I have a variables file that includes important info about our databases; the server they are on, the db version, the DB_HOME directory, etc. In the variables file, I would like to dynamically create lists that capture the unique values of those properties, so they can be easily iterated through in a task.
I have equivalent functionality by creating the list on the fly in a task's loop option, but that means repeating that loop syntax (violates DRY principle) and I would like less sophisticated Ansible colleagues to be able to use a pre-defined list.
example of the variables file databases.yml:
databases:
- name: test_db1
server: ora_901
listener: LISTENER_XYZ
version: '11.2.0.4'
oracle_home: '/app/oracle/product/11.2.0.4/db_home'
- name: test_db2
server: ora_902
listener: LISTENER_ABC
version: '11.2.0.4'
oracle_home: '/app/oracle/product/11.2.0.4/db_home'
## This didn't work... was hoping I could build this list dynamically
listeners:
- name: "{{ item }}"
loop: "{{ databases | map(attribute = 'listener') | list | unique }}"
servers:
- name: "{{ item }}"
loop: "{{ databases | map(attribute = 'server') | list | unique }}"
I would then use this loop through either the 'listeners' or 'servers' lists directly with some tasks.
When I tried a task that referenced the listeners variable, it failed. Referencing databases works and all items are returned, so I know it's getting some data from the vars_file...
- vars_files:
- vars/databases.yml
tasks:
- debug:
msg: "{{ databases }}"
- debug:
msg: "{{ listeners }}"
TASK [debug] **************************************************************************
ok: [FQDN] => {
"msg": [
{
"listener": "LISTENER_XYZ",
"name": "test_db1",
"oracle_home": "/app/oracle/product/11.2.0.4/db_home",
"server": "ora_901",
"version": "11.2.0.4"
},
{
"listener": "LISTENER_ABC",
"name": "test_db2",
"oracle_home": "/app/oracle/product/11.2.0.4/dbhome_1",
"server": "ora_902",
"version": "11.2.0.4"
},
fatal: [FQDN]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'item' is undefined\n\nThe error appears to have been in '/home/xxx/test_vars.yml': line 21, column 5, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n - debug:\n ^ here\n"}
I would really like to keep these dynamic definitions in the same place as the server definitions, and don't see why it wouldn't be possible, I'm just sure I'm using the wrong mechanism.
Check this out from Ansible doc// Just to give you an idea, about "loop_control".
You can nest two looping tasks using include_tasks. However, by default Ansible sets the loop variable item for each loop. This means the inner, nested loop will overwrite the value of item from the outer loop. You can specify the name of the variable for each loop using loop_var with loop_control:
# main.yml
- include_tasks: inner.yml
loop:
- 1
- 2
- 3
loop_control:
loop_var: outer_item
# inner.yml
- debug:
msg: "outer item={{ outer_item }} inner item={{ item }}"
loop:
- a
- b
- c
Related
Could someone let me know how we can create a code as below?
- name: TEST1
set_fact:
list_a: "{{ list_a + [item.json.SearchResult.resources] }}"
with_items:
- "{{ source_list.results[0] }}"
- "{{ source_list.results[1] }}"
- "{{ source_list.results[x] }}"
... (unknown how many items in result from API)
vars:
list_a: []
source_list.results[x] comes from an API result. The reason why I need to create an array is that the number of API result is maximum 100. But there are over 500 items.
Note: since we have no idea what you initial data structure looks like exactly, the below might not be 100% fitting your use case. For your next questions, please read How to ask and pay attention to the Minimal, complete and reproducible example section. Thanks
You are taking this the wrong way. Simply extract the attribute you need from each result using the map(attribute=x) Jinja2 filter.
For the below I inferred (see above note) that:
you called your API with ansible.builtin.uri in a loop to get batches of 100 results which are returned as a list in the SearchResult.ressources field
you want in the end a flattened list where all resources are at top level
- name: Show my list of single attributes
ansible.builtin.debug:
var: "source_list.results
| map(attribute='json.SearchResult.resources') | flatten"
You actually don't need to set_fact:
For a single use, just use the above expression directly in the relevant parameter (e.g. loop or a module param....) or eventually declare this in a var at task level.
If you want to reuse this in different parts of your playbook, just declare a var at play level and expand it anywhere once you have called your API and populated the source_list var. In that case, just add a default value to prevent an error if API was not yet called.
