Task Scripts

The inputs feature of a task allows us to pass in two types of inputs:

• requirements/dependencies to be processed/tested/compiled
• task scripts to be executed to perform complex behavior

A common pattern is for Concourse tasks to run: complex shell scripts rather than directly invoking commands as we did in the Hello World tutorial (we ran uname command with arguments -a).

Let's refactor task-hello-world/task_ubuntu_uname.yml into a new task task-scripts/task_show_uname.yml with a separated task script task-scripts/task_show_uname.sh

cd ../task-scripts
fly -t tutorial e -c task_show_uname.yml

The former specifies the latter as its task script:

run:
  path: ./task-scripts/task_show_uname.sh

Where does the ./task-scripts/task_show_uname.sh file come from?

From section 2 we learned that we could pass inputs into the task. The task configuration task-scripts/task_show_uname.yml specifies one input:

inputs:
- name: task-scripts

Since input task-scripts matches the current directory task-scripts we did not need to specify fly execute -i task-scripts=..

The current directory was uploaded to the Concourse task container and placed inside the task-scripts directory.

Therefore its file task_show_uname.sh is available within the Concourse task container at task-scripts/task_show_uname.sh.

The only further requirement is that task_show_uname.sh is an executable script.