generate_secrets: Enable memcached authentication in production.

Signed-off-by: Anders Kaseorg <anders@zulipchat.com>

puppet/zulip/files/sasl2/memcached.conf

@@ -0,0 +1,2 @@
+mech_list: plain
+sasldb_path: /etc/sasl2/memcached-sasldb2

puppet/zulip/manifests/memcached.pp

@@ -1,11 +1,58 @@
 class zulip::memcached {
-  $memcached_packages = ['memcached']
+  include zulip::sasl_modules
+
+  $memcached_packages = $::osfamily ? {
+    'debian' => [ 'memcached', 'sasl2-bin' ],
+    'redhat' => [ 'memcached' ],
+  }
   package { $memcached_packages: ensure => 'installed' }
 
   $memcached_memory = zulipconf('memcached', 'memory', $zulip::base::total_memory_mb / 8)
+  file { '/etc/sasl2':
+    ensure => directory,
+  }
+  file { '/etc/sasl2/memcached-zulip-password':
+    # We cache the password in this file so we can check whether it
+    # changed and avoid running saslpasswd2 if it didn't.
+    require => File['/etc/sasl2'],
+    owner   => 'root',
+    group   => 'root',
+    mode    => '0600',
+    content => zulipsecret('secrets', 'memcached_password', ''),
+    notify  => Exec[generate_memcached_sasldb2],
+  }
+  exec { 'generate_memcached_sasldb2':
+    creates => '/etc/sasl2/memcached-sasldb2',
+    require => [
+      Package[$memcached_packages],
+      Package[$zulip::sasl_modules::sasl_module_packages],
+      File['/etc/sasl2/memcached-zulip-password'],
+    ],
+    # Pass the hostname explicitly because otherwise saslpasswd2
+    # lowercases it and memcached does not.
+    command => "bash -c 'saslpasswd2 -p -f /etc/sasl2/memcached-sasldb2 \
+-a memcached -u \"\$HOSTNAME\" zulip < /etc/sasl2/memcached-zulip-password'",
+  }
+  file { '/etc/sasl2/memcached-sasldb2':
+    require => Exec[generate_memcached_sasldb2],
+    owner   => 'memcache',
+    group   => 'memcache',
+    mode    => '0600',
+  }
+  file { '/etc/sasl2/memcached.conf':
+    require => File['/etc/sasl2'],
+    owner   => 'root',
+    group   => 'root',
+    mode    => '0644',
+    source  => 'puppet:///modules/zulip/sasl2/memcached.conf',
+    notify  => Service[memcached],
+  }
   file { '/etc/memcached.conf':
     ensure  => file,
-    require => Package[memcached],
+    require => [
+      Package[$memcached_packages],
+      Package[$zulip::sasl_modules::sasl_module_packages]
+    ],
     owner   => 'root',
     group   => 'root',
     mode    => '0644',

puppet/zulip/templates/memcached.conf.template.erb

@@ -27,7 +27,7 @@ logfile /var/log/memcached.log
 
 # Run the daemon as root. The start-memcached will default to running as root if no
 # -u command is present in this config file
--u nobody
+-u memcache
 
 # Specify which IP address to listen on. The default is to listen on all IP addresses
 # This parameter is one of the only security measures that memcached has, so make sure
@@ -50,3 +50,6 @@ logfile /var/log/memcached.log
 
 # Maximize core file limit
 # -r
+
+# Enable SASL authentication
+-S

scripts/lib/install

@@ -293,6 +293,16 @@ EOF
 
 case ",$PUPPET_CLASSES," in
     *,zulip::voyager,* | *,zulip::dockervoyager,* | *,zulip::app_frontend,*)
+        if [ -z "$NO_OVERWRITE_SETTINGS" ] || ! [ -e "/etc/zulip/settings.py" ]; then
+            cp -a "$ZULIP_PATH"/zproject/prod_settings_template.py /etc/zulip/settings.py
+            if [ -n "$EXTERNAL_HOST" ]; then
+                sed -i "s/^EXTERNAL_HOST =.*/EXTERNAL_HOST = '$EXTERNAL_HOST'/" /etc/zulip/settings.py
+            fi
+            if [ -n "$ZULIP_ADMINISTRATOR" ]; then
+                sed -i "s/^ZULIP_ADMINISTRATOR =.*/ZULIP_ADMINISTRATOR = '$ZULIP_ADMINISTRATOR'/" /etc/zulip/settings.py
+            fi
+        fi
+        ln -nsf /etc/zulip/settings.py "$ZULIP_PATH"/zproject/prod_settings.py
         "$ZULIP_PATH"/scripts/setup/generate_secrets.py --production
         ;;
 esac
@@ -353,19 +363,6 @@ EOF
     service nginx restart
 fi
 
-if [ "$has_appserver" = 0 ]; then
-    if [ -z "$NO_OVERWRITE_SETTINGS" ] || ! [ -e "/etc/zulip/settings.py" ]; then
-        cp -a "$ZULIP_PATH"/zproject/prod_settings_template.py /etc/zulip/settings.py
-        if [ -n "$EXTERNAL_HOST" ]; then
-            sed -i "s/^EXTERNAL_HOST =.*/EXTERNAL_HOST = '$EXTERNAL_HOST'/" /etc/zulip/settings.py
-        fi
-        if [ -n "$ZULIP_ADMINISTRATOR" ]; then
-            sed -i "s/^ZULIP_ADMINISTRATOR =.*/ZULIP_ADMINISTRATOR = '$ZULIP_ADMINISTRATOR'/" /etc/zulip/settings.py
-        fi
-    fi
-    ln -nsf /etc/zulip/settings.py "$ZULIP_PATH"/zproject/prod_settings.py
-fi
-
 if [ "$has_rabbit" = 0 ]; then
     if ! rabbitmqctl status >/dev/null; then
         set +x

scripts/setup/generate_secrets.py

@@ -17,6 +17,7 @@ import argparse
 import uuid
 import configparser
 from zerver.lib.utils import generate_random_token
+from zproject import settings
 
 os.chdir(os.path.join(os.path.dirname(__file__), '..', '..'))
 
@@ -80,6 +81,13 @@ def generate_secrets(development=False):
     if need_secret('camo_key'):
         add_secret('camo_key', get_random_string(64))
 
+    if (
+        not development
+        and settings.MEMCACHED_LOCATION == "127.0.0.1:11211"
+        and need_secret("memcached_password")
+    ):
+        add_secret("memcached_password", generate_random_token(64))
+
     # zulip_org_key is generated using os.urandom().
     # zulip_org_id does not require a secure CPRNG,
     # it only needs to be unique.