How to Use command in Envoirment Variable Ansible Playbook - ansible

I am trying to use hostname -f command in variable with ansible-playbook. After I set the variable, I will use it in sed command. When manually execute the commands it works but with Ansible, variable does not work.
When I echo $hostn output is empty.
---
- hosts: test
become: true
become_user: root
tasks:
- name: test
shell: "{{ item }}"
with_items:
- hostn=`hostname -f` <<<<<< not working
- echo $hostn <<<<<< not working
- sed -i "s/test/$hostn/g" /file <<<< manually works
Can you help me?

My advise would be that you should not try to fit all your commands in Ansible shell this way, but rather translate them into the corresponding Ansible modules.
What you are looking to achieve can be done with the replace module — in place of sed — and the Ansible fact ansible_hostname — in place of hostname -f.
This would be the equivalent playbook:
- hosts: test
become: true
become_user: root
tasks:
- replace:
path: /file
regexp: test
replace: "{{ ansible_hostname }}"

Related

How to set shell output to a variable in ansible

I need to get a shell output to a variable in set_fact in ansible. And this variable is referred in the somewhere in the same playbook but targeting a different set of hosts
But I am not sure how to do that.
This is my playbook:
---
- hosts: kube-master
tasks:
- name: Print the value
become: true
shell: |
echo "hi"
set_fact:
banuka: <value-taken-from-above-shell-command>
- hosts: kube-minions
tasks:
- name: Print the variable
become: true
shell: |
echo {{banuka}}
But I don't know these:
1. How to get the shell command output to the variable in set_fact and refer it somewhere
2. Is it possible to have multiple hosts (as shown in the above playbook)
I would do it the following way:
---
- hosts: master01
tasks:
- name: Print the value
shell: |
echo "hi"
register: somevariablename
- name: set fact
set_fact:
myvar: "{{ somevariablename.stdout }}"
- hosts: kube-minions
tasks:
- name: Print the variable
shell: |
echo "{{ hostvars['master01'].myvar }}"
It's important to understand, that set_fact only set a variable on the host which it's executed. Since you have a group kube-master it could be executed on each. I had the same issue in a playbook with Kubernetes-Masters and i used one of them as a "primary" e.q. master01. Then the echo hi will only be executed on that one.
In the second hostgroup, you must refer to the hostvars of your kube-master host like the master01.
Do you have the need to run over all the hosts in the group kube-master?

How to execute shell commands in ansible containing special characters

How to execute shell commands in ansible along with special characters?
---
- name: Displaying the ORACLE_HOME
hosts: "{{ hostname }}"
tasks:
- name:
shell: echo $ORACLE_HOME
I want the output of echo $ORACLE_HOME
You need to write something like this :
---
- name: Displaying the ORACLE_HOME
hosts: "{{ hostname }}"
tasks:
- name:
shell: echo $ORACLE_HOME
register: var
- debug: msg="{{ var }}"
or
you can use the registered variable as var.stdout in your code.
As per your comment, use below command to use the shell variable in your playbook :
shell: source <Absolute-Path>/.bash_profile && echo $ORACLE_HOME

Can ansible variables be used to declare hosts in a playbook?

I have a playbook in the format below:
---
- hosts: myIP
tasks:
- name: Install a yum package in Ansible example
yum:
name: ThePackageIWantToInstall
state: present
where myIP and ThePackageIWantToInstall are variables.
When the job template runs, I would like the user in the extra variables popup to be able to go with:
myIP = 192.168.1.1
ThePackageIWantToInstall = nano
As the documentation doesn't provide an example of supplying a variable via a job template, is this possible?
Yes.
- name: Do The Thing
hosts: "{{ foo }}"
roles:
- "{{ role }}"
Need mustaches and quotes.
to run from popup
(I don't use this, but it was suggested as an edit, thanks...)
foo: value
I have achieved similar thing with add_hosts. Here iam not installing package but creating file with name passed from command line. Any number of hosts (separated by commas can be passed from command line).
# cat addhost2.yml
- hosts: localhost
gather_facts: no
tasks:
- add_host:
name: "{{ item }}"
groups: hosts_from_commandline
with_items: "{{ new_hosts_passed.split(',') }}"
- hosts: hosts_from_commandline
tasks:
- name: Ansible create file with name passed from commandline
file:
path: "/tmp/{{ filename_from_commandline }}"
state: touch
# ansible-playbook -i hosts addhost2.yml --extra-vars='new_hosts_passed=192.168.3.104,192.168.3.113 filename_from_commandline=lathamdkv'
Hope this helps

How to get value of --limit argument inside an Ansible playbook?

