Python migration with Alembic

$ pip install alembic
$ alembic init --template generic alembic

edit alembic.ini

sqlalchemy.url = mysql://root:@localhost/database_name
$ alembic current
$ alembic revision -m "Init"
$ alembic upgrade head
INFO [alembic.migration] Context impl MySQLImpl. INFO [alembic.migration] Will assume non-transactional DDL. INFO [alembic.migration] Running upgrade None -> 174f01a0ar12, Init

Get rid of “Another update is currently in progress” in WordPress

When you updating one of your resources in wordpress, accidentally you close the window (that’s what I did).

Then when you try to update it again, there is still another process already running. You need to get rid of this before you continue.

Use wp-cli:

wp option delete core_updater.lock

Setup python app in centos from scratch (centos 6.9+uwsgi+nginx+flask+mysql)

Initial setup

$ sudo yum update
$ sudo yum install epel-release
$ sudo yum groupinstall "Development tools"
$ sudo yum install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel telnet htop
$ sudo yum install python-devel python-virtualenv
$ sudo yum install mysql-connector-python mysql-devel mysql-server

Install Python

Download and install Python :

./configure && make && make altinstall

Install uWSGI

$ wget
$ which python2.7
$ sudo /usr/local/bin/python2.7
$ which pip2.7
$ sudo /usr/local/bin/pip2.7 install uWSGI
$ which uwsgi
$ uwsgi --version

Setup vassels

$ sudo mkdir -p /etc/uwsgi/vassels

Setup Emperor service

$ sudo vim /etc/init.d/emperor
# chkconfig: 2345 99 10
# Description: Starts and stops the emperor-uwsgi
# See how we were called.
RUNEMPEROR="/usr/local/bin/uwsgi --emperor=/etc/uwsgi/vassels"
start() {
if [ -f /var/run/$PIDNAME ] && kill -0 $(cat /var/run/$PIDNAME); then
echo 'Service emperor-uwsgi already running' >&2
return 1
echo 'Starting Emperor...' >&2
local CMD="$RUNEMPEROR &> \"$LOGFILE\" & echo \$!"
su -c "$CMD" > "$PIDFILE"
echo 'Service started' >&2
stop() {
if [ ! -f "$PIDFILE" ] || ! kill -0 $(cat "$PIDFILE"); then
echo 'Service emperor-uwsgi not running' >&2
return 1
echo 'Stopping emperor-uwsgi' >&2
kill -7 $(cat "$PIDFILE") && rm -f "$PIDFILE"
echo 'Service stopped' >&2
status() {
if [ ! -f "$PIDFILE" ]; then
echo "Emperor is not running." >&2
return 1
echo "Emperor (pid  `cat ${PIDFILE}`) is running..."
ps -ef |grep `cat $PIDFILE`| grep -v grep
case "$1" in
echo "Usage: emperor {start|stop|restart}"
exit 1

 Setup app user & environment

$ useradd foobar
$ usermod -md /srv/foobar foobar
$ chmod 755 /srv/foobar
$ sudo su - foobar
foobar@local~$ virtualenv --python=python2.7 ~/venv
foobar@local~$ mkdir www
foobar@local~$ mkdir logs
foobar@local~$ touch logs/uwsgi.log
foobar@local~$ touch uwsgi.ini
foobar@local~$ echo "source ~/venv/bin/activate" >> ~/.bashrc
foobar@local~$ source ~/venv/bin/activate
(venv)foobar@local~$ vim uwsgi.ini
master = true
processes = 2
socket = /tmp/foobar.sock
chdir = /srv/foobar/www
virtualenv = /srv/foobar/venv
module = app:app
uid = foobar
chown-socket = foobar:nginx
chmod-socket = 660
vacuum = true
die-on-term = true
python-autoreload = 3
py-autoreload = 1
logger = file:/srv/foobar/logs/uwsgi.log

Exit from foobar user & create uwsgi symlink

(venv)foobar@local~$ exit
$ sudo ln -s /srv/foobar/uwsgi.ini /etc/uwsgi/vassels/foobar.ini

Start emperor service & setup set the startup

$ sudo service emperor start
$ sudo chkconfig emperor on

How to move your old repo to github

Before you begin, you might want to add your ssh key into your github account.

// push master branch
$ cd /repo-directory
$ git remote rename origin bitbucket
$ git remote add origin
$ git push origin master
$ git remote rm bitbucket
// push another branch
$ git checkout develop
$ git push origin -u develop

Setup read and write samba share in vagrant centos

Tested on vagrant centos 6.9
In your vagrant machine:

$ sudo yum install samba samba-common samba-client

Setup samba config, place this config at the bottom of the file:

$ sudo vim /etc/samba/smb.conf
browseable = yes
path = /srv/foobar
guest ok = yes
public = yes
read only = no
create mask = 0644
directory mask = 0755
force user = foobar
valid users = foobar
writable = yes
$ sudo /etc/init.d/smb restart

Setup your samba user password, this password will be used for mount the directory from your local machine:

$ sudo smbpasswd -a foobar

In your local machine:

Mount the foobar project directory, enter your samba password here:

$ sudo mount -t cifs -o username=foobar,uid=1003,gid=1003 // /tmp/foobar

Explanations command line above:

1003 is the user local id, you can check it by type:

$ id
uid=1003(mylocaluser) gid=1003(mylocaluser) is the vagrant ip address

tmp/foobar is a mounted folder from original directory in vagrant