Difference between shell and environment variables

Citing this source, Standard UNIX variables are split into two categories, environment variables and shell variables. In broad terms, shell variables apply only to the current instance of the shell and are used to set short-term working conditions; environment variables have a farther reaching significance, and those set at login are valid for the duration … Read more

Referencing Environment Variables in web.xml

You can use Ant-style variable substitution in any of the tomcat xml config files, such as: <servlet-mapping> <servlet-name>mvc-dispatcher</servlet-name> <url-pattern>${foo}</url-pattern> </servlet-mapping> Where foo is a Java System Property (sysprop). You can’t use OS Environment Variables (envvars) directly, I think… To use envvars, you can put set “CATALINA_OPTS=-DsomeJavaSysProp=%SOME_OS_ENVVAR%” in bin/setenv.bat (or similarly in bin/setenv.sh for *nix). You … Read more

Where to store sensitive data in public rails app?

TLDR: Use environment variables! I think @Bryce’s comment offers an answer, which I’ll just flush out. It seems one approach Heroku recommends is to use environment variables to store sensitive information (API key strings, database passwords). So survey your code and see in which you have sensitive data. Then create environment variables (in your .bashrc … Read more

Override env values defined in container spec

From Kubernetes API reference: envFrom : List of sources to populate environment variables in the container. The keys defined within a source must be a C_IDENTIFIER. All invalid keys will be reported as an event when the container is starting. When a key exists in multiple sources, the value associated with the last source will … Read more