k8s_nfs_persistent_volume

Create nfs persistent volume:

What you need

• NFS Server I have used NFS already installed on my QNAP NAS (You need to enable NO_ROOT_SQUASH on permissions)

• K8s cluster

Now having your NFS share here 192.168.1.11/Persistentvolume/ you can try if it works with mount

sudo mount -t nfs 192.168.1.11:/PersistentVolume /mnt/PersistentVolume

Later on you can secure access with password.

If everything works fine we need persistent volume on our cluster

persistentvolume.yml

apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv0001
spec:
  capacity:
    storage: 100Gi
  accessModes:
  - ReadWriteMany
  mountOptions:
    - nfsvers=4.1
  nfs:
    path: /PersistentVolume/pv0001
    server: 192.168.1.11
  persistentVolumeReclaimPolicy: Retain

Apply above yaml to the cluster

kubectl apply -f persistentvolume.yml

Now we need to declare persistent volume claim

persistentvolumeclaim.yml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pv-claim
spec:
  accessModes:
    - ReadWriteMany 
  resources:
    requests:
      storage: 10Gi

Apply

kubectl apply -f persistentvolumeclaim.yml

Check if it has been bound:

kubectl get pv

NAME     CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                    STORAGECLASS   REASON   AGE
pv0001   100Gi      RWX            Retain           Bound    default/mysql-pv-claim                           2d4h

kubectl get pvc 
NAME              STATUS    VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS   AGE
mysql-pv-claim    Bound     pv0001   100Gi      RWX                           2d4h

To install zabbix server quickly zabbix comes with help as they have prebuild their product with docker images. There is lots of official zabbix images on dockerhub so it can just overwhelm you. There are mixes of all different possibilities like zabbix with mysql or postgres or either sqlite, zabbix served bt nginx or apache or java gateway. Depending on stack which is closest to you you can easily build docker-compose that will just run selected stack in seconds. My pick was nginx mysql so to set up fully running zabbix server we need 3 images

• mysql-server

• zabbix-web - web interface

• zabbix-server - main zabbix process responsible for polling and trapping data and sending notifications to users.

In addition you can add postfix mail server for notifying users but its not a must as you can use your own mail server if so - just remove postfix service from example below.

Notice(you may want to use some specific versions or alpine versions for production env)

Create some directory (directory name is crucial here for visibility and future maitenance of your containers and volumes or networks as the name will be used as prefix for docker containers created by docker-compose and also volumes directories so it will be easier to identify in future which volume belongs to which stack In Ubuntu volumes are usually being kept in/var/lib/docker/volumes but you can mount any directory from host by just specifying absolute or relative path in service configuration so for instance for mysql in example to mount mysql_data_dir just outside of our containers folder

volumes:
  - '../mysql_data_dir:/var/lib/mysql'

Now within directory create docker-compose.yml with selected technologies in my case it is: #docker-compose.yml

version: '3'

services:
  db:
    image: mysql:latest
    restart: always
    expose:
      - '3336'
    environment:
      MYSQL_ROOT_PASSWORD: 'my_secret_password'
      MYSQL_USER: 'zabbixuser'
      MYSQL_PASSWORD: 'zabbix_password'
      MYSQL_ROOT_HOST: '%'
    volumes:
      - 'mysql_data_dir:/var/lib/mysql'


  zabbix-server:
    image: zabbix/zabbix-server-mysql
    links:
      - "db:mysql"
      - "postfix:postfix"
    environment:
      MYSQL_ROOT_PASSWORD: 'my_secret_password'
      MYSQL_USER: 'zabbixuser'
      MYSQL_PASSWORD: 'zabbixpassassword'
      DB_SERVER_HOST: 'mysql'


