George Opritescu

Developer from somewhere

curl basic auth

curl -u user:password http://your_website
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curl

push local database to heroku

In case you already have data, you have to do the reset. Make sure you know what you’re doing, because the reset is a destructive operation.

$ heroku pg:reset DATABASE_URL -r heroku
$ heroku pg:push your_db DATABASE_URL -r heroku
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heroku postgres

setting headers on the capybara driver

Capybara.current_session.driver.header("X-Ninja", "true")
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capybara ruby rails

environment variables in nginx

Allowing environment variables in nginx config:

env YOUR_BACKEND;

http {
  server {
      set_by_lua $your_backend 'return os.getenv("YOUR_BACKEND")';
      ...
      location ~ ^/to_your_backend/(.*)$ {
          set $url_full         '$1';
          ...
          proxy_pass             http://$your_backend/$url_full;
      }
  }
}
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nginx environment lua

fixing chrome's open link blank page behaviour

Whenever clicking a link that should open chrome, like for example a link in the terminal, I always got a new chrome window with a blank page. Turns out it was because the file in $HOME/.local/share/applications/google-chrome.desktop had this as Exec:

Exec=/opt/google/chrome/chrome

instead of:

Exec=/opt/google/chrome/chrome %U

Found the answer here

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chrome ubuntu

gnu parallel processing example

Here’s a simple script that does work :)

def do_work(argument)
  puts "#{Time.now} Processing #{argument}"
  sleep 5
  puts "#{Time.now} Done processing #{argument}"
end

do_work(ARGV[0])

When running this, I get the following output on my machine:

2016-01-07 16:14:18 +0100 Processing 1
2016-01-07 16:14:23 +0100 Done processing 1

If we would like to run the script for more than one argument, it would take us some time. Luckily, we can use parallel to speed things up:

$ (echo 1;echo 2) | parallel -j+0 --eta 'ruby initial.rb {}'
When using programs that use GNU Parallel to process data for publication please cite:

  O. Tange (2011): GNU Parallel - The Command-Line Power Tool,
  ;login: The USENIX Magazine, February 2011:42-47.

This helps funding further development; and it won't cost you a cent.
Or you can get GNU Parallel without this requirement by paying 10000 EUR.

To silence this citation notice run 'parallel --bibtex' once or use '--no-notice'.


Computers / CPU cores / Max jobs to run
1:local / 4 / 2

Computer:jobs running/jobs completed/%of started jobs/Average seconds to complete
ETA: 0s Left: 2 AVG: 0.00s  local:2/0/100%/0.0s 2016-01-07 16:12:02 +0100 Processing 1
2016-01-07 16:12:07 +0100 Done processing 1
2016-01-07 16:12:02 +0100 Processing 2
2016-01-07 16:12:07 +0100 Done processing 2
ETA: 0s Left: 0 AVG: 0.00s  local:0/2/100%/2.5s

As we can see from the timestamps, both scripts started at the same time, and were executed in parallel. The -j+0 flag tells parallel to use as many cores as possible to complete the jobs.

Alternatively, this has a simpler syntax:

parallel --eta -j+0 'ruby initial.rb {}' ::: 1 2

or, with a shell glob:

parallel --eta -j+0 'ruby initial.rb {}' ::: *.txt

More examples here

GNU citation:

1

O. Tange (2011): GNU Parallel - The Command-Line Power Tool, The USENIX Magazine, February 2011:42-47.
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ruby parallel

git export and apply patch

Generating the patch from a commit:

git format-patch -1 SHA

Applying a patch:

git am < your.patch
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git

refresh_token not sent in google oauth2 response

I kept receiving tokens such as:

{ access_token: 'REDACTED', token_type: 'Bearer', expiry_date: 1452085069587 }

when making calls to google api, even though I was doing the call like this:

var url = cli.generateAuthUrl({
  access_type: 'offline',
  scope: 'https://www.googleapis.com/auth/calendar',
})

As it turns out, you only get the refresh_token on the first authorization, so you should save it then. To address this, go to google apps, and revoke the app’s access to your API ( calendar in my case ), and go through the authorization flow again.

This time you’ll receive a refresh_token as well.

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oauth2 google api

enumerable#find raise exception

The following will raise an exception, and you won’t have to deal with nil:

[1,2,3].find(-> { raise "Expected to find 4 in the array"}) {|e| e == 4}
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ruby rails

ruby hash self merge

Useful trick, if you have a hash like this:

a = {1 => [2,3,4], 2 => [3,4,5], 3 => [4,5,6,7]}

and you would like to get to a hash containing the same keys, but the count of the values:

a = {1 => 3, 2 => 3, 3 => 4}
a.merge(a) {|k,v| v.count }

hash#merge takes the following params:

merge(other_hash){|key, oldval, newval| block} → new_hash
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ruby rails