Example for the second case above in this pseudo playbook
---
- hosts: localhost
gather_facts: false
vars:
list_a: "{{ source_list.results | d([])
| map(attribute='json.SearchResult.resources') | flatten }}"
tasks:
- name: "This will return an empty list (i.e. [])
as we did not populate source_list yet"
ansible.builtin.debug:
var: list_a
- name: Call our API and register source_list
ansible.builtin.uri:
uri: https://my.api.com/api/v1/some/endpoint
# [... more parameters here ... ]
loop: "{{ my_list_of_ressources }}"
register: source_list
- name: "This will now return a populated list
after calling the API and registering source_list"
ansible.builtin.debug:
var: list_a
Now, to still give a direct answer to your initial question: you can construct that list iteratively inside a set_fact task. This is definitely not efficient as it involves a task running inside a loop (both unneeded as demonstrated above) and possibly on multiple hosts in your play. But for learning purpose, here it is:
- name: very inefficient way to get the same result as above
set_fact:
list_a: "{{ list_a | d([]) + item.SearchResult.resources }}"
loop: "{{ source_list.results }}"
After reading #Zeitounator's answer, I realized I was taking this the wrong way. I used the idea in the answer (json query and flatten) and I changed my task to the below which works as expected.
- name: Create ID list from API result data
set_fact:
list_a: "{{ source_list | json_query('results[*].json.SearchResult.resources[*].id') | flatten }}"
- name: API get again with id
uri:
url: "{{ request_url }}/{{ item }}"
...
register: result_data
with_items:
- "{{ list_a }}"
I'm trying to update a configuration file for a NiFi deployment, the inital deployment configuration needs to include the nodes to allow HTTPS connections to be established between them.
I have an ansible tasks that makes the required structural changes to the configuration files, but I can't seem to get the right details inserted.
- name: Add each host to the authorizers.xml
lineinfile:
path: /opt/nifi/conf/authorizers.xml
line: "<property name=\"Node Identity {{ item }}\">CN={{ item }}, OU=NiFi</property>"
insertafter: <!--accessPolicyProvider Node Identities-->
loop: "{{ query('inventory_hostnames', 'nifi') }}"
This puts the ip addresses for the hosts, and I need to get the ansible_hostname for each node instead.
I've played around with ansible_play_batch and loop: "{{ groups['nifi'] }}" but I'm getting the result, outputting the ip addresses instead of the short hostnames each time.
The short hostnames are not stored in my ansible configuration anywhere, they are (if I understand correctly) determined at run time via the gathering facts process. I'd really like to not have to put the node names into a list variable.
Q: "Get the ansible_hostname for each node"
A: Given the inventory
shell> cat hosts
[nifi]
10.1.0.51
10.1.0.52
The playbook below
- hosts: nifi
tasks:
- debug:
var: ansible_hostname
gives (abridged)
ok: [10.1.0.51] =>
ansible_hostname: test_01
ok: [10.1.0.52] =>
ansible_hostname: test_02
It's possible to iterate the hosts in the group and get ansible_hostname from the hostvars. For example, delegate_to localhost and run_once
- debug:
msg: "{{ hostvars[item].ansible_hostname }}"
loop: "{{ groups.nifi }}"
delegate_to: localhost
run_once: true
gives
ok: [10.1.0.51 -> localhost] => (item=10.1.0.51) =>
msg: test_01
ok: [10.1.0.51 -> localhost] => (item=10.1.0.52) =>
msg: test_02
I want to run a loop in Ansible the number of times which is defined in a variable. Is this possible somehow?
Imagine a list of servers and we want to create some numbered files on each server. These values are defined in vars.yml:
server_list:
server1:
name: server1
os: Linux
num_files: 3
server2:
name: server2
os: Linux
num_files: 2
The output I desire is that the files /tmp/1, /tmp/2 and /tmp/3 are created on server1, /tmp/1 and /tmp/2 are created on server2. I have tried to write a playbook using with_nested, with_dict and with_subelements but I can't seem to find any way to to this:
- hosts: "{{ target }}"
tasks:
- name: Load vars
include_vars: vars.yml
- name: Create files
command: touch /tmp/{{ loop_index? }}
with_dict: {{ server_list[target] }}
loop_control:
loop_var: {{ item.value.num_files }}
If I needed to create 50 files on each server I can see how I could do this if I were to have a list variable for each server with 50 items in it list which is simply the numbers 1 to 50, but that would be a self defeating use of Ansible.
There is a chapter in the docs: Looping over Integer Sequences (ver 2.4)
For your task:
- file:
state: touch
path: /tmp/{{ item }}
with_sequence: start=1 end={{ server_list[target].num_files }}
Update: things has changed in Ansible 2.5. See separate docs page for sequence plugin.
