I've worked with R for a while, but I'm very new to Linux. I've been able to get the sample app working on Shiny Server on my AWS EC2 Instance (the one that begins "If you're seeing this page, that means Shiny Server is installed and running. Congratulations!"), but when I try to replace the sample app with my own app, I'm unsuccessful. Also, I started with the R Studio AMI from http://www.louisaslett.com/RStudio_AMI/ but changed the config file multiple times from the default while troubleshooting.
Attempt 1: Using R Studio Server in the SampleApps directory, I removed index.html and the sample-apps directory. I added in a new directory called facilities containing a server.R file and a ui.R file. Then restarted R with
$ sudo systemctl stop shiny-server
$ sudo systemctl start shiny-server
Then I returned to 12.34.56.789/shiny/rstudio/ which had shown the original app, and it still did. But I was expecting it would have switched to my facilities app.
Attempt 2: Locate my files and move them to /srv/shiny-server/
# Remove sample app:
$ sudo rm /srv/shiny-server/index.html
$ sudo rm -rf /srv/shiny-server/sample-apps
# Copy files from R Studio Server location to Shiny Server
$ locate -br '^server.R$' # to find file path
$ cd /srv/shiny-server/
$ sudo mkdir facilities
$ cp /home/rstudio/ShinyApps/facilities/server.R /srv/shiny-server/facilities/server.R
$ cp /home/rstudio/ShinyApps/facilities/ui.R /srv/shiny-server/facilities/ui.R
Page not found on 12.34.56.789/shiny/rstudio/ nor on 12.34.56.789/rstudio/facilities
Attempt 3: Replace only the specific server.R and ui.R files from the "hello" sample app with my server.R and ui.R files to see if my app would show up embedded in the demo.
$ cp /home/rstudio/ShinyApps/facilities/server.R /srv/shiny-server/sample-apps/hello/server.R
$ cp /home/rstudio/ShinyApps/facilities/ui.R /srv/shiny-server/sample-apps/hello/ui.R
then stopped and started the shiny server again with systemctl. The result was the sample app showed up with an error in the box where the sample shiny app had been.
Attempt 4: Find and fix problem with config file
$ sudo nano /opt/shiny-server/config/default.config
and changed "run_as" from "shiny" to the non-root username I'd been using: "rstudio"
I also changed the hosting model to user_dirs to use ShinyApps folder in R Studio Server. Stopped and started shiny-server as above, but got "Page Not Found" when I went to the same URL listed above.
The app works great when I run it on R Studio Server clicking "Run App" which is on the same Instance/server as shiny-server, but I'm missing the step of actually deploying it somehow. What am I missing?
I figured out the answer to my own question. When I used the AMI from http://www.louisaslett.com/RStudio_AMI/ I set up the Dropbox linkage described on this same page. This is a feature where you can access files on Dropbox from within R Studio Server. While working in R Studio Server I changed the file path within read.csv() to the linked Dropbox directory within server.R and ui.R. They render fine within R Studio Server, but when I copied the files to /srv/shiny-server/ Shiny Server wasn't able to access the files via Dropbox or at least I hadn't set it up to do so.
I moved the files to a directory /home/rstudio/data/example.csv and changed the file paths in read.csv() within server.R and ui.R. Then I re-copied server.R and ui.R from /home/rstudio/ShinyApps/facilities/ into /srv/shiny-server/
When I went back to 12.34.56.789:3838 then my app appeared.