I am trying to read a file's contents and use it in my ruby code. In this step, I am not trying to do anything on the bootstrapped node. All I want to do is read a JSON file that will reside in cookbook's files folder and read the contents of the file and do something. I just want to use the value coming from JSON in my code itself. The code example is shown below. Any help is appreciated.
Attributes: default.rb
default["xyz"]["ohs_servers"]=[
{"hostname"=> "intf301.linux.xyz.com","name" => "INTFIN_OHS_001", "short_name" => "OGS", "port" => "9931"},
{"hostname"=> "intf302.linux.xyz.com","name" => "INTFIN_OHS_001", "short_name" => "OHS", "port" => "9931"}
]
Machines: machines.rb
require 'rubygems'
require 'json'
require 'pp'
json = File.read('environment.json')
obj = JSON.parse(json)
number = obj["name"]
x = node["xyz"]["ohs_servers"][number]["hostname"]
JSON file in cookbook's files folder: environment.json
{
"template_name": "environment_template",
"number": 0
}
Even if I don't really get why you don't want to use attributes for this:
What you want is to ensure the cookbook files are in the cache even if there's no resource calling them, the way to go is to configure the client.rb on the node with the no_lazy_load attribute to true
Quoting the documentation about this option:
no_lazy_load Use to download all cookbook files and templates at the
beginning of the chef-client run. Default value: true.
I'm unsure if the default value has changed with 12 or on wich version, but I'm quite sure it was false in chef 11 (loading file or template when the provider referencing them is called)
Then you can read your file using
File::read("#{Chef::Config['file_cache_path']}/cookbooks/my_cookbook/files/my_file.json")
Edit: Just saw the comment of Stephen King, I more or less paraphrased Seth Vargo's answer here :/
use cookbook_file and then add run_action(:create)
cookbook_file "myfile.txt" do
path "somepathyouwantthefilebe/myfile.txt"
source "myfile.txt" #the name of the file in files folder of your cookbook"
end.run_action(:create) # read notes** bellow
then you can have some ruby code to read from it
for example
File::read("somepathyouwantthefilebe/myfile.txt")
** the run action is nessecary since you are combining ruby code and resources in chef-zero
Related
I have a .properties files as below:
user:abcd
pwd:xyz
system:test
Next, I have a ruby script with Watir for browser automation. In this script, I have statements like
browser.text_field(:id => 'identifierId').set "#{user}:variable to be replaced by its value from .properties file".
Similarly, other values need to be replaced for "pwd" and "system".
I tried the solution per below posts:
Replace properties in one file from those in another in Ruby
However, "set" command is setting whatever has been paased as arguments to it instead of replacing the variable with its value.
Please help.
You have to read the information out of the file.
Most Watir users leverage yaml files for this.
config/properties.yml:
user: abcd
pwd: xyz
system: test
Then read the yaml file & parse your data:
properties = YAML.safe_load(IO.read('config/properties.yml'))
text_field = browser.text_field(id: 'identifierId')
text_field.set properties['user']
Alternately you can take a look at Cheezy's Fig Newton gem, which is designed to work with his Page Object gem
I would like to copy http://seapower/spring.txt and http://seapower/has_sprung.txt and append second one to the first one in a new file named src_filepath.txt:
remote_file 'src_filepath.txt' do
source 'http://seapower/spring.txt', 'http://seapower/has_sprung.txt'
checksum node['nginx']['foo123']['checksum']
owner 'root'
group 'root'
mode '0755'
end
It doesn't work and just copy the first file to src_filepath.txt
Something like this is probably a good place to start and then tweak however you like:
cache1 = "#{Chef::Config[:file_cache_path]}/content1"
cache2 = "#{Chef::Config[:file_cache_path]}/content2"
# this will not redownload if cache1 exists and has not been updated
remote_file cache1 do
source "http://source.url/content1"
end
# this will not redownload if cache1 exists and has not been updated
remote_file cache2 do
source "http://source.url/content2"
end
# this will not update the file if the contents has not changed
file "/my/combined/file" do
content lazy { IO.read(cache1) + IO.read(cache2) }
end
This is not something Chef supports directly. You could use multiple remote_file resources and either a ruby_block or execute plus cat to implement the concat.
remote_file does not support concatenation, so you would not be able to implement this using that resource directly, however you could piece together the desired result using the file resource and Net::HTTP like so:
file_path = '/path/to/your_whole_file'
unless File.exist?(file_path) &&
Digest::SHA256.hexdigest(File.read(file_path)) == 'your_file_checksum'
file file_path do
content(
Net::HTTP.get(URI('http://source.url/content1')) +
Net::HTTP.get(URI('http://source.url/content2'))
)
owner 'root'
group 'root'
mode '0755'
end
end
The reason for the Digest::SHA256 call at the beginning is to prevent Chef from trying to download both files during every Chef run. Note that you may have to require the net/http and digest gems at the top of your recipe for this to work.