  zabbix-web:
    image: zabbix/zabbix-web-nginx-mysql
    ports:
      - '7777:80'
    links:
      - "db:mysql"
      - "zabbix-server:zabbix-server"
      - "postfix:postfix"
    environment:
      MYSQL_ROOT_PASSWORD: 'my_secret_password'
      MYSQL_USER: 'zabbixuser'
      MYSQL_PASSWORD: 'zabbixpassassword'
      DB_SERVER_HOST: 'mysql'
      ZBX_SERVER_HOST: "zabbix-server"
      PHP_TZ: "Europe/London"
  postfix:
    image: catatnight/postfix
    hostname: support
    environment:
      - maildomain=mydomain.com
      - smtp_user=admin:my_password
    ports:
      - "25:25"
    expose:
      - "25"
    volumes:
      - /etc/nginx/ssl/postfix:/etc/postfix/certs
      - /etc/nginx/ssl/postfix:/etc/opendkim/domainkeys
volumes:
  mysql_data_dir:
    driver: local

The above solution is just enough to start zabbix server up and running in couple seconds. To do it just run: .. code-block:: bash

sudo docker-compose up

Thats it!!! You now have your zabbix running on port 7777

So what happened here docker-compose up has build and runned 3 containers by running zabbix container it discovered there are no tables in mysql and has built them.

Now you just need to add agents/servers you want to monitor. Check out adding agent in separate post

Versions: (versions I've used in this example Feb 2018):

Docker-compose: 1.17.0, build ac53b73 Docker: 17.09.1-ce, build 19e2cf6 Kernel: 4.13.0-36-generic System: Ubuntu 16.04.3 LTS

Zabbix is very powerfull tool which its using agents (or SNMP) to monitor server resources. Adding agent is easy but I had couple problems doing that when I used agent straight from my ubuntus (16.04.3) repo as there was no encryption functionality in this agent well I guess so as agent didn't recognize tls psk configuration so not very nice as by installing agent straight form repo with "sudo apt-get update && sudo apt-get install zabbix-agent" I had limited functionality and unencrypted server-agent traffic. So there are 2 options we can install zabbix agent or use zabbix agent docker container. Adding zabbix agent to host system. For current day 3.2 is the latest so please change latest accordingly of how this artcile is old. wget http://repo.zabbix.com/zabbix/3.2/ubuntu/pool/main/z/zabbix-release/zabbix-release_3.2-1+xenial_all.deb sudo dpkg -i zabbix-release_3.2-1+xenial_all.deb sudo apt-get update apt-get purge zabbix-agent #remove previous if installed apt-get install zabbix-agent

Now there are 3 basic options that need to be changed in agent config file: /etc/zabbix/zabbix_agentd.conf

Server=ip of zabbix server ServerActive=ip of zabbix server Hostname=My host name

sudo service zabbix-agent restart

Check files changed between branches

git diff --name-status master..devel

Check changes on file form different branch/commit

git diff commit_hash -- filename

Same as above between 2 branches/commits

git diff commit_hash master -- filename

Check full file history

git log -p -- filename

Check who broke production server :

git blame filename

Merge as one commit (need to commit afterwards) its not default like in normal merge:

git merge --squash branch

List of commits in git local storage

git reflog

Take(checkout) file from different branch/commit

git checkout develop -- filename
git checkout commit_hash -- filename

Reset current branch to remote:

git reset --hard origin/current_branch
git reset --hard origin/master

Save and depracate changes which were not commited

git stash
git stash save -a

Restore stash (by picking selected)

git stash list
git stash pop {0}

Recently I wrote fabric deployment scrip maybe someone will find it usefull.

It enables possibility to run "group execute" task with

fab live_servers pull restart

or single host

fab live1 pull

All we need to do is to define group or sinle host as function afterwards I used end update decorator.

I know there could be also something like duplication of tasks with separate servers fab live1 pull live2 pull but I believe that fabric was written for distributed systems which has different paths of apps and users etc.

also roledefs with extra dict keys didn't work for me)? I want to keep this simple single/multiple host deployment commands like : fab live_servers pull, fab test pull

from fabric.api import run, env, local, get, cd
from fabric.tasks import execute
import inspect
import sys
import os
import re
from StringIO import StringIO

# fabfile author: Grzegorz Stencel
# usage:
# run: fab help for examples
# fab staging svnxapp:app=holdings_and_quotes,layout.py,permissions.py restart
# fab test svnxlib

