Shiny App not working on Shiny Server with no log file present

Question

I have an application that works on a local R server (port 8787). When I move it to Shiny Server (port 3838), I receive the message

ERROR: An error has occurred. Check your logs or contact the app author for clarification.

And there is no log file present in /var/log/shiny-server.log

This is my configuration file:

# Instruct Shiny Server to run applications as local user
run_as : HOME_USER:;

# Define a server that listens on port 3838
server {
  listen 3838;

#preserve_logs true;
  # Define a location at the base URL
 location / {

# Host the directory of Shiny Apps stored in this directory
site_dir /srv/shiny-server;

# Log all Shiny output to files in this directory
log_dir /var/log/shiny-server;
preserve_logs true;
# When a user visits the base URL rather than a particular application,
# an index of the applications available in this directory will be shown.
directory_index on;
 }
}

Could someone check my configuration file? Thank you

have you seen this: http://rstudio.github.io/shiny-server/os/latest/#home_user — MLavoie, Mar 15 '17 at 21:43
Thank you! You set the wheels spinning... I'll post answer below. — A. Ganady, Mar 16 '17 at 20:31

score 16 · Accepted Answer · edited Feb 25 '18 at 12:03

16

Apparently sanitize error messages is true by default for my configuration. Add
options(shiny.sanitize.errors = FALSE) to your app.

In the configuration file, place

sanitize_errors false;
preserve_logs true;

within server to resolve permanently.

edited Feb 25 '18 at 12:03

Dawny33

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answered Mar 16 '17 at 20:41

A. Ganady

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3

`preserve_logs` needs to at the root level, not withing `server`. – SaschaH Jul 15 '19 at 13:41
1

may I suggest that you point to where the configuration file is in the answer? `/etc/shiny-server/shiny-server.conf` – Giacomo Jan 19 '21 at 12:49

score 3 · Answer 2 · answered Apr 19 '17 at 03:11

3

Shiny also dumps errors and messages on the Console. You can access it by pressing Ctrl + Shift + J in your chrome or Opera browser.

answered Apr 19 '17 at 03:11

M.Qasim

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score 0 · Answer 3 · edited Aug 16 '17 at 13:54

I had the same problem. In my server.R I was using another R file: once I renamed it to "global.R" everything worked.

I started getting meaningful logs about missing packages. The packages need to be installed using install.package("x", lib = "/usr/local/lib/R/site-library").
Make sure that the "shiny" user or whatever user you have specified in /etc/shiny-server/shiny-server.conf has access to /usr/local/lib/R/site-library.

Shiny App not working on Shiny Server with no log file present

3 Answers3