title: Install pip in docker
body: <p>I'm not able to install pip in Docker.</p>
  
  <p>Here's my Dockerfile:</p>
  
  <pre><code>FROM ubuntu:14.04
  
  # Install dependencies
  RUN apt-get update -y
  RUN apt-get install -y git curl apache2 php5 libapache2-mod-php5 php5-mcrypt php5-mysql python3.4 python-pip
  </code></pre>
  
  <p>When building, I get:</p>
  
  <pre><code>Sending build context to Docker daemon 109.6 kB
  Step 1 : FROM ubuntu:14.04
   ---&gt; b549a9959a66
  Step 2 : RUN apt-get update -y
   ---&gt; Using cache
   ---&gt; 84577471562c
  Step 3 : RUN apt-get install -y git curl apache2 php5 libapache2-mod-php5 php5-mcrypt php5-mysql python3.4 python-pip
   ---&gt; Running in 49252a6d0eb1
  Reading package lists...
  Building dependency tree...
  Reading state information...
  python3.4 is already the newest version.
  The following extra packages will be installed:
    apache2-bin apache2-data binutils build-essential ca-certificates cpp
    cpp-4.8 dpkg-dev fakeroot g++ g++-4.8 gcc gcc-4.8 git-man krb5-locales
    libalgorithm-diff-perl libalgorithm-diff-xs-perl libalgorithm-merge-perl
    libapr1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap libasan0
    libasn1-8-heimdal libatomic1 libc-dev-bin libc6-dev libcloog-isl4 libcurl3
    libcurl3-gnutls libdpkg-perl libedit2 liberror-perl libfakeroot
    libfile-fcntllock-perl libgcc-4.8-dev libgmp10 libgomp1 libgssapi-krb5-2
    libgssapi3-heimdal libhcrypto4-heimdal libheimbase1-heimdal
    libheimntlm0-heimdal libhx509-5-heimdal libidn11 libisl10 libitm1
    libk5crypto3 libkeyutils1 libkrb5-26-heimdal libkrb5-3 libkrb5support0
    libldap-2.4-2 libmcrypt4 libmpc3 libmpfr4 libmysqlclient18 libpython-stdlib
    libpython2.7-minimal libpython2.7-stdlib libquadmath0 libroken18-heimdal
    librtmp0 libsasl2-2 libsasl2-modules libsasl2-modules-db libstdc++-4.8-dev
    libtimedate-perl libtsan0 libwind0-heimdal libx11-6 libx11-data libxau6
    libxcb1 libxdmcp6 libxext6 libxml2 libxmuu1 linux-libc-dev lsof make
    manpages manpages-dev mysql-common openssh-client openssl patch php5-cli
    php5-common php5-json php5-readline psmisc python python-chardet
    python-chardet-whl python-colorama python-colorama-whl python-distlib
    python-distlib-whl python-html5lib python-html5lib-whl python-minimal
    python-pip-whl python-pkg-resources python-requests python-requests-whl
    python-setuptools python-setuptools-whl python-six python-six-whl
    python-urllib3 python-urllib3-whl python-wheel python2.7 python2.7-minimal
    python3-pkg-resources rsync sgml-base ssl-cert xauth xml-core xz-utils
  Suggested packages:
    www-browser apache2-doc apache2-suexec-pristine apache2-suexec-custom ufw
    apache2-utils binutils-doc cpp-doc gcc-4.8-locales debian-keyring
    g++-multilib g++-4.8-multilib gcc-4.8-doc libstdc++6-4.8-dbg gcc-multilib
    autoconf automake1.9 libtool flex bison gdb gcc-doc gcc-4.8-multilib
    libgcc1-dbg libgomp1-dbg libitm1-dbg libatomic1-dbg libasan0-dbg
    libtsan0-dbg libquadmath0-dbg gettext-base git-daemon-run
    git-daemon-sysvinit git-doc git-el git-email git-gui gitk gitweb git-arch
    git-bzr git-cvs git-mediawiki git-svn php-pear glibc-doc krb5-doc krb5-user
    libmcrypt-dev mcrypt libsasl2-modules-otp libsasl2-modules-ldap
    libsasl2-modules-sql libsasl2-modules-gssapi-mit
    libsasl2-modules-gssapi-heimdal libstdc++-4.8-doc make-doc man-browser
    ssh-askpass libpam-ssh keychain monkeysphere ed diffutils-doc
    php5-user-cache python-doc python-tk python-genshi python-lxml
    python-distribute python-distribute-doc python2.7-doc binfmt-support
    python3-setuptools openssh-server sgml-base-doc openssl-blacklist debhelper
  Recommended packages:
    ssh-client python-dev-all
  The following NEW packages will be installed:
    apache2 apache2-bin apache2-data binutils build-essential ca-certificates
    cpp cpp-4.8 curl dpkg-dev fakeroot g++ g++-4.8 gcc gcc-4.8 git git-man
    krb5-locales libalgorithm-diff-perl libalgorithm-diff-xs-perl
    libalgorithm-merge-perl libapache2-mod-php5 libapr1 libaprutil1
    libaprutil1-dbd-sqlite3 libaprutil1-ldap libasan0 libasn1-8-heimdal
    libatomic1 libc-dev-bin libc6-dev libcloog-isl4 libcurl3 libcurl3-gnutls
    libdpkg-perl libedit2 liberror-perl libfakeroot libfile-fcntllock-perl
    libgcc-4.8-dev libgmp10 libgomp1 libgssapi-krb5-2 libgssapi3-heimdal
    libhcrypto4-heimdal libheimbase1-heimdal libheimntlm0-heimdal
    libhx509-5-heimdal libidn11 libisl10 libitm1 libk5crypto3 libkeyutils1
    libkrb5-26-heimdal libkrb5-3 libkrb5support0 libldap-2.4-2 libmcrypt4
    libmpc3 libmpfr4 libmysqlclient18 libpython-stdlib libpython2.7-minimal
    libpython2.7-stdlib libquadmath0 libroken18-heimdal librtmp0 libsasl2-2
    libsasl2-modules libsasl2-modules-db libstdc++-4.8-dev libtimedate-perl
    libtsan0 libwind0-heimdal libx11-6 libx11-data libxau6 libxcb1 libxdmcp6
    libxext6 libxml2 libxmuu1 linux-libc-dev lsof make manpages manpages-dev
    mysql-common openssh-client openssl patch php5 php5-cli php5-common
    php5-json php5-mcrypt php5-mysql php5-readline psmisc python python-chardet
    python-chardet-whl python-colorama python-colorama-whl python-distlib
    python-distlib-whl python-html5lib python-html5lib-whl python-minimal
    python-pip python-pip-whl python-pkg-resources python-requests
    python-requests-whl python-setuptools python-setuptools-whl python-six
    python-six-whl python-urllib3 python-urllib3-whl python-wheel python2.7
    python2.7-minimal python3-pkg-resources rsync sgml-base ssl-cert xauth
    xml-core xz-utils
  0 upgraded, 130 newly installed, 0 to remove and 4 not upgraded.
  Need to get 61.9 MB of archives.
  After this operation, 213 MB of additional disk space will be used.
  Err http://archive.ubuntu.com/ubuntu/ trusty-updates/main libroken18-heimdal amd64 1.6~git20131207+dfsg-1ubuntu1.1
    Could not resolve 'archive.ubuntu.com'
  Err http://archive.ubuntu.com/ubuntu/ trusty-updates/main libasn1-8-heimdal amd64 1.6~git20131207+dfsg-1ubuntu1.1
    Could not resolve 'archive.ubuntu.com'
  
