I'm trying to assign hostname to a few hosts, gathering it from inventory.
My inventory is:
[masters]
master.domain.tld
[workers]
worker1.domain.tld
worker2.domain.tld
[all:vars]
ansible_user=root
ansible_ssh_private_key_file=~/.ssh/id_rsa
The code I'm using is:
- name: Set hostname
shell: hostnamectl set-hostname {{ item }}
with_items: "{{ groups['all'] }}"
Unfortunately, code iterate all items (both IPs and hostnames) and assigns to all 3 hosts the last item...
Any help would be much appreciated.
Don't loop: this is going through all your hosts on each target. Use only the natural inventory loop and the inventory_hostname special var.
Moreover, don't use shell when there is a dedicated module
- name: Assign hostname
hosts: all
gather_facts: false
tasks:
- name: Set hostname for target
hostname:
name: "{{ inventory_hostname }}"
Related
I want to dynamically create an in-memory inventory which is a filter of a standard inventory including only the host where a specific service is installed. The filtered inventory is to be used in a subsequent play.
So I identify the IP address of the host where the service is installed.
- name: find where the service is installed
win_service:
name: "{{ service }}"
register: service_info
This returns a boolean 'exists' value. Using this value as a condition an attempt to add the host where the service is running is made.
- name: create filtered in memory inventory
add_host:
name: "{{ ansible_host }}"
when: service_info.exists
The add_host module bypasses the play host loop and only runs once for all the hosts in the play, as such this only works if the host that add_host runs against is the one that has the service installed.
Below is an attempt to force add_host to iterate across the hosts in the inventory however it appears that the hostvars and therefore service_info.exists are not being passed through to add_host and therefore the conditional 'when' check always returns false.
- name: create filtered in memory inventory
add_host:
name: "{{ ansible_host }}"
when: service_info.exists
with_items: "{{ ansible_play_batch }}"
Is there a way to pass the hosts with their hostvars to add_host as a iterator?
I suggest to create a tasks before add_host to create a temporary file on executor with the list of server matching the condition, and then looping in module add_host over the file.
example taken from Improving use of add_host in ansible that I asked before
---
- hosts: servers
tasks:
- name: find where the service is installed
win_service:
name: "{{ service }}"
register: service_info
- name: write server name in file on control node
lineinfile:
path: /tmp/servers_foo.txt
state: present
line: "{{ inventory_hostname }}"
delegate_to: 127.0.0.1
when: service_info.exists
- name: assign target to group
add_host:
name: "{{ item }}"
groups:
- foo
with_lines: cat /tmp/servers_foo.txt
delegate_to: 127.0.0.1
I want to write a bootstrapper playbook for new machines in Ansible which will reconfigure the network settings. At the time of the first execution target machines will have DHCP-assigned address.
The user who is supposed to execute the playbook knows the assigned IP address of a new machine. I would like to prompt the user for is value.
vars_prompt module allows getting input from the user, however it is defined under hosts section effectively preventing host address as the required value.
Is it possible without using a wrapper script modifying inventory file?
The right way to do this is to create a dynamic host with add_host and place it in a new group, then start a new play that targets that group. That way, if you have other connection vars that need to be set ahead of time (credentials/keys/etc) you could set them on an empty group in inventory, then add the host to it dynamically. For example:
- hosts: localhost
gather_facts: no
vars_prompt:
- name: target_host
prompt: please enter the target host IP
private: no
tasks:
- add_host:
name: "{{ target_host }}"
groups: dynamically_created_hosts
- hosts: dynamically_created_hosts
tasks:
- debug: msg="do things on target host here"
You could pass it with extra-vars instead.
Simply make your hosts section a variable such as {{ hosts_prompt }} and then pass the host on the command line like so:
ansible-playbook -i inventory/environment playbook.yml --extra-vars "hosts_prompt=192.168.1.10"
Or if you are using the default inventory file location of /etc/ansible/hosts you could simply use:
ansible-playbook playbook.yml --extra-vars "hosts_prompt=192.168.1.10"
Adding to Matt's answer for multiple hosts.
input example would be 192.0.2.10,192.0.2.11
- hosts: localhost
gather_facts: no
vars_prompt:
- name: target_host
prompt: please enter the target host IP
private: no
tasks:
- add_host:
name: "{{ item }}"
groups: dynamically_created_hosts
with_items: "{{ target_host.split(',') }}"
- hosts: dynamically_created_hosts
tasks:
- debug: msg="do things on target host here"
Disclaimer: The accepted answer offers the best solution to the problem. While this one is working it is based on a hack and I leave it as a reference.
