The Shell

One line

The shell is a yaml definition for executing a Bash script.

- shell:
    script: echo "hello world!"

As an alternative when given script content is a valid path and filename of an existing Bash script then those one will be taken. Please note that the content of each script is copied into a temporary one and executed.

Multipe lines

You also can have multiple lines:

- shell:
    script: |
        echo "hello world 1!"
        echo "hello world 2!"

Jinja templating supported

Jinja templating is supported. Currently two variables are available:


Gives you access to the environment variables as defined when the spline tool has been started; in addition you can add environment variables or overwrite existing ones. Please note that the value is always a string.


The model is a dictionary (map) with keys and the values can be any valid yaml construct that results in a valid Python data hierarchy.


You can specify a field variable on each shell and the output of the Bash will be stored under the defined name. However a special note on this: when you define a task block for parallel tasks then one task cannot access a variable by another parallel task in same execution block; but when such tasks are separated by an env entry each task after that entry is able to use it also those run in parallel too. More on this you can read in the chapter about tasks.

Here’s a simple example for the access:

- tasks:
    - env:
        count: "3"

    - shell:
        script: echo "{{ env.USER }}"
        variable: user

    - shell:
        script: |
            {% for c in range(env.count|int) %}
            echo "{{ c+1 }}:{{ env.message }}"
            {% endfor %}
            echo "USER={{ variables.user }}"
            echo "foo={{ model['foo'] }}"

More details on env and model you can see in a separate chapter.


Finally you can specify tags:

- shell:
    script: echo "hello world!"
        - simple
- shell:
    script: echo "hello world!"
        - test

Executing the spline tool you can specify –tags=test which executes shells only with given tag. You also can specify a comma separted list of tags to allow more shells: –tags=test,simple

One usecase might be to isolate a shell for testing purpose.

“With” attribute

Using the with attribute you can run same task as often as many entries you provide. The entries are representing a list but the item can be any valid yaml structure; in the example a dictionary is used:

- shell:
    script: |
        echo "{{ item.message }}: start"
        sleep {{ item.time }}
        echo "{{ item.message }}: done"
        - message: first
          time: 3
        - message: second
          time: 2
        - message: third
          time: 1

You also can use a rendered with like following when you put the list of items into the model:

- shell:
    script: echo "{{ item }}"
    with: "{{ }}"

Finally all generated tasks (shell or docker container) are added to the list of tasks to be processed and it depends on the setup of the tasks block whether those tasks are executed in order or in parallel. Please have a look and try the example with.yaml in the repository.


Colors are working fine!

- shell:
    script: |
        echo -e "\e[31mRed World\e[0m"
        echo -e "\e[33mOrange World\e[0m"
        echo -e "\e[34mBlue World\e[0m"
        echo -e "\e[35mMagenta World\e[0m"

Conditional tasks

The field when allows you to define a condition; when evaluated as true then the task is executed otherwise not. More details you can read in the separate section Conditional Tasks.