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Utilities

Getting started

The Makester utilities are Python scripts that available to your project when you create the Makester environment with:

make py-install-makester

makester usage

venv/bin/makester
makester usage message.
Usage: makester [OPTIONS] COMMAND [ARGS]...

 Makester CLI tool

╭─ Options ────────────────────────────────────────────────────────────────────────────────────────╮
│ --quiet          Disable logs to screen (to log level "ERROR")                                   │
│ --help           Show this message and exit.                                                     │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯
╭─ Commands ───────────────────────────────────────────────────────────────────────────────────────╮
│ backoff       Wait until dependent service is ready.                                             │
│ templater     Template against environment variables or optional JSON values.                    │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯

makester backoff

Makester v0.1.4

src/waitster.py was refactored into the makester backoff CLI in Makester v0.1.4.

Wait until dependent service is ready:

venv/bin/makester backoff --help
makester backoff usage message.
 Usage: makester backoff [OPTIONS] HOST PORT

 Wait until dependent service is ready.

╭─ Arguments ──────────────────────────────────────────────────────────────────────────────────────╮
│ *    host      TEXT     Host name of service connection. [required]                              │
│ *    port      INTEGER  Service port number. [required]                                          │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯
╭─ Options ────────────────────────────────────────────────────────────────────────────────────────╮
│ --detail  -d      TEXT  Meaningful description for backoff port [default: Service]               │
│ --help                  Show this message and exit.                                              │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯

makester backoff will poll port for 300 seconds before a time out error is reported.

makester backoff Example

Start listening on a port:

nc -l 19999

Poll the port:

venv/bin/makester backoff localhost 19999 --detail "Just a port check ..."
Backoff polling port 19999 for service readiness.
2022-12-13 07:55:20,037:makester:INFO: Checking host:port localhost:19999 Just a port check ... ...
2022-12-13 07:55:21,042:makester:INFO: Port 19999 ready

makester templater

Makester v0.1.4

src/templatester.py was refactored into the makester templater CLI in Makester v0.1.4.

Template against environment variables or optional JSON values (--mapping switch):

venv/bin/makester templater --help
makester templater usage message.
╭─ Arguments ──────────────────────────────────────────────────────────────────────────────────────╮
│ *    template      TEXT  Path to Jinja2 template (absolute, or relative to user home) [required] │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯
╭─ Options ────────────────────────────────────────────────────────────────────────────────────────╮
│ --filter   -f      TEXT  Environment variable filter (ignored when mapping is taken from JSON    │
│                          file)                                                                   │
│ --mapping  -m      TEXT  path to JSON mappings (absolute, or relative to user home)              │
│ --write    -w            Write out templated file alongside Jinja2 template                      │
│ --help                   Show this message and exit.                                             │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯

makester templater takes a file path as defined by the template positional argument and renders the template against target variables. The variables can be specified as a JSON document defined by --mapping.

The template files needs to end with a .j2 extension. If the --write switch is provided, then the generated content will be output to the template path less the .j2 extension.

A special custom filter env_override is available to bypass MAPPING values and source the environment for variable substitution. Use the custom filter env_override in your template as follows:

"test" : {{ "default" | env_override('CUSTOM') }}

Provided an environment variable as been set:

export CUSTOM=some_value

The template will render:

test: some_value

Otherwise:

test: default

makester templater Example

Create the Jinja2 template:

cat << EOF > my_template.j2
This is my CUSTOM variable value: {{ CUSTOM }}
EOF

Template!

CUSTOM=bananas venv/bin/makester --quiet templater my_template.j2
makester templater example output.
This is my CUSTOM variable value: bananas

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