SERVER_BRANCHES = {
    'live': 'master',
    'sit': 'sit',
    'uat': 'uat',
    'live2':'master',
    'live3':'master'

}
# MAIN CONF
SERVERS = {
    'local': {
        'envname': 'local',
        'user': 'greg',
        'host': 'localhost',
        'host_string': 'localhost',
        'path': os.environ.get('SITE_ROOT', '/opt/myapp/test'),
        'www_root': 'http://localhost:8081/',
        'retries_before_killing': 3,
        'retry_sleep': 2
    },
    'test': {
        'envname': 'test',
        'user': 'root',
        'host': 'myapp-test.stencel.com',
        'host_string': 'myapp-test.stencel.com',
        'path': '/var/www/myapp/test/',
        'www_root': 'http://myapp-test.stencel.com/',
        'retries_before_killing': 3,
        'retry_sleep': 2
    },
    'uat': {
        'envname': 'uat',
        'user': 'myapp',
        'host': 'uat.myapp2.stencel.com',
        'host_string': 'uat.myapp2.stencel.com',
        'key_filename': 'deploy/keys/id_rsa',
        'path': '/opt/myapp/uat/',
        'www_root': 'http://uat.myapp2.stencel.com/',
        'retries_before_killing': 3,
        'retry_sleep': 2
    },
    'sit': {
        'envname': 'sit',
        'user': 'myapp',
        'host': 'sit.myapp2.stencel.com',
        'host_string': 'sit.myapp2.stencel.com',
        'key_filename': 'deploy/keys/id_rsa',
        'path': '/opt/myapp/sit/',
        'www_root': 'http://sit.myapp2.stencel.com/',
        'retries_before_killing': 3,
        'retry_sleep': 2
    },
    'live': {
        'envname': 'live',
        'user': 'myapp',
        'host': '10.10.10.10',
        'host_string': 'myapp2.stencel.com',
        'path': '/opt/myapp/live/',
        'www_root': 'http://myapp2.stencel.com/',
        'retries_before_killing': 3,
        'retry_sleep': 2
    },
    'live2': {
        'envname': 'live2',
        'user': 'root',
        'host': '10.10.10.11',
        'host_string': 'live2.stencel.com',
        'path': '/var/www/myapp/live/',
        'www_root': 'http://myapp2.stencel.com/',
        'retries_before_killing': 3,
        'retry_sleep': 2
    },
    'live3': {
        'envname': 'live3',
        'user': 'root',
        'host': '10.10.10.12',
        'host_string': 'live3.stencel.com',
        'path': '/var/www/myapp/live/',
        'www_root': 'http://myapp2.stencel.com/',
        'retries_before_killing': 3,
        'retry_sleep': 2
    },

}

LIVE_HOSTS = ['live', 'live2', 'live3']


def list_hosts():
    """
    Lists available myapp hosts
    """
    print " Single hosts(if you want to pull from svn only to one of them):"
    print '   %s' % '\n   '.join([a for a in SERVERS])
    print " Multiple hosts"
    print '   live (which contains %s)' % ','.join([a for a in LIVE_HOSTS])


def test():
    """
    single host definition , "fab test restart" wil restart this one host

    """
    env.update(dict(SERVERS['test']))


def localhost():
    """
    single host definition , "fab test restart" wil restart this one host

    """
    env.update(dict(SERVERS['local']))


def uat():
    """
    single host definition , "fab uat restart" wil restart this single host

    """
    env.update(dict(SERVERS['uat']))


def sit():
    """
    single host

    """
    env.update(dict(SERVERS['sit']))


#  SERVERS GRcompanyS DEFINITION
def live():
    """
    multiple grcompany of hosts - running: "fab live restart" will restart all live servers

    """
    env['hosts'] = [SERVERS[a]['host'] for a in LIVE_HOSTS]

