Ansible lookup env with $ and inject into jj2 template not working - ansible

Question

We're using Ansible playbook with GitLab CI in this project, where we'd pass some variables from ENV_FILE through Ansible playbook, then rendering JJ2 template with them.
Now the problem occurs when some variable has $ in its value, which seems interpreted as shell variable at some point, and the final value is rendered incorrect.
For example, in ENV_FILE
(set via GitLab CI Settings > CI/CD > Variables menu):
export FIRST_VAR=...
export SOME_VAR='123$abc#xyz'
export SOME_OTHER_VAR=...
And the final result in docker-compose.yaml becomes 123#xyz
EDIT: We just tried changing to export SOME_VAR='123''$''abc#xyz', the final result becomes 123abc#xyz, still missing the $.
gitlab-ci.yaml
deploy:
stage: deploy
environment:
name: dev
script:
- source $ENV_FILE
- cd ansible && ansible-playbook -i inventory/dev.ini runapp.yaml --vault-password-file=${ANSIBLE_VAULT_FILE}
runapp.yaml
- hosts: app
become: yes
roles:
- { role: some_app }
vars:
SOME_VAR: "{{ lookup('env', 'SOME_VAR') }}"
Task File:
- name: "Templating docker-compose file"
become: yes
template:
src: app-docker-compose.yaml.j2
dest: /opt/someapp/docker-compose.yaml
app-docker-compose.yaml.j2
someapp-svc:
image: someapp:version
restart: always
ports:
- ####:####
environment:
SOME_VAR: {{ SOME_VAR }}
Any hint about this?
Thanks!

Answer 1

I can reproduce that behavior when setting a CI/CD variable containing $; the docs kind of hint at it, although the docs are written as if the problem only applies when setting variables inside .gitlab-ci.yml which is demonstrably false
If you want a CI/CD variable to contain a literal $, it needs to be doubled, so SOME_VAR would need to be written as 123$$abc#xyz in the CI/CD configuration page in order for it to materialize as 123$abc#xyz inside the pipeline (although as the comments correctly point out, one will want to be exceedingly careful about the use of source to avoid further interpolation)