customsearch_image.rb

# In Gemfile:
# gem 'google-api-client', '0.9.pre3'

require 'google/apis/customsearch_v1'

Customsearch = Google::Apis::CustomsearchV1
search = Customsearch::CustomsearchService.new

# https://cse.google.com/cse/all
# Click name of CSE to edit
# Image search => On
# Sites to search => Search the entire web but emphasize included sites
search.key = 'insert here'

# Details: Search Engine ID
cx = 'insert here'

search_term = 'snow'

results = search.list_cses(
  search_term,
  cx: cx,
  search_type: 'image'
)

puts results.items.sample.link