Protractor installed in offline mode - error for webdriver-manager start - what am I doing wrong - selenium

Question

I need to install and use Protractor / Selenium on the machine without Internet access.
To do that, I've tried to download all needed files and copy them to the destination machine.
On my machine (with Internet access)
I installed Protractor and Selenium webdriver with the following command:
npm install -g protractor
webdriver-manager update
On destination machine (without Internet access)
I copied all files from the location returned by npm config get prefix to the computer without Internet access.
Then I executed following command on the machine without Internet access:
npm --cache-min 9999999 install -g protractor
which seems to succeed.
However, when I try to execute webdriver-manager start command, I receive following error message:
events.js:183
throw er; // Unhandled 'error' event
^
Error: getaddrinfo ENOTFOUND chromedriver.storage.googleapis.com
chromedriver.storage.googleapis.com:443
at errnoException (dns.js:50:10)
at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:92:26)
I receive the same error when executing webdriver-manager update (as in this case: webdriver-manager start: Error: connect ETIMEDOUT)
Question
What am I doing wrong? How should I properly setup Protractor and webdriver on the machine without Internet access?

Answer 1

Because webdriver-manager start will look up the latest version number of selenium-server.jar and webdriver binaries through internet no matter they are already exists on local.
But webdriver-manager not supply cmd option to disable the looking up.
The quick way is to run the java cmd behind webdriver-manager start directly to skip the looking up.
java
-Dwebdriver.chrome.driver=C:\Tools\npm-global\node_modules\webdriver-manager\selenium\chromedriver_2.38.exe
-Dwebdriver.gecko.driver=C:\Tools\npm-global\node_modules\webdriver-manager\selenium\geckodriver-v0.20.1.exe
-jar C:\Tools\npm-global\node_modules\webdriver-manager\selenium\selenium-server-standalone-3.11.0.jar
-port 4444
The complex way is to change webdriver-manager code or setup a mirror on local and use cmd option: --alternate_cdn and point it to your local mirror url. ( I didn't verify this can work, get it after read some source code)