After install docker need to add ca certificate to CentOS 7 copy ca certificates into
/etc/pki/ca-trust/source/anchors/
after than use follow command to update certificates
# update-ca-trust
now add proxy settings into docker config file /etc/sysconfig/docker as follow
HTTP_PROXY="" HTTPS_PROXY=""
if use docker community edition (docker-ce) can use a conf file to set proxy, es /etc/systemd/system/docker.service.d/http-proxy.conf:
[Service] Environment="HTTP_PROXY=http://proxy.example.com:80/" "NO_PROXY=localhost,127.0.0.1,docker-registry.example.com,.corp"
can see documentation here: https://docs.docker.com/config/daemon/systemd/#httphttps-proxy
for sudo without password add row indo /etc/sudoers
[USER] ALL=(ALL) NOPASSWD: /usr/bin/docker
configure docker engine to start at boot:
systemctl enable docker systemctl restart docker