can't execute rsDriver (connection refused)

问题:

I can't get anywhere with R selenium. Here's the first step and my output:

library(RSelenium)
rD <- rsDriver()
# checking Selenium Server versions:
#   BEGIN: PREDOWNLOAD
# BEGIN: DOWNLOAD
# BEGIN: POSTDOWNLOAD
# checking chromedriver versions:
#   BEGIN: PREDOWNLOAD
# BEGIN: DOWNLOAD
# BEGIN: POSTDOWNLOAD
# checking geckodriver versions:
#   BEGIN: PREDOWNLOAD
# BEGIN: DOWNLOAD
# BEGIN: POSTDOWNLOAD
# checking phantomjs versions:
#   BEGIN: PREDOWNLOAD
# BEGIN: DOWNLOAD
# BEGIN: POSTDOWNLOAD
# [1] "Connecting to remote server"
# Error in checkError(res) : 
#   Undefined error in httr call. httr output: Failed to connect to localhost port 4567: Connection refused
# In addition: Warning message:
#   In rsDriver() : Could not determine server status.

What did I miss ?

回答1:

When trying to run the deprecated checkForServer() Selenium offers two options:

• use rsDriver
• use Docker

see:

RSelenium::checkForServer()
# Error: checkForServer is now defunct. Users in future can find the function in 
# file.path(find.package("RSelenium"), "examples/serverUtils"). The
# recommended way to run a selenium server is via Docker. Alternatively
# see the RSelenium::rsDriver function.

Everybody seems to have issues with rsDriver and Docker is the recommended option so we'll go this route:

• install docker
• run it, restart computer as requested
• pull image by running in command line: docker pull selenium/standalone-firefox(or chrome instead of firefox) or in R shell('docker pull selenium/standalone-firefox')
• start server by running in command line: docker run -d -p 4445:4444 selenium/standalone-firefox or in R shell('docker run -d -p 4445:4444 selenium/standalone-firefox')
• Then run remDr <- remoteDriver(remoteServerAddr = "localhost", port = 4445L, browserName = "firefox'") . The doc suggests something different with a virtual machine but i couldn't get it to work.

With this I was set, here is my code:

shell('docker run -d -p 4445:4444 selenium/standalone-firefox')
remDr <- remoteDriver(remoteServerAddr = "localhost", port = 4445L, browserName = "firefox")
remDr$open()
remDr$navigate("http://www.google.com/ncr")
remDr$getTitle()
# [[1]]
# [1] "Google" 

The doc for more info:

• https://cran.r-project.org/web/packages/RSelenium/vignettes/RSelenium-basics.html
• https://cran.r-project.org/web/packages/RSelenium/vignettes/RSelenium-docker.html

回答2:

In case that is still useful, I was running into the same problem today and was able to fix it by installing a Java Development Kit (Java SE Development Kit 11.0.1).

I was getting an error message from my computer to that effect, as well as the same R error as mentioned in this question, and it fixed it.

For a reproducible example, I was able to replicate this tutorial.

sessionInfo() R version 3.4.4 (2018-03-15) Platform: x86_64-apple-darwin15.6.0 (64-bit) Running under: macOS High Sierra 10.13.5

Matrix products: default
BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/3.4/Resources/lib/libRlapack.dylib

locale:
[1] fr_CA.UTF-8/fr_CA.UTF-8/fr_CA.UTF-8/C/fr_CA.UTF-8/fr_CA.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] RSelenium_1.7.5

loaded via a namespace (and not attached):
[1] Rcpp_0.12.17     XML_3.98-1.11    binman_0.1.1     assertthat_0.2.0 rappdirs_0.3.1   bitops_1.0-6    
[7] R6_2.2.2         jsonlite_1.5     semver_0.2.0     httr_1.3.1       curl_3.2         xml2_1.2.0      
[13] subprocess_0.8.3 tools_3.4.4      wdman_0.2.4      yaml_2.1.18      compiler_3.4.4   caTools_1.17.1  
[19] openssl_1.0.1