I found out it was possible use a currently undocumented hack (credit to Bruce P for pointing me to the post) that turns the value of -i / --inventory parameter into an ad hoc list of hosts (reference). With just the hostname/ip address and a trailing space (like below) it refers to a single host without the need for the inventory file to exist.
Command:
ansible-playbook -i "192.168.1.21," playbook.yml
And accordingly playbook.yml can be run against all hosts (which in the above example will be equal to a single host 192.168.1.21):
- hosts: all
The list might contain more than one ip address -i "192.168.1.21,192.168.1.22"
Adding to Jacob's and Matt's examples, with the inclusion of a username and password prompt:
---
- hosts: localhost
pre_tasks:
- name: verify_ansible_version
assert:
that: "ansible_version.full is version_compare('2.10.7', '>=')"
msg: "Error: You must update Ansible to at least version 2.10.7 to run this playbook..."
vars_prompt:
- name: target_hosts
prompt: |
Enter Target Host IP[s] or Hostname[s] (comma separated)
(example: 1.1.1.1,myhost.example.com)
private: false
- name: username
prompt: Enter Target Host[s] Login Username
private: false
- name: password
prompt: Enter Target Host[s] Login Password
private: true
tasks:
- add_host:
name: "{{ item }}"
groups: host_groups
with_items:
- "{{ target_hosts.split(',') }}"
- add_host:
name: login
username: "{{ username }}"
password: "{{ password }}"
- hosts: host_groups
remote_user: "{{ hostvars['login']['username'] }}"
vars:
ansible_password: "{{ hostvars['login']['password'] }}"
ansible_become: yes
ansible_become_method: sudo
ansible_become_pass: "{{ hostvars['login']['password'] }}"
roles:
- my_role
The following:
store_controller:
hosts:
SERVER:
ansible_host: "{{ STORE_CTL }}"
mgmt_ip: "{{ ansible_host }}"
global_mgmt:
hosts:
SERVER:
ansible_host: "{{ NOMAD_SERVER }}"
mgmt_ip: "{{ ansible_host }}"
node_exporter: ##if comment the part from here to end, it's ok####
hosts:
"{{ item }}":
ansible_host: "{{ item }}"
mgmt_ip: "{{ ansible_host }}"
with_items:
- "172.7.7.1"
- "172.7.7.9"
- "172.7.7.12"
But Ansible doesn't let me use 'with_items' here. It seems that ansible does not support iterator over hosts.
How can I define the hosts array in group node_exporter for my three IPs ?
All you need to define is this:
node_exporter:
hosts:
172.7.7.1:
172.7.7.9:
172.7.7.12:
vars:
mgmt_ip: "{{ inventory_hostname }}"
Explanation:
mgmt_ip defines only a template (string value) which will be resolved at the time it is used.
For each target machine inventory_hostname (thus mgmt_ip) will resolve to the IP address of currently executing host.
Using ansible_host to assign the same value as the inventory host name is an empty action, so you don't need that at all.
I don't think it brings any value/clarity to the code, but since you commented it was working for you, that's the way to achieve it with multiple hosts. All you achieve is creating an alias mgmt_ip to inventory_hostname.
Regarding the premise of the question:
with_items: for YAML is a dictionary key name (string value). It is Ansible that might or might not make use of it.
It makes use of it when it is specified in a task (there it has a semantic meaning).
Otherwise it either ignores it (never uses this key), or reports an error.
Looking quickly at your code, you have an indentation problem.
Try to add 2 spaces before "{{item}}:"
Here is a simple cluster inventory:
[cluster]
host1
host2
host3
Each host has an interface configured with ipv4 address. This information could be gathered with setup module and will be in ansible_facts.ansible_{{ interface }}.ipv4.address.