In ansible, is it possible to get the value of the argument to the "--limit" option within a playbook? I want to do is something like this:
---
- hosts: all
remote user: root
tasks:
- name: The value of the --limit argument
debug:
msg: "argument of --limit is {{ ansible-limit-arg }}"
Then when I run he command:
$ ansible-playbook getLimitArg.yaml --limit webhosts
I'll get this output:
argument of --limit is webhost
Of course, I made up the name of the variable "ansible-limit-arg", but is there a valid way of doing this? I could specify "webhosts" twice, the second time with --extra-args, but that seems a roundabout way of having to do this.
Since Ansible 2.5 you can access the value using a new magic variable ansible_limit, so:
- debug:
var: ansible_limit
Have you considered using the {{ ansible_play_batch }} built-in variable?
- hosts: all
become: "False"
gather_facts: "False"
tasks:
- name: The value of the --limit argument
debug:
msg: "argument of --limit is {{ ansible_play_batch }}"
delegate_to: localhost
It won't tell you exactly what was entered as the argument but it will tell you how Ansible interpreted the --limit arg.
You can't do this without additional plugin/module. If you utterly need this, write action plugin and access options via cli.options (see example).
P.S. If you try to use --limit to run playbooks agains different environments, don't do it, you can accidentally blow your whole infrastructure – use different inventories instead.
Here is the small code block to achieve the same
- block:
- shell: 'echo {{inventory_hostname}} >> /tmp/hosts'
- shell: cat /tmp/hosts
register: servers
- file:
path: /tmp/hosts
state: absent
delegate_to: 127.0.0.1
- debug: var=servers.stdout_lines
Then use stdout_lines output as u wish like mine
- add_host:
name: "{{ item }}"
groups: cluster
ansible_user: "ubuntu"
with_items:
- "{{ servers.stdout_lines }}"

Ansible writing output from multiple task to a single file

In Ansible, I have written an Yaml playbook that takes list of host name and the executes command for each host. I have registered a variable for these task and at the end of executing a task I append output of each command to a single file.
But every time I try to append to my output file, only the last record is getting persisted.
---
- hosts: list_of_hosts
become_user: some user
vars:
output: []
tasks:
- name: some name
command: some command
register: output
failed_when: "'FAILED' in output"
- debug: msg="{{output | to_nice_json}}"
- local_action: copy content='{{output | to_nice_json}}' dest="/path/to/my/local/file"
I even tried to append using lineinfile using insertafter parameter yet was not successful.
Anything that I am missing?
You can try something like this:
- name: dummy
hosts: myhosts
serial: 1
tasks:
- name: create file
file:
dest: /tmp/foo
state: touch
delegate_to: localhost
- name: run cmd
shell: echo "{{ inventory_hostname }}"
register: op
- name: append
lineinfile:
dest: /tmp/foo
line: "{{ op }}"
insertafter: EOF
delegate_to: localhost
I have used serial: 1 as I am not sure if lineinfile tasks running in parallel will garble the output file.
Ansible doc recommend use copy:
- name: get jstack
shell: "/usr/lib/jvm/java/bin/jstack -l {{PID_JAVA_APP}}"
args:
executable: /bin/bash
register: jstackOut
- name: write jstack
copy:
content: "{{jstackOut.stdout}}"
dest: "tmp/jstack.txt"
If you want write local file, add this:
delegate_to: localhost
Why to complicate things ?
I did this like that and it worked:
ansible-playbook your_playbook.yml >> /file/you/want/to/redirect/output.txt
you can also try some parsing with grep or some other stuff with tee -a.

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