    # env.update(dict(SERVERS['staging']))


def env_update(func):
    """
    Decorator - needs to be added to each task in fabricfile - for multiple host task execution
    """

    def func_wrapper(*args, **kwargs):
        if not len(env.hosts):
            return func(*args, **kwargs)
        else:
            env.update(dict(SERVERS[filter(lambda x: SERVERS[x]['host'] == env.host, MyApp_SERVERS)[0]]))
            func(*args, **kwargs)

    return func_wrapper


@env_update
def bundle_media():
    """
    bundles media like css and js to one file.
    example:
        fab test bundle_media
    """
    # export DJANGO_SETTINGS_MODULE=settings
    #run("cd {0} && source settings/{1}-config.sh && python scripts/bundle_media.py".format(env.path,env.envname))
   run("source /usr/share/virtualenvwrapper/virtualenvwrapper.sh && workon {0} && python scripts/bundle_media.py".format("%s-myapp" % env.envname if env.envname<> 'live' else 'MyApp-test')) #change live venv to be live-MyApp

def _valid_branch(env):
    branch = run("cd {0} && git rev-parse --abbrev-ref HEAD".format(env.path))
    return branch == SERVER_BRANCHES[env.envname] and not env.envname=='local'


@env_update
def pull(*args, **kwargs):
    if _valid_branch(env):
        with cd(env.path):
            run("git fetch origin")
            run("git reset --hard origin/%s" % branch)
    else:
        print "Error : Server is checked out to wrong branch!!!"


            #run('git fetch --quiet')
            #run('git fetch --tags --quiet')

@env_update
def reload():
    """
    Reload specified servers - kills unused gunicorn workers but waits workers with old code to finish processing.

    """
    bundle_media()

    #if env.envname in ('uat', 'staging', 'live'):
    f = StringIO()
    get("/opt/myapp/%s/pid" % env.envname,f)
    pid = re.search(r'\d+',f.getvalue()).group()
    run("ps aux | grep gunicorn | grep %s | grep master | grep -v grep | awk '{print $2}'" % env.envname)
    run("kill -HUP %s" % pid)


@env_update
def restart():
    """
    Hard restarts specified servers

    """
    bundle_media()
    run("ps aux | grep gunicorn | grep %s | grep master | grep -v grep | awk '{print $2}'" % env.envname)
    run("supervisorctl stop myapp-%s && supervisorctl start MyApp-%s" % (env.envname,env.envname))
    run("ps aux | grep gunicorn | grep %s | grep master | grep -v grep | awk '{print $2}'" % env.envname)


def help():
    fabric_functions = ['run', 'execute', 'local', 'func_wrapper']
    functions = set([obj.__name__ if obj.__name__ not in fabric_functions else '' for name, obj in
                     inspect.getmembers(sys.modules[__name__]) if inspect.isfunction(obj)])
    functions.remove('')
    print "usage: \n  fab [host/grcompany of hosts] [commands] (optional command with arguments command:kwarg=val,arg1,arg2,arg3)"
    print "\navailable servers:"
    list_hosts()
    print "\ncommands:\n  %s" % ', '.join([a for a in functions])
    print "\nexamples:\n  staging svnxapp:app=holdings_and_quotes,layout.py,permissions.py restart"
    print "  fab test restart"
    print "  fab staging svnxapp:app=holdings_and_quotes,lib/quote.py,layout.py,models.py"
    print "  fab staging svnxapp:app=holdings_and_quotes,lib/quote.py restart"
    print "  fab test build"
    print "  fab test bundle_media restart"
    print " For svnx whole app (comma in the end):"
    print "  fab test svnxapp:app=medrep,"
    print " For global lib:"
    print "  fab test svnxlib"
    print " For whole global media:"
    print "  fab test svnxmedia:"
    print " For global media file:"
    print "  fab test svnxmedia:javascript"
    print "  fab test svnxmedia:javascript/company/checklist.js"
    print "\nIf .js file in args like : fab staging svnxapp:app=holdings_and_quotes,media/js/quote.js,layout.py,models.py"
    print "It will bundle media itself"
    print "Restart test staging without params:\n  fab restart"
    for f in functions:
        print f
        print globals()[f].__doc__
        print "\n"



@env_update
def accessguni():
    run("tail /var/log/myapp/access-%s.log" % env.envname.upper() )

@env_update
def accessgunilive():
    run("tail -f /var/log/myapp/access-%s.log" % env.envname.upper() )

