Today I learned how to automate SSH logins when a password is required. In order to make this happen we need to first install expect

Install Expect

brew install expect

Create bash scripts

cd /usr/bin/local
touch exp
touch ssh-custom
chmod u+x exp ssh-custom

Open the exp file and enter in the following:

#!/usr/bin/expect -f
set timeout 20

set cmd [lrange $argv 0 end]

# Check if SSHPASS is set
if {[info exists env(SSHPASS)]} {
    set password $env(SSHPASS)
} else {
    puts "Error: SSHPASS environment variable not set."
    exit 1
}

spawn ssh $cmd
expect "password for your-username:"
send "$password\r"
interact

The string on the line expect "password for your-username:" will need to match the text that gets displayed when you ssh normally to whatever server is requiring a password. This will be what expect waits for before entering in your password.

Now open the ssh-custom file and enter the following. This will be what we eventually setup an alias for that will divert the ssh command to the exp file that will handle servers that require a password.

#!/bin/bash

if [ "$1" == "production" ]; then
    exp production
else
    # Default behavior for other SSH commands
    ssh "$@"
fi

Now we need to setup the environment variable and alias. Assuming you use zsh, add the following to your .zshrc file.

alias ssh="ssh-custom"
export SSHPASS="yoursshpassword"

Profit

Now when you run ssh production it will automatically enter your password.

Today I learned how to reduce the clickable area of a label element to only the text.

label {
  display: inline-block;
}

class Products
  default_scope where(enabled: true)
  scope :disabled, -> { unscope(enabled: false) }
end

class Products
  default_scope where(enabled: true)
end

product = Products.first
product.rewhere(enabled: false)

Problem

You have a report that expects a boolean. Sometimes the it is run from a job that passes in a boolean. And sometimes it is executed from a controller using a param that comes in as "true" or "false".

How do you ensure "true" and true are both treated as a boolean?

Solution

Force string to boolean using ActiveModel::Type::Boolean.new.cast

irb(main)> ActiveModel::Type::Boolean.new.cast('true')
=> true

irb(main)> ActiveModel::Type::Boolean.new.cast(true)
=> true

Problem

Let’s say you create the following Rails migration forgetting to add code to the change method. You then issue the rails migration command rails migrate

class AddAwesomeToStuff< ActiveRecord::Migration[6.0]
  def change
  end
end

You then update the migration with your desired changes and try issuing the migrate command again. Nothing happens. It is because each time a migration runs the version number is stored in a table that prevents the same migration running more than once.

class AddAwesomeToStuff< ActiveRecord::Migration[6.0]
  def change
    change_table :stuff do |t|
      t.string :awesome
    end
  end
end

Solution

Force a migration to run in the Rails console

irb(main)> require "#{Rails.root.to_s}/db/migrate/20211004223636_add_awesome_to_stuff.rb"
irb(main)> AddAwesomeToStuff.migrate(:up)