Enable overwriting of links (solves #351)

[xanonid]

No description provided.

[priyawadhwa]

/ok-to-test

[priyawadhwa]

Hey @xanonid, thanks for contributing this fix! Could you add Dockerfile_test_extraction in the dockerfiles directory so that our integration tests can make sure extraction works for this image?

A simple Dockerfile:

FROM docker.elastic.co/kibana/kibana@sha256:e61c1122d9bc8dc8a113c79a035cf3c34d09674685f550ec842afc2d923ad568

should suffice.

[xanonid]

@priyawadhwa Thanks, I added a Dockerfile for the integration test as suggested.

[xanonid]

@sharifelgamal Seems like the kokoro check did not run again. Is there something I can do?

[dlorenc]

I'll try poking kokoro...

[dlorenc]

The test failure is:

    		]time="2018-09-21T07:44:27-07:00" level=warning msg="remove /tmpfs/tmp/gcr.iokaniko-testkaniko-dockerfile_test_replaced_hardlinks081715982/root/.bash_profile: permission denied"
    		time="2018-09-21T07:44:28-07:00" level=warning msg="remove /tmpfs/tmp/gcr.iokaniko-testdocker-dockerfile_test_replaced_hardlinks989545749/root/.bash_profile: permission denied"

which looks like an issue with the base image and container-diff.

I'll look into it a bit...

[dlorenc]

Is there any way you could reproduce this with a simpler base image than:

docker.elastic.co/kibana/kibana@sha256:e61c1122d9bc8dc8a113c79a035cf3c34d09674685f550ec842afc2d923ad568

[xanonid]

@dlorenc I replaced the test image. Hopefully, this works better. Could you trigger kokoro again if necessary, please?

[rroller]

I can confirm that this change corrects the issue below... (I've tested it with one of my builds and it works fine now)

This is the error prior to applying the change in this PR:

INFO[0000] Downloading base image gcr.io/google-appengine/openjdk:8 
INFO[0000] Mounted directories: [/kaniko /var/run /etc/mtab /proc /dev /dev/pts /sys /sys/fs/cgroup /sys/fs/cgroup/systemd /sys/fs/cgroup/cpuset /sys/fs/cgroup/blkio /sys/fs/cgroup/freezer /sys/fs/cgroup/cpu,cpuacct /sys/fs/cgroup/devices /sys/fs/cgroup/pids /sys/fs/cgroup/rdma /sys/fs/cgroup/memory /sys/fs/cgroup/net_cls,net_prio /sys/fs/cgroup/perf_event /sys/fs/cgroup/hugetlb /dev/mqueue /source /containers /dev/termination-log /etc/resolv.conf /etc/hostname /etc/hosts /dev/shm /run/secrets/kubernetes.io/serviceaccount /proc/bus /proc/fs /proc/irq /proc/sys /proc/sysrq-trigger /proc/kcore /proc/timer_list /sys/firmware] 
INFO[0000] Extracting layer 0                           
error building image: error building stage: link /bin/gunzip /bin/uncompress: file exists

[xanonid]

@dlorenc kokoro seemed to fail again 😞. Probably the base image was not different enough to the last? Is there another way than simple try-and-error?

[priyawadhwa]

Hey @xanonid, I looked into the failing test and I think I've fixed the issue in #363. Once that merges you can rebase and we can rerun kokoro, which I think should work at that point.

[xanonid]

@priyawadhwa Thanks - great news. BTW, I added another commit which fixes problems, if symlinks are replaced by normal files.

[priyawadhwa]

@xanonid awesome, I just merged #363 so if you rebase we can rerun the tests.

[xanonid]

@priyawadhwa I rebased the commits.

[dlorenc]

Let's see what Kokoro thinks!

[xanonid]

@dlorenc The Kokoro run was successful 👍

[dlorenc]

Woohoo!

[rroller]

Just confirming, this PR did fix my issues.

FROM gcr.io/kaniko-project/executor:59cb0ebec969fde3f8c8c7c9468d50580eb1e1ac

Thanks!

[yurrriq]

This issue is now solved for us too, but #245 is still a blocker.