![]() ![]() ![]() The following example shows the required changes in the case of a Python Django app:,If you select a port less than 1024 when adding Dockerfiles to the workspace, the Docker extension cannot create a Dockerfile that runs the container as a non-root user. ![]() You can usually search for any occurrences of the old port number in tasks.json and replace it with the new port number. # /usr/bin/socat UNIX-LISTEN:/var/run/docker-userns.sock,user=231072,group=231072,mode=0660,fork UNIX-CLIENT:/var/run/docker.Next, ensure the docker run task in tasks.json also expects the same port. Starting the socat we need to specify the both endpoints – first the new one following by existing root-owned socket. The second socket can easily be assigned and accessible for processes inside the container. srw-rw- 1 root docker 0 Jan 16 22:52 docker.sock another socket! And another process may be the owner of the socket. The endpoints can be by example the socket type of SOCK_STREAM. It created two bidirectional pipes (byte streams) and transfer data between them. It is available in most Linux distributions by default. The solution to our problem is a small application – socat. If we bind the socket to the container it won’t be accessible because of the ownersip and permission mismatch The socat The first column is the user ID – on my system it is 231072. The process running in the container from the host perspective is a non-root process if we use the user namespaces 231072 512 0.0 1.4 20888 13856 ? Ss Jan16 0:16 /usr/bin/python2 /usr/bin/supervisord The Docker socket permissions in such case should look like that srw-rw- 1 root docker 0 Jan 16 22:52 docker.sock ![]() Using the user namespaces we face the situation where the dockerd process (the Docker Engine) is run as root while the containers itself uses non-root PID. The owner of the socket is the process creating it. To make it, even more, simpler think of the socket as of the file on the filesystem which you read from and write to sequences of bytes. To make it simpler, in this case, think of it as of TCP connections, but instead of connecting to IP and port you connect to a socket on the host. Unix socket is a special handler that allows applications to communicate. But there is an easy workaround for this problem Namespaces and containers It make the host socket inaccessible for the processes inside the container. The problem is the socket on the hosts is owned by the root, while the root PID from inside of your container is remapped to non-root PID on the host. It is required if you run Docker inside of the Docker container or you deploy a tool that will manage your Docker hosts or Docker Swarm cluster. In some cases you may need to access the host resource from the container like the Docker own socket. User namespaces provides the mechanism of remapping container resources to host resources limiting container access to the host system. The namespaces makes the process run on the host thinks that it has its own access to some global resources like the PIDs. One of the recommended change to improve Docker security is isolation of the containers in user namespace which was introduced in Docker Engine 1.10. Nothing is secure by default and Docker is no exception. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |