devstack/lib/apache
Matthew Treinish 477a962861 Enable graceful shutdown for services
1] Process using uwsgi:
   uwsgi services doesn't support for graceful shutting down [1].
   It requires some changes in unit files [2] including adding below
   graceful shutdown hook and changing KillSignal:
      --hook-master-start "unix_signal:15 gracefully_kill_them_all
   All the steps and changes required are specified in etherpad [1].

2] Non uwsgi services needs below changes:
   In [service] section:
   a. Add KillMode = process
   b. Add TimeoutStopSec = infinity

NOTE:
Creating unit file for services other than uwsgi is handled by the
'write_user_unit_file' function [3]. This function is common for all
the services so this patch adds the above mentioned parameters for
services using ServiceLauncher also though they don't require.

Added a new stackrc variable WORKER_TIMEOUT which is required to add
graceful shutdown support to uwsgi services. It will be set as a value
to 'worker-reload-mercy' [4] in uwsgi file of service. The default
value set to this variable is 90.

[1] https://etherpad.openstack.org/p/uwsgi-issues
[2] https://www.freedesktop.org/software/systemd/man/systemd.kill.html
[3] 2967ca3dfd/functions-common (L1439-L1461)
[4] http://uwsgi-docs.readthedocs.io/en/latest/Options.html#worker-reload-mercy

Co-Authored-By: Dinesh Bhor <dinesh.bhor@nttdata.com>
Change-Id: Ia95291325ce4858b47102dd49504250183f339ab
2017-09-06 11:55:04 +05:30

370 lines
13 KiB
Bash

#!/bin/bash
#
# lib/apache
# Functions to control configuration and operation of apache web server
# Dependencies:
#
# - ``functions`` file
# - ``STACK_USER`` must be defined
#
# lib/apache exports the following functions:
#
# - install_apache_wsgi
# - apache_site_config_for
# - enable_apache_site
# - disable_apache_site
# - start_apache_server
# - stop_apache_server
# - restart_apache_server
# Save trace setting
_XTRACE_LIB_APACHE=$(set +o | grep xtrace)
set +o xtrace
# Allow overriding the default Apache user and group, default to
# current user and his default group.
APACHE_USER=${APACHE_USER:-$STACK_USER}
APACHE_GROUP=${APACHE_GROUP:-$(id -gn $APACHE_USER)}
# Set up apache name and configuration directory
# Note that APACHE_CONF_DIR is really more accurately apache's vhost
# configuration dir but we can't just change this because public interfaces.
if is_ubuntu; then
APACHE_NAME=apache2
APACHE_CONF_DIR=${APACHE_CONF_DIR:-/etc/$APACHE_NAME/sites-available}
APACHE_SETTINGS_DIR=${APACHE_SETTINGS_DIR:-/etc/$APACHE_NAME/conf-enabled}
elif is_fedora; then
APACHE_NAME=httpd
APACHE_CONF_DIR=${APACHE_CONF_DIR:-/etc/$APACHE_NAME/conf.d}
APACHE_SETTINGS_DIR=${APACHE_SETTINGS_DIR:-/etc/$APACHE_NAME/conf.d}
elif is_suse; then
APACHE_NAME=apache2
APACHE_CONF_DIR=${APACHE_CONF_DIR:-/etc/$APACHE_NAME/vhosts.d}
APACHE_SETTINGS_DIR=${APACHE_SETTINGS_DIR:-/etc/$APACHE_NAME/conf.d}
fi
APACHE_LOG_DIR="/var/log/${APACHE_NAME}"
# Functions
# ---------
# Enable apache mod and restart apache if it isn't already enabled.
function enable_apache_mod {
local mod=$1
# Apache installation, because we mark it NOPRIME
if is_ubuntu; then
# Skip mod_version as it is not a valid mod to enable
# on debuntu, instead it is built in.
if [[ "$mod" != "version" ]] && ! a2query -m $mod ; then
sudo a2enmod $mod
restart_apache_server
fi
elif is_suse; then
if ! a2enmod -q $mod ; then
sudo a2enmod $mod
restart_apache_server
fi
elif is_fedora; then
# pass
true
else
exit_distro_not_supported "apache enable mod"
fi
}
# NOTE(sdague): Install uwsgi including apache module, we need to get
# to 2.0.6+ to get a working mod_proxy_uwsgi. We can probably build a
# check for that and do it differently for different platforms.
function install_apache_uwsgi {
local apxs="apxs2"
if is_fedora; then
apxs="apxs"
fi
# Ubuntu xenial is back level on uwsgi so the proxy doesn't
# actually work. Hence we have to build from source for now.
#
# Centos 7 actually has the module in epel, but there was a big
# push to disable epel by default. As such, compile from source
# there as well.
local dir
dir=$(mktemp -d)
pushd $dir
pip_install uwsgi
pip download uwsgi -c $REQUIREMENTS_DIR/upper-constraints.txt
local uwsgi
uwsgi=$(ls uwsgi*)
tar xvf $uwsgi
cd uwsgi*/apache2
sudo $apxs -i -c mod_proxy_uwsgi.c
popd
# delete the temp directory
sudo rm -rf $dir
if is_ubuntu || is_suse ; then
# we've got to enable proxy and proxy_uwsgi for this to work
sudo a2enmod proxy
sudo a2enmod proxy_uwsgi
elif is_fedora; then
# redhat is missing a nice way to turn on/off modules
echo "LoadModule proxy_uwsgi_module modules/mod_proxy_uwsgi.so" \
| sudo tee /etc/httpd/conf.modules.d/02-proxy-uwsgi.conf
fi
restart_apache_server
}
# install_apache_wsgi() - Install Apache server and wsgi module
function install_apache_wsgi {
# Apache installation, because we mark it NOPRIME
if is_ubuntu; then
# Install apache2, which is NOPRIME'd
install_package apache2
if python3_enabled; then
if is_package_installed libapache2-mod-wsgi; then
uninstall_package libapache2-mod-wsgi
fi
install_package libapache2-mod-wsgi-py3
else
install_package libapache2-mod-wsgi
fi
elif is_fedora; then
sudo rm -f /etc/httpd/conf.d/000-*
install_package httpd mod_wsgi
# For consistency with Ubuntu, switch to the worker mpm, as
# the default is prefork
sudo sed -i '/mod_mpm_prefork.so/s/^/#/g' /etc/httpd/conf.modules.d/00-mpm.conf
sudo sed -i '/mod_mpm_worker.so/s/^#//g' /etc/httpd/conf.modules.d/00-mpm.conf
elif is_suse; then
install_package apache2 apache2-mod_wsgi
else
