indexing variable list using a variable

[Trond Hindenes]

Hi guys, 

I'm testing out some variable logic here, would really appreciate some help. 

I have the following content in one of my vars_files:

---

db:

  - backend_oslo:

      - name: db01

        primary: server1

        secondaries:

          - server2

          - server3

  - backend_stockholm:

      - name: db02

        primary: server4

        secondaries:

          - server5

          - server6

At a certain point in my playbook I have for instance "backend_oslo" in a fact (I'm picking up this thru group_names earlier in the play)

I'd like to be able to register the "contents" of the "backend_oslo" item in a dynamic fact so that I can access:

      - name: db01

        primary: server1

        secondaries:

          - server2

          - server3

This is an exercise in trying to keep my intentory files as light as possible. I'm not 100% comfortable with the list logic of yaml and how to index into them dynamically. Is what I'm trying to do even possible using the built-in filters?

[Brian Coca]

set_fact: mybackend="{{hostvars[inventory_hostname]['db'][varwithbackendnumber]}}"




--
Brian Coca

[Trond Hindenes]

THanks Brian. I can't seem to get this working. I can access the individual items using indexing

(this works: 

- set_fact: mybackend="{{ db[0] }}"

)

But I can't for the life of me figure out how to access by "item name" (or if that's even a valid thing in yaml). I can obviously redo the way I format the contents of my variable file, but I can't seem to strike gold. Struggling to find a good example of this in the docs/examples.

[Trond Hindenes]

hm, maybe I'd be better off splitting the different location vars into separate files, and then use 

with_first_found

I could then loop over group_names until the node found a valid variable file. 

[Trond Hindenes]

Just for reference, this is what I ended up doing:

1. in my play, I created separate vars files for each site, these correspond to the current host's group membership:

    - include_vars: "{{ item }}"

      with_first_found:

      - "db_{{ autogroup2 }}.yml"

2. in each var file I used the following structure:

---

  databases: 

    - 

      name: "DB1"

      primary: "Server1"

      secondaries: null

    - 

      name: "DB2"

      primary: "Server1"

      secondaries: null

3. this allowed me to access for example each db's name like so:

    - name: print stufs

      debug: msg="{{ item }}.name"

      with_items: databases

[Brian Coca]

i was going to say, you cannot reference lists by name
so

db:
- first:
stuff: lasdjkf
la: dida
- second:
stuff: aslkdfjsk
la: lala

is a list, if you wanted to reference by name you need to make it a
hash/dictionary so you can only get first through db[0].

db:
first:
stuff: lasdjkf
la: dida
second:
stuff: aslkdfjsk
la: lala

now you can do db['first']

--
Brian Coca