How do to get IPv4 addresses for interface from each individual host and make them available to each host in cluster so that each host knows all cluster IPs?
How this could be implemented in a role?
As #larsks already commented, the information is available in hostvars. If you, for example, want to print all cluster IPs you'd iterate over groups['cluster']:
- name: Print IP addresses
debug:
var: hostvars[item]['ansible_eth0']['ipv4']['address']
with_items: "{{ groups['cluster'] }}"
Note that you'll need to gather the facts first to populate hostvars for the cluster hosts. Make sure you have the following in the play where you call the task (or in the role where you have the task):
- name: A play
hosts: cluster
gather_facts: yes
After searching for a while on how to make list variables with Jinja2. Here is complete solution that requires cluster_interface variable and pings all nodes in cluster to check connectivity:
---
- name: gather facts about {{ cluster_interface }}
setup:
filter: "ansible_{{ cluster_interface }}"
delegate_to: "{{ item }}"
delegate_facts: True
with_items: "{{ ansible_play_hosts }}"
when: hostvars[item]['ansible_' + cluster_interface] is not defined
- name: cluster nodes IP addresses
set_fact:
cluster_nodes_ips: "{{ cluster_nodes_ips|default([]) + [hostvars[item]['ansible_' + cluster_interface]['ipv4']['address']] }}"
with_items: "{{ ansible_play_hosts }}"
- name: current cluster node IP address
set_fact:
cluster_current_node_ip: "{{ hostvars[inventory_hostname]['ansible_' + cluster_interface]['ipv4']['address'] }}"
- name: ping all cluster nodes
command: ping -c 1 {{ item }}
with_items: "{{ cluster_nodes_ips }}"
changed_when: false
I have 3 remote VMs and 1 ansible node.
I am getting the hostname of some VMs by running hostname command on those remote VMs through ansible shell module and registering that output in hostname_output variable.
Then I want to add those VM's IP (collected using gather_facts: True, {{ ansible_default_ipv4.address }} ) with their hostname and append it to a file temp_hostname on localhost, hence I am delegating the task to localhost.
But the issue is, when I see on console, the lineinfile module says that line has been added when the module executed for each node and delegated to localhost, but when I check the file on the localhost, only 1 entry is shown on localhost instead of 3.
---
- name: get hostnames of dynamically created VMs
hosts: all
remote_user: "{{ remote_user }}"
gather_facts: True
tasks:
- name: save hostname in variable, as this command is executed remotely, and we want the value on the ansible node
shell: hostname
register: hostname_output
- name: writing hostname_output in ansible node in file on ansible node
lineinfile:
line: "{{ ansible_default_ipv4.address }} {{ hostname_output.stdout }}"
dest: temp_hostname
state: present
delegate_to: 127.0.0.1
I even tried with copy module as specified in Ansible writing output from multiple task to a single file , but that also gave same result i.e 1 entry only.
---
- name: get hostnames of dynamically created VMs
hosts: all
remote_user: "{{ remote_user }}"
gather_facts: True
tasks:
- name: save hostname in variable, as this command is executed remotely, and we want the value on the ansible node
shell: hostname
register: hostname_output
- name: writing hostname_output in ansible node in file on ansible node
copy:
content: "{{ ansible_default_ipv4.address }} {{ hostname_output.stdout }}"
dest: /volume200gb/sushil/test/code_hostname/temp_hostname
delegate_to: 127.0.0.1
Finally when I used shell module with redirection operator, it worked as I wanted i.e 3 entries in file on localhost.