Also, because it's against best practices to put Ruby code directly into your recipes, you may want to wrap the above code in a simple custom resource.
I've got a project structure as follows:
info.config (just a JSON file w/ prefs+creds)
main.rb
tasks/
test.rb
In both main.rb (at the root of the project), and test.rb (under the tasks folder), I want to be able to read and parse the info.config file. I've figured out how to do that in main.rb with the following:
JSON.parse(File.read('info.config'))
Of course, that doesn't work in test.rb.
Question: How can I read the file from a test.rb even though it's one level deeper in the hierarchy?
Appreciate any guidance I can get! Thanks!
Use relative path:
path = File.join(
File.dirname(File.dirname(File.absolute_path(__FILE__))),
'info.config'
)
JSON.parse(File.read(path))
File.dirname(File.absolute_path(__FILE__)) will give you the directory where test.rb resides. -> (1)
File.dirname(File.dirname(File.absolute_path(__FILE__))) will give you parent directory of (1).
Reference: File::absolute_path, File::dirname
UPDATE
Using File::expand_path is more readable.
path = File.expand_path('../../info.config', __FILE__)
JSON.parse(File.read(path))
What I usually do is:
Create file called environment or similar in your project root. This file has only one purpose - to extend load path:
require 'pathname'
ROOT_PATH = Pathname.new(File.dirname(__FILE__))
$:.unshift ROOT_PATH
Require this file at the beginning of your code. From now on every time you call require, you can use relative_path to you root directory, without worrying where file you are requiring it from is located.
When using File, you can simple do:
File.open(ROOT_PATH.join 'task', 'test.rb')
You can do as below using File::expand_path :
path = File.expand_path("info.config","#{File.dirname(__FILE__)}/..")
JSON.parse(File.read(path))
File.dirname(__FILE__) will give you the path as "root_path_of_your_projet/tasks/".
"#{File.dirname(__FILE__)}/.." will give you the path as "root_path_of_your_projet/". .. means go one level up from the current directory.
File.expand_path("info.config","root_path_of_your_projet/") will give you the actual path to the file as "root_path_of_your_projet/info.config".
You can also use __dir__ instead of File.dirname(__FILE__).
__dir__ : Returns the canonicalized absolute path of the directory of the file from which this method is called.
Hope that explanation helps.
I've one file, main.rb with the following content:
require "tokenizer.rb"
The tokenizer.rb file is in the same directory and its content is:
class Tokenizer
def self.tokenize(string)
return string.split(" ")
end
end
If i try to run main.rb I get the following error:
C:\Documents and Settings\my\src\folder>ruby main.rb
C:/Ruby193/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- tokenizer.rb (LoadError)
from C:/Ruby193/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require '
from main.rb:1:in `<main>'
I just noticed that if I use load instead of require everything works fine. What may the problem be here?
I just tried and it works with require "./tokenizer".
Just do this:
require_relative 'tokenizer'
If you put this in a Ruby file that is in the same directory as tokenizer.rb, it will work fine no matter what your current working directory (CWD) is.
Explanation of why this is the best way
The other answers claim you should use require './tokenizer', but that is the wrong answer, because it will only work if you run your Ruby process in the same directory that tokenizer.rb is in. Pretty much the only reason to consider using require like that would be if you need to support Ruby 1.8, which doesn't have require_relative.
The require './tokenizer' answer might work for you today, but it unnecessarily limits the ways in which you can run your Ruby code. Tomorrow, if you want to move your files to a different directory, or just want to start your Ruby process from a different directory, you'll have to rethink all of those require statements.
Using require to access files that are on the load path is a fine thing and Ruby gems do it all the time. But you shouldn't start the argument to require with a . unless you are doing something very special and know what you are doing.
When you write code that makes assumptions about its environment, you should think carefully about what assumptions to make. In this case, there are up to three different ways to require the tokenizer file, and each makes a different assumption:
require_relative 'path/to/tokenizer': Assumes that the relative path between the two Ruby source files will stay the same.
require 'path/to/tokenizer': Assumes that path/to/tokenizer is inside one of the directories on the load path ($LOAD_PATH). This generally requires extra setup, since you have to add something to the load path.
require './path/to/tokenizer': Assumes that the relative path from the Ruby process's current working directory to tokenizer.rb is going to stay the same.
