Using command line kill/power off a virtual machine

VMWARE ESXI CLI

Using the ESXi esxcli command to power off a virtual machine

The esxcli command can be used locally or remotely to power off a virtual machine running on ESXi 5.x or later. For more information, see the esxcli vm Commands section in the vSphere Command-Line Interface Reference.

  1. Open a console session where the esxcli tool is available, either in the ESXi Shell, the vSphere Management Assistant (vMA), or the location where the vSphere Command-Line Interface (vCLI) is installed.
  2. Get a list of running virtual machines, identified by World ID, UUID, Display Name, and path to the .vmx configuration file by running this command:esxcli vm process list
  3. Power off the virtual machine from the list by running this command:esxcli vm process kill --type= [soft,hard,force] --world-id= WorldNumberNotes:
    • Three power-off methods are available. Soft is the most graceful, hard performs an immediate shutdown, and force should be used as a last resort.
    • alternate power off command syntax is: esxcli vm process kill -t [ soft,hard,force] -w WorldNumber
  4. Repeat Step 2 and validate that the virtual machine is no longer running.

Using the ESXi command-line utility vim-cmd to power off the virtual machine

  1. On the ESXi console, enter Tech Support mode and log in as root. For more information, see Tech Support Mode for Emergency Support (1003677).
  2. Get a list of all registered virtual machines, identified by their VMID, Display Name, and path to the .vmx configuration file by running this command:vim-cmd vmsvc/getallvms
  3. Get the current state of a virtual machine by running this command:vim-cmd vmsvc/power.getstate VMID
  4. Shutdown the virtual machine using the VMID found in Step 2 and run this command:vim-cmd vmsvc/power.shutdown VMIDNote: If the virtual machine fails to shut down, run this command:

    vim-cmd vmsvc/power.off VMID

Note: this article is for my quick reference, VMware KB reference (https://kb.vmware.com/s/article/1014165)

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Default ssh username for AMI – AWS EC2 Instances

Amazon EC2
Amazon EC2

Just for my quick reference:

  • For an Amazon Linux AMI, the user name is ec2-user.
  • For a Centos AMI, the user name is centos.
  • For a Debian AMI, the user name is admin or root.
  • For a Fedora AMI, the user name is ec2-user or fedora.
  • For a RHEL AMI, the user name is ec2-user or root.
  • For a SUSE AMI, the user name is ec2-user or root.
  • For an Ubuntu AMI, the user name is ubuntu or root.
  • Otherwise, if ec2-user and root don’t work, check with the AMI provider.

Reference AWS Guide: 

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AccessingInstancesLinux.html#ssh-prereqs

Scan for new SCSI drives without the need to reboot the VM – LINUX

New disk presented to the running LINUX virtual machine will not display the device into operating system unless you reboot the server.

Found another way to achieve this and thought to note it down here for my future reference.

Run the following commands:

The first command returns the SCSI host in use which in this case is host2.:

grep mpt /sys/class/scsi_host/host?/proc_name

The next command, performs a bus scan.

echo “- – -“ > /sys/class/scsi_host/host2/scan

Fdisk is used to list all the available drives on the machine.

Validate if you can view new disk:

fdisk -l

If the newly added drive is still not discovered, then unfortunately just reboot the VM.

Content Referenced article: https://www.altaro.com/vmware/managing-disk-space-linux-vm/

 

Install MHA on RHEL6 / CentOS6 for mySQL

Configure Proxy for Internet

#export http_proxy=http://proxy.xxxx.intra:00
#export https_proxy=https://proxy.xxxx.intra:00

Note: My environment is using a proxy server for Internet access, if you have direct access to internet ignore this step.

Configure RedHat subscription for yum

#subscription-manager register –username admin-example –password secret –auto-attach

Download epel-release package on machine

#wget https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm

Note: the package will be downloaded on the path you are standing – verify from “pwd” command

Install epel-package

#yum install -y epel-release-latest-6.noarch.rpm

Install perl packages

#yum -y install perl-DBD-MySQL perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-Config-IniFiles ncftp perl-Params-Validate perl-CPAN perl-Test-Mock-LWP.noarch perl-LWP-Authen-Negotiate.noarch perl-devel

Install more perl packages

#yum install perl-ExtUtils-CBuilder perl-ExtUtils-MakeMaker

Download MHA Packages (Node & Manager)

https://code.google.com/p/mysql-master-ha/wiki/Downloads?tm=2

– MHA Manager 0.56 rpm RHEL6 – mha4mysql-manager-0.56-0.el6.noarch.rpm
– MHA Node 0.56 rpm RHEL6 – mha4mysql-node-0.56-0.el6.noarch.rpm

Once downloaded copy to server via WinSCP or SSH (somehow it is not working properly in wget for me)

Install MHA Packages

#yum -y install mha4mysql-node-0.56-0.el6.noarch.rpm

#yum -y install mha4mysql-manager-0.56-0.el6.noarch.rpm

Note: Move to directory where packages are downloaded

Docker – Basic Cheat Sheet

docker.com
docker.com

As a learning curve, I had marked Docker in my list

So just tipping some quick commands for your and my own reference as it is not a primary tool I am using day-to-day

Display Docker Images:

$ docker images

Run Docker Image:

$ docker run hello-world

Note: If you do not have an image in your local machine, docker will look into docker hub (over the internet)

Write a docker file:

$ mkdir dockerfolder

$ cd dockerfolder

$ vim newdockerfile

RUN apt-get -y update && apt-get install -y telnet

save and close your newdockerfile “wq!”

Build and image from our Docker File

$ docker build -t telnet-install .

