Concourse CI, get and put a git-resource - concourse

Question

I'm trying to use a git-resource to get, modify and push a file but it isn't work, can someone help me?
The two resources point to the same git repository and the goal is to add a file in the repository.
I can't understand where I'm wrong, concourse output is green but the repository doesn't have the new file
This is the job:
jobs:
- name: myjob
plan:
- get: input-repo
- get: output-repo
- task: simpletask
config:
platform: linux
image_resource:
type: docker-image
source:
repository: ubuntu
run:
path: sh
args:
- -exc
- |
cat a_file > output-repo/another_file
inputs:
- name: input-repo
- name: output-repo
- put: input-repo
params: { repository: output-repo }

Answer 1

you should not need two different resources for this. What you want to do is to get (git clone) the repo, modify it, git commit it and then put (git push) it.
So you want something like this.
jobs:
- name: myjob
plan:
- get: repo
- task: simpletask
config:
platform: linux
image_resource:
type: docker-image
source:
repository: ubuntu
run:
path: sh
args:
- -exc
- |
cp -r repo changed-repo
cat a_file > changed-repo/another_file
git add .
git commit -m "message"
inputs:
- name: repo
- put: repo
params: { repository: changed-repo }