Undefined variable when passing dictionary to a submodule-role - ansible

Question

I'm having a really weird problem on my ansible role. I send two dictionaries to a submodule like that:
import_role:
name: .submodules/monitoring-plugins
vars:
monitoring_plugins:
check_content:
command: "files/icinga/commands/check_content"
dest: "{{ icinga_server_plugin_directory }}"
group: "root"
owner: "root"
mode: "0755"
package: "curl"
src: "files/plugins/server/check_content"
check_http_response_time:
command: "files/icinga/commands/check_http_response_time"
dest: "{{ icinga_server_plugin_directory }}"
group: "root"
owner: "root"
mode: "0775"
src: "files/plugins/server/check_http_response_time"
check_https_response_time:
command: "files/icinga/commands/check_https_response_time"
dest: "{{ icinga_server_plugin_directory }}"
group: "root"
owner: "root"
mode: "0775"
src: "files/plugins/server/check_https_response_time"
check_port:
command: "files/icinga/commands/check_port"
dest: "{{ icinga_server_plugin_directory }}"
group: "root"
owner: "root"
mode: "0775"
src: "files/plugins/server/check_port"
check_ssl_cert:
command: "files/icinga/commands/check_ssl_cert"
dest: "{{ icinga_server_plugin_directory }}"
group: "root"
owner: "root"
mode: "0775"
src: "files/plugins/server/check_ssl_cert"
custom_services:
content:
service-preamble: 'apply Service "content"'
configuration: |
{{ common_service_header }}
assign where host.vars.ansible.system == "Linux"
definition:
"{{ lookup('template', 'config/services/content.conf') }}"
http_response_time:
service-preamble: 'apply Service "http_response_time"'
configuration: |
{{ common_service_header }}
assign where host.vars.ansible.system == "Linux"
definition:
"{{ lookup('template', 'config/services/http_response_time.conf') }}"
https_response_time:
service-preamble: 'apply Service "https-response-time"'
configuration: |
{{ common_service_header }}
assign where host.vars.ansible.system == "Linux"
definition:
"{{ lookup('template', 'config/services/https_response_time.conf') }}"
http_port:
service-preamble: 'apply Service "http-port"'
configuration: |
{{ common_service_header }}
assign where host.vars.ansible.system == "Linux"
definition:
"{{ lookup('template', 'config/services/http_port.conf') }}"
https_port:
service-preamble: 'apply Service "https-port"'
configuration: |
{{ common_service_header }}
assign where host.vars.ansible.system == "Linux"
definition:
"{{ lookup('template', 'config/services/https_port.conf') }}"
ssl_cert:
service-preamble: 'apply Service "ssl-cert"'
configuration: |
{{ common_service_header }}
assign where host.vars.ansible.system == "Linux"
definition:
"{{ lookup('template', 'config/services/ssl_cert.conf') }}"
on the submodule I created two debug tasks:
- debug:
var: monitoring_plugins
- debug:
var: custom_services
output:
ok: [server.test] => {
"monitoring_plugins": {
"check_content": {
"command": "files/icinga/commands/check_content",
"dest": "/usr/lib/nagios/plugins",
"group": "root",
"mode": "0755",
"owner": "root",
"package": "curl",
"src": "files/plugins/server/check_content"
},
"check_http_response_time": {
"command": "files/icinga/commands/check_http_response_time",
"dest": "/usr/lib/nagios/plugins",
"group": "root",
"mode": "0775",
"owner": "root",
"src": "files/plugins/server/check_http_response_time"
},
"check_https_response_time": {
"command": "files/icinga/commands/check_https_response_time",
"dest": "/usr/lib/nagios/plugins",
"group": "root",
"mode": "0775",
"owner": "root",
"src": "files/plugins/server/check_https_response_time"
},
"check_port": {
"command": "files/icinga/commands/check_port",
"dest": "/usr/lib/nagios/plugins",
"group": "root",
"mode": "0775",
"owner": "root",
"src": "files/plugins/server/check_port"
},
"check_ssl_cert": {
"command": "files/icinga/commands/check_ssl_cert",
"dest": "/usr/lib/nagios/plugins",
"group": "root",
"mode": "0775",
"owner": "root",
"src": "files/plugins/server/check_ssl_cert"
}
}
}
TASK [.submodules/monitoring-plugins : debug] ************************************
ok: [server.test] => {
"custom_services": "VARIABLE IS NOT DEFINED!"
}
Does anybody have any idea what could possibly go wrong? I sent both of them from the very same task but yet one of them looks just fine and the other don't. I even tried to remove the submodule and add it again but it still doesn't work. Any other suggestions would be very appreciated!

Answer 1

The background
A var containing other vars expansion being undefined cannot be interpreted and is undefined.
$ ansible localhost -e undef="{{ i_dont_exist }}" -m debug -a var=undef
localhost | SUCCESS => {
"undef": "VARIABLE IS NOT DEFINED!"
}
To see what is going wrong, you need to actually expand the var at debug time
$ ansible localhost -e undef="{{ i_dont_exist }}" -m debug -a msg="{{ undef }}"
localhost | FAILED! => {
"msg": "The task includes an option with an undefined variable. The error was: 'i_dont_exist' is undefined"
}
Your specific case
The root cause is that common_service_header is undefined. Since it is used inside your variable definition for the role include, ansible tries to interpret it, fails, and the var stays undefined.
You will actually see the same result for monitoring_plugins if you undefine icinga_server_plugin_directory.
To have some more info on what actually happens, the "trick" is to force ansible to interpret the variable in your debug. There are two possible ways to do this:
- name: Use a simple jinja2 expansion
debug:
msg: "{{ custom_services }}"
- name: Use a the 'vars' lookup
debug:
msg: "{{ lookup('vars', 'custom_services') }}"
Which then gives a more meaningful info (reformated for legibility....):
TASK [.submodules/monitoring-plugins : debug] *****************************
fatal: [localhost]: FAILED! => {"msg": "The task includes an option with an
undefined variable. The error was: 'common_service_header' is undefined\n\n
The error appears to be in
'/some/path/.submodules/monitoring-plugins/tasks/main.yml': line 4, column 3,
but may\nbe elsewhere in the file depending on the exact syntax problem.\n\n
The offending line appears to be:\n\n
msg: \"{{ lookup('vars', 'monitoring_plugins') }}\"\n- debug:\n ^ here\n"}