Create a stand-alone Greenbar app

[christophermaier]

While it is easy to test Greenbar templates for the embedded operable bundle, it is currently not possible (or, at least, really hard!) to similarly test templates for external bundles.

To help with this, we should provide a stand-alone Greenbar application (either an all-encompassing escript, a Docker container, or something else). This could be incorporated into bundle testing procedures, allowing bundle authors to be confident that their templates compile. With a basic directive processor included, they could also see a version of the final rendered output (as testing directly against Greenbar directives is a bit low-level).

[kevsmith]

gbexec

Tool providing offline template execution and testing.

Docs

gbexec <template_file> [<json_file>|-] (-s,--slack|-c, --hipchat)

When <json_file> is - then gbexec will read input JSON from stdin.

Options

1. -s, --slack Render template output into Slack's Markdown-based format
2. -c, --hipchat Render template output into HipChat's HTML-based format

Examples

gbexec templates/users.greenbar /tmp/users.json -s
cat /tmp/demo_data.json | gbexec templates/vms.greenbar - -c

Implementation notes

• Build as an escript packaged app for simplicity and dev speed
• gbexec should reuse the HipChat and Slack provider's TemplateProcessors.
• Probably worth investigating how we could extract those providers into separate OTP apps to facilitate easy reuse.

[kevsmith]

Tasks

• Extract template processors into separate library
• gbexec app skeleton
• Add Slack template support to gbexec
• Add HipChat template support to gbexec

[kevsmith]

See gbexec