dockerenv

cmattoon/dockerenv

Retrieves values from Docker environment variables

The primary use case for this was inspecting TLS certificates in Docker environment variables, which looks something like this:

Verify a TLS cert in a container abc123 with PEM data in MYAPP_TLS_CRT and MYAPP_TLS_KEY:

$ ./dockerenv --container-id abc123 tls verify --cert MYAPP_TLS_CRT --key MYAPP_TLS_KEY
YYYY/MM/DD HH:MM:SS Loaded X509KeyPair with 1 certs
YYYY/MM/DD HH:MM:SS Certificate 0 (CA: false)
YYYY/MM/DD HH:MM:SS =========================
YYYY/MM/DD HH:MM:SS 	Subject          : CN=myapp-tls-certificate-subject
YYYY/MM/DD HH:MM:SS 	Subject Key Id   :
YYYY/MM/DD HH:MM:SS
YYYY/MM/DD HH:MM:SS 	Issuer           : CN=myapp-selfsigned-ca
YYYY/MM/DD HH:MM:SS 	Authority Key Id :
YYYY/MM/DD HH:MM:SS
YYYY/MM/DD HH:MM:SS 	Not Before : YYYY-MM-DD HH:MM:SS +0000 UTC   (1 month ago)
YYYY/MM/DD HH:MM:SS 	Not After  : YYYY-MM-DD HH:MM:SS +0000 UTC   (5 months from now)
YYYY/MM/DD HH:MM:SS
...

To save the value of MYAPP_DATABASE_PASS in container abc123 to the local var DB_PASSWORD:

$ DB_PASSWORD=$(dockerenv -c abc123 -v MYAPP_DATABASE_PASS)