CODEWITHSUNDEEP
dockerdockerfile
vaibhav.g
vaibhav.g

Reputation: 759

Docker exec command

When i am entering docker container using exec command, i see the following -" root@a76900dc9d7f:/var/lib/docker/aufs/mnt/a76900dc9d7fef697b1392793a651752b40879d2ef5e2e1a4947d5f965434866#"
If i do "ls", I can see directory like var, lib, run.
So when i am executing command like - vi /var/myfile.txt, it is creating file in the host machine var directory. for it to create in my container var directory, i need to execute - " vi var/myFile.txt" which is very weird. can someone explain this behaviour

Some more information:
uname -a
Linux ad-docker-qa-0002 3.2.0-4-amd64 #1 SMP Debian 3.2.68-1+deb7u6 x86_64 GNU/Linux

Dockerfile:

FROM debian:wheezy

RUN echo 'nameserver 8.8.8.8' > /etc/resolve.conf
ENV DEBIAN_FRONTEND=noninteractive
RUN sed -i -e"s/exit 101/exit 0/" /usr/sbin/policy-rc.d


RUN apt-get update && apt-get install -y --force-yes procps \
psmisc \
openjdk-7-jre \
openjdk-7-jdk \
wget \
tar

RUN wget http://supergsego.com/apache/kafka/0.8.2.1/kafka_2.10-0.8.2.1.tgz
RUN wget http://mirrors.ukfast.co.uk/sites/ftp.apache.org/zookeeper/stable/zookeeper-3.4.6.tar.gz
RUN tar xvzf kafka_2.10-0.8.2.1.tgz
RUN tar -xvf zookeeper-3.4.6.tar.gz

EXPOSE 2181
EXPOSE 9092

ADD finalscript.sh /finalscript.sh
RUN chmod 777  /finalscript.sh
COPY startScript.sh /startScript.sh
RUN chmod 777 /startScript.sh

ENTRYPOINT ["/startScript.sh"]

#Startscript in the entrypoint create folders and run the kafka start script

I am starting the container using following syntax: 

docker run  -d --name my_kafka-kafka-apache  -p 2181:2181 -p 9092:9092 -v $(pwd)/config/kafka-apache:/var/config_copy/my_kafka/kafka-apache  my_kafka-kafka-apache-image

I ran the script suggested in the comment.

warning: /proc/config.gz does not exist, searching other paths for kernel config ...
info: reading kernel config from /boot/config-3.2.0-4-amd64 ...

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_DEVPTS_MULTIPLE_INSTANCES: 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: missing
- CONFIG_MACVLAN: enabled (as module)
- CONFIG_VETH: enabled (as module)
- CONFIG_BRIDGE: enabled (as module)
- CONFIG_BRIDGE_NETFILTER: enabled
- CONFIG_NF_NAT_IPV4: missing
- 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_NF_NAT: enabled (as module)
- CONFIG_NF_NAT_NEEDED: enabled
- CONFIG_POSIX_MQUEUE: enabled

Optional Features:
- CONFIG_USER_NS: enabled
- CONFIG_SECCOMP: enabled
- CONFIG_MEMCG_KMEM: missing
- CONFIG_MEMCG_SWAP: missing
- CONFIG_MEMCG_SWAP_ENABLED: missing
- CONFIG_RESOURCE_COUNTERS: enabled
- CONFIG_BLK_CGROUP: enabled
- CONFIG_IOSCHED_CFQ: enabled
- CONFIG_BLK_DEV_THROTTLING: missing
- CONFIG_CGROUP_PERF: enabled
- CONFIG_CGROUP_HUGETLB: missing
- CONFIG_NET_CLS_CGROUP: enabled
- CONFIG_NETPRIO_CGROUP: missing
- CONFIG_CFS_BANDWIDTH: missing
- CONFIG_FAIR_GROUP_SCHED: enabled
- CONFIG_RT_GROUP_SCHED: missing
- CONFIG_EXT3_FS: enabled (as module)
- CONFIG_EXT3_FS_XATTR: enabled
- CONFIG_EXT3_FS_POSIX_ACL: enabled
- CONFIG_EXT3_FS_SECURITY: enabled
- CONFIG_EXT4_FS: enabled (as module)
- CONFIG_EXT4_FS_POSIX_ACL: enabled
- CONFIG_EXT4_FS_SECURITY: enabled
- Storage Drivers:
  - "aufs":
    - CONFIG_AUFS_FS: enabled (as module)
  - "btrfs":
    - CONFIG_BTRFS_FS: enabled (as module)
  - "devicemapper":
    - CONFIG_BLK_DEV_DM: enabled (as module)
    - CONFIG_DM_THIN_PROVISIONING: enabled (as module)
  - "overlay":
    - CONFIG_OVERLAY_FS: missing
  - "zfs":
    - /dev/zfs: missing
    - zfs command: missing
    - zpool command: missing

Upvotes: 1

Views: 1525

Answers (1)

thaJeztah
thaJeztah

Reputation: 28997

Based on the information provided, docker is installed on a kernel version that's too old to run docker and doesnt have all feature required to safely run docker.

Docker requires kernel 3.10 as a minimum (preferably newer), and always make sure your kernel is up-to-date to minimize security risks.

Although Debian wheezy is still supported, if possible, I'd recommend to upgrade to a newer release (Jessie).

Upvotes: 1

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