Ruby Env Variable not interpolated when parsed using Nokogiri xpath

Question

I have a private gitlab repo and I want to clone it. I have the password in an Environment variable. My gitlab repo URL with username and password variable is from the XML file.

sample.xml

<git>
   <name>repo</name>
   <link>https://user:#{ENV['password']}@gitlab.com/myrepo.git</link>
</git>

Ruby code:

@sample = Nokogiri::XML(File.open("sample.xml")
repo_link = @sample.xpath("/git/link/text()")
Git.clone(repo_link, 'repodir').checkout('master')

When I try the above code, #{ENV['password'] is not getting resolved and passed as it is to the GIT module.

Current: https://user:#{ENV['password']}@gitlab.com/myrepo.git

Expectation: https://user:<actual_password>@gitlab.com/myrepo.git

Kindly help with a way to fix this..

I can modify the XML file, Ruby code, or the GITLAB URL format. But the flow is fixed where the URL will be in XML and I have to parse it and clone the repo using Ruby.

Thanks in advance !!

Answer 1

#{} means nothing in XML; an XML parser won't (and shouldn't) interpolate it...

You can use ERB templating, like this:

sample.xml

<% require 'cgi' %>
<git>
   <name>repo</name>
   <link>https://user:<%= CGI.escapeHTML ENV['password'] %>@gitlab.com/myrepo.git</link>
</git>

Important : I use CGI#escapeHTML for making sure that your password doesn't break the XML.

Ruby code:

require 'erb'

xml = ERB.new(File.read('sample.xml'), nil, "<>").result
@sample = Nokogiri::XML(xml)
...

---

An other solution would be to put a placeholder in the XML, like this:

sample.xml

<% require 'cgi' %>
<git>
   <name>repo</name>
   <link>https://user:%{password}@gitlab.com/myrepo.git</link>
</git>

And replace it with the value in the Ruby code:

require 'cgi'

xml = File.read.sub(/%{password}/, CGI.escapeHTML ENV['password'])
@sample = Nokogiri::XML(xml)
...