How to see docker image contents

Question

I did a docker pull and can list the image that s downloaded  I want to see the contents of this image  Did a search on the net but no straight answer

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With Docker EE for Windows  17 06 2-ee-6 on Hyper-V Server 2016  all contents of Windows Containers can be examined at C  ProgramData docker windowsfilter  path of the host OS    No special mounting needed    Folder prefix can be found by container id from docker ps -a output

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EXPLORING DOCKER IMAGE   Figure out what kind of shell is in there bash or sh     Inspect the image first  docker inspect name-of-container-or-image Look for entrypoint or cmd in the JSON return   Then do  docker run --rm -it --entrypoint  bin bash name-of-image  once inside do  ls -lsa or any other shell command like  cd    The -it stands for interactive    and TTY  The --rm stands for remove container after run  If there are no common tools like ls or bash present and you have access to the Dockerfile simple add the common tool as a layer  example  alpine Linux   RUN apk add --no-cache bash  And when you don t have access to the Dockerfile then just copy extract the files from a newly created container and look through them  docker create  lt image gt     returns container ID the container is never started  docker cp  lt container ID gt   lt source path gt   lt destination path gt  docker rm  lt container ID gt  cd  lt destination path gt   amp  amp  ls -lsah

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We can try a simpler one as follows   docker image inspect image id   This worked in Docker version   DockerVersion    18 05 0-ce

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You should not start a container just to see the image contents  For instance  you might want to look for malicious content  not run it  Use  create  instead of  run    docker create --name  tmp     image tag docker export tmp      tar t docker rm tmp

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There is a free open source tool called Anchore that you can use to scan container images   This command will allow you to list all files in a container image  anchore-cli image content myrepo app latest files  https   anchore com opensource

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To list the detailed content of an image you have to run docker run --rm image name ls -alR where --rm means remove as soon as exits form a container

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You can just run an interactive shell container using that image and explore whatever content that image has   For instance   docker run -it image name sh   Or following for images with an entrypoint  docker run -it --entrypoint sh image name   Or  if you want to see how the image was build  meaning the steps in its Dockerfile  you can   docker image history --no-trunc image name  gt  image history   The steps will be logged into the image history file

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The accepted answer here is problematic  because there is no guarantee that an image will have any sort of interactive shell   For example  the drone drone image contains on a single command  drone  and it has an ENTRYPOINT as well  so this will fail     docker run -it drone drone sh FATA 0000  DRONE HOST is not properly configured           And this will fail     docker run --rm -it --entrypoint sh drone drone docker  Error response from daemon  oci runtime error  container linux go 247  starting container process caused  exec    sh    executable file not found in  PATH     This is not an uncommon configuration  many minimal images contain only the binaries necessary to support the target service   Fortunately  there are mechanisms for exploring an image filesystem that do not depend on the contents of the image   The easiest is probably the docker export command  which will export a container filesystem as a tar archive   So  start a container  it does not matter if it fails or not      docker run -it drone drone sh FATA 0000  DRONE HOST is not properly configured           Then use docker export to export the filesystem to tar     docker export   docker ps -lq    tar tf -   The docker ps -lq there means  give me the id of the most recent docker container    You could replace that with an explicit container name or id

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docker save nginx  gt  nginx tar tar -xvf nginx tar   Following files are present    manifest json     Describes filesystem layers and name of json file that has the Container properties   json     Container properties      Each    layerid    directory contains json file describing layer property and filesystem associated with that layer  Docker stores Container images as layers to optimize storage space by reusing layers across images    https   sreeninet wordpress com 2016 06 11 looking-inside-container-images   OR   you can use dive to view the image content interactively with TUI     https   github com wagoodman dive

[docker] How to see docker image contents

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