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cloud engineer

restart

Rebuild Docker containers

How to rebuild your application from scratch using Docker.

#!/bin/bash
docker-compose down -v
docker rmi $(docker images -a -q)
docker-compose up -d
docker-compose restart -t 10

Steps

  • Purge the containers.
  • Delete docker images.
  • Reinitiate docker.
  • Restart docker.

Tomcat Install

Tomcat requires JRE.

wget jre-8uversion-linux-x64.tar.gz
# or
apt-get install default-jdk

Install Tomcat 8 on Linux.

wget https://mirrors.gigenet.com/apache/tomcat/tomcat-8/v8.5.66/bin/apache-tomcat-8.5.66.tar.gz
tar zxpvf apache-tomcat-8.5.66.tar.gz
cd /opt/tomcat/apache-tomcat-8.5.66/bin/
./startup.sh

Status|Start|Stop|Restart Tomcat.

systemctl status tomcat8
systemctl start tomcat8
systemctl stop tomcat8
systemctl restart tomcat8

Winbind Fix

Here’s the process to restore Winbind.

Restore old config.

cp /etc/sssd/sssd.conf-xxxxxxx /etc/sssd/sssd.conf
cp /etc/krb5.conf-xxxxxxx /etc/krb5.conf

Disable SSSD. Authconfig creates /etc/nswitch.conf.

authconfig --disablesssd --disablesssdauth --updateall

Start Winbind.

service winbind start; service smb start; service nmb start

GCE Agent Bash

This is a Bash script to restart a service.

#!/bin/bash
 
SERVICE=google_osconfig_agent
AGENT=google-osconfig-agent
 
if (( $(ps -ef | grep -v grep | grep $SERVICE | wc -l) > 0 ))
then
    echo "$AGENT service running, everything is fine"
else
    echo "$AGENT is not running"
    echo "Restarting service"
    systemctl start $AGENT
    sleep 5s
    if (( $(ps -ef | grep -v grep | grep $SERVICE | wc -l) > 0 ))
    then
      sleep 2s
      echo "$AGENT service is now running"
    fi
fi

GCE Agent Powershell

This is a Powershell script to restart a service if it’s down.

$ServiceName = 'GCEAgent'
$arrService = Get-Service -Name $ServiceName
 
if ($arrService.Status -ne 'Running')
{
 
    Start-Service $ServiceName
    write-host $arrService.status
    write-host 'Service starting'
    Start-Sleep -seconds 60
    $arrService.Refresh()
    if ($arrService.Status -eq 'Running')
    {
        Write-Host 'GCE Agent Service is now Running'
    }
 
}
else
{
    Write-Host 'GCE Agent Service is Running'
}

WordPress Permalinks Not Working

Here’s a couple of things you can do to check if WordPress permalinks is not working.

  1. Make sure .htaccess has the right permissions.
  2. Make sure a2enmod Apache module is enabled.
  3. Restart the Apache server.
chmod 664 /var/www/domain.com/.htaccess
a2enmod rewrite
systemctl restart apache2

NFS Fails to Mount on Bootup

Check if rpcbind is running.

service rpcbind status|start|stop|restart

Or you can also clean the NFS cache.

service rpcbind stop
service nfslock stop
rm -rf /var/lib/nfs/statd/sm/*
rm -rf /var/lib/nfs/statd/sm.bak/*
service rpcbind start
service nfslock start

Restart SSSD Service

Just documenting how to restart SSSD service. SSSD is a service that allows Active Directory groups access to Linux systems.

systemctl restart sssd.service

For other or older Linux distros, you may have to use this:

service sssd restart

You can always try the other if one doesn’t work.