A docker machine must have minimal OS environment value in order to function correctly.
docker-machine env default
Output:
SET DOCKER_TLS_VERIFY=1
SET DOCKER_HOST=tcp://192.168.99.100:2376
SET DOCKER_CERT_PATH=C:\Users\gerard\.docker\machine\machines\default
SET DOCKER_MACHINE_NAME=default
REM Run this command to configure your shell:
REM @FOR /f "tokens=*" %i IN ('docker-machine env default') DO @%i
Environment variables
The following list of environment variables are supported by the docker command line:
DOCKER_API_VERSION The API version to use (e.g. 1.19)
DOCKER_CERT_PATH The location of your authentication keys.
DOCKER_DRIVER The graph driver to use.
DOCKER_HOST Daemon socket to connect to.
DOCKER_NOWARN_KERNEL_VERSION Prevent warnings that your Linux kernel is unsuitable for Docker.
DOCKER_RAMDISK If set this will disable ‘pivot_root’.
DOCKER_TLS_VERIFY When set Docker uses TLS and verifies the remote.
DOCKER_CONTENT_TRUST When set Docker uses notary to sign and verify images. Equates to –disable-content-trust=false for build, create, pull, push, run.
DOCKER_CONTENT_TRUST_SERVER The URL of the Notary server to use. This defaults to the same URL as the registry.
DOCKER_TMPDIR Location for temporary Docker files.
Because Docker is developed using ‘Go’, you can also use any environment variables used by the ‘Go’ runtime. In particular, you may find these useful: