Configify

Configify lets you write templates in Jinja2, which get context variables from a hierarchy of parameter YAML files.

Simple templates

Params are loaded from yaml files, in sequence, where the later files override any keys from earlier files.

nginx_vhost.conf.j2

server {
    listen {{ port }};
    {% for alias in aliases -%}
    location /{{ alias.name }} { alias {{ alias.path }}; autoindex on; }
    {% endfor -%}
}

nginx.yaml

port: 80
aliases:
 - name: doc
   path: /opt/app/doc
 - name: video
   path: /home/myuser/video

Configifile

template: nginx_vhost.conf.j2
params:
 - nginx.yaml

OUTPUT

server {
    listen 80;
    location /doc { alias /opt/app/doc; autoindex on; }
    location /video { alias /home/myuser/video; autoindex on; }

}

Initial context via CLI

You can set an initial set of context parameters right from the CLI. You might want to use this as some sort of an argument to filter output in the template, or just as extra input.

Configifile

Same as simple templates example above

nginx_vhost.conf.j2

server {
    listen {{ port }};
    {% for alias in aliases %}{% if not only_alias or alias.name == only_alias -%}
    location /{{ alias.name }} { alias {{ alias.path }}; autoindex on; }
    {% endif %}{% endfor -%}
}

nginx.yaml

aliases:
 - name: doc
   path: /opt/app/doc
 - name: video
   path: /home/myuser/video

OUTPUT configify port=8080 only_alias=doc

server {
    listen 8080;
    location /doc { alias /opt/app/doc; autoindex on; }

}

Templated context parameters

Params YAML files are also run throught Jinja2 before being parsed as YAML. The context parameters they get are all the parameters that have been parsed up until that point (any previous YAML parameters files).

nginx_vhost.conf.j2

Same as simple templates example above

nginx_base.yaml

port: 80
app_docs:
 - first_app
 - second_app
 - other_app

nginx_generated.yaml

aliases:
{%- for app in app_docs %}
 - name: doc/{{ app }}
   path: /opt/{{ app }}/doc
{% endfor -%}

Configifile

template: nginx_vhost.conf.j2
params:
 - nginx_base.yaml
 - nginx_generated.yaml

OUTPUT

server {
    listen 80;
    location /doc/first_app { alias /opt/first_app/doc; autoindex on; }
    location /doc/second_app { alias /opt/second_app/doc; autoindex on; }
    location /doc/other_app { alias /opt/other_app/doc; autoindex on; }

}

Post-processed variables

You can defer the procesing of a parameter until after all parameters have been loaded by putting a $ in front of it. This way, you can have parameters that depend on values that have yet to be processed. Remembor to enclose any template values in a raw tag.

port: 80
$logfile: {% raw %}/var/log/server_{{ port }}{% endraw %}

Inline template filter

In your parameters, you may like to use a lightweight, partial template similar to a format string. There's the inline_tpl filter that we've added so that you can do just this. The template in the parameter will recieve the current context parameters, as well as any extra kwargs passed to the filter. It will not receieve the local context (eg loop variables).

params.yaml

servername_tpl: "{% raw %}{{ subdomain.name }}.mydomain.com{% endraw %}"
subdomains:
 - name: doc
   port: 80
 - name: app
   port: 443

nginx_vhosts.conf.j2

{%- for subdomain in subdomains %}
server {
    listen {{ subdomain.port }};
    servername {{ servername_tpl | inline_tpl(subdomain=subdomain) }};
}
{% endfor -%}

OUTPUT

server {
    listen 80;
    servername doc.mydomain.com;
}

server {
    listen 443;
    servername app.mydomain.com;
}

Params file globs

You can load up your params files from file globs, making it easy to add new variables and overrides.

Configifile

template: tpl.j2
params:
 - dev-*.yaml
 - test-?.yaml
 - prod-[au,uk,us].yaml