Expected behavior MD5 checksums would be the same Actual behavior File is corrupted/MD5 checksum is off Information The file in question is a large shell script (2.4GB) with embedded binary compressed data. Using Dockerfile ADD command or docker cp of the file to container, then running md5sum results in different checksums than source. Also errors consistent with corruption when trying to decompress embedded tar. File size appears exactly the same. Accessing file via volume mount in container doesn't have these problems.
Checksums and decompression work. Steps to reproduce the behavior.
checksum on Mac. docker cp file to container. attach to container.
checksum on container doesn't match.
Where do Docker containers get their time information? I've created some containers from the basic ubuntu:trusty image, and when I run it and request 'date', I get UTC time. For awhile I got around this by doing the following in my Dockerfile: RUN sudo echo 'America/LosAngeles' /etc/timezone However, for some reason that stopped working.
Searching online I saw the below suggested: docker run -v /etc/timezone:/etc/timezone image-name Both these methods correctly set the timezone though! $ cat /etc/timezone America/LosAngeles $ date Tue Apr 14 23:46:51 UTC 2015 Anyone know what gives? The secret here is that dpkg-reconfigure tzdata simply creates /etc/localtime as a copy, hardlink or symlink (a symlink is preferred) to a file in /usr/share/zoneinfo.
So it is possible to do this entirely from your Dockerfile. Consider: ENV TZ=America/LosAngeles RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ /etc/timezone And as a bonus, TZ will be set correctly in the container as well.
This is also distribution-agnostic, so it works with pretty much any Linux. Note: if you are using an alpine based image you have to install the tzdata first.
Docker Image Corruption Issue 2542 Docker/for-mac Github Free
(see this issue ) Looks like this: RUN apk add -no-cache tzdata ENV TZ America/LosAngeles. Mounting /etc/localtime in the image, so it is in sync with host -v is the most popular one. But see: it is not correct because it does not work when the software requires instead the file /etc/timezone to be set. That way you are using leaves it as the default value etc/UTC.
I have determined that actually there is no foolproof elegant way to set the time zone inside of a docker container. So have finally settled on this solution: App dockerfile: # Relocate the timezone file RUN mkdir -p /config/etc && mv /etc/timezone /config/etc/ && ln -s /config/etc/timezone /etc/ App entrypoint script: # Set timezone as specified in /config/etc/timezone dpkg-reconfigure -f noninteractive tzdata Data volume /config dockerfile, localized to a specific country or region: # Set the time zone RUN echo 'Europe/London' /config/etc/timezone. It is not elegant because involving 3 separate files, and re-creating /etc/localtime on every runtime container start. Which is rather wasteful. However it does work properly, and successfully achieve separation between the base app image, and each per-country localized configuration. In 3 lines of code. Thanks to VonC for the information and link to the issue.
This seems like such a convoluted mess, so I did some testing on my own idea of how to solve this and it seems to work great. docker run -it ubuntu:trusty /bin/bash #dpkg-reconfigure tzdata (follow prompts to select my timezone) docker commit container-id chocko/ubuntu:local Then I updated my Dockerfiles to reflect this: FROM chocko/ubuntu:local There must be something wrong with this because it seems too easy to be overlooked. Or is this acceptable?