Generate report from shiny app with markdown : file not found - r

Question

I want to generate a pdf report from my shiny app on shiny server. It work well on my computer.
I try to put in on my shiny server, but when i want to generate the report, I get a firefox "file not found" page instead of getting the pdf.
I use the code shown at : https://shiny.rstudio.com/articles/generating-reports.html
I also try to use directly my .Rmd file instead of copy/paste it to the temp dir, but I got the same error.
My server file :
output$pdfGen <- downloadHandler(
# For PDF output, change this to "report.pdf"
filename = "rapport_preci.pdf",
content = function(file) {
withProgress(message = "Génération du pdf en cours", value = 0,{
src <- normalizePath('report.Rmd')
# temporarily switch to the temp dir, in case you do not have write
# permission to the current working directory
owd <- setwd(tempdir())
on.exit(setwd(owd))
file.copy(src, 'report.Rmd', overwrite = TRUE)
# Set up parameters to pass to Rmd document
params <- list(varSite = input$pdfSite,
...
varTrans= input$valTrans1
)
# Knit the document, passing in the `params` list, and eval it in a
# child of the global environment (this isolates the code in the document
# from the code in this app).
out <- render("report.Rmd", output_file = file,
params = params,
encoding = "UTF-8"
)
file.rename(out, file)
})
}
)
I think my app does not found my .Rmd file, but how do I fix that ? All my files are in the same folder.

Answer 1

I just run part of the code, and apparently the problem is when you set owd <- setwd(tempdir())
Here is what that does:
> tempdir()
[1] "/tmp/RtmpKafhlt"
> owd = setwd(tempdir())
> owd
[1] "/home/med"
and you probably don't have access to the home dir of the host server. You need to set replace on.exit(setwd(owd)) with on.exit(owd)