puppet: Add Zulip specific postgres configuration for 9.6.

Mostly, this involves adding the big block at the bottom and making
9.6 a variable so that it's easier to compare different versions of
these.

puppet/zulip/templates/postgresql/9.6/postgresql.conf.template.erb

@@ -38,15 +38,15 @@
 # The default values of these variables are driven from the -D command-line
 # option or PGDATA environment variable, represented here as ConfigDir.
 
-data_directory = '/var/lib/postgresql/9.6/main'		# use data in another directory
+data_directory = '/var/lib/postgresql/<%= scope["zulip::base::postgres_version"] %>/main'		# use data in another directory
 					# (change requires restart)
-hba_file = '/etc/postgresql/9.6/main/pg_hba.conf'	# host-based authentication file
+hba_file = '/etc/postgresql/<%= scope["zulip::base::postgres_version"] %>/main/pg_hba.conf'	# host-based authentication file
 					# (change requires restart)
-ident_file = '/etc/postgresql/9.6/main/pg_ident.conf'	# ident configuration file
+ident_file = '/etc/postgresql/<%= scope["zulip::base::postgres_version"] %>/main/pg_ident.conf'	# ident configuration file
 					# (change requires restart)
 
 # If external_pid_file is not explicitly set, no extra PID file is written.
-external_pid_file = '/var/run/postgresql/9.6-main.pid'			# write an extra PID file
+external_pid_file = '/var/run/postgresql/<%= scope["zulip::base::postgres_version"] %>-main.pid'			# write an extra PID file
 					# (change requires restart)
 
 
@@ -462,7 +462,7 @@ log_timezone = 'UTC'
 
 # - Process Title -
 
-cluster_name = '9.6/main'			# added to process titles if nonempty
+cluster_name = '<%= scope["zulip::base::postgres_version"] %>/main'			# added to process titles if nonempty
 					# (change requires restart)
 #update_process_title = on
 
@@ -478,7 +478,7 @@ cluster_name = '9.6/main'			# added to process titles if nonempty
 #track_io_timing = off
 #track_functions = none			# none, pl, all
 #track_activity_query_size = 1024	# (change requires restart)
-stats_temp_directory = '/var/run/postgresql/9.6-main.pg_stat_tmp'
+stats_temp_directory = '/var/run/postgresql/<%= scope["zulip::base::postgres_version"] %>-main.pg_stat_tmp'
 
 
 # - Statistics Monitoring -
@@ -641,3 +641,61 @@ default_text_search_config = 'pg_catalog.english'
 #------------------------------------------------------------------------------
 
 # Add settings for extensions here
+timezone = 'UTC'
+default_text_search_config = 'zulip.english_us_search'
+
+log_destination = 'stderr'
+logging_collector = on
+log_directory = '/var/log/postgresql'
+log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log'
+log_rotation_age = 7d
+log_rotation_size = 100MB
+log_min_duration_statement = 500
+log_line_prefix = '%m [%c]: [%l-1] '
+log_checkpoints = on
+log_lock_waits = on
+log_temp_files = 0
+log_autovacuum_min_duration = 100
+
+autovacuum_freeze_max_age = 2000000000
+vacuum_freeze_min_age     = 1000000000
+vacuum_freeze_table_age   = 1800000000
+
+# Performance settings
+maintenance_work_mem = <%= scope["zulip::postgres_appdb_tuned::maintenance_work_mem"] %>MB
+effective_cache_size = <%= scope["zulip::postgres_appdb_tuned::effective_cache_size"] %>MB
+work_mem = <%= scope["zulip::postgres_appdb_tuned::work_mem"] %>MB
+shared_buffers = <%= scope["zulip::postgres_appdb_tuned::shared_buffers"] %>MB
+wal_buffers = 4MB
+checkpoint_completion_target = 0.7
+<% if @random_page_cost != '' -%>
+random_page_cost = <%= @random_page_cost %>
+<% end -%>
+<% if @effective_io_concurrency != '' -%>
+effective_io_concurrency = <%= @effective_io_concurrency %>
+<% end -%>
+
+<% if @listen_addresses != '' -%>
+listen_addresses = <%= @listen_addresses %>
+<% end -%>
+
+<% if @replication != '' -%>
+# Master replication settings (ignored on standby)
+wal_level = hot_standby
+max_wal_senders = 5
+archive_mode = on
+archive_command = '/usr/local/bin/env-wal-e wal-push %p'
+
+# Standby replication settings (ignored on master)
+hot_standby = on
+<% end -%>
+
+<% if @ssl_cert_file != '' -%>
+ssl_cert_file = '<%= @ssl_cert_file %>'		# (change requires restart)
+<% end -%>
+<% if @ssl_key_file != '' -%>
+ssl_key_file = '<%= @ssl_key_file %>'		# (change requires restart)
+<% end -%>
+<% if @ssl_ca_file != '' -%>
+ssl_ca_file = '<%= @ssl_ca_file %>'		# (change requires restart)
+<% end -%>