Fix stopping of old test cluster when pg_ctl is not in the path

If the pg_ctl binary was not in the path we would fail to stop the
running database clusters so let's use our helper for getting the path
to the binary.

To keep the code simple we also move the stopping of the existing
cluster to the code which starts it since that is only where we,
at least currently, knows the path the the binaries.

Author: jeltz

spec/helpers.rb

@@ -188,32 +188,6 @@ def log_and_run( logpath, *cmd )
 
 	extend Loggable
 
-	### Check the current directory for directories that look like they're
-	### testing directories from previous tests, and tell any postgres instances
-	### running in them to shut down.
-	def stop_existing_postmasters
-		# tmp_test_0.22329534700318
-		pat = Pathname.getwd + 'tmp_test_*'
-		Pathname.glob( pat.to_s ).each do |testdir|
-			datadir = testdir + 'data'
-			pidfile = datadir + 'postmaster.pid'
-			if pidfile.exist? && pid = pidfile.read.chomp.to_i
-				trace "pidfile (%p) exists: %d" % [ pidfile, pid ]
-				begin
-					Process.kill( 0, pid )
-				rescue Errno::ESRCH
-					trace "No postmaster running for %s" % [ datadir ]
-					# Process isn't alive, so don't try to stop it
-				else
-					trace "Stopping lingering database at PID %d" % [ pid ]
-					run 'pg_ctl', '-D', datadir.to_s, '-m', 'fast', 'stop'
-				end
-			else
-				trace "No pidfile (%p)" % [ pidfile ]
-			end
-		end
-	end
-
 	class PostgresServer
 		include Loggable
 
@@ -238,6 +212,7 @@ def initialize(name, port: 23456, postgresql_conf: '')
 
 			begin
 				@pgdata.mkpath
+				stop_existing_cluster
 				setup_cluster(postgresql_conf)
 				start_cluster
 			rescue => err
@@ -317,6 +292,25 @@ def start_cluster
 			log_and_run @logfile, pg_bin_path('pg_ctl'), '-w', '-o', sopt, '-D', @pgdata.to_s, 'start'
 		end
 
+		def stop_existing_cluster
+			pidfile = @pgdata + 'postmaster.pid'
+
+			if pidfile.exist? && pid = pidfile.read.chomp.to_i
+				trace "pidfile (%p) exists: %d" % [ pidfile, pid ]
+				begin
+					Process.kill( 0, pid )
+				rescue Errno::ESRCH
+					trace "No postmaster running for %s" % [ @pgdata ]
+					# Process isn't alive, so don't try to stop it
+				else
+					trace "Stopping lingering database at PID %d" % [ pid ]
+					run pg_bin_path('pg_ctl'), '-D', @pgdata.to_s, '-m', 'fast', 'stop'
+				end
+			else
+				trace "No pidfile (%p)" % [ pidfile ]
+			end
+		end
+
 		def generate_ssl_certs(output_dir)
 			gen = CertGenerator.new(output_dir)
 
@@ -701,8 +695,6 @@ def set_etc_hosts(hostaddr, hostname)
 
 	### Automatically set up and tear down the database
 	config.before(:suite) do |*args|
-		PG::TestingHelpers.stop_existing_postmasters
-
 		ENV['PGHOST'] = 'localhost'
 		ENV['PGPORT'] ||= "23456"
 		port = ENV['PGPORT'].to_i