Remove the istio-specific logic in the migrate process

Wait for the database to be available instead, so that the migrations
can run in deployments without istio (e.g. with contour).

[#175367511]

Authored-by: Matt Royal <mroyal@pivotal.io>

Author: matt-royal

Procfile

@@ -3,5 +3,5 @@ local-worker:       bundle exec rake jobs:local
 api-worker:         bundle exec rake jobs:generic
 clock:              bundle exec rake clock:start
 deployment-updater: bundle exec rake deployment_updater:start
-migrate:            /bin/bash -c 'bundle exec rake db:wait_for_istio && bundle exec rake db:setup_database && bundle exec rake db:terminate_istio'
+migrate:            /bin/bash -c 'bundle exec rake db:connect && bundle exec rake db:setup_database'
 

lib/tasks/db.rake

@@ -1,4 +1,5 @@
 require 'httpclient'
+require 'retryable'
 
 namespace :db do
   desc 'Create a Sequel migration in ./db/migrate'
@@ -38,6 +39,13 @@ namespace :db do
     migrate
   end
 
+  desc 'Make up to 5 attempts to connect to the database. Succeed it one is successful, and fail otherwise.'
+  task :connect do
+    RakeConfig.context = :migrate
+
+    connect
+  end
+
   desc 'Rollback migrations to the database (one migration by default)'
   task :rollback, [:number_to_rollback] do |_, args|
     RakeConfig.context = :migrate
@@ -171,24 +179,6 @@ namespace :db do
     end
   end
 
-  desc 'Wait for Istio sidecar to startup'
-  task :wait_for_istio do
-    puts 'Waiting indefinitely for Istio sidecar to be healthy'
-
-    sleep(5) until istio_sidecar_is_healthy?
-
-    puts 'Istio sidecar is now healthy'
-  end
-
-  desc 'Terminate Istio sidecar for migration job'
-  task :terminate_istio do
-    puts 'Terminating Istio sidecar'
-
-    terminate_istio_sidecar
-
-    puts 'Istio sidecar is now terminated'
-  end
-
   namespace :dev do
     desc 'Migrate the database set in spec/support/bootstrap/db_config'
     task :migrate do
@@ -237,6 +227,20 @@ namespace :db do
     task recreate: %w[parallel:drop parallel:create]
   end
 
+  def connect
+    Steno.init(Steno::Config.new(sinks: [Steno::Sink::IO.new($stdout)]))
+    logger = Steno.logger('cc.db.connect')
+    log_method = lambda do |retries, exception|
+      logger.info("[Attempt ##{retries}] Retrying because [#{exception.class} - #{exception.message}]: #{exception.backtrace.first(5).join(' | ')}")
+    end
+
+    Retryable.retryable(sleep: 1, tries: 5, log_method: log_method) do
+      VCAP::CloudController::DB.connect(RakeConfig.config.get(:db), logger)
+    end
+
+    logger.info("Successfully connected to database")
+  end
+
   def migrate
     Steno.init(Steno::Config.new(sinks: [Steno::Sink::IO.new($stdout)]))
     db_logger = Steno.logger('cc.db.migrations')
@@ -298,18 +302,4 @@ namespace :db do
       end
     end
   end
-
-  def istio_sidecar_is_healthy?
-    client = HTTPClient.new
-    response = client.request(:get, 'http://localhost:15020/healthz/ready')
-
-    response.code == 200
-  rescue StandardError
-  end
-
-  def terminate_istio_sidecar
-    client = HTTPClient.new
-    response = client.request(:post, 'http://localhost:15000/quitquitquit')
-    raise StandardError.new("Failed to terminate Istio sidecar. Received response code: #{response.code}") unless response.code == 200
-  end
 end