Merge pull request #3 from PRX/feat/dovetail_router_dns_tool

Script for checking/changing dovetail router DNS regions

Formula/prx-dev-tools.rb

@@ -10,6 +10,7 @@ def install
     bin.install "bin/awsso.rb" => "awsso"
     bin.install "bin/awstunnel"
     bin.install "bin/prx-cfn-tree.rb" => "prx-cfn-tree"
+    bin.install "bin/prx-dovetail-regions.rb" => "prx-dovetail-regions"
     bin.install "bin/prx-empty-log-groups.rb" => "prx-empty-log-groups"
     bin.install "bin/prx-github-repo-audit.rb" => "prx-github-repo-audit"
     bin.install "bin/prx-immortal-log-groups.rb" => "prx-immortal-log-groups"

bin/prx-dovetail-regions.rb

@@ -0,0 +1,112 @@
+#!/usr/bin/env ruby
+# View/update which Dovetail Router regions DNS is pointing at.
+
+require "bundler/inline"
+
+gemfile do
+  source "https://rubygems.org"
+  gem "awesome_print"
+  gem "aws-sdk-route53"
+  gem "prx-ruby-aws-creds"
+  gem "slop"
+end
+
+OPTS = Slop.parse do |o|
+  o.string "-p", "--profile", "AWS profile", default: "prx-legacy-route53"
+  o.string "-r", "--region", 'Region (e.g., "us-east-1")', default: "us-east-1"
+  o.string "-e", "--environment", 'E.g. "production" or "staging"', required: true
+  o.string "-c", "--change", 'Set region(s) for dovetail router to serve in (e.g., "us-east-1" or "all")', default: nil
+  o.on "-h", "--help" do
+    puts o
+    exit
+  end
+end
+
+ZONE_NAME = "prx.tech"
+ALL_REGIONS = %w[us-east-1 us-west-2]
+if %w[stag staging].include?(OPTS[:environment].to_s.downcase)
+  ALIAS = "dovetail-router.staging.u.#{ZONE_NAME}"
+  GROUP = "dovetail-router-alb-latency-group.stag.#{ZONE_NAME}"
+  REGIONS = ALL_REGIONS.map { |r| [r, "dovetail-router.staging.#{r}.#{ZONE_NAME}"] }.to_h
+elsif %w[prod production].include?(OPTS[:environment].to_s.downcase)
+  ALIAS = "dovetail-router.u.#{ZONE_NAME}"
+  GROUP = "dovetail-router-alb-latency-group.prod.#{ZONE_NAME}"
+  REGIONS = ALL_REGIONS.map { |r| [r, "dovetail-router.#{r}.#{ZONE_NAME}"] }.to_h
+else
+  abort "Invalid environment".red
+end
+
+CHANGE =
+  if OPTS[:change] == "all"
+    GROUP
+  elsif REGIONS.key?(OPTS[:change])
+    REGIONS[OPTS[:change]]
+  elsif OPTS[:change]
+    abort "Invalid change region".red
+  end
+
+# check if a route53 aws profile exists
+creds =
+  begin
+    PrxRubyAwsCreds.client_credentials
+  rescue
+    puts "Unable to get AWS client credentials!".red
+    puts "\nDid you add a #{"[profile prx-legacy-route53]".yellow} to your ~/.aws/config?"
+    exit 1
+  end
+
+# find hosted zone
+client = Aws::Route53::Client.new(region: OPTS[:region], credentials: creds, retry_mode: "adaptive")
+res = client.list_hosted_zones_by_name(dns_name: "#{ZONE_NAME}.")
+zone_id = res.hosted_zones&.first&.id
+abort "Hosted zone '#{ZONE_NAME}' not found!".red unless zone_id
+
+# get current aliases
+res = client.list_resource_record_sets(hosted_zone_id: zone_id, start_record_name: ALIAS, max_items: 2)
+a_rec = res.resource_record_sets.find { |r| r.name == "#{ALIAS}." && r.type == "A" }
+aaaa_rec = res.resource_record_sets.find { |r| r.name == "#{ALIAS}." && r.type == "AAAA" }
+abort "Missing A record for #{ALIAS}".red unless a_rec
+abort "Missing AAAA record for #{ALIAS}".red unless aaaa_rec
+
+puts "Current #{ALIAS}"
+puts "-" * (8 + ALIAS.length)
+puts "A    --> #{a_rec.alias_target.dns_name.blue}"
+puts "AAAA --> #{aaaa_rec.alias_target.dns_name.blue}"
+abort "Mismatching A/AAAA records!".red if a_rec.alias_target.dns_name != aaaa_rec.alias_target.dns_name
+exit unless CHANGE
+
+if a_rec.alias_target.dns_name == "#{CHANGE}."
+  puts "\nNothing to change"
+  exit
+end
+
+puts "\nChanges #{ALIAS}"
+puts "-" * (8 + ALIAS.length)
+puts "A    --> #{CHANGE.green}."
+puts "AAAA --> #{CHANGE.green}."
+
+if OPTS[:change] == "all"
+  puts "\nThis will #{"balance".green} all dovetail traffic/processing between #{"all".green} regions"
+else
+  puts "\nThis will move all dovetail traffic/processing to the #{OPTS[:change].green} region"
+end
+
+print "\nProceed with DNS changes? (y/n) "
+exit unless $stdin.gets.chomp.strip == "y"
+
+print "Really? You're sure this won't just make things worse? (aye/nay) "
+exit unless $stdin.gets.chomp.strip == "aye"
+
+print "You know, Fixed and Failure both start out the same way - proceed anyways? (yep/nope) "
+exit unless $stdin.gets.chomp.strip == "yep"
+
+batch = {
+  changes: [
+    {action: "UPSERT", resource_record_set: a_rec.to_h},
+    {action: "UPSERT", resource_record_set: aaaa_rec.to_h}
+  ]
+}
+batch[:changes][0][:resource_record_set][:alias_target][:dns_name] = "#{CHANGE}."
+batch[:changes][1][:resource_record_set][:alias_target][:dns_name] = "#{CHANGE}."
+client.change_resource_record_sets(hosted_zone_id: zone_id, change_batch: batch)
+puts "\nDovetail Router aliases successfully updated".green