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daniel9x
daniel9x

Reputation: 805

How to pass environment variable values into files in the docker container I'm trying to run

Let's say I have a config file in my docker container located here:

/opt/jboss/bin/config.xml

The Config file looks like this:

<Database-Password>$PASSWORD</Database-Password>

I want to pass the actual password in when I go to run the docker container using the "--env-file" argument.

This is the contents on the env-file I'm passing in:

PASSWORD=MyPassword

I understand the VARIABLE=VALUE syntax. "MyPassword" is the value of the Password variable.

How will docker know to find the specific file (/opt/jboss/bin/config.xml) with this variable and swap it out? Am I declaring the variable correctly in the config file? For some reason I'm having trouble finding this information.

Upvotes: 1

Views: 1973

Answers (2)

Sobrique
Sobrique

Reputation: 53478

The short answer is - it won't necessarily. Unless you have some mechanism to rewrite your config file from the host environment.

This is pretty easy in a shell script - you can just refer to it as you have done.

But an XML file isn't "run" in that sense, so it probably won't just work.

As an example - if you want to 'edit' your xml, you could do it with perl - but you'll have to install a bit more stuff to get it to work:

perl -MXML::Twig -e'XML::Twig -> new ( twig_handlers => { Database-Password => sub { $_ -> set_text ( $ENV{PASSWORD} ) } } ) -> parsefile_inplace("/opt/jboss/bin/config.xml")'

(This will need both perl and XML::Twig installing, so there may be better options)

Upvotes: 1

user2915097
user2915097

Reputation: 32156

the syntax in your env file should be

variable=value

see the doc at https://docs.docker.com/engine/reference/commandline/run/

extract

cat ./env.list TEST_FOO=BAR

Upvotes: 0

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