I think that for most people and most situations, the assumptions made in options #1 and #2 are more likely to hold true over time.
Ruby 1.9 has removed the current directory from the load path, and so you will need to do a relative require on this file, as David Grayson says:
require_relative 'tokenizer'
There's no need to suffix it with .rb, as Ruby's smart enough to know that's what you mean anyway.
require loads a file from the $LOAD_PATH. If you want to require a file relative to the currently executing file instead of from the $LOAD_PATH, use require_relative.
I would recommend,
load './tokenizer.rb'
Given, that you know the file is in the same working directory.
If you're trying to require it relative to the file, you can use
require_relative 'tokenizer'
I hope this helps.
Another nice little method is to include the current directory in your load path with
$:.unshift('.')
You could push it onto the $: ($LOAD_PATH) array but unshift will force it to load your current working directory before the rest of the load path.
Once you've added your current directory in your load path you don't need to keep specifying
require './tokenizer'
and can just go back to using
require 'tokenizer'
This will work nicely if it is in a gem lib directory and this is the tokenizer.rb
require_relative 'tokenizer/main'
For those who are absolutely sure their relative path is correct, my problem was that my files did not have the .rb extension! (Even though I used RubyMine to create the files and selected that they were Ruby files on creation.)
Double check the file extensions on your file!
What about including the current directory in the search path?
ruby -I. main.rb
I used jruby-1.7.4 to compile my ruby code.
require 'roman-numerals.rb'
is the code which threw the below error.
LoadError: no such file to load -- roman-numerals
require at org/jruby/RubyKernel.java:1054
require at /Users/amanoharan/.rvm/rubies/jruby-1.7.4/lib/ruby/shared/rubygems/custom_require.rb:36
(root) at /Users/amanoharan/Documents/Aptana Studio 3 Workspace/RubyApplication/RubyApplication1/Ruby2.rb:2
I removed rb from require and gave
require 'roman-numerals'
It worked fine.
The problem is that require does not load from the current directory. This is what I thought, too but then I found this thread. For example I tried the following code:
irb> f = File.new('blabla.rb')
=> #<File:blabla.rb>
irb> f.read
=> "class Tokenizer\n def self.tokenize(string)\n return string.split(
\" \")\n end\nend\n"
irb> require f
LoadError: cannot load such file -- blabla.rb
from D:/dev/Ruby193/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `req
uire'
from D:/dev/Ruby193/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `req
uire'
from (irb):24
from D:/dev/Ruby193/bin/irb:12:in `<main>'
As it can be seen it read the file ok, but I could not require it (the path was not recognized). and here goes code that works:
irb f = File.new('D://blabla.rb')
=> #<File:D://blabla.rb>
irb f.read
=> "class Tokenizer\n def self.tokenize(string)\n return string.split(
\" \")\n end\nend\n"
irb> require f
=> true
As you can see if you specify the full path the file loads correctly.
First :
$ sudo gem install colored2
And,you should input your password
Then :
$ sudo gem update --system
Appear
Updating rubygems-update
ERROR: While executing gem ... (OpenSSL::SSL::SSLError)
hostname "gems.ruby-china.org" does not match the server certificate
Then:
$ rvm -v
$ rvm get head
Last
What language do you want to use?? [ Swift / ObjC ]
ObjC
Would you like to include a demo application with your library? [ Yes / No ]
Yes
Which testing frameworks will you use? [ Specta / Kiwi / None ]
None
Would you like to do view based testing? [ Yes / No ]
No
What is your class prefix?
XMG
Running pod install on your new library.
you need to give the path.
Atleast you should give the path from the current directory. It will work for sure.
./filename
I'm looking for a simple, concise example of using the inotify gem to detect a change to a directory.
It lacks examples.
There's an example in examples/watcher.rb.
That link is to aredridel's repo, since it looks like you linked to aredridel's docs, and aredridel is the one who wrote the example.
One of my projects I have used ruby-inotify for monitoring file creation under specific folder using following code
# frozen_string_literal: true
require 'rb-inotify'
# observe indicate folder, trigger event after
module ObserveFiles
def self.observe
watcher = INotify::Notifier.new
directory = CONFIG['xml_folder'] # folder that want to watch
watcher.watch(directory, :create) do |event|
# do your work where
# here, event.name is created file name
# event.absolute_name file absolute path
end
watcher.run
end
end
Use this code like
ObserveFiles.observe
Hope this will help someone.