如何使用Chef食谱删除文件中的一行？

Question

I want to delete the line configuration (This word "configuration" is inside the angular brackets in the file "hdfs-site.xml"). I tried using this code but no luck.

ruby_block "delete_lines_in_hdfs_site" do
block do
  file = Chef::Util::FileEdit.new("/opt/hadoop-2.4.1/etc/hadoop/hdfs-site.xml")
  file.search_file_delete_line(/<configuration>/)
end
end

Answer 1

You do not add to or remove lines from files with chef. Instead you replace the configuration file with yours, which you put into your cookbook under files/ or templates/ forlder.

template "/opt/hadoop-2.4.1/etc/hadoop/hdfs-site.xml"

or

cookbook_file "/opt/hadoop-2.4.1/etc/hadoop/hdfs-site.xml"

When you just add/replace lines in config files, you cannot be sure, that after upgrade of installed software your config files are right.

Answer 2

You need to end the ruby block with

file.write_file

Otherwise the changes are not written out.

While I agree that using a template is preferred and considered best practices, there are times you need to edit an existing file which may have variations and not fit the template model.