Build docker-compose.yml from templates

mkdcontmpl : MaKe Docker Compose ON TeMPLates.

Implements build docker-compose.yml and .env files from templates. The system operates with the concept of context and service.

Main commands (makefile targets)

Command	Description
help	Show this help; help.% — detail helps check help.about
initCtx	Create new 'context' from .default: CTX=<context>
listCtx	List all contexts
listSrv	List all services in context
listSrvVersion	List services with versions: SRV=<name>
addCtxSrv	Add service to context: SRV=<name>
enableCtxSrv	Enable service in context: SRV=<name>
disableCtxSrv	Disable service in context: SRV=<name>
rmCtxSrv	Remove service from context: SRV=<name>
buildCtx	Build context: CTX=<context>

Example

• Initialize context 'myctx' from template '.default'

$ make initCtx NEWCTX=myctx

• Add service nginxto context myctx — that is, copy files from folder:

  • .template/docker-compose/template/*.tmpl > ./.context/myctx/.tmpl/

    and create directories:

  • .context/myctx/.tmpl/

  • .context/myctx/.yml/

  • .context/myctx/.environ/

• Add service 'nginx' to context 'myctx'

  $ make addCtxSrv CTX=myctx SRV=nginx

• Now you can edit files in directories to castomize configuration of the 'nginx' service:

  • .context/myctx/.environ/nginx.env
  • .context/myctx/.yml/nginx.service.env
  • .context/myctx/.yml/nginx.volume.env

• Build context myctx — create files

  • .context/myctx/docker-compose.yml
  • .context/myctx/.env

$ make buildCtx CTX=myctx

Dependencies

The main utility on which the Jinja template engine depends is
— MiniJinja

The scripts also use standard Unix utilities :

Command	Description
minijinja-cli	a powerful but minimal dependency template engine for Rust compatible with Jinja/Jinja2
sed	stream editor for filtering and transforming text
cp	copy files and directories
ln -s	make links between files
mkdir	make a directory
sort	sort lines of text files
truncate	shrink or extend the size of a file to the specified size
uniq	report or omit repeated lines
awk	using by keymap functions

Installation

• MiniJinja

MiniJinja is also available as an (optionally pre-compiled) command line executable called minijinja-cli

$ curl -sSfL https://github.com/mitsuhiko/minijinja/releases/latest/download/minijinja-cli-installer.sh | sh
$ echo "Hello {{ name }}" | minijinja-cli - -Dname=World
Hello World

Alternatively, if you have Rust and the Cargo package manager installed, you also can install the 'minijinja-cli' using the command

$ cargo install minijinja-cli

---

How it work

$ make help.about

Shortly, context — is a directory with a name set by the environment variable CTX, context-directory is located at the folder named .context. The .context/$(CTX)/ directory contains templates (Jinja/Jinja2) at the .context/$(CTX)/.tmpl folder for build docker-compose.yml. YML-files from the .context/$(CTX)/.yml/ directory describe the services available for this context, every file $(SRV).service.yml describe some service with name $(SRV) . Env-files from the directory .context/$(CTX)/.environ/ set environment variables for each service $(SRV).env. The command like:

$ make buildCtx CTX=test

created 'docker-compose.yml' & '.env' files at the ./.context/test folder.