New loop syntax is:
- file:
state: touch
path: /tmp/{{ item }}
loop: "{{ query('sequence', 'start=1 end='+(server_list[target].num_files)|string) }}"
Unfortunately sequence accepts only string-formatted parameters, so parameters passing to query looks quite clumsy.
I have a set of variables which define FQDNs.
domains:
- erp: erp.mycompany.com
- crm: crm.mycompany.com
- git: git.mycompany.com
Indeed, I both need to loop over them and access them namely (in a template file). So accessing them like domains.erpworks like a charm. But I can't get ansible to loop over these.
Obviously, if I do:
- name: Print domains
debug:
msg: test {{ item }}
with_items:
- "{{ domains }}"
It prints both the key and the value… And if I do:
- name: Print domains
debug:
msg: test {{ domains[{{ item }}] }}
with_items:
- "{{ domain }}"
But that doesn't work. I also tried the hashes form as mentionned in the docs, but didn't get any luck either…
Finally, I had to use a dict.
It didn't work the first time because unlike with_items, which has the items going each on their own line, with_dict is a one liner without - before the element to loop through.
domains:
erp:
address: erp.mycompany.com
crm:
address: crm.mycompany.com
git:
address: git.mycompany.com
# used by letsencrypt
webserverType: apache2
withCerts: true
tasks:
- name: Print phone records
debug:
msg: "{{ item.value.address }}"
with_dict: "{{ domains }}"
# I can still access a given domain by its name when needed like so:
{{ domains.erp.address }}
Looks like you figured out your issue. Your original attempt uses a list of dictionaries that do not contain the same keys, making it difficult to access the values uniformly across each list item.
Your second solution creates a dictionary where the keys refer to other dictionaries.
Another solution than what you posted if you still wanted to use a list:
- hosts: localhost
vars:
domains:
- name: erp
address: erp.mycompany.com
- name: crm
address: crm.mycompany.com
- name: git
address: git.mycompany.com
tasks:
- name: Print phone records
debug:
msg: "{{ item.address }}"
with_items: "{{ domains }}"
To me this approach is simpler but your second approach works as well.
I am writing a playbook that ensure nodes appear in /etc/fstab.
I am using loops to prevent code duplication.
The logic is first to check if the line appears using grep (with perl regex because it is a multi line) and store the results in a register.
Then I want to add only the lines that are not in fstab file. To achieve that I need to loop over list (the register with the grep return codes) and a dictionary (that contains the fstab entries).
I am having errors with the parallel loop. I tried to follow these steps.
One or more undefined variables: 'str object' has no attribute 'item'
tasks/fstab.yaml:
---
- name: Make dirs
sudo: yes
file: path={{ item.value }} state=directory
with_dict:
"{{ fstab.paths }}"
- name: Check whether declared in fstab
sudo: no
command: grep -Pzq '{{ item.value }}' /etc/fstab
register: is_declared
with_dict:
"{{ fstab.regexs }}"
- name: Add the missing entries
sudo: yes
lineinfile: dest=/etc/fstab line="{{ item.1.item.value }}"
when: item.0.rc == 1
with_together:
- "{{ is_declared.results }}"
- "{{ fstab.entries }}"
vars/main.yml:
---
fstab:
paths:
a: "/mnt/a"
b: "/mnt/b"
regexs:
a: '\n# \(a\)\nfoo1'
b: '\n# \(b\)\nfoo2'
entries:
a: "\n# (a)\nfoo1"
b: "\n# (b)\nfoo2"
I am not using template on purpose (I want to add entries to existing files and not to over write them).
UPDATE: I see ansible has module "mount" which deals with fstab. However I am still looking for a solution to this issue because I might be needed it again later on.
I have a couple ideas as to why your original approach was failing, but let's scratch that for a moment. It looks like you're overcomplicating things- why not use a complex list var to tie it all together, and use the regexp arg to the lineinfile module instead of a separate regex task? (though your sample data should work fine even without the regexp param) Something like:
---
- name: Make dirs
sudo: yes
file: path={{ item.path }} state=directory
with_items: fstab
- name: Add the missing entries
sudo: yes
lineinfile: dest=/etc/fstab line={{ item.entry }} regexp={{ item.regex }}
with_items: fstab
fstab:
- path: /mnt/a
regex: '\n# \(a\)\nfoo1'
entry: "\n# (a)\nfoo1"
- path: /mnt/b
regex: '\n# \(b\)\nfoo2'
entry: '\n# (b)\nfoo2'