have persistent IP address • Port publishing creates docker proxy processes • Out-of-memory errors can knock down your OS • Dangling and untagged images pollute FS Gotchas
22 # SSH $ ufw allow 80 # HTTP $ ufw allow from 10.0.1.25 to any port 5432 In multi host environment you need to publish ports: $ docker run -d -p 5432:5432 postgres:9.5 You still can access the host from unrestricted machines: $ psql -h ip-address mydb Docker and UFW
latest 3cfbce003800 43 hours ago 1.016 GB <none> <none> 58e12b181489 2 days ago 1.016 GB <none> <none> 09c6230a686f 2 days ago 1.024 GB <none> <none> 559efd23e19c 2 days ago 1.024 GB <none> <none> ec6f4f18c90c 2 days ago 1.035 GB <none> <none> c50506c9fa32 2 days ago 1.034 GB <none> <none> dd9429b92f28 3 days ago 1.033 GB <none> <none> 60534a5aa2b6 3 days ago 1.033 GB <none> <none> 46a302aa0da1 3 days ago 1.029 GB <none> <none> 3497cd79d8e0 3 days ago 1.029 GB <none> <none> b154ef538cb2 3 days ago 1.029 GB <none> <none> b6a176f9183c 3 days ago 1.027 GB # Or list ALL images $ docker images -a Dangling Images
Deleted: sha256:58e12b18148976dda668b1d001745853d4997 Deleted: sha256:fd0161ef5c76870cd7a2afe8cada44de5474594 Deleted: sha256:22b96627b93798445d9af6e53bfbc68fde4df14 Deleted: sha256:03879b4386b3362486fc2fe209433dd7177e16 Deleted: sha256:09c6230a686f907721bc4bbfe4009c10872253 Deleted: sha256:088e3f6d5febe3ef82543345aacb12dd7df1ea2 Error response from daemon: conflict: unable to delete 3cfbce003800 (cannot be forced) - image is being used by running container 9298939fdffd Docker won’t delete images that are being used. Tag your images.