---
- name: get hostnames of dynamically created VMs
hosts: all
remote_user: "{{ remote_user }}"
gather_facts: True
tasks:
- name: save hostname in variable, as this command is executed remotely, and we want the value on the ansible node
shell: hostname
register: hostname_output
- name: writing hostname_output in ansible node in file on ansible node
shell: echo -e "{{ ansible_default_ipv4.address }} {{ hostname_output.stdout }}" >> temp_hostname
delegate_to: 127.0.0.1
I am calling this ansible-playbook get_hostname.yml using command:
ansible-playbook -i hosts get_hostname.yml --ssh-extra-args="-o StrictHostKeyChecking=no" --extra-vars "remote_user=cloud-user" -vvv
My hosts file is:
10.194.11.86 private_key_file=/root/.ssh/id_rsa
10.194.11.87 private_key_file=/root/.ssh/id_rsa
10.194.11.88 private_key_file=/root/.ssh/id_rsa
I am using ansible 2.1.0.0
I am using default ansible.cfg only, no modications
My question is why lineinfile and copy module didn't work? Did I miss anything or wrote something wrongly
I tried to reproduce your issue and it did not happen for me, I suspect this is a problem with your version of ansible, try with the latest.
That being said, I think you might be able to make it work using serial: 1, it is probably an issue with file locking that I don't see happening in ansible 2.3. I also think that instead of using a shell task to gather the hostname you could use the ansible_hostname variable which is provided as an ansible fact, and you can also avoid gathering ALL facts if all you want is the hostname by adding a task for that specifically. In the end, it would look like this:
---
- name: get hostnames of dynamically created VMs
hosts: all
serial: 1
remote_user: "{{ remote_user }}"
tasks:
- name: Get hostnames
setup:
filter: ansible_hostname
- name: writing hostname_output in ansible node in file on ansible node
lineinfile:
line: "{{ ansible_default_ipv4.address }} {{ ansible_hostname }}"
dest: temp_hostname
state: present
delegate_to: 127.0.0.1
I get inconsistent results using your first code block with lineinfile. Sometimes I get all 3 IPs and hostnames in the destination file and sometimes I only get 2. I'm not sure why this is happening but my guess is that Ansible is trying to save changes to the file at the same time and only one change gets picked up.
The second code block won't work since copy will overwrite the file unless content matches what is already there. The last host that runs will be the only IP/hostname in the destination file.
To work around this, you can loop over your play_hosts (the active hosts in the current play) and reference their variables using hostvars.
- name: writing hostname_output in ansible node in file on ansible node
lineinfile:
line: "{{ hostvars[item]['ansible_default_ipv4'].address }} {{ hostvars[item]['hostname_output'].stdout }}"
dest: temp_hostname
state: present
delegate_to: 127.0.0.1
run_once: True
with_items: "{{ play_hosts }}"
Or you can use a template with the same logic
- name: writing hostname_output in ansible node in file on ansible node
template:
src: IP_hostname.j2
dest: temp_hostname
delegate_to: 127.0.0.1
run_once: True
IP_hostname.j2
{% for host in play_hosts %}
{{ hostvars[host]['ansible_default_ipv4'].address }} {{ hostvars[host]['hostname_output'].stdout }}
{% endfor %}
The problem is here that there is multiple concurrent writes to only one file. That leads to unexpected results:
A solution for that is to use serial: 1 on your play, which forces non-parallel execution among your hosts.
But it can be a performance killer depending on the number of hosts.
I would suggest using another solution: instead of writing to only one file, each host delegation could write on its own file (here using the inventory_hostname value). Therefore, it will have no more concurrent writes.
After that, you can use the module assemble to merge all the file in one. Here is an example (untested):
---
- name: get hostnames of dynamically created VMs
hosts: all
remote_user: "{{ remote_user }}"
gather_facts: True
tasks:
- name: save hostname in variable, as this command is executed remotely, and we want the value on the ansible node
shell: hostname
register: hostname_output
- name: deleting tmp folder
file: path=/tmp/temp_hostname state=absent
delegate_to: 127.0.0.1
run_once: true
- name: create tmp folder
file: path=/tmp/temp_hostname state=directory
delegate_to: 127.0.0.1
run_once: true
- name: writing hostname_output in ansible node in file on ansible node
template: path=tpl.j2 dest=/tmp/temp_hostname/{{ inventory_hostname }}
delegate_to: 127.0.0.1
- name: assemble hostnames
assemble: src=/tmp/temp_hostname/ dest=temp_hostname
delegate_to: '{{ base_rundeck_server }}'
run_once: true
Obviously you have to create the tpl.j2 file.