Note: we are using a period in the end of docker build command to represent the newdockerfile within the directory

If you want to run new build file: “docker run telnet-install”

Tag your image-id: (required if you want to push to docker hub)

$ docker tag 693bce725149 terminaltolinux/telnet-install:latest

Note: image id can be found from “docker images” command

Login to docker hub:

$ docker login –username=terminaltolinux –email=terminal@linux.com

Note: after docker login command it will prompt for password, prior have a docker hub account

Push docker image to docker hub account:

$ docker push terminaltolinux/telnet-install

Note: Verify from docker hub account, the docker image will be pushed. Prior create a repo on docker hub

Delete a docker image:

$ docker rmi -f terminaltolinux/telnet-install

Pull docker image from docker hub account:

$ docker run terminaltolinux/telnet-install

Note: it will not find in the local machine as we deleted earlier and will fetch it online and run it, however “docker pull terminaltolinux/telnet-install” can also be used to just pull the image.

Search docker image:

$ docker search mysql

Search docker image with number of stars:

$ docker search -s 1 mysql

Run docker image in background:

$ docker run -d mysql

Run docker image with interactive session:

$ docker run -it ubuntu

List running containers

$ dockers ps

Inspect a container

$ docker inspect <container-id>

Note: container-id will be available from “docker ps”

Logs of standard error or standard out

$ docker log <container-id>

Commit changes to container and save as a separate image. (tag it):

$ docker commit <container-id> nginx-ubuntu

Port binding to container

$ docker run -d -p 6379 reds

Note: -p binds port but if we wanted to map this port directly on the host, we will use the option -p 6379:6379 and if with particular ip then -p 127.0.0.1:6379:6379

Binding directories

$ docker run -d -v “/home/docker/data”:/data reds

Start a container

$ docker start <container-id>

Stop a container

$ docker stop <container-id>

Remove an exited container

$ docker rm <container-id>

Restart a container

$ docker restart <container-id>

Use docker with proxy:

If you want to run docker with environment proxy, edit /etc/default/docker amend your entry for http_proxy

TIP:

If we don’t tell docker explicitly we want to map port, it will block access through that port (because containers are isolated until you tell them you want access)

ANSIBLE 2.0.2.0 – Basic Cheat Sheet – CentOS 6

Ansible,com
Ansible.com

To install Ansible:

# wget http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpminstall epel-release

# yum install epel-release-6-8.noarch.rpm

# yum update

# yum install ansible -y

Add remote hosts:

$ vim /etc/ansible/hosts

192.168.0.1 (your remote server IP) or
hostname.hostname.local (your remote server hostname)

Ping remote hosts: (if using ssh keys for authentication –ask-pass is not required)

$ ansible all -m ping –ask-pass

Ping remote hosts with specific account: (if using ssh keys for authentication –ask-pass is not required)

$ ansible all -m ping –ask-pass -u root

Execute command on remote server shell:

$ ansible all -m shell -a “mkdir /home/ansible/testdirectory” –ask-pass -u root

Remove file from remote server:

$ ansible all -m file -a “dest=/tmp/test.sh state=absent” –ask-pass -u root

Install apache on remote server:

$ ansible all -m yum -a “name=httpd state=latest” -u root

Change file permissions:

$ ansible all -m file -a “dest=/home/ansible/testfile.txt mode=600 owner=ansible group=anisble”

Confirm if package installed but do not update

$ ansible all -m yum -a “name=telnet state=present”

Confirm package is latest version

$ ansible all -m yum -a “name=telnet state=latest”

Confirm package is not installed

$ ansible all -m yum -a “name=telnet state=absent”

Start service

$ ansible all -m service -a “name=httpd state=started”

Restart service

$ ansible all -m service -a “name=httpd state=restarted”

Stop serivce

$ ansible all -m service -a “name=httpd state=stopped”

 

Gathering Facts

$ ansible all -m setup

Distribute Linux flavors in Ansible host file:

$ vim /etc/ansible/hosts

[RHEL]
192.168.1.1
rhel.redhat.test
[SUSE]
192.168.1.2
suse.opensuse.test

Only send instructions on RHEL hosts:

$ ansible RHEL  -m shell -a “mkdir /home/ansible/testfolder” 

Ansible use YaML for Automation and known as Playbook in Ansible

create a playbook i.e an .yaml file eg: telnetPlaybook.yaml


– hosts: SUSE
remote_user: root
tasks:
– zypper: name=telnet state=latest
– hosts: RHEL
remote_user: root
tasks:
– yum: name=telnet state=latest

Run playbook with Ansible: (-f switch allow the execution to be performed on multiple hosts parallel)

$ ansible-playbook telnetPlaybook.yaml -f 10

Ansible Modules (-m): These are few but there is huge list.

command – execute commands and this is default module of Ansible.
copy – copy files
shell – use remote shell to execute
file – file operations
ping – ping remote hosts
yum – Redhat package manager
git – use GIT
user – user creation, manipulation
service – manage services

If you find it interesting, spread the word 🙂

Add static proxy as Env Variable in CentOS / RedHat

PROXY
PROXY

My office environment like many others are providing us Internet via proxy, on Windows Machine/Servers as they are part of domain the policy is pushed and as you login with your domain account you will find it available.

However on Linux servers I always go ahead with doing the following:

export http_proxy=http://proxy.blah.blah:80

And whenever the servers were required to reboot the proxy used to wipe out.

This time I made sure to make it static and plan to push it via Ansible to all the Linux babies I love.

Logged in from root account:

vim /etc/environment
http_proxy=http://proxy.blah.blah:80

Save the file – Re-initialize the shell or logout and login back. You will not have to re-add it back again.

To verify the variable

echo $http_proxy