exit_distro_not_supported "apache wsgi installation"
fi
# WSGI isn't enabled by default, enable it
enable_apache_mod wsgi
}
# apache_site_config_for() - The filename of the site's configuration file.
# This function uses the global variables APACHE_NAME and APACHE_CONF_DIR.
#
# On Ubuntu 14.04+, the site configuration file must have a .conf suffix for a2ensite and a2dissite to
# recognise it. a2ensite and a2dissite ignore the .conf suffix used as parameter. The default sites'
# files are 000-default.conf and default-ssl.conf.
#
# On Fedora and openSUSE, any file in /etc/httpd/conf.d/ whose name ends with .conf is enabled.
#
# On RHEL and CentOS, things should hopefully work as in Fedora.
#
# The table below summarizes what should happen on each distribution:
# +----------------------+--------------------+--------------------------+--------------------------+
# | Distribution | File name | Site enabling command | Site disabling command |
# +----------------------+--------------------+--------------------------+--------------------------+
# | Ubuntu 14.04 | site.conf | a2ensite site | a2dissite site |
# | Fedora, RHEL, CentOS | site.conf.disabled | mv site.conf{.disabled,} | mv site.conf{,.disabled} |
# +----------------------+--------------------+--------------------------+--------------------------+
function apache_site_config_for {
local site=$@
if is_ubuntu; then
# Ubuntu 14.04 - Apache 2.4
echo $APACHE_CONF_DIR/${site}.conf
elif is_fedora || is_suse; then
# fedora conf.d is only imported if it ends with .conf so this is approx the same
local enabled_site_file="$APACHE_CONF_DIR/${site}.conf"
if [ -f $enabled_site_file ]; then
echo ${enabled_site_file}
else
echo ${enabled_site_file}.disabled
fi
fi
}
# enable_apache_site() - Enable a particular apache site
function enable_apache_site {
local site=$@
# Many of our sites use mod version. Just enable it.
enable_apache_mod version
if is_ubuntu; then
sudo a2ensite ${site}
elif is_fedora || is_suse; then
local enabled_site_file="$APACHE_CONF_DIR/${site}.conf"
# Do nothing if site already enabled or no site config exists
if [[ -f ${enabled_site_file}.disabled ]] && [[ ! -f ${enabled_site_file} ]]; then
sudo mv ${enabled_site_file}.disabled ${enabled_site_file}
fi
fi
}
# disable_apache_site() - Disable a particular apache site
function disable_apache_site {
local site=$@
if is_ubuntu; then
sudo a2dissite ${site} || true
elif is_fedora || is_suse; then
local enabled_site_file="$APACHE_CONF_DIR/${site}.conf"
# Do nothing if no site config exists
if [[ -f ${enabled_site_file} ]]; then
sudo mv ${enabled_site_file} ${enabled_site_file}.disabled
fi
fi
}
# start_apache_server() - Start running apache server
function start_apache_server {
start_service $APACHE_NAME
}
# stop_apache_server() - Stop running apache server
function stop_apache_server {
if [ -n "$APACHE_NAME" ]; then
stop_service $APACHE_NAME
else
exit_distro_not_supported "apache configuration"
fi
}
# restart_apache_server
function restart_apache_server {
# Apache can be slow to stop, doing an explicit stop, sleep, start helps
# to mitigate issues where apache will claim a port it's listening on is
# still in use and fail to start.
restart_service $APACHE_NAME
}
function write_uwsgi_config {
local file=$1
local wsgi=$2
local url=$3
local http=$4
local name=""
name=$(basename $wsgi)
# create a home for the sockets; note don't use /tmp -- apache has
# a private view of it on some platforms.
local socket_dir='/var/run/uwsgi'
# /var/run will be empty on ubuntu after reboot, so we can use systemd-temptiles
# to automatically create $socket_dir.
sudo mkdir -p /etc/tmpfiles.d/
echo "d $socket_dir 0755 $STACK_USER root" | sudo tee /etc/tmpfiles.d/uwsgi.conf
sudo systemd-tmpfiles --create /etc/tmpfiles.d/uwsgi.conf
local socket="$socket_dir/${name}.socket"
# always cleanup given that we are using iniset here
rm -rf $file
iniset "$file" uwsgi wsgi-file "$wsgi"
iniset "$file" uwsgi processes $API_WORKERS
# This is running standalone
iniset "$file" uwsgi master true
