service { "sshd" :
  ensure => "running",
  enable => "true",
  require => Package["openssh-server"],
}

file { "/etc/ssh/sshd_config" :
  notify => Service["sshd"],
  mode   => 700,
  owner  => root,
  group  => root,
  source => "puppet:///modules/openssh-server/sshd_config",
}

# find /etc/puppet/ -name "*.pp" -exec puppet parser validate {} \;

# find /etc/puppet/ -name "*.erb" -exec puppet parser validate {} \;

curl -X GET http://127.0.0.1:8080/v4/resources --data-urlencode  query@<query_file>

curl -X GET http://127.0.0.1:8080/v4/nodes
curl -X GET http://127.0.0.1:8080/v4/facts
curl -X GET http://127.0.0.1:8080/v4/facts/kernel
curl -X GET http://127.0.0.1:8080/v4/nodes --data-urlencode 'query=["not",["=","report-timestamp",null]]'
curl -X GET http://127.0.0.1:8080/v4/nodes --data-urlencode 'query=["<","report-timestamp","2016-08-15T00:00:01.000Z"]'
curl -X GET http://127.0.0.1:8080/v4/facts --data-urlencode 'query=["=","name","apt_reboot_required"]'

# crontab -l
#        0 3 * * * /usr/bin/monit unmonitor myservice
#        0 4 * * * /usr/bin/monit monitor myservice

# monit unmonitor all

# monit -g myservicegroup unmonitor

rs.initiate(
   {
      _id: "myclust",
      version: 1,
      members: [
         { _id: 0, host : "10.0.0.1" },
         { _id: 2, host : "10.0.0.2" },
         { _id: 2, host : "10.0.0.3" }
      ]
   }
)

:> rs.status()

:PRIMARY> rs.add('10.0.0.3')

:SECONDARY> rs.syncFrom('10.0.0.1')

:SECONDARY> rs.freeze(120)

:PRIMARY> rs.stepDown(120)

:> db.serverStatus()

# mongostat
# mongotop

:> db.serverStatus().wiredTiger.cache

storage:
 wiredTiger:
  engineConfig:
    configString : cache_size=1024M

# mongodump --host 127.0.0.1 -o mongoback/

# mongorestore mongoback/

if test -f /sys/kernel/mm/transparent_hugepage/enabled; then
   echo never > /sys/kernel/mm/transparent_hugepage/enabled
fi
if test -f /sys/kernel/mm/transparent_hugepage/defrag; then
   echo never > /sys/kernel/mm/transparent_hugepage/defrag
fi

# qemu-img convert -f raw -O qcow2 image.raw image.qcow2

# su - postgres
# psql

postgres=# \l

postgres=# \du

postgres=# CREATE ROLE demorole1 WITH LOGIN ENCRYPTED PASSWORD 'password1' CREATEDB;

postgres=# CREATE ROLE demorole1 WITH LOGIN ENCRYPTED PASSWORD
postgres=# 'password1' CREATEDB CREATEROLE REPLICATION SUPERUSER;

postgres=# ALTER ROLE demorole1 CREATEROLE CREATEDB REPLICATION SUPERUSER;

postgres=# DROP ROLE demorole1;

postgres=# CREATE DATABASE demodb1 WITH OWNER demorole1 ENCODING 'UTF8';

postgres=# GRANT ALL PRIVILEGES ON DATABASE demodb1 TO demorole1;

postgres=# DROP DATABASE demodb1;

postgres=# \c <databasename>

postgres=# \dt

postgres=# \d <tablename>

SELECT * from pg_stat_activity ;

SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname = 'mydataabse' AND leader_pid IS NULL;

postgres=# \x on

postgres=#
\copy (
select * from truc
) To 'output.csv' With CSV DELIMITER ';' HEADER

postgres=# SELECT pg_cancel_backend(<pid of the process>)
postgres=# SELECT pg_terminate_backend(<pid of the process>)

SELECT * FROM pg_catalog.pg_tables;

$ pg_dump -h ${TARGET_HOST} -p ${PG_PORT} -U ${PG_USER} -Fd -f ${TARGET_DIR} ${PG_DB}
$ pg_restore -c -Fd -d ${PG_DB} ${BACKUP_DIR}

$ pg_dump -U username -h hostname dbname > dump.sql
$ psql -U username -d dbname -f dump.sql

postgres=# select client_addr, state, sent_location, write_location,flush_location, replay_location from pg_stat_replication;

postgres=# select now() - pg_last_xact_replay_timestamp() AS replication_delay;

select pg_xlog_replay_pause();

select pg_xlog_replay_resume();

/etc/init.d/postgresql stop

/usr/lib/postgresql/9.5/bin/pg_controldata /var/lib/postgresql/9.5/main/

sudo -u postgres /usr/lib/postgresql/9.5/bin/pg_resetxlog -o $NEXTOID -x $NEXTXID -f /var/lib/postgresql/9.5/main/

/etc/init.d/postgresql start

vagrant init

vagrant up

vagrant status

vagrant ssh

vagrant halt

vagrant destroy

# exiqgrep -i -f fromuser@domain.com | xargs exim -Mrm

# exiqgrep -i -t touser@domain.com | xargs exim -Mrm

# exim -qf

$ mysqld --wsrep-new-cluster &

$ mysqld --wsrep_cluster_address=gcomm://192.168.0.1  # DNS names work as well

mysql> show global status like '%wsrep%';