A simple CLI templating tool written in golang.

If you have go installed:

$ go get github.com/noqcks/gucci

Or you can just download the binary and move it into your PATH:

VERSION=1.2.2
wget -q https://github.com/noqcks/gucci/releases/download/${VERSION}/gucci-v${VERSION}-darwin-amd64
chmod +x gucci-v${VERSION}-darwin-amd64
mv gucci-v${VERSION}-darwin-amd64 /usr/local/bin/gucci

gucci can locate a template in multiple ways.

Pass the template file path as the first argument:

$ gucci template.tpl > template.out

Supply the template through standard input:

$ gucci
Start typing stuff {{ print "here" }}
^d
Start typing stuff here

Via piping:

$ echo '{{ html "<escape-me/>" }}' | gucci

gucci can receive variables for use in templates in the following ways (in order of lowest to highest precedence):

• A JSON or YAML file
• Environment variables
• Variable command options

Given an example variables file:

# vars.yaml
hosts:
  - name: bastion
  - name: app

Pass it into gucci with -f or --vars-file:

$ gucci -f vars.yaml template.tpl

Here, MY_HOST is available to the template:

$ export MY_HOST=localhost
$ gucci template.tpl

Pass variable options into gucci with -s or --set-var, which can be repeated:

$ gucci -s foo.bar=baz template.tpl

Variable option keys are split on the . character, and nested such that the above example would equate to the following yaml variable input:

foo:
  bar: baz

All of the existing golang templating functions are available for use.

gucci ships with the sprig templating functions library offering a wide variety of template helpers. Sprig's env and expandenv functions are disabled in favor of gucci's own environment variable parsing (see below).

Furthermore, this tool also includes custom functions:

• shell: For arbitrary shell commands

  {{ shell "echo hello world" }}
  

  Produces:

  hello world
  

• toYaml: Print items in YAML format

  {{ $myList := list "a" "b" "c" }}
  {{ toYaml $myList }}
  

  Produces:

  - a
  - b
  - c
  

NOTE: gucci reads and makes available all environment variables.

For example a var $LOCALHOST = 127.0.0.1

gucci template.tpl > template.conf

# template.tpl
{{ .LOCALHOST }}

gucci template.tpl > template.conf -->

# template.conf
127.0.0.1

simple enough!

For an iteration example, you have $BACKENDS=server1.com,server2.com

# template.tpl
{{ range split .BACKENDS "," }}
server {{ . }}
{{ end }}

gucci template.tpl > template.conf -->

# template.conf
server server1.com
server server2.com

Setup:

go get github.com/noqcks/gucci
go get github.com/onsi/ginkgo/ginkgo
go get github.com/onsi/gomega

Run tests:

ginkgo ./...