How do we set environment variables for our containers? With a traditional server, we would SSH in to the server and type the command export PORT=8080 in our terminal and it would be available as long as the server was up.
Docker run image environment variables how to#
Hopefully you can see how environment variables are valuable tools for configuration and secret management, but you may be confused how to use them in a volatile and ephemeral environment like containers and Docker. By definition, environment variables only exist in a single environment, so they are not stored in shared areas like source control. But environment variables really shine when it comes to secrets. Here is another example of how environment variables can be simple values, like a password, or can also kick off complex actions, like creating a new database.Īs you can see with these examples, an environment variable may be optional and is not necessarily a secret.
Docker run image environment variables install#
When set to true, the box install command will be run before the server is started to ensure any dependencies configured in your box.json file are installed.The port which your server should start on.We can see some examples of these configuration environment variables in the ortussolutions/commandbox Docker image: This also enables reuse of our images since we can change behaviors and values on the fly. The time to reach for an environment variable is when you may want a different value or set of behaviors between development and production. Why Environment VariablesĮnvironment variables are configuration values specific to the container (or environment) they are running in. What are our options for configuration and secrets when we want to avoid using web-based administrators (both for convenience and security).Ī powerful tool in our configuration / security toolbelt when using Docker is to use environment variables. Configuration files are somewhat new for the CFML world. A common question that comes up when dealing with docker is how to configure it without using a web-based administrator.
