mac 上没有显示环境变量

Question

Environment variables set outside the shell, through ~/.bash_profile or ~/.bashrc do not appear to docker, or env, despite being accessible in the shell.

Bash_profile contains the line TEST_ENV_VAR=123 , after restarting terminal, the variable can be accessed through $TEST_ENV_VAR , however docker and env cannot access this environment variable.

Henrys-MacBook-Pro:~ henry$ echo $TEST_ENV_VAR 
123          
Henrys-MacBook-Pro:~ henry$ docker run -it -e TEST_ENV_VAR ubuntu env | grep TEST_ENV_VAR
Henrys-MacBook-Pro:~ henry$ env | grep TEST_ENV_VAR

And yet the terminal can access it, and even pass it into docker:

Henrys-MacBook-Pro:~ henry$ docker run -it -e TEST_ENV_VAR=${TEST_ENV_VAR} ubuntu env | grep TEST_ENV_VAR
TEST_ENV_VAR=123

And the issue isn't an issue with environment variable in general, as variables set in the terminal work as expected:

Henrys-MacBook-Pro:~ henry$ export TEST_ENV_VAR=1234
Henrys-MacBook-Pro:~ henry$ docker run -it -e TEST_ENV_VAR ubuntu env | grep TEST_ENV_VAR
TEST_ENV_VAR=1234

I'm running macOS Mojave, 10.14.5, classic terminal, docker 19.03.4, the output of ls -al ~:

-rw-r--r--   1 henry  staff    455 Nov 12 11:50 .bash_profile

Answer 1

docker doesn't actually start a container. Instead, it sends a message to the Docker engine (running in a separate environment unrelated to the environment in which docker is executed) requesting that it start a container for you. As such, the new container won't inherit any of variables in your current shell environment.

With your TEST_ENV_VAR=${TEST_ENV_VAR} attempt, you are explicitly telling docker to create an environment variable named TEST_ENV_VAR , with the value produced by expanding TEST_ENV_VAR now , in the new container, rather than trying to inherit the variable from the appropriate environment.

Even ignoring that, you aren't actually creating an environment variable with TEST_ENV_VAR=123 ; you've only created an ordinary shell variable. For env to see it, you need to first export it.

$ TEST_ENV_VAR=123
$ env | grep TEST_ENV_VAR
$ export TEST_ENV_VAR
$ env | grep TEST_ENV_VAR
TEST_ENV_VAR=123

Answer 2

The.bash_profile is for your user. Docker is running in its own environment (as opposed to running in a subshell spawned by your user). Export only sends information down into child shells. You need to make the variable available at a higher level.

/etc/environment 

Be careful in there.

Alternatively, you may look into asking Docker to make these changes itself.