# Set die-on-term & exit-on-reload so that uwsgi shuts down
iniset "$file" uwsgi die-on-term true
iniset "$file" uwsgi exit-on-reload true
# Set worker-reload-mercy so that worker will not exit till the time
# configured after graceful shutdown
iniset "$file" uwsgi worker-reload-mercy $WORKER_TIMEOUT
iniset "$file" uwsgi enable-threads true
iniset "$file" uwsgi plugins python
# uwsgi recommends this to prevent thundering herd on accept.
iniset "$file" uwsgi thunder-lock true
# Set hook to trigger graceful shutdown on SIGTERM
iniset "$file" uwsgi hook-master-start "unix_signal:15 gracefully_kill_them_all"
# Override the default size for headers from the 4k default.
iniset "$file" uwsgi buffer-size 65535
# Make sure the client doesn't try to re-use the connection.
iniset "$file" uwsgi add-header "Connection: close"
# This ensures that file descriptors aren't shared between processes.
iniset "$file" uwsgi lazy-apps true
# If we said bind directly to http, then do that and don't start the apache proxy
if [[ -n "$http" ]]; then
iniset "$file" uwsgi http $http
else
local apache_conf=""
apache_conf=$(apache_site_config_for $name)
echo "SetEnv proxy-sendcl 1" | sudo tee $apache_conf
iniset "$file" uwsgi socket "$socket"
iniset "$file" uwsgi chmod-socket 666
echo "ProxyPass \"${url}\" \"unix:${socket}|uwsgi://uwsgi-uds-${name}/\" retry=0 " | sudo tee -a $apache_conf
enable_apache_site $name
restart_apache_server
fi
}
# For services using chunked encoding, the only services known to use this
# currently are Glance and Swift, we need to use an http proxy instead of
# mod_proxy_uwsgi because the chunked encoding gets dropped. See:
# https://github.com/unbit/uwsgi/issues/1540 You can workaround this on python2
# but that involves having apache buffer the request before sending it to
# uwsgi.
function write_local_uwsgi_http_config {
local file=$1
local wsgi=$2
local url=$3
name=$(basename $wsgi)
# create a home for the sockets; note don't use /tmp -- apache has
# a private view of it on some platforms.
# always cleanup given that we are using iniset here
rm -rf $file
iniset "$file" uwsgi wsgi-file "$wsgi"
port=$(get_random_port)
iniset "$file" uwsgi http-socket "127.0.0.1:$port"
iniset "$file" uwsgi processes $API_WORKERS
# This is running standalone
iniset "$file" uwsgi master true
# Set die-on-term & exit-on-reload so that uwsgi shuts down
iniset "$file" uwsgi die-on-term true
iniset "$file" uwsgi exit-on-reload true
iniset "$file" uwsgi enable-threads true
iniset "$file" uwsgi plugins python
# uwsgi recommends this to prevent thundering herd on accept.
iniset "$file" uwsgi thunder-lock true
# Set hook to trigger graceful shutdown on SIGTERM
iniset "$file" uwsgi hook-master-start "unix_signal:15 gracefully_kill_them_all"
# Set worker-reload-mercy so that worker will not exit till the time
# configured after graceful shutdown
iniset "$file" uwsgi worker-reload-mercy $WORKER_TIMEOUT
# Override the default size for headers from the 4k default.
iniset "$file" uwsgi buffer-size 65535
# Make sure the client doesn't try to re-use the connection.
iniset "$file" uwsgi add-header "Connection: close"
# This ensures that file descriptors aren't shared between processes.
iniset "$file" uwsgi lazy-apps true
iniset "$file" uwsgi chmod-socket 666
iniset "$file" uwsgi http-raw-body true
iniset "$file" uwsgi http-chunked-input true
iniset "$file" uwsgi http-auto-chunked true
iniset "$file" uwsgi http-keepalive false
# Increase socket timeout for slow chunked uploads
iniset "$file" uwsgi socket-timeout 30
enable_apache_mod proxy
enable_apache_mod proxy_http
local apache_conf=""
apache_conf=$(apache_site_config_for $name)
echo "KeepAlive Off" | sudo tee $apache_conf
echo "ProxyPass \"${url}\" \"http://127.0.0.1:$port\" retry=0 " | sudo tee -a $apache_conf
enable_apache_site $name
restart_apache_server
}
function remove_uwsgi_config {
local file=$1
local wsgi=$2
local name=""
name=$(basename $wsgi)
rm -rf $file
disable_apache_site $name
}
# Restore xtrace
$_XTRACE_LIB_APACHE
# Tell emacs to use shell-script-mode
## Local variables:
## mode: shell-script
## End: