set ansible fact from concatenation of two lists - list

Question

I wish to combine the output of two commands into one new variable that i can use as args for another command:
---
- hosts: '{{target}}'
tasks:
- name: determine storage nfs mount points
shell: /usr/sbin/showmount -d | grep -v Directories
register: nfs
ignore_errors: yes
- debug: var=nfs.stdout_lines
- name: determine storage xrd mount points
shell: df | grep /xrd | awk '{print $6}'
register: xrd
- debug: var=xrd.stdout_lines
- name: determine all mount points
set_fact: mounts="{{ nfs.stdout_lines }} + {{ xrd.stdout_lines }}"
- name: run gather script
script: gather.py {{mounts.stdout_lines|join(" ")}} > /tmp/gather.txt
register: gather
however, when i run it it comes out with:
PLAY [ltda-srv050] *************************************************************
TASK [setup] *******************************************************************
ok: [ltda-srv050]
TASK [determine storage nfs mount points] **************************************
fatal: [ltda-srv050]: FAILED! => {"changed": true, "cmd": "/usr/sbin/showmount -d | grep -v Directories", "delta": "0:00:00.011269", "end": "2016-09-14 23:48:14.489385", "failed": true, "rc": 1, "start": "2016-09-14 23:48:14.478116", "stderr": "clnt_create: RPC: Program not registered", "stdout": "", "stdout_lines": [], "warnings": []}
...ignoring
TASK [debug] *******************************************************************
ok: [ltda-srv050] => {
"nfs.stdout_lines": []
}
TASK [determine storage xrd mount points] **************************************
changed: [ltda-srv050]
TASK [debug] *******************************************************************
ok: [ltda-srv050] => {
"xrd.stdout_lines": [
"/xrd/cache1",
"/xrd/cache2",
"/xrd/cache3",
"/xrd/cache4",
"/xrd/cache5",
"/xrd/cache6",
"/xrd/cache7",
"/xrd/cache8",
"/xrd/cache9",
"/xrd/cache10",
"/xrd/cache11"
]
}
TASK [determine all mount points] **********************************************
ok: [ltda-srv050]
TASK [run gather script] *******************************************************
fatal: [ltda-srv050]: FAILED! => {"failed": true, "msg": "the field 'args' has an invalid value, which appears to include a variable that is undefined. The error was: 'list object' has no attribute 'stdout_lines'\n\nThe error appears to have been in '/afs/slac.stanford.edu/u/sf/ytl/work/storage/gather_file_attributes/retrieve_file_attributes.yml': line 21, column 7, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n - name: run gather script\n ^ here\n"}
NO MORE HOSTS LEFT *************************************************************
[WARNING]: Could not create retry file 'retrieve_file_attributes.retry'. [Errno 2] No such file or directory: ''
PLAY RECAP *********************************************************************
ltda-srv050 : ok=6 changed=1 unreachable=0 failed=1
help...?

Answer 1

mounts is already a list, so removing it trying to call .stdout_lines on it fails - removing .stdout_lines works :)