add check for compatible Docker OS type

[jetersen]

as Windows containers are not supported at the moment

resolves #1765

works out great 🙌

aug. 24, 2019 12:26:02 PM org.testcontainers.dockerclient.DockerClientProviderStrategy lambda$getFirstValidStrategy$1
INFO: Loaded org.testcontainers.dockerclient.NpipeSocketClientProviderStrategy from ~/.testcontainers.properties, will try it first
aug. 24, 2019 12:26:02 PM org.testcontainers.dockerclient.DockerClientProviderStrategy getClientForConfig
INFO: Will use 'okhttp' transport
aug. 24, 2019 12:26:03 PM org.testcontainers.dockerclient.NpipeSocketClientProviderStrategy test
INFO: Accessing docker with local Npipe socket (npipe:////./pipe/docker_engine)
aug. 24, 2019 12:26:03 PM org.testcontainers.dockerclient.DockerClientProviderStrategy getClientForConfig
INFO: Will use 'okhttp' transport
aug. 24, 2019 12:26:03 PM org.testcontainers.dockerclient.NpipeSocketClientProviderStrategy test
INFO: Accessing docker with local Npipe socket (npipe:////./pipe/docker_engine)
aug. 24, 2019 12:26:03 PM org.testcontainers.dockerclient.DockerClientProviderStrategy getClientForConfig
INFO: Will use 'okhttp' transport
aug. 24, 2019 12:26:09 PM org.testcontainers.dockerclient.DockerMachineClientProviderStrategy test
INFO: Found docker-machine, and will use machine named 
aug. 24, 2019 12:26:09 PM org.testcontainers.dockerclient.DockerClientProviderStrategy lambda$getFirstValidStrategy$3
SEVERE: Could not find a valid Docker environment. Please check configuration. Attempted configurations were:
aug. 24, 2019 12:26:09 PM org.testcontainers.dockerclient.DockerClientProviderStrategy lambda$getFirstValidStrategy$3
SEVERE:     NpipeSocketClientProviderStrategy: failed with exception InvalidConfigurationException (Windows containers are currently not supported)
aug. 24, 2019 12:26:09 PM org.testcontainers.dockerclient.DockerClientProviderStrategy lambda$getFirstValidStrategy$3
SEVERE:     NpipeSocketClientProviderStrategy: failed with exception InvalidConfigurationException (Windows containers are currently not supported)
aug. 24, 2019 12:26:09 PM org.testcontainers.dockerclient.DockerClientProviderStrategy lambda$getFirstValidStrategy$3
SEVERE:     WindowsClientProviderStrategy: failed with exception TimeoutException (Timeout waiting for result with exception). Root cause ConnectException (Connection refused: connect)
aug. 24, 2019 12:26:09 PM org.testcontainers.dockerclient.DockerClientProviderStrategy lambda$getFirstValidStrategy$3
SEVERE:     DockerMachineClientProviderStrategy: failed with exception InvalidConfigurationException (Exception when executing docker-machine status )
aug. 24, 2019 12:26:09 PM org.testcontainers.dockerclient.DockerClientProviderStrategy lambda$getFirstValidStrategy$3
SEVERE: As no valid configuration was found, execution cannot continue

[bsideup]

A few things here:

1. please check for "linux" instead of "not windows", just in case
2. I would make it more generic, for every strategy. e.g. check for OSType after calling .test() in DockerClientProviderStrategy

[jetersen]

@bsideup checking for linux could mean if they ever introduced a hybrid mode we would have to adapt. Whereas by checking for windows could keep the same check.

[bsideup]

@Casz we would have to adapt if they introduce macOS or ARM containers too, so I would rather stick to what we explicitly support

[jetersen]

This will unblock something like this
https://github.com/casz/vault-java-driver/tree/chore/singleTestPackage
https://github.com/casz/vault-java-driver/runs/202447075

[bsideup]

The implementation looks good, pinging @rnorth and @kiview to check the wording, just in case

[rnorth]

That looks good to me, thank you @Casz.

[jetersen]

Thank you 🙌