tbd

"to be defined"

A really simple way to create text templates with placeholders.

This tool is deliberately simple and trivial, no advanced features.

If you need advanced templates rendering which supports complex syntax and a huge list of datasources (JSON, YAML, AWS EC2 metadata, BoltDB, Hashicorp > Consul and Hashicorp Vault secrets), I recommend you use one of these:

• gotemplate
• pongo2
• quicktemplate

How does a template looks like ?

A template is a text document in which you can insert placeholders for the text you want to make dynamic.

• a placeholder is delimited by {{ and }} - (i.e. {{ FULL_NAME }})
• all text outside placeholders is copied to the output unchanged

Example:

apiVersion: v1
kind: Pod
metadata:
  name: {{ metadata.name }}
  labels:
    app: {{ metadata.labels.app }}
 spec:
  containers:
    - name: {{ container.1.name }}
      image: {{ container.1.image }}
      ports:
        - containerPort: {{ container.1.port }}
    - name: {{ container.2.name }}
      image: {{ container.2.image }}
      ports:
        - containerPort: {{ container.2.port }}

Another example:

{{ greeting }}

I will be out of the office from {{ start.date }} until {{ return.date }}. 
If you need immediate assistance while I’m away, please email {{ contact.email }}.

Best,
{{ name }}

How can I define placeholders values?

Create a text file in which you enter the values for the placeholders.

• define a placeholder value using KEY = value (or KEY: value)
• empty lines are skipped
• lines beginning with # are treated as comments

Example:

# metadata values
metadata.name = rss-site
metadata.labels.app = web

# containers values
container.1.name = front-end
container.1.image = nginx
container.1.port = 80

container.2.name = rss-reader
container.2.image: nickchase/rss-php-nginx:v1
container.2.port: 88

Another example...

greeting: Greetings
start.date: August, 9 
return.date: August 23
contact.email: [email protected]
name: Pinco Pallo 

How fill in the template?

$ tbd -vars /path/to/your/vars /path/to/your/template

Example:

$ tbd -vars testdata/sample1.vars testdata/sample1.yml.tbd

👉 you can also specify an HTTP url to fetch your template and/or placeholders values.

Example:

$ tbd -vars https://raw.githubusercontent.com/lucasepe/tbd/main/testdata/sample2.vars \
    https://raw.githubusercontent.com/lucasepe/tbd/main/testdata/sample2.txt.tbd

and the output is...

Greetings

I will be out of the office from August, 9 until August 23. 
If you need immediate assistance while I’m away, please email [email protected].

Best,
Pinco Pallo

How to list all template placeholders?

• simply omit the -vars flag

$ tbd /path/to/your/template

Example:

$ tbd testdata/sample1.yml.tbd

How to install?

If you have golang installed:

$ go install github.com/lucasepe/tbd@latest

This will create the executable under your $GOPATH/bin directory.

Ready-To-Use Releases

If you don't want to compile the sourcecode yourself, here you can find the tool already compiled for:

• MacOS
• Linux
• Windows

Credits

Thanks to @valyala for the fasttemplate library - which I have modified by adding and removing some functions for the tbd purpose.