Search code examples
dockerdockerfiledocker-machine

permission denied in containers after moving docker home


Initially docker files system was located in /var/lib/docker Everything was working fine,But due to some space constrain ,We had to move to /Proj/docker & docker service is running.

Active: active (running) since Thu 2019-03-28 09:36:59 UTC; 22h ago Docs: https://docs.docker.com Main PID: 27007 (dockerd) Tasks: 27 Memory: 726.5M CGroup: /system.slice/docker.service └─27007 /usr/bin/dockerd --selinux-enabled -g /Proj/docker

But after that , I am getting permission denied

  [user@host]# sudo docker run  -it oraclelinux:7-slim bash
 bash-4.2# ls
  ls: cannot open directory : Permission denied

**unless I am running  with privilage flag set to true** 

  [user@host]# sudo docker run  -it --privileged=true  oraclelinux:7-slim bash
 bash-4.2# ls
bin  boot  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var

Can you please help to resolve this  

please find additional info

[user@host ~]$ systemctl status docker
● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/docker.service.d
           └─docker-sysconfig.conf, https-proxy.conf
   Active: active (running) since Thu 2019-03-28 09:36:59 UTC; 1 day 2h ago
     Docs: https://docs.docker.com
 Main PID: 27007 (dockerd)
    Tasks: 27
   Memory: 726.9M
   CGroup: /system.slice/docker.service
           └─27007 /usr/bin/dockerd --selinux-enabled -g /Proj/docker

		   


[user@host ~]$ cat /etc/systemd/system/docker.service.d/docker-sysconfig.conf
[Service]
ExecStart=
EnvironmentFile=-/etc/sysconfig/docker
EnvironmentFile=-/etc/sysconfig/docker-storage
EnvironmentFile=-/etc/sysconfig/docker-network
ExecStart=/usr/bin/dockerd \
          $OPTIONS \
          $DOCKER_STORAGE_OPTIONS \
          $DOCKER_NETWORK_OPTIONS \
          $INSECURE_REGISTRY \
          -g /Proj/docker
		  
		  
[user@host ~]$ cat /etc/systemd/system/docker.service.d/https-proxy.conf
[Service]
Environment="HTTPS_PROXY=http://proxyip:port"



[user@host~]# ls -lrth /Proj/docker
total 56K
drwx------.  4 root root 4.0K Mar 22 07:42 plugins
drwx------.  3 root root 4.0K Mar 22 07:42 image
drwx------.  2 root root 4.0K Mar 22 07:42 volumes
drwx------.  2 root root 4.0K Mar 22 07:42 trust
drwxr-x---.  3 root root 4.0K Mar 22 07:42 network
drwx------.  2 root root 4.0K Mar 22 07:42 swarm
drwx------.  2 root root 4.0K Mar 22 07:42 builder
drwx------.  4 root root 4.0K Mar 22 07:42 buildkit
drwx------.  2 root root 4.0K Mar 28 09:36 runtimes
drwx------.  2 root root 4.0K Mar 28 13:02 tmp
drwx------. 33 root root  12K Mar 29 07:45 overlay2
drwx------.  6 root root 4.0K Mar 29 07:45 containers


Solution

  • We did change the docker graph too so what we did was de following on RedHat 7.6:

    • Stop dockerd
    • Move everything from /var/lib/docker to /Docker/Storage
    • Change configuration on /etc/docker/daemon.json:

    {

    "graph":"/Docker/Storage"
    

    }

    • And:

    /usr/lib/systemd/system/docker.service:

    [Unit]
    Description=Docker Application Container Engine
    Documentation=https://docs.docker.com
    BindsTo=containerd.service
    After=network-online.target firewalld.service
    Wants=network-online.target
    Requires=docker.socket
    
    [Service]
    Type=notify
    # the default is not to use systemd for cgroups because the delegate issues still
    # exists and systemd currently does not support the cgroup feature set required
    # for containers run by docker
    ExecStart=/usr/bin/dockerd -H fd://
    ExecReload=/bin/kill -s HUP $MAINPID
    TimeoutSec=0
    RestartSec=2
    Restart=always
    
    # Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229.
    # Both the old, and new location are accepted by systemd 229 and up, so using the old location
    # to make them work for either version of systemd.
    StartLimitBurst=3
    
    # Note that StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230.
    # Both the old, and new name are accepted by systemd 230 and up, so using the old name to make
    # this option work for either version of systemd.
    StartLimitInterval=60s
    
    # Having non-zero Limit*s causes performance problems due to accounting overhead
    # in the kernel. We recommend using cgroups to do container-local accounting.
    LimitNOFILE=infinity
    LimitNPROC=infinity
    LimitCORE=infinity
    
    # Comment TasksMax if your systemd version does not supports it.
    # Only systemd 226 and above support this option.
    TasksMax=infinity
    
    # set delegate yes so that systemd does not reset the cgroups of docker containers
    Delegate=yes
    
    # kill only the docker process, not all processes in the cgroup
    KillMode=process
    
    • Then systemctl daemon-reload
    • Finally systemctl start dockerd

    Hope this helps