CODEWITHSUNDEEP
shelldockermakefile
Aimee
Aimee

Reputation: 23

In Makefile use environment variable defined in Docker container to run a command

I am trying to run a command from a docker-compose service, and I want to to use the environment variables defined in my container like this:

In my Makefile:

sqlcmd: 
    docker-compose run sqlcmd sqlcmd -S sqlserver -U "$SQL_HOST" -P "$SQL_PASSWORD"

Then I run make sqlcmd.

But it's printing out truncated words. What I want it to do is use the environment variables $SQL_HOST and $SQL_PASSWORD, which are defined in the container.

How do I get this to escape properly?

Upvotes: 2

Views: 3092

Answers (1)

Nick ODell
Nick ODell

Reputation: 25344

To get a literal $, use $$.

docker-compose run sqlcmd sqlcmd -S sqlserver -U "$$SQL_HOST" -P "$$SQL_PASSWORD"

If SQL_HOST and SQL_PASSWORD are variables defined earlier in your Makefile, (rather than environment variables) you need to write it like this:

SQL_HOST=localhost
SQL_PASSWORD=hunter2
sqlcmd: 
    docker-compose run sqlcmd sqlcmd -S sqlserver -U "$(SQL_HOST)" -P "$(SQL_PASSWORD)"

PS: Welcome to the site.

EDIT: To delay expansion of the variables until the container has started, you need to prevent your shell from expanding them. If a variable is enclosed in single quotes, the shell will not try to expand it.

Here's an example:

docker-compose run sqlcmd sqlcmd -S sqlserver -U '"$$SQL_HOST"' -P '"$$SQL_PASSWORD"'

EDIT EDIT: I guess you need this too, to tell Docker to use the shell to expand the variables:

docker-compose run sqlcmd sh -c 'sqlcmd -S sqlserver -U "$$SQL_HOST" -P "$$SQL_PASSWORD"'

Upvotes: 1

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