contrib/dockerrpm

extensions: support callbacks after another extension loads

An upcoming patch will introduce a dependency between the color and
pager extensions. To prepare for this, we teach extensions how to
register callbacks that can execute when another extension loads.

This patch is based on code provided by Matt Mackall. But significant
parts have changed (such as the ability to register multiple callbacks
and the change in behavior to always call a callback).

I believe that always firing the callback is a good practice. I think
the common use for this feature will be for extensions to say "run this
one-time setup code, after this other extension if possible." Always
running the callback will facilitate this.

#!/bin/bash -e

BUILDDIR=$(dirname $0)
ROOTDIR=$(cd $BUILDDIR/..; pwd)

if which docker.io >> /dev/null 2>&1 ; then
  DOCKER=docker.io
elif which docker >> /dev/null 2>&1 ; then
  DOCKER=docker
else
  echo "Error: docker must be installed"
  exit 1
fi

$DOCKER -h 2> /dev/null | grep -q Jansens && { echo "Error: $DOCKER is the Docking System Tray - install docker.io instead"; exit 1; }
$DOCKER version | grep -q "^Client version:" || { echo "Error: unexpected output from \"$DOCKER version\""; exit 1; }
$DOCKER version | grep -q "^Server version:" || { echo "Error: could not get docker server version - check it is running and your permissions"; exit 1; }

PLATFORM="$1"
[ "$PLATFORM" ] || { echo "Error: platform name must be specified"; exit 1; }
shift # extra params are passed to buildrpm

DFILE="$ROOTDIR/contrib/docker/$PLATFORM"
[ -f "$DFILE" ] || { echo "Error: docker file $DFILE not found"; exit 1; }

CONTAINER="hg-dockerrpm-$PLATFORM"

DBUILDUSER=build
(
cat $DFILE
echo RUN groupadd $DBUILDUSER -g `id -g`
echo RUN useradd $DBUILDUSER -u `id -u` -g $DBUILDUSER
) | $DOCKER build --tag $CONTAINER -

RPMBUILDDIR=$ROOTDIR/packages/$PLATFORM
contrib/buildrpm --rpmbuilddir $RPMBUILDDIR --prepare $*

DSHARED=/mnt/shared
$DOCKER run -u $DBUILDUSER --rm -v $RPMBUILDDIR:$DSHARED $CONTAINER \
    rpmbuild --define "_topdir $DSHARED" -ba $DSHARED/SPECS/mercurial.spec --clean

$DOCKER run -u $DBUILDUSER --rm -v $RPMBUILDDIR:$DSHARED $CONTAINER \
    createrepo $DSHARED

cat << EOF > $RPMBUILDDIR/mercurial.repo
# Place this file in /etc/yum.repos.d/mercurial.repo
[mercurial]
name=Mercurial packages for $PLATFORM
# baseurl=file://$RPMBUILDDIR/
baseurl=http://hg.example.com/build/$PLATFORM/
skip_if_unavailable=True
gpgcheck=0
enabled=1
EOF

echo
echo "Build complete - results can be found in $RPMBUILDDIR"