README
¶
tmpl8
Generic (and Kubernetes-friendly) Templating Engine using the Go text/template engine and Sprig functions.
Features
- Supports JSON, YAML, and TOML as input/output formats
- Uses the Go text/template engine
- Includes the full Masterminds/sprig function library
- Additional built-in template functions (see Template Functions)
- Import templates and data directly from a Kubernetes ConfigMap
- Chain multiple templates and multiple input objects
define/blockhelpers shared across all template sources
Installation
Download a pre-built binary for your platform from the GitHub Releases page (Linux, macOS, and Windows — amd64/arm64).
Or install from source with Go:
go install github.com/AB-Lindex/tmpl8@latest
Usage
tmpl8 [--input INPUT] [--output FILE] [-v] [-t] [--raw] [--split] [-z] TEMPLATE [TEMPLATE ...]
Supported input formats: JSON, YAML
Options
| Option | Description |
|---|---|
-i / --input |
Input file(s) to import. Use - for stdin or ?inlinedata for inline data. Can be specified multiple times. |
-z |
Add an empty object as input (for template-only processing) |
-o / --output |
Write output to a file instead of stdout |
-v / --verbose |
Verbose output |
-t / --trace |
Trace output (implies verbose) |
-r / --raw |
Do not ensure each template block ends with a newline (not recommended for YAML output) |
-s / --split |
Split a JSON array input into separate objects (similar to YAML --- separators) |
--left-delimiter |
Template opening delimiter (default: {{) |
--right-delimiter |
Template closing delimiter (default: }}) |
--version |
Display current version |
Template argument forms
| Form | Description |
|---|---|
file.tmpl |
A single template file |
@filelist.lst |
A text file containing a list of template filenames (one per line) |
k8s:ns/name |
All values from a Kubernetes ConfigMap, imported as templates. No kubectl required; uses in-cluster token or kubeconfig. |
?inline |
Inline template text (no file needed) |
Examples
# Read input.json and apply it to t1.yaml and t2.yaml
$ tmpl8 <input.json t1.yaml t2.yaml
Equivalent commands
$ tmpl8 <input.json t1.yaml t2.yaml >output.txt
$ tmpl8 -i input.json t1.yaml t2.yaml -o output.txt
$ cat input.json | tmpl8 @t.lst >output.txt
where t.lst contains:
t1.yaml
t2.yaml
See the examples/ folder for more detailed walkthroughs.
Inline data
Prefix an argument with ? to use the remaining text as raw data instead of a filename. Works for both -i inputs and template arguments.
$ tmpl8 -i '?name: alpha' '?{{ .name | upper }}'
ALPHA
Custom delimiters
Use --left-delimiter and --right-delimiter when template sources must preserve Go-style {{ and }} expressions for another tool.
$ tmpl8 --left-delimiter '[[' --right-delimiter ']]' -i '?name: alpha' '?[[ .name | upper ]]'
ALPHA
Template Functions
In addition to the full Sprig library, tmpl8 provides these built-in functions:
| Function | Description |
|---|---|
toYaml |
Marshal a value to a YAML string |
fromYaml |
Parse a YAML string into a map |
fromYamlArray |
Parse a YAML array string into a slice |
toJson |
Marshal a value to a JSON string |
fromJson |
Parse a JSON string into a map |
fromJsonArray |
Parse a JSON array string into a slice |
toToml |
Marshal a value to a TOML string |
readfile |
Read the contents of a file as a string |
version |
Return the current tmpl8 version string |
isfunc |
Check whether a given function name is available in the template context |
define/block support
Any define/block helpers defined in a template are available in all subsequent template sources and can be overridden by later templates.
Kubernetes support
To import data from a Kubernetes ConfigMap, use a filename of the form k8s:namespace/configmap.
All values within the ConfigMap will be imported as templates (or as inputs when used with -i).
$ tmpl8 k8s:default/my-templates input-data.yaml
Documentation
¶
There is no documentation for this package.
Source Files