Ansible - passing JSON string in environment to shell module

Question

I am trying to pass JSON string in environment.

- name: Start {{service_name}}
  shell: \"<> --server.port={{service_por         


        

Answer 1

There is a thing about Ansible template engine.
If a string seems like an object (starts with { or [) Ansible converts it into object. See code.

To prevent this, you may use one of STRING_TYPE_FILTERS:

- SPRING_APPLICATION_JSON: "{{ {'test-host.1':test_host_1,'test-host.2':test_host_2} | to_json }}"

P.S. this is why hack with space character from @techraf's answer works: Ansible misses startswith("{") comparison and don't convert string to object.

Answer 2

Quick hack: add a space to the variable definition (after the first single quote) - a single space doesn't influence the actual variable value (space will be ignored):

- name: Start {{service_name}}
  shell: "<<starting springboot jar>> --server.port={{service_port}}\""
  environment:
    - SPRING_APPLICATION_JSON: ' {"test-host.1":"{{test_host_1}}","test-host.2":"{{test_host_2}}"}'

---

With the space Ansible passes to shell (test1, test2 are values I set):

SPRING_APPLICATION_JSON='"'"' {"test-host.1":"test1","test-host.2":"test2"}'"'"'

Without the space:

SPRING_APPLICATION_JSON='"'"'{'"'"'"'"'"'"'"'"'test-host.2'"'"'"'"'"'"'"'"': '"'"'"'"'"'"'"'"'test2'"'"'"'"'"'"'"'"', '"'"'"'"'"'"'"'"'test-host.1'"'"'"'"'"'"'"'"': '"'"'"'"'"'"'"'"'test1'"'"'"'"'"'"'"'"'}'"'"'

Order is reversed too. Seems like without a space it interprets the JSON, with the space as string.

^{I don't really get why it happens so...}