  .
  .
  .
  
  Err http://archive.ubuntu.com/ubuntu/ trusty-security/main python2.7 amd64 2.7.6-8ubuntu0.2
    Could not resolve 'archive.ubuntu.com'
  E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/h/heimdal/libroken18-heimdal_1.6~git20131207+dfsg-1ubuntu1.1_amd64.deb  Could not resolve 'archive.ubuntu.com'
  
  E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/h/heimdal/libasn1-8-heimdal_1.6~git20131207+dfsg-1ubuntu1.1_amd64.deb  Could not resolve 'archive.ubuntu.com'
  
  E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/k/krb5/libkrb5support0_1.12+dfsg-2ubuntu5.2_amd64.deb  Could not resolve 'archive.ubuntu.com'
  
  E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/s/ssl-cert/ssl-cert_1.0.33_all.deb  Could not resolve 'archive.ubuntu.com'
  
  E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
  The command '/bin/sh -c apt-get install -y git curl apache2 php5 libapache2-mod-php5 php5-mcrypt php5-mysql python3.4 python-pip' returned a non-zero code: 100
  </code></pre>
  
  <p>Having read <a href="https://stackoverflow.com/a/34145676/1040915">this answer</a>, I tried adding the line <code>RUN "sh" "-c" "echo nameserver 8.8.8.8 &gt;&gt; /etc/resolv.conf"</code> - the error this time is:</p>
  
  <pre><code>...
  ...
  Reading state information...
  E: Unable to locate package php5-mcrypt
  E: Unable to locate package python-pip
  The command '/bin/sh -c apt-get install -y git curl apache2 php5 libapache2-mod-php5 php5-mcrypt php5-mysql python3.4 python-pip' returned a non-zero code: 100
  </code></pre>
  
  <p>What am I doing wrong? I've seen some claims that I should try a different version of Ubuntu, but switching to 13.1 didn't change anything.</p>