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|
# frozen_string_literal: true
#
# Author:: Tim Dysinger (<tim@dysinger.net>)
# Author:: Benjamin Black (<bb@chef.io>)
# Author:: Christopher Brown (<cb@chef.io>)
# Copyright:: Copyright (c) Chef Software Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
require "net/http" unless defined?(Net::HTTP)
module Ohai
module Mixin
##
# This code parses the EC2 Instance Metadata API to provide details
# of the running instance.
#
# Earlier version of this code assumed a specific version of the
# metadata API was available. Unfortunately the API versions
# supported by a particular instance are determined at instance
# launch and are not extended over the life of the instance. As such
# the earlier code would fail depending on the age of the instance.
#
# The updated code probes the instance metadata endpoint for
# available versions, determines the most advanced version known to
# work and executes the metadata retrieval using that version.
#
# If no compatible version is found, an empty hash is returned.
#
module Ec2Metadata
EC2_METADATA_ADDR ||= "169.254.169.254"
EC2_SUPPORTED_VERSIONS ||= %w{ 1.0 2007-01-19 2007-03-01 2007-08-29 2007-10-10 2007-12-15
2008-02-01 2008-09-01 2009-04-04 2011-01-01 2011-05-01 2012-01-12
2014-02-25 2014-11-05 2015-10-20 2016-04-19 2016-06-30 2016-09-02 }.freeze
EC2_ARRAY_VALUES ||= %w{security-groups local_ipv4s}.freeze
EC2_ARRAY_DIR ||= %w{network/interfaces/macs}.freeze
EC2_JSON_DIR ||= %w{iam}.freeze
def best_api_version
@api_version ||= begin
logger.trace("Mixin EC2: Fetching http://#{EC2_METADATA_ADDR}/ to determine the latest supported metadata release")
response = http_client.get("/")
if response.code == "404"
logger.trace("Mixin EC2: Received HTTP 404 from metadata server while determining API version, assuming 'latest'")
return "latest"
elsif response.code != "200"
raise "Mixin EC2: Unable to determine EC2 metadata version (returned #{response.code} response)"
end
# Note: Sorting the list of versions may have unintended consequences in
# non-EC2 environments. It appears to be safe in EC2 as of 2013-04-12.
versions = response.body.split("\n").sort
until versions.empty? || EC2_SUPPORTED_VERSIONS.include?(versions.last)
pv = versions.pop
logger.trace("Mixin EC2: EC2 lists metadata version: #{pv} not yet supported by Ohai") unless pv == "latest"
end
logger.trace("Mixin EC2: Latest supported EC2 metadata version: #{versions.last}")
if versions.empty?
raise "Mixin EC2: Unable to determine EC2 metadata version (no supported entries found)"
end
versions.last
end
end
# a net/http client with a timeout of 10s and a keepalive of 10s
#
# @return [Net::HTTP]
def http_client
@conn ||= Net::HTTP.start(EC2_METADATA_ADDR).tap do |h|
h.read_timeout = 10
h.keep_alive_timeout = 10
end
end
# Get metadata for a given path and API version
#
# Typically, a 200 response is expected for valid metadata.
# On certain instance types, traversing the provided metadata path
# produces a 404 for some unknown reason. In that event, return
# `nil` and continue the run instead of failing it.
def metadata_get(id, api_version)
path = "/#{api_version}/meta-data/#{id}"
logger.trace("Mixin EC2: Fetching http://#{EC2_METADATA_ADDR}#{path}")
response = http_client.get(path)
case response.code
when "200"
response.body
when "404"
logger.trace("Mixin EC2: Encountered 404 response retrieving EC2 metadata path: #{path} ; continuing.")
nil
else
raise "Mixin EC2: Encountered error retrieving EC2 metadata (#{path} returned #{response.code} response)"
end
end
def fetch_metadata(id = "", api_version = nil)
metadata = {}
retrieved_metadata = metadata_get(id, best_api_version)
if retrieved_metadata
retrieved_metadata.split("\n").each do |o|
key = expand_path("#{id}#{o}")
if key[-1..-1] != "/"
metadata[metadata_key(key)] =
if EC2_ARRAY_VALUES.include? key
retr_meta = metadata_get(key, best_api_version)
retr_meta ? retr_meta.split("\n") : retr_meta
else
metadata_get(key, best_api_version)
end
elsif (not key.eql?(id)) && (not key.eql?("/"))
name = key[0..-2]
sym = metadata_key(name)
if EC2_ARRAY_DIR.include?(name)
metadata[sym] = fetch_dir_metadata(key, best_api_version)
elsif EC2_JSON_DIR.include?(name)
metadata[sym] = fetch_json_dir_metadata(key, best_api_version)
else
fetch_metadata(key, best_api_version).each { |k, v| metadata[k] = v }
end
end
end
metadata
end
end
def fetch_dir_metadata(id, api_version)
metadata = {}
retrieved_metadata = metadata_get(id, api_version)
if retrieved_metadata
retrieved_metadata.split("\n").each do |o|
key = expand_path(o)
if key[-1..-1] != "/"
retr_meta = metadata_get("#{id}#{key}", api_version)
metadata[metadata_key(key)] = retr_meta || ""
elsif not key.eql?("/")
metadata[key[0..-2]] = fetch_dir_metadata("#{id}#{key}", api_version)
end
end
metadata
end
end
def fetch_json_dir_metadata(id, api_version)
metadata = {}
retrieved_metadata = metadata_get(id, api_version)
if retrieved_metadata
retrieved_metadata.split("\n").each do |o|
key = expand_path(o)
if key[-1..-1] != "/"
retr_meta = metadata_get("#{id}#{key}", api_version)
data = retr_meta || ""
json = String(data)
parser = FFI_Yajl::Parser.new
metadata[metadata_key(key)] = parser.parse(json)
elsif not key.eql?("/")
metadata[key[0..-2]] = fetch_json_dir_metadata("#{id}#{key}", api_version)
end
end
metadata
end
end
def fetch_userdata
logger.trace("Mixin EC2: Fetching http://#{EC2_METADATA_ADDR}/#{best_api_version}/user-data/")
response = http_client.get("/#{best_api_version}/user-data/")
response.code == "200" ? response.body : nil
end
def fetch_dynamic_data
@fetch_dynamic_data ||= begin
response = http_client.get("/#{best_api_version}/dynamic/instance-identity/document/")
if json?(response.body) && response.code == "200"
FFI_Yajl::Parser.parse(response.body)
else
{}
end
end
end
private
def expand_path(file_name)
path = file_name.gsub(/\=.*$/, "/")
# ignore "./" and "../"
path.gsub(%r{/\.\.?(?:/|$)}, "/")
.sub(%r{^\.\.?(?:/|$)}, "")
.sub(/^$/, "/")
end
def metadata_key(key)
key.gsub(%r{\-|/}, "_")
end
end
end
end
|
