Ansible - grab a key from a dictionary (but not in a loop)
Given a nested dictionary...
mysql_dbs:
db1:
user: db1user
pass: "jdhfksjdf"
accessible_from: localhost
db2:
user: db2user
pass: "npoaivrpon"
accessible_from: localhost
You can either use dotted notation:
- debug:
var: mysql_dbs.db1
Or you can use a more Python-esque syntax:
- debug:
var: mysql_dbs['db1']
It looks like you tried to use an unholy hybrid:
mysql_dbs[db1]
In this case, you are trying to dereference a variable named db1
,
which presumably doesn't exist and would lead to a "variable is
undefined" sort of error.
Update
Your question is unclear because in your example you have...
with_items: '{{ mysql_dbs[db1] }}'
...which looks like you are trying to do exactly what I have described here. If what you actually want to do is iterate over the keys of the mysql_dbs
dictionary, remember that it is simply a Python dictionary and you have available all the standard dictionary methods, so:
- debug:
msg: "key: {{ item }}"
with_items: "{{ mysql_dbs.keys() }}"
The output of which would be:
TASK [debug] *******************************************************************
ok: [localhost] => (item=db1) => {
"item": "db1",
"msg": "key: db1"
}
ok: [localhost] => (item=db2) => {
"item": "db2",
"msg": "key: db2"
}
ticktockhouse
Updated on July 31, 2020Comments
-
ticktockhouse almost 4 years
Another question regarding dictionaries in Ansible!
For convenience, I have certain values for mysql databases held in dictionaries, which works fine to loop over using
with_dict
to create the DBs and DB users.mysql_dbs: db1: user: db1user pass: "jdhfksjdf" accessible_from: localhost db2: user: db2user pass: "npoaivrpon" accessible_from: localhost
task:
- name: Configure mysql users mysql_user: name={{ item.value.user }} password={{ item.value.pass }} host={{ item.value.accessible_from }} priv={{ item.key }}.*:ALL state=present with_dict: "{{ mysql_dbs }}"
However, I would like to use the key from one of the dictionaries in another task, but I don't want to loop over the dictionaries, I would only like to use one at a time. How would I grab the key that describes the dictionary (sorry, not sure about terminology)?
problem task:
- name: Add the db1 schema shell: mysql {{ item }} < /path/to/db1.sql with_items: '{{ mysql_dbs[db1] }}'
Error in ansible run:
fatal: [myhost]: FAILED! => {"failed": true, "msg": "'item' is undefined"}
I'm willing to believe
with_items
isn't the best strategy here, but does anyone have any ideas what is the right one?Thanks in advance, been stuck on this for a while now...