tmux in CoreOS?

[Carl Su]

I'd like to do some tasks (e.g. docker pull/push) in tmux to make sure that
it's running even when I lost my SSH connections. Can I have a tmux installed
in CoreOS? If not, what can I do?

[Alex Polvi]

Carl, you might consider writing a systemd unit file, or running systemd-run. Having your process controlled by the init system will make sure it works regardless of your ssh connection. 

Futhermore, a docker pull actually causes the docker daemon to do the download... meaning if you lose your ssh connection it will still be running. 

-Alex

[Carl]

I see. Thank you very much.

[Philip Southam]

Carl,

You can try the following (I realize this may be a little late, but in case others want to do the same).

------------------------------------
 

Build a static TMUX (modified from this)

On your local system (or system with a build environment), create build-tmux.sh with the following conents:

#!/usr/bin/env bash
pushd $(dirname $0) > /dev/null; CURRABSPATH=$(readlink -nf "$(pwd)"); popd > /dev/null; # Get the directory in which the script resides
set -x
MUSLPKG="musl:musl.tgz:http://www.musl-libc.org/releases/musl-1.1.4.tar.gz"
LEVTPKG="libevent:libevent2.tgz:https://cloud.github.com/downloads/libevent/libevent/libevent-2.0.21-stable.tar.gz"
TMUXPKG="tmux:tmux.tgz:http://iweb.dl.sourceforge.net/project/tmux/tmux/tmux-1.9/tmux-1.9a.tar.gz"
NCRSPKG="ncurses:ncurses.tgz:http://ftp.gnu.org/pub/gnu/ncurses/ncurses-5.9.tar.gz"
TEMPDIR="$CURRABSPATH/tmp"
TMPLIB="tempinstall/lib"
TMPINC="tempinstall/include"
MUSLCC="$TEMPDIR/musl/tempinstall/bin/musl-gcc"
[[ -d "$TEMPDIR" ]] || mkdir "$TEMPDIR" || { echo "FATAL: Could not create $TEMPDIR."; exit 1; }
for i in "$MUSLPKG" "$NCRSPKG" "$LEVTPKG" "$TMUXPKG"; do
    NAME=${i%%:*}
    i=${i#*:}
    TGZ=${i%%:*}
    URL=${i#*:}
    [[ -d "$TEMPDIR/$NAME" ]] && rm -rf "$TEMPDIR/$NAME"
    [[ -d "$TEMPDIR/$NAME" ]] || mkdir  "$TEMPDIR/$NAME" || { echo "FATAL: Could not create $TEMPDIR/$NAME."; exit 1; }
    [[ -f "$CURRABSPATH/$TGZ" ]] || curl -o "$CURRABSPATH/$TGZ" "$URL" || wget -O "$CURRABSPATH/$TGZ" "$URL" || { echo "FATAL: failed to fetch $URL."; exit 1; }
    echo "Unpacking $NAME" && tar --strip-components=1 -C "$TEMPDIR/$NAME" -xf "$TGZ" && mkdir "$TEMPDIR/$NAME/tempinstall" \
        || { echo "FATAL: Could not unpack one of the required source packages. Check above output for clues."; exit 1; }
    echo "Building $NAME (this may take some time)"
    (
        PREFIX="$TEMPDIR/$NAME/tempinstall"
        case $NAME in
            musl )
                (cd "$TEMPDIR/$NAME" && ./configure --enable-gcc-wrapper --prefix="$PREFIX") && \
                make -C "$TEMPDIR/$NAME" && make -C "$TEMPDIR/$NAME" install
                ;;
            ncurses )
                (cd "$TEMPDIR/$NAME" && ./configure --without-ada --without-cxx --without-progs --without-manpages --disable-db-install --without-tests --with-default-terminfo-dir=/usr/share/terminfo --with-terminfo-dirs="/etc/terminfo:/lib/terminfo:/usr/share/terminfo" --prefix="$PREFIX" CC="$MUSLCC") && \
                make -C "$TEMPDIR/$NAME" && make -C "$TEMPDIR/$NAME" install
                ;;
            libevent )
                (cd "$TEMPDIR/$NAME" && ./configure --enable-static --enable-shared --disable-openssl --prefix="$PREFIX" CC="$MUSLCC") && \
                make -C "$TEMPDIR/$NAME" && make -C "$TEMPDIR/$NAME" install
                ;;
            tmux )
                (cd "$TEMPDIR/$NAME" && ./configure --enable-static --prefix="$PREFIX" CC="$MUSLCC" CPPFLAGS="-I$TEMPDIR/libevent/$TMPINC -I$TEMPDIR/ncurses/$TMPINC -I$TEMPDIR/ncurses/$TMPINC/ncurses" LDFLAGS="-L$TEMPDIR/libevent/$TMPLIB -L$TEMPDIR/ncurses/$TMPLIB" LIBS=-lncurses) && \
                make -C "$TEMPDIR/$NAME" && make -C "$TEMPDIR/$NAME" install
                strip $PREFIX/bin/tmux
                ;;
        esac
    ) 2>&1 |tee "$TEMPDIR/${NAME}.log" > /dev/null || { echo "FATAL: failed to build $NAME. Consult $TEMPDIR/${NAME}.log for details."; exit 1; }
    unset CC
done

Upload to Server

And place the binary where you can use it, say /opt/bin/.

$ scp tmp/tmux/tempinstall/bin/tmux core@example.com:
$ ssh core@example.com
$ sudo mv tmux /opt/bin # create this dir if it doesn't exist before moving

Run

$ sudo systemd-run --gid=core --uid=core -r  /bin/sh -c "/opt/bin/tmux -C"
$ /opt/bin/tmux a

You may be thinking, why not just run it via /opt/bin/tmux without using systemd-run? Go ahead and try it. As soon as you disconnect your ssh connection, the tmux session is killed. Running it via systemd-run keeps the session around.

[Carl]

Philip,

Thank you so much for helping me. I never could have figured this out without your help.

I'll try to make my own tmux to see if it worked.

[Philip Southam]

Carl,

If you trust me, you can download the static binary saving you the trouble of going through the aforementioned steps via the following link.

https://objects.dreamhost.com:443/philipsoutham.public/dist/tmux.gz

https://objects.dreamhost.com:443/philipsoutham.public/dist/tmux.gz.sha256

[Igor Bukanov]

Philip,

When building on Fedora 21 the tmux static build script fails when configuring ncurses. To fix that I added --disable-shared to the configure command for musl. I also replaced --enable-shared with --disable-shared for libevent configure. After that the script successfully built tmux :)

[Richard Phillips]

Old thread, but fantastically helpful. Thought I would share my systemd tmux.conf that is working for me..

[Unit]

Description=Tmux Startup

After=startups.service

[Service]

Type=oneshot

RemainAfterExit=yes

ExecStart=/opt/bin/tmux -C

ExecStop=/opt/bin/tmux kill-server

KillMode=none

[Install]

WantedBy=multi-user.target

[Sean Kane]

This is an easy option, assuming you trust the builds:

mkdir -p /opt/bin
export PATH=$PATH:/opt/bin
cd /opt/bin
wget http://s.minos.io/s -O static-get
chmod a+rx ./static-get
cd /opt
/opt/bin static-get tmux
tar xf tmux-*.tar.xz
/opt/bin/tmux

For more information see:

• https://github.com/minos-org/minos-static
  
• http://s.minos.io/