title: Wget in Dockerfile, files disappear in container
body: <p>In a Docker file I use wget to download file in the image. But when I use this image in a docker-compose file, the container doesn't contains the files...</p>
  
  <pre><code>    FROM debian:8
  
      RUN apt-get update &amp;&amp; apt-get install -y wget &amp;&amp; rm -rf /var/lib/apt/lists/*
  
      RUN mkdir -p /blast  &amp;&amp; cd /blast
      RUN wget ftp://ftp.ncbi.nlm.nih.gov/blast/executables/blast+/LATEST/ncbi-blast-2.6.0+-x64-linux.tar.gz
      RUN tar zxvpf ncbi-blast-2.6.0+-x64-linux.tar.gz &amp;&amp; rm ncbi-blast-2.6.0+-x64-linux.tar.gz
      RUN export PATH=$PATH:/blast/ncbi-blast-2.6.0+/bin
      #&amp;&amp; export BLASTDB=/blast/blastdb
  
      CMD ["sleep", "infinity"]
  </code></pre>
  
  <p>In the container I've the /blast folder, but not the files... Someon know how I can do a wget and keep files ? And why they disappear ?</p>
  
  <p>EDIT</p>
  
  <p>The docker history</p>
  
  <pre><code>    IMAGE               CREATED             CREATED BY                                      SIZE                COMMENT
      13361cc1dda8        9 minutes ago       /bin/sh -c #(nop)  CMD ["sleep" "infinity"]     0 B                 
      748afb9b0a0a        9 minutes ago       /bin/sh -c #(nop) WORKDIR /blast                0 B                 
      6eb2b58af7d4        9 minutes ago       /bin/sh -c export PATH=$PATH:/blast/ncbi-b...   0 B                 
      1331a22dcf67        10 minutes ago      /bin/sh -c wget ftp://ftp.ncbi.nlm.nih.gov...   675 MB              
      83d2844843e5        35 minutes ago      /bin/sh -c mkdir -p /blast  &amp;&amp; cd /blast        0 B                 
      6b0b6a13ae47        41 minutes ago      /bin/sh -c apt-get update &amp;&amp; apt-get insta...   41.2 MB             
      054abe38b1e6        12 hours ago        /bin/sh -c #(nop)  CMD ["/bin/bash"]            0 B                 
      &lt;missing&gt;           12 hours ago        /bin/sh -c #(nop) ADD file:712c48086043553...   123 MB         
  </code></pre>
  
  <p>The output of docker-compose build (extract part)</p>
  
  <pre><code>    2017-04-25 07:41:47 (10.1 MB/s) - 'ncbi-blast-2.6.0+-x64-linux.tar.gz' saved [222504398]
  
      ncbi-blast-2.6.0+/
      ncbi-blast-2.6.0+/ChangeLog
      ncbi-blast-2.6.0+/LICENSE
      ncbi-blast-2.6.0+/ncbi_package_info
      ncbi-blast-2.6.0+/doc/
      ncbi-blast-2.6.0+/doc/README.txt
      ncbi-blast-2.6.0+/bin/
      ncbi-blast-2.6.0+/bin/makeblastdb
      ncbi-blast-2.6.0+/bin/tblastx
      ncbi-blast-2.6.0+/bin/tblastn
      ncbi-blast-2.6.0+/bin/blastn
      ncbi-blast-2.6.0+/bin/blastdb_aliastool
      ncbi-blast-2.6.0+/bin/update_blastdb.pl
      ncbi-blast-2.6.0+/bin/windowmasker
      ncbi-blast-2.6.0+/bin/psiblast
      ncbi-blast-2.6.0+/bin/blastx
      ncbi-blast-2.6.0+/bin/rpsblast
      ncbi-blast-2.6.0+/bin/segmasker
      ncbi-blast-2.6.0+/bin/blastdbcheck
      ncbi-blast-2.6.0+/bin/rpstblastn
      ncbi-blast-2.6.0+/bin/deltablast
      ncbi-blast-2.6.0+/bin/makembindex
      ncbi-blast-2.6.0+/bin/convert2blastmask
      ncbi-blast-2.6.0+/bin/blastp
      ncbi-blast-2.6.0+/bin/dustmasker
      ncbi-blast-2.6.0+/bin/makeprofiledb
      ncbi-blast-2.6.0+/bin/blastdbcmd
      ncbi-blast-2.6.0+/bin/legacy_blast.pl
      ncbi-blast-2.6.0+/bin/blast_formatter
      ncbi-blast-2.6.0+/README
       ---&gt; 1331a22dcf67
      Removing intermediate container 06070bb79e70
  </code></pre>