How to fix ParameterCircularReferenceException? - php

Question

I have a symfony2 appliciation. We have previously set up a docker-compose stack for development, and this is why we want all its configuration to bet set via environment variables instead of the parameters.yml.
Hence I replaced the content of my parameters.yml from:
parameters:
locale: 'en'
secret: 'SOME_SECURITY_TOKEN'
...
to:
parameters:
locale: '%locale%'
secret: '%secret%'
...
My docker-compose.yml file contains:
my_app:
hostname: my-app
build: .
dockerfile: Dockerfile.dev
ports:
- "9080:80"
- "9043:433"
environment:
LOCALE: en
SECRET: SOME_SECURITY_TOKEN
...
Yet after rebuilding my container I get the exception:
ParameterCircularReferenceException in ParameterBag.php line 209: Circular reference detected for parameter "secret" ("secret" > "secret").
1. in ParameterBag.php line 209
2. at ParameterBag->resolveString('%secret%', array('secret' => true)) in ParameterBag.php line 185
3. at ParameterBag->resolveValue('%secret%', array('secret' => true)) in ParameterBag.php line 214
4. at ParameterBag->resolveString('%secret%', array('secret' => true)) in ParameterBag.php line 185
5. at ParameterBag->resolveValue('%secret%', array()) in ParameterBag.php line 175
6. at ParameterBag->resolveValue(array('secret' => '%secret%', 'router' => array('resource' => '%kernel.root_dir%/config/routing.yml', 'strict_requirements' => null), 'form' => null, 'csrf_protection' =>
null, 'validation' => array('enable_annotations' => true), 'templating' => array('engines' => array('twig')), 'default_locale' => '%locale%', 'trusted_hosts' => null, 'trusted_proxies' => null,
'session' => array('handler_id' => 'api.session.handler.memcached'), 'fragments' => null, 'http_method_override' => true), array()) in ParameterBag.php line 175
7. at ParameterBag->resolveValue(array(array('secret' => '%secret%', 'router' => array('resource' => '%kernel.root_dir%/config/routing.yml', 'strict_requirements' => null), 'form' => null,
'csrf_protection' => null, 'validation' => array('enable_annotations' => true), 'templating' => array('engines' => array('twig')), 'default_locale' => '%locale%', 'trusted_hosts' => null,
'trusted_proxies' => null, 'session' => array('handler_id' => 'api.session.handler.memcached'), 'fragments' => null, 'http_method_override' => true), array('router' =>
array('resource' => '%kernel.root_dir%/config/routing_dev.yml', 'strict_requirements' => true), 'profiler' => array('only_exceptions' => false)))) in MergeExtensionConfigurationPass.php line 45
8. at MergeExtensionConfigurationPass->process(object(ContainerBuilder)) in MergeExtensionConfigurationPass.php line 39
9. at MergeExtensionConfigurationPass->process(object(ContainerBuilder)) in Compiler.php line 107
10. at Compiler->compile(object(ContainerBuilder)) in ContainerBuilder.php line 589
11. at ContainerBuilder->compile() in bootstrap.php.cache line 2687
12. at Kernel->initializeContainer() in bootstrap.php.cache line 2465
13. at Kernel->boot() in bootstrap.php.cache line 2496
14. at Kernel->handle(object(Request)) in app_dev.php line 30
Yet in my container I do see the env variables:
le-container:/var/www/my-app# env
SECRET=SOME_SECURITY_TOKEN
LOCALE=en
What am I doing wrong and how to fix it?

Answer 1

For some reason, adding a prefix to my environment variable fixed the issue:
parameters:
locale: '%foo_locale%'
secret: '%foo_secret%'
and of course whenever the variable is set as well. My current working theory is that symfony doesn't like having the same parameter name and env variable, yet I am not sure.

Answer 2

parameters:
locale: '%locale%'
secret: '%secret%'
Is useless construction, locale and secret already is parameters. Just remove this block.

Answer 3

There is a solution to use external parameters. Prefix your variables with "SYMFONY__". In your case it would be:
my_app:
...
environment:
SYMFONY__APP__LOCALE: en
SYMFONY__APP__SECRET: SOME_SECURITY_TOKEN
...
And in your parameters you can call it as followed:
parameters:
locale: %app.locale%
secret: %app.secret%