I want to replace properties in one file from those in another. (I am new to ruby, and read about Ruby and YAML. I have a Java background)
Eg.
File 1
server_ip_address=$[ip]
value_threshold=$[threshold]
system_name=$[sys_name]
File 2
ip=192.168.1.1
threshold=10
sys_name=foo
The ruby script should replace the $ values by their real values (I do not know if $[] is the format used in ruby. Also do Files 1 and 2 have to be YAML files, or erb files?) and produce File 1 as :
server_ip_address=192.168.1.1
value_threshold=10
system_name=foo
I searched the web for this, but could not express it in the right keywords to find a solution/pointer to a solution/reference material on google. How can this be done by a ruby script?
Thanks
If you can switch the formats, this should be as easy as:
require 'yaml'
variables = YAML.load(File.open('file2.yaml'))
template = File.read('file1.conf')
puts template.gsub(/\$\[(\w+)\]/) { variables[$1] }
Your template can stay as-is, but the substitution file would look like:
ip: 192.168.1.1
threshold: 10
sys_name: foo
This makes it easy to read in using the YAML library.
Related
I'm doing one project for puppet, however currently stuck in one logic.
Thus, want to know can we fetch variable from .yaml, .json or plain text file in puppet manifest file.
For example,
My puppet manifest want to create user but the variable exist in the .yaml or any configuration file, hence need to fetch the varibale from the outside file. The puppet manifest also can do looping if it exist multiple users in .yaml file.
I read about hiera but let say we are not using hiera is there any possible way.
There are a number of ways you can do this using a combination of built-in and stdlib functions, at least for YAML and JSON.
Using the built-in file function and the parseyaml or parsejson stdlib functions:
Create a file at mymodule/files/myfile.yaml:
▶ cat files/myfile.yaml
---
foo: bar
Then in your manifests read it into a string and parse it:
$myhash = parseyaml(file('mymodule/myfile.yaml'))
notice($myhash)
That will output:
Notice: Scope(Class[mymodule]): {foo => bar}
Or, using the loadyaml or loadjson stdlib functions:
$myhash = loadyaml('/etc/puppet/data/myfile.yaml')
notice($myhash)
The problem with that approach is that you need to know the path to file on the Puppet master. Or, you could use a Puppet 6 deferred function and read the data from a file on the agent node.
(Whether or not you should do this is another matter entirely - hint: answer is you almost certainly should be using Hiera - but that isn't the question you asked.)
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
In order to have only a single point of configuration for my app I need to make a YAML config file that is also valid ruby code. I.e. a mixed syntax file that can be parsed as YAML and parsed as ruby.
My application is a suite of processes managed by the god gem. I want to load a new group of maintained processes (watches) for each new configuration file.
God allows loading a new app.god (ruby) file with new watches defined, but I don't want an app.god and app.yml, just one file. Simplest might be to just have the app.god file and include the configuration within that, but I preferred the idea of a yml file that was also valid ruby code.
#I found this that might be helpful:
#This is a valid ruby and a valid YAML file
#Comments are the same in YAML and ruby
true ?true:
- <<YAML.to_i
# At this point in ruby it is the contents of a here doc (that will be
# converted to an integer and negated if true happens not to be true)
# In YAML it is a hash with the first entry having key "true ?true"
# representing a list containing the string "- <<YAML.to_i"
# If your YAML object should be a list not a hash you could remove the first line
any_valid_yaml: from here
a_list:
- or
- anything
- really
#Then mark the end of the YAML document with
---
#And YAML is done and ignores anything from here on
#Next terminate the ruby here document
YAML
#Now we're in ruby world
#this = "pure ruby"
def anything(ruby)
"here"
end
I'm using this bit of code that I found on stackoverflow to write data to a file.
begin
file = File.open("/tmp/some_file", "w")
file.write("your text")
rescue IOError => e
#some error occur, dir not writable etc.
ensure
file.close unless file == nil
end
where it says your text if I put one of my variable names it will fill in the correct string used as that variable but ideally what I want is to have more than one variable in the output ideally in CSV. Something like:
file.write(var1 ^ var2 ^ var3)
Where each of my variables are seperated by a carrot symbol. How can I do this?
Actually There is a gem for CSV although there is a CSV library in standard ruby library.
Take a look at examples and you will find out that writing CSV files in ruby is much more easier that you thought.
http://fastercsv.rubyforge.org/classes/FasterCSV.html
http://fastercsv.rubyforge.org/
Ruby Stdlib: http://ruby-doc.org/stdlib-1.9.3/libdoc/csv/rdoc/CSV.html#method-c-generate
I want to write a ruby script that read from a config file that will have filenames, and then when I run the script it will take the tail of each file and output the console.
What's the best way to go about doing this?
Take a look at File::Tail gem.
You can invoke linux tail -number_of_lines file_name command from your ruby script and let it print on console or capture output and print it yourself (if you need to do something with these lines before you print it)
We have a configuration file that contain a list of the log files; for example, like this:
---
- C:\fe\logs\front_end.log
- C:\mt\logs\middle_tier.log
- C:\be\logs\back_end.log
The format of the configuration file is a yaml simple sequence , therefore suppose we named this file 'settings.yaml'
The ruby script that take the tail of each file and output the console could be like this:
require 'yaml'
require 'file-tail'
logs = YAML::load(File.open('settings.yaml'))
threads = []
logs.each do |the_log|
threads << Thread.new(the_log) { |log_filename|
File.open(log_filename) do |log|
log.extend(File::Tail)
log.interval = 10
log.backward(10)
log.tail { |line| p "#{File.basename(the_log,".log")} - #{line}" }
end
}
end
threads.each { |the_thread| the_thread.join }
Note: displaying each line I wanted to prefix it with the name of the file from which it originates, ...this for me is a good option but you can edit the script to change as you like ; is the same for the tails parameters.
if file-tail is missing in your environment, follow the link as #Mark Thomas posts in his answear; i.e you need to:
> gem install file-tail
I found the file-tail gem to be a bit buggy. I would write to a file and it would read the entire file again instead of just thelines appended. This happened even though I had log.backward set to 0. I ended up writing my own and figured that I would share it here in case any one else is looking for a Ruby alternative to the file-tail gem. You can find the repo here. It uses non_blocking io, so it will catch amendments to the file immediately. There is one caveat that can be easily fixed if you can program in the Ruby programming language; log.backward is hard coded to be -1.