(ip, -1L))
    return(ip)
  
  ip = gsub("({\"ip\":\"|\"})", "", ip, perl=TRUE)
  return(ip)
}

ip_external_myexternalip = function()
{
  url = "http://myexternalip.com/raw"
  ip = get_external(url)
  
  return(ip)
}



### interface
ip_external = function()
{
  services = c("amazonaws", "httpbin", "ipify", "myexternalip")
  fns = paste0("ip_external_", services, "()")
  
  # randomize order
  fns = sample(fns)
  
  num_tries = 1L
  alldone = FALSE
  for (try in 1:num_tries)
  {
    for (fn in fns)
    {
      ip = eval(parse(text=fn))
      if (identical(ip, -1L))
        Sys.sleep(0.2)
      else
      {
        alldone = TRUE
        break
      }
    }
    
    if (alldone)
      break
  }
  
  if (identical(ip, -1L))
    stop("Unable to determine external IP")
  
  return(ip)
}