x-yuri

There exists a way in the shell to do different kinds of checks, like if a file exists:

$ if [ -e some-file ]; then echo exists; fi
exists

x-yuri

#!/usr/bin/env bash
set -eu

portainer=https://example.com
user=name
password=...
endpoint=name
stack=name

auth_resp=$(http POST "$portainer/api/auth" Username="$user" Password="$password")

x-yuri

What happens when you get disconnected from a server?

There are basically two modes in which ssh can operate: 1) interactive, 2) non-interactive. These are not official terms. I'm using them here in place of otherwise wordy names like, "an ssh session with an allocated pseudo terminal." To run a command in non-interactive mode you do:

$ ssh host echo test

Interactive mode is entered when you either do:

x-yuri

Debian Wheezy

/opt/eff.org/certbot/venv/bin/python: No module named pip.__main__; 'pip' is a package and cannot be directly executed
Traceback (most recent call last):
  File "/tmp/tmp.Xxcju1yqBr/pipstrap.py", line 177, in <module>
    sys.exit(main())
  File "/tmp/tmp.Xxcju1yqBr/pipstrap.py", line 149, in main
    pip_version = StrictVersion(check_output([python, '-m', 'pip', '--version'])
  File "/usr/lib/python2.7/subprocess.py", line 544, in check_output

x-yuri

config/environments/production/custom.json:

{
  "prefixed-router": {
    "enabled": true
  }
}

x-yuri

I was building a docker image. Nothing foretold troubles, but then:

       Step 7/13 : RUN SECRET_KEY_BASE=`bin/rake secret` RAILS_ENV=production         bin/rails assets:precompile
        ---> Running in 51605ddacc67
       FATAL: Listen error: unable to monitor directories for changes.
       Visit https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers for info 
on how to fix this.

x-yuri

You might have run, or might run in the future (or never run for that mater) into the following issue. Let's do bundle init, create 1.rb:

require 'rubygems'
require 'bundler'
Bundler.setup(:default)

Then add require 'byebug'; debugger to the beginning of the

x-yuri

The straightforward answer is: "You can't." But a more deliberate one would be: "You can't after Bundle.setup has finished executing."

But how does it achieve that? First we've got to clarify a couple of things about rubygems and the require method. The bare require method knows nothing about gems. It requires files, resolving their names (paths indeed) relative to paths from the $LOAD_PATH variable. $LOAD_PATH is not particularly big at the start of an invocation:

x-yuri

version: '3'
services:
  s1:
    image: postgres:12
    container_name: ${prefix}_compose_anonymous
    ports:
      - $pg_port:5432

x-yuri

class A
  def im; end
  def self.cm; end
end

def superclasses c
  r = []
  while c.superclass
    r << c.superclass
    c = c.superclass