Creating New Templates
You can create your own templates in the workflow catalog that you or your colleagues can use to render fuzzfiles and run workflows.
Begin by navigating to the workflow catalog and selecting “Create Application” in the upper right corner.
From here you can populate all of the fields. The Name, Category, and Description fields are
self-explanatory. You will need to provide a Template. This is a normal Fuzzfile with variables
inserted using double curly braces and a dot (i.e. {{.VariableName}}).
You might find it easy to create a fuzzfile using the Workflow Editor, and then replace specific values with variables.
The templating feature in the workflow catalog is implemented using Go text/template and slim-sprig. The latter allows you to do more complex operations like creating conditional logic!
Once you have your template specified, you can add inputs for all of your variables. Then you can scroll to the bottom and save your template with the Save Application button.
Now you are ready to test your new template! Find it in the workflow catalog and interact with it as described in the previous two sections.
To create a template in the workflow catalog using the CLI, you’ll need to manually author both a template file and a values file.
The template file is a YAML file with the syntax of a fuzzfile that also includes
placeholders for values you want users to customize. These placeholders use the syntax
{{.VariableName}}, where VariableName is a unique identifier for each parameterized value.
The templating feature in the workflow catalog is implemented using the Go text/template and slim-sprig. The latter allows you to do more complex operations like creating conditional logic!
Here’s an example template file for a simple “Hello World” workflow:
version: v1
jobs:
helloworld:
image:
uri: {{.ContainerUri}}
policy:
retry:
attempts: 1
timeout:
execute: {{.Timeout}}
command:
- /bin/sh
- '-c'
- {{.Script}}
resource:
cpu:
cores: {{.Cores}}
affinity: NUMA
memory:
size: {{.Memory}}
It is important to provide users with additional details about the possible values for these variables and their purposes. This ensures clarity and helps prevent errors when rendering the fuzzfile. The values file serves this purpose.
The values file must define all variables used in your template. Here is an example corresponding to the “Hello World” template above:
values:
- name: ContainerUri
display_name: URI for the docker image to use for this workflow
string_value: docker://alpine:latest
- name: Timeout
display_name: How long to wait for the workflow job to complete
string_value: 5m0s
- name: Cores
display_name: How many CPU cores to allocate for the workflow job
uint_value: 1
- name: Memory
display_name: How much memory to allocate for the workflow job
string_value: 1GiB
- name: Script
display_name: Script to run for the 'hello world' job
string_value: echo "Hello, world! Hostname ${HOSTNAME}"
Each entry for a variable has the following attributes:
- name: The variable name (without the dot prefix used in the template)
- display_name: A user-friendly explanation of what the variable does
- Value type: One of the following, depending on the data type:
string_value: For text values, durations, sizes, etc.uint_value: For unsigned integers (whole numbers)float_value: For decimal numbersbool_value: For true/false values
The value type is indicated by the key name. The value of the key is the default value for the variable.
Once you’ve created both files, add the template to the workflow catalog using the create
command:
# fuzzball application create <TEMPLATE_FILE> <VALUES_FILE> [flags]
For example:
# fuzzball application create hello-world-template.yaml hello-world-values.yaml \
--name "Hello World" \
--description "A simple Hello World example" \
--category "EXAMPLES"
Application created with ID: 00000000-0000-0000-0000-000000000000
Find your template listed amongst the other templates in the workflow catalog by using the
fuzzball application list command.