CODEWITHSUNDEEP
linuxdockerdockerfilecentos7
Jayce
Jayce

Reputation: 93

Dockerfile ADD doesn't work

When I was trying to build my own docker image with Dockerfile, I found that files doesn't copied into my image after I use ADD or COPY command.

To test the ADD command, I create a simple dockerfile like this:

FROM centos:7
MAINTAINER jayce 

RUN mkdir ~/var
ADD . ~/var/
RUN cd ~/var
RUN ls -la ~/var
RUN cat ~/var/test.txt

And my file structure is simple like this:

[sysmanager@jayce-vm-centos test]$ tree
.
├── Dockerfile
└── test.txt

0 directories, 2 files

When I use docker build command to build an image, the process goes like this:

[sysmanager@jayce-vm-centos test]$ sudo docker build .
Sending build context to Docker daemon 3.072 kB
Step 1 : FROM centos:7
 ---> 67591570dd29
Step 2 : MAINTAINER jayce
 ---> Running in 966b82d33d91
 ---> 22e938a4b921
Removing intermediate container 966b82d33d91
Step 3 : RUN mkdir ~/var
 ---> Running in e9ed8986f793
 ---> 672ebaac6e2c
Removing intermediate container e9ed8986f793
Step 4 : ADD . ~/var/
 ---> 592eb5f1b653
Removing intermediate container 6d0adfab0bbf
Step 5 : RUN cd ~/var
 ---> Running in 085c524f3999
 ---> b0b4edf374f2
Removing intermediate container 085c524f3999
Step 6 : RUN ls -la ~/var
 ---> Running in e454df478b21
total 0
drwxr-xr-x. 2 root root   6 Mar 31 09:08 .
dr-xr-x---. 3 root root 125 Mar 31 09:08 ..
 ---> 53557c808816
Removing intermediate container e454df478b21
Step 7 : RUN cat ~/var/test.txt
 ---> Running in 64f1a5a8e039
cat: /root/var/test.txt: No such file or directory
The command '/bin/sh -c cat ~/var/test.txt' returned a non-zero code: 1
[sysmanager@jayce-vm-centos test]$

The process ends with the cat command didn't found the test.txt I added into the image with the dockerfile script.

This confused me a lot and I tried it in different environment but none of my attempts failed. Is there something I missed?

My docker version:

Client:
 Version:         1.12.6
 API version:     1.24
 Package version: docker-common-1.12.6-11.el7.centos.x86_64
 Go version:      go1.7.4
 Git commit:      96d83a5/1.12.6
 Built:           Tue Mar  7 09:23:34 2017
 OS/Arch:         linux/amd64

Server:
 Version:         1.12.6
 API version:     1.24
 Package version: docker-common-1.12.6-11.el7.centos.x86_64
 Go version:      go1.7.4
 Git commit:      96d83a5/1.12.6
 Built:           Tue Mar  7 09:23:34 2017
 OS/Arch:         linux/amd64

Somebody help me! Thanks in advance!

Upvotes: 5

Views: 12988

Answers (2)

周卓涵
周卓涵

Reputation: 19

Please pay attention if you are using an ADD command to copy a TAR COMPRESSED FILE into container. Add command will automatic extract this compressed tar file into the target destination. So that you might not find this tar file in the container. Below dockerfile document says:

Consequently, the best use for ADD is local tar file auto-extraction into the image, as in ADD rootfs.tar.xz /.

Upvotes: 1

vmatekole
vmatekole

Reputation: 126

Your source directory is correct — '.'. Your destination dir may lead to issues (~/var). I would specify the absolute path of the home dir intended e.g.

/home//var. Furthermore, you can inspect the Docker image at the layer the build broke — in your case: 

docker run --rm -it 64f1a5a8e039 bash

Further details here: How can I inspect the file system of a failed `docker build`?

Upvotes: 6

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