@env_update
def errorguni():
    run("tail /var/log/myapp/error-%s.log" % env.envname.upper() )

@env_update
def errorgunilive():
    run("tail -f /var/log/myapp/error.log" % env.envname.upper() )

def hostname():
    run('uname -a')

@env_update
def uptime():
    run('uptime')

Tempted by post on official google admins blog http://googlewebmastercentral.blogspot.co.uk/2014/08/https-as-ranking-signal.html it's about higher ranking when having https. So I have recently bought cheap ssl certificate from known issuer COMODO and upgraded my server with it but it caused several problems when I redirected from 80 to 443 some 3rd party apps (like userena for django) created loops but I found solution quickly it was to put USERENA_USE_HTTPS=True in settings.py but it still sends more forgot password mails than it should but it's different story.

Comming back to point if you are experiencing error "sec_error_unknown_issuer" in firefox after implementing COMODO Positive-SSL certificate this solution may help you. Don't know exactly but I read that it has something to do with chain certificates they should be bundled inside you website certificate. And remember you have to do it in right order because first one should be your servers certificate cause it's signed with key) and nginx or whatever you use may have problems after reloading service.

My command for bundling was:

cat exerceo_pl.crt COMODORSADomainValidationSecureServerCA.crt COMODORSAAddTrustCA.crt AddTrustExternalCARoot.crt > exerceo_pl.bundled.crt after that I had just to point my nginx.conf to new bundled certificate. And after all reaload of nginx fixed my unknow issuer firefox problem.

adding resolution 1)generate mode cvt 2560 1440 60 ➜ blog git:(website) ✗ cvt 2560 1440 60 # 2560x1440 59.96 Hz (CVT 3.69M9) hsync: 89.52 kHz; pclk: 312.25 MHz Modeline "2560x1440_60.00" 312.25 2560 2752 3024 3488 1440 1443 1448 1493 -hsync +vsync

2)add it to xrandr sudo xrandr --newmode "2560x1440_60.00" 312.25 2560 2752 3024 3488 1440 1443 1448 1493 -hsync +vsync setting resolution

3)sudo xrandr --addmode VGA-0 "1680x1050_60.00"

xrandr -q xrandr --verbose

xrandr --output HDMI-0 --mode 2560x1440

irst generate a "modeline" by using cvt Syntax is: cvt width height refreshrate

cvt 1680 1050 60 this gives you:

# 1680x1050 59.95 Hz (CVT 1.76MA) hsync: 65.29 kHz; pclk: 146.25 MHz Modeline "1680x1050_60.00" 146.25 1680 1784 1960 2240 1050 1053 1059 1089 -hsync +vsync Now tell this to xrandr:

sudo xrandr --newmode "1680x1050_60.00" 146.25 1680 1784 1960 2240 1050 1053 1059 1089 -

First clone the two screens, (the smaller screen will display the top left portion of the virtual screen)

xrandr --output VGA --auto --right-of LVDS

xrandr --output LVDS --mode 1280x800

xrandr --output LVDS --mode 1280x800 --rate 75

xrandr --output LVDS --auto

xrandr --output LVDS --off --output HDMI-0 --auto

xrandr --output VGA1 --mode 1024x768 --rate 60

#Laptop right extra Monitor Left

xrandr --output VGA1 --left-of LVDS1

#Laptop left extra Monitor right

xrandr --output LVDS1 --left-of VGA1

#This is to set your primary monitor.

#This sets your laptop monitor as your primary monitor.

xrandr --output LVDS1 --primary

#This sets your VGA monitor as your primary monitor.

xrandr --output VGA1 --primary

xrandr --output VGA1 --mode 1024x768 --rate 60

xrandr --pos <x>x<y>

$ xrandr --left-of <output>

$ xrandr --right-of <output>

$ xrandr --above <output>

$ xrandr --below <output>

Option '-pos' is more flexible which can place output to anywhere, for example:

$ xrandr --output VGA1 --pos 200x200 $ xrandr --output LVDS1 --pos 400x500

xrandr -o right