e2j2 (environment to jinja2 variables) is a commandline tool which will render jinja2 templates to textfiles. all environment variables can be used in the jinja2 templates, within the environment variables you can use special tags which give you the option to insert json, json file paths, base64 hashes, consul kv keys.
e2j2 is intended to be used within docker containers, you can simply add the j2 extention to a configuration file and then run e2j2 before you're starting the actual executable.
lets assume we want to render the following server block in nginx, if we place the server configuration in a nginx include directory for example /etc/nginx/conf.d
server {
server_name {{ NGINX.server_name }};
listen 80;
listen [::]:80;
error_page 500 502 503 504 /50x.html;
location / {
index {{ NGINX.index_page }};
root {{ NGINX.web_root }};
}
location ~ \.php$ {
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_pass unix:{{ NGINX.fpm_socket }};
fastcgi_split_path_info ^(.+\.php)(/.+)$;
include {{ NGINX.fcgi_params }};
root {{ NGINX.web_root }};
try_files $uri =404;
}
}if you then set the NGINX environment variable, running e2j2 will render the jinja2 template and place it in the same folder:
~> export NGINX=export NGINX='json:
{
"server_name": "www.myweb.com",
"index_page": "index.php",
"web_root": "/usr/local/www/myweb",
"fcgi_params": "/usr/local/etc/nginx/myweb-fcgi-params",
"fpm_socket": "/var/run/php-fpm/myweb.socket"
}'
~> e2j2
In: .
rendering: nginx_vhost_config.conf.j2=>done => writing: nginx_vhost_config.conf=>done
~> cat nginx_vhost_config.conf
server {
server_name www.myweb.com;
listen 80;
listen [::]:80;
error_page 500 502 503 504 /50x.html;
location / {
index index.php;
root /usr/local/www/myweb;
}
location ~ \.php$ {
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_pass unix:/var/run/php-fpm/myweb.socket;
fastcgi_split_path_info ^(.+\.php)(/.+)$;
include /usr/local/etc/nginx/myweb-fcgi-params;
root /usr/local/www/roundcube;
try_files $uri =404;
}
}Example:
setting:
MYENVVAR='plain environment variable'
will render envvar-example.j2 to:
This is a plain environment variable
Example:
setting:
MYJSONVAR='json:{"key": "json-example"}'
will render json-example.j2 to:
This is a json-example
Example:
setting:
MYJSONFILEVAR='jsonfile:jsonfile-example.json'
will render jsonfile-example.j2 to:
This is a jsonfile example with subkey
Example:
Setting:
export MYBASE64VAR='base64:YmFzZTY0IGV4YW1wbGU='
will render base64-example.j2 to:
This is a base64 example
Configuration:
You can configure the consul tag by setting the CONSUL_CONFIG environment variable. The following config items are supported:
| Item | Explanation | Default |
|---|---|---|
| scheme | url scheme http or https | http |
| host | consul host | localhost |
| port | consul http(s) port | 8500 |
| token | consul token | none |
Config example:
$ read -d '' CONSUL_CONFIG << EOF
> {
> "scheme": "https",
> "host": "consul.foobar.tld",
> "port": 443,
> "token": "abcdef01-0123-abcd-1234-0123456789ab"
> }
> EOF
Example:
Setting:
key: consulvar in consul to value: consul example
and
export MYCONSULVAR='consul:consulvar'
will render consul-example.j2 to:
This is a consul example