CircleCI Artifact Retrieval via the API

circleci.rb

# Finds a CircleCI job of a given name, and retrieves an artifact from a given CircleCI project build
# Usage: 
#   $ API_TOKEN=xxx GITHUB_USERNAME=bsimpson GITHUB_PROJECT=some-project TARGET_JOB=lighthouse ARTIFACT=averages_pageload ruby ./circleci.rb

require "net/http"
require "json"

API_TOKEN = ENV["API_TOKEN"]
LIMIT = 100
GITHUB_USERNAME = ENV["GITHUB_USERNAME"]
GITHUB_PROJECT = ENV["GITHUB_PROJECT"]
TARGET_JOB = ENV["TARGET_JOB"]
ARTIFACT = ENV["ARTIFACT"]

#  Recent builds for a single project
# curl https://circleci.com/api/v1.1/project/:vcs-type/:username/:project?circle-token=:token&limit=20&offset=5&filter=completed
def find_job(job=TARGET_JOB)
  offset = 0

  while offset < LIMIT * 10 do
    url = "https://circleci.com/api/v1.1/project/github/%{github_username}/%{github_project}?circle-token=%{token}&limit=%{limit}&offset=%{offset}"
    uri = URI.parse url % {
      github_username: GITHUB_USERNAME,
      github_project: GITHUB_PROJECT,
      token: API_TOKEN,
      limit: LIMIT,
      offset: offset
    }

    response = Net::HTTP.get(uri)
    jobs = JSON.parse(response)
    matching_job = jobs.detect { |job| job["build_parameters"]["CIRCLE_JOB"].match(TARGET_JOB) }
    if matching_job
      return matching_job
    end

    puts "Trying offset #{offset}..."
    offset += LIMIT
  end

  puts "Exhausted pages"
end

# Return artifacts of a build
# curl https://circleci.com/api/v1.1/project/:vcs-type/:username/:project/:build_num/artifacts?circle-token=:token
def find_artifacts(job, artifact=ARTIFACT)
  build_num = job["build_num"]

  url = "https://circleci.com/api/v1.1/project/github/%{github_username}/%{github_project}/%{build_num}/artifacts?circle-token=%{token}"
  uri = URI.parse url % {
    github_username: GITHUB_USERNAME,
    github_project: GITHUB_PROJECT,
    build_num: build_num,
    token: API_TOKEN
  }

  response = Net::HTTP.get(uri)
  artifacts = JSON.parse(response)

  matching_artifact = artifacts.detect { |artifact| artifact["path"].match(ARTIFACT) }

  return matching_artifact
end

# Download an artifact
# https://132-55688803-gh.circle-artifacts.com/0//tmp/circle-artifacts.7wgAaIU/file.txt?circle-token=:token
def download_artifact(artifact)
  url = "#{artifact["url"]}?circle-token=%{token}"
  uri = URI.parse url % {
    token: API_TOKEN
  }

  response = Net::HTTP.get(uri)

  puts response
  return response
end

job = find_job
artifact = find_artifacts(job)
download_artifact(artifact)