pre-check before install docker

docker pre-install kernel-check

Docker官方明确要求了kernel版本要在version 3.10及以上，（但是在centos上还是遇到了很多bug，如果你用centos7我觉得应该在3.18以上，ubuntu的内核比较新，出问题较少）另外官方还是提供了一个check脚本，所以我们可以利用这个脚本check下我们的kernel缺少那些东西。

step

1、curl https://raw.githubusercontent.com/docker/docker/master/contrib/check-config.sh > check-config.sh
2、bash ./check-config.sh

result

[root@master1 ~]# bash check-config.sh
warning: /proc/config.gz does not exist, searching other paths for kernel config ...
info: reading kernel config from /boot/config-3.10.0-693.el7.x86_64 ...

Generally Necessary:
- cgroup hierarchy: properly mounted [/sys/fs/cgroup]
- CONFIG_NAMESPACES: enabled
- CONFIG_NET_NS: enabled
- CONFIG_PID_NS: enabled
- CONFIG_IPC_NS: enabled
- CONFIG_UTS_NS: enabled
- CONFIG_CGROUPS: enabled
- CONFIG_CGROUP_CPUACCT: enabled
- CONFIG_CGROUP_DEVICE: enabled
- CONFIG_CGROUP_FREEZER: enabled
- CONFIG_CGROUP_SCHED: enabled
- CONFIG_CPUSETS: enabled
- CONFIG_MEMCG: enabled
- CONFIG_KEYS: enabled
- CONFIG_VETH: enabled (as module)
- CONFIG_BRIDGE: enabled (as module)
- CONFIG_BRIDGE_NETFILTER: enabled (as module)
- CONFIG_NF_NAT_IPV4: enabled (as module)
- CONFIG_IP_NF_FILTER: enabled (as module)
- CONFIG_IP_NF_TARGET_MASQUERADE: enabled (as module)
- CONFIG_NETFILTER_XT_MATCH_ADDRTYPE: enabled (as module)
- CONFIG_NETFILTER_XT_MATCH_CONNTRACK: enabled (as module)
- CONFIG_NETFILTER_XT_MATCH_IPVS: enabled (as module)
- CONFIG_IP_NF_NAT: enabled (as module)
- CONFIG_NF_NAT: enabled (as module)
- CONFIG_NF_NAT_NEEDED: enabled
- CONFIG_POSIX_MQUEUE: enabled
- CONFIG_DEVPTS_MULTIPLE_INSTANCES: enabled

Optional Features:
- CONFIG_USER_NS: enabled
  (RHEL7/CentOS7: User namespaces disabled; add 'user_namespace.enable=1' to boot command line)
- CONFIG_SECCOMP: enabled
- CONFIG_CGROUP_PIDS: enabled
- CONFIG_MEMCG_SWAP: enabled
- CONFIG_MEMCG_SWAP_ENABLED: enabled
    (cgroup swap accounting is currently enabled)
- CONFIG_MEMCG_KMEM: enabled
- CONFIG_RESOURCE_COUNTERS: missing
- CONFIG_BLK_CGROUP: enabled
- CONFIG_BLK_DEV_THROTTLING: enabled
- CONFIG_IOSCHED_CFQ: enabled
- CONFIG_CFQ_GROUP_IOSCHED: enabled
- CONFIG_CGROUP_PERF: enabled
- CONFIG_CGROUP_HUGETLB: enabled
- CONFIG_NET_CLS_CGROUP: enabled
- CONFIG_NETPRIO_CGROUP: enabled
- CONFIG_CFS_BANDWIDTH: enabled
- CONFIG_FAIR_GROUP_SCHED: enabled
- CONFIG_RT_GROUP_SCHED: enabled
- CONFIG_IP_VS: enabled (as module)
- CONFIG_IP_VS_NFCT: enabled
- CONFIG_IP_VS_RR: enabled (as module)
- CONFIG_EXT3_FS: missing
- CONFIG_EXT3_FS_XATTR: missing
- CONFIG_EXT3_FS_POSIX_ACL: missing
- CONFIG_EXT3_FS_SECURITY: missing
    (enable these ext3 configs if you are using ext3 as backing filesystem)
- CONFIG_EXT4_FS: enabled (as module)
- CONFIG_EXT4_FS_POSIX_ACL: enabled
- CONFIG_EXT4_FS_SECURITY: enabled
- Network Drivers:
  - "overlay":
    - CONFIG_VXLAN: enabled (as module)
      Optional (for encrypted networks):
      - CONFIG_CRYPTO: enabled
      - CONFIG_CRYPTO_AEAD: enabled
      - CONFIG_CRYPTO_GCM: enabled (as module)
      - CONFIG_CRYPTO_SEQIV: enabled
      - CONFIG_CRYPTO_GHASH: enabled (as module)
      - CONFIG_XFRM: enabled
      - CONFIG_XFRM_USER: enabled
      - CONFIG_XFRM_ALGO: enabled
      - CONFIG_INET_ESP: enabled (as module)
      - CONFIG_INET_XFRM_MODE_TRANSPORT: enabled (as module)
  - "ipvlan":
    - CONFIG_IPVLAN: missing
  - "macvlan":
    - CONFIG_MACVLAN: enabled (as module)
    - CONFIG_DUMMY: enabled (as module)
  - "ftp,tftp client in container":
    - CONFIG_NF_NAT_FTP: enabled (as module)
    - CONFIG_NF_CONNTRACK_FTP: enabled (as module)
    - CONFIG_NF_NAT_TFTP: enabled (as module)
    - CONFIG_NF_CONNTRACK_TFTP: enabled (as module)
- Storage Drivers:
  - "aufs":
    - CONFIG_AUFS_FS: missing
  - "btrfs":
    - CONFIG_BTRFS_FS: enabled (as module)
    - CONFIG_BTRFS_FS_POSIX_ACL: enabled
  - "devicemapper":
    - CONFIG_BLK_DEV_DM: enabled (as module)
    - CONFIG_DM_THIN_PROVISIONING: enabled (as module)
  - "overlay":
    - CONFIG_OVERLAY_FS: enabled (as module)
  - "zfs":
    - /dev/zfs: missing
    - zfs command: missing
    - zpool command: missing

Limits:
- /proc/sys/kernel/keys/root_maxkeys: 1000000