To start this handson lab,you need following resources.
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prerequisites
1. server.cnl.com – 1 CPU – 1GB RAM (Python 2.7) - Ansible Server
2. node1.cnl.com – 1 CPU – 1GB RAM ( python 2.6 and above) - Ansible Client 1
3. node2.cnl.com – 1 CPU – 1GB RAM ( python 2.6 and above) - Ansible Client 2
from ansible server login as an ansible user as per class 4.From ansible user
execute below command
ansible all -m ping
this above ping command should return with ping / pong green color.
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Using the shell module looks like this:
$ ansible all -m shell -a 'echo $TERM'
To transfer a file directly to many servers:
$ ansible all -m copy -a "src=/etc/hosts dest=/tmp/hosts"
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File Transfer
The file module allows changing ownership and permissions on files. These same
options can be passed directly to the copy module as well:
ansible webservers -m file -a "dest=/var/tmp/a.txt mode=600"
ansible webservers -m file -a "dest=/var/tmp/a.txt mode=600 owner=mdehaan
group=mdehaan"
The file module can also create directories, similar to mkdir -p:
ansible webservers -m file -a "dest=/var/tmp/testing mode=755 owner=mdehaan
group=mdehaan state=directory"
As well as delete directories (recursively) and delete files:
ansible webservers -m file -a "dest=/var/tmp/testing state=absent"
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Managing Packages
There are modules available for yum and apt. Here are some examples with yum.
Ensure a package is installed, but don’t update it:
ansible webservers -m yum -a "name=acme state=present"
Ensure a package is installed to a specific version:
ansible webservers -m yum -a "name=httpd-2.4.6-9* state=present"
Ensure a package is at the latest version:
ansible webservers -m yum -a "name=httpd state=latest"
Ensure a package is not installed:
ansible webservers -m yum -a "name=httpd state=absent"
Ansible has modules for managing packages under many platforms. If there isn’t a
module for your package manager, you can install packages using the command module
or (better!) contribute a module for your package manager. Stop by the mailing list
for info/details.
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Users and Groups
The ‘user’ module allows easy creation and manipulation of existing user accounts,
as well as removal of user accounts that may exist:
ansible all -m user -a "name=foo password=KEnTeaStIFY"
ansible all -m user -a "name=foo state=absent"
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Managing Services
Ensure a service is started on all webservers:
ansible webservers -m service -a "name=httpd state=started"
Alternatively, restart a service on all webservers:
ansible webservers -m service -a "name=httpd state=restarted"
Ensure a service is stopped:
ansible webservers -m service -a "name=httpd state=stopped"
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ansible ad hoc ping command example
ansible all -m ping
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What if you do not have SSH key-based authentication, then enter the user name and
password while invoking the command as shown below.
ansible multi -m ping --user=vagrant --ask-pass
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ansible ad hoc command to check uptime
ansible ad hoc command to check uptime
In this example, we are going to know the uptime of the hosts. Ansible provides two
major modules to run the command over the host group or on the remote server.
Which one to pick is not a big confusion if you know what are they and their
capabilities
FAQ: Ansible command vs shell module
Here are the commands you can use to get the uptime. All three commands would yield
you the same results.
ansible all -m command -a uptime
ansible all -m shell -a uptime
ansible all -a uptime
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ansible ad hoc command to check memory usage
ansible all -a "free -m"
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ansible ad hoc command to get physical memory allocated to the host
ansible all -m shell -a "cat /proc/meminfo|head -2"
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ad hoc command to Create a unix user group
ansible all -m group -a "name=weblogic state=present"
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ad hoc command to Create a unix user
ansible all -m user -a "name=weblogic group=weblogic createhome=yes" -b
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ansible ad hoc command to Create a Directory with 755 permission
ansible all -m file -a "path=/opt/oracle state=directory mode=0755" -b
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ansible ad hoc command to Create a file with 755 permission
ansible all -m file -a "path=/tmp/testfile state=touch mode=0755"
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ad hoc command to Change ownership of a file
ansible all -m file -a "path=/opt/oracle group=weblogic owner=weblogic" -i
ansible_hosts -b
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ansible ad hoc command to check free disk space of hosts
ansible all -a "df -h"
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ansible ad hoc command to Install a package using yum command
ansible all -m yum -a "name=httpd state=installed"
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ansible ad hoc command to Start or stop the service
# To Start
ansible multi -m service -a "name=httod state=started enabled=yes"
# To Stop
ansible multi -m service -a "name=httpd state=stop enabled=yes"
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Managing Cron Job and Scheduling with Ansible ad hoc
# Run the job every 15 minutes
$ ansible all -m cron -a "name='daily-cron-all-servers' minute=*/15
job='/path/to/minute-script.sh'"
# Run the job every four hours
$ ansible all -m cron -a "name='daily-cron-all-servers' hour=4 job='/path/to/hour-
script.sh'"
# Enabling a Job to run at system reboot
$ ansible all -m cron -a "name='daily-cron-all-servers' special_time=reboot
job='/path/to/startup-script.sh'"
# Scheduling a Daily job
$ ansible all -m cron -a "name='daily-cron-all-servers' special_time=daily
job='/path/to/daily-script.sh'"
# Scheduling a Weekly job
$ ansible all -m cron -a "name='daily-cron-all-servers' special_time=weekly
job='/path/to/daily-script.sh'"
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ansible ad hoc command to reboot remote system
n this example we are going to reboot the remote system using the shell module and
Poll 0, it represents fire and forget
To know more about Ansible async and poll refer this article
Rebooting the host in the background is the best example for fire and forget or
async and poll.
ansible all -b -B 1 -P 0 -m shell -a "sleep 5 && reboot"
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ansible ad hoc command to check service status
In this example, we are going to see how to check the status of service using
ansible ad hoc command
ansible all -m shell -a "service httpd status"
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ansible ad hoc command to copy file local to remote
The following ad hoc command with copy module copies the file from Src location on
the local control machine to the specified location on the remote server
ansible all -m copy -a "src=~/var/tmp/index.html dest=/var/www/html owner=apache
group=apache mode=0644"
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ansible ad hoc command to copy directory local to remote
This is an ansible AD HOC command to copy a directory to the remote server
ansible all -m copy -a "src=/var/tmp/test dest=/var/tmp/test owner=apache
group=apache mode=0644 " -i ansible_hosts -b
You need to notice that there is no / at the end of src path. It is just
/var/tmp/test
If you put a slash at the end. It would copy only the contents of the directory
alone but not the directory.
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ansible ad hoc command to list NFS mounts
ansible all -m shell -a 'df -h -T|grep -i nfs' -i ansible_hosts
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adhoc command to collect memory, cpu and OS distribution of a host
ansible node2 -m setup -a "filter=ansible_distribution*"
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ansible ad hoc command to stop, start, restart, reload service
Simple way to restart any service with Ansible ad hoc command is to use Shell
module with the actual service or systemctl command
ansible all -m shell -a "service nginx restart" -b
You can also use Ansible’s built in systemd module otherwise like this.
ansible all -m systemd -a "name=nginx state=reloaded"
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ad hoc command to download file from URL
To download a file from URL in ansible ad hoc. You can either invoke linux commands
like CURL or WGET but the preferred way is to use the get_url module of Ansible.
This is how you can use get_url module in Ansible ad hoc to download a file in
remote system
ansible all -m get_url -a "url=https://nodejs.org/dist/v14.17.4/node-v14.17.4-
linux-x64.tar.xz dest=/tmp mode=0755"
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ad hoc command to check listening ports
ansible all -m listen_ports_facts
