gitcache-server

#!/bin/bash

# Copyright (c) 2013: José Bollo (jobol), Stéphane Desneux (kooltux)
# All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Library General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

ts_start=$(date +%s)
op_start=$ts_start
op_elapsed() { echo $(date +%s) | awk -vts1="$op_start" '{printf("%d",($1-ts1+1));}'; }

srvid="gitcache-server($(id -un)@$(hostname -f))"
userip=$(echo $SSH_CONNECTION | awk '{print $1}')

prefixoutput() { awk -vX="$srvid" -vts1="$ts_start" -vRS='[\r\n]' '{ ts2=strftime("%s"); printf("%s - %ds - %s%s",X,(ts2-ts1+1),$0,RT);fflush();}' >&2; }
exec 2> >(prefixoutput)

log() { 
    [[ -n "$GIT_CACHE_LOG" ]] && echo $(date "+%Y%m%d %H:%M:%S") [$userip] $(op_elapsed)s - "$@" >>$GIT_CACHE_LOG; 
    op_start=$(date +%s)
}

error() { echo "ERROR: $*" >&2; log "ERROR: $*"; exit 1; }
info() { echo "$*" >&2; }

[[ -r ~/.gitcache-server.conf ]] && . ~/.gitcache-server.conf

[[ $# -eq 0 ]] && error "Invalid arguments."

[[ -z "$GIT_CACHE_DIR" ]] && error "GIT_CACHE_DIR is not defined"

#####################################################
# FETCHING (not cloning mean FETCHING)
#####################################################
arg2=$2
if [[ "$1" != "--clone" ]]; then
    shift $(($# - 1))
    info using cache directory $1
    if [[ -d "$1" ]]; then
        cd "$1" 2>/dev/null || error "directory not found $1"
        info refreshing cache from $(git ls-remote --get-url origin)
        # remove the tags to fetch them (for syncing with deleted tags)
        git tag -l 2>/dev/null | xargs git tag -d >&/dev/null
        # fetch with prune (for syncing with deleted branches)
        #git fetch --prune --progress origin +refs/heads/*:refs/remotes/origin/* +refs/changes/*:refs/changes/* >&2
        git fetch --prune --progress >&2
        log "fetch => fetch : $1"
        info uploading changes to client
        git-upload-pack .
        log "fetch <= upload : $1"
        exit
    else
        # for any reason, the cache dir has disappeared
        # rebuild url from directory to clone
        arg2=$(sed -e "s|$GIT_CACHE_DIR/*||" -e 's|/|:|' <<<$1)
	info "Cache directory is not present. Cloning from $arg2"
    fi
fi

#####################################################
# CLONING (but it may mean fetching...)
#####################################################

# get the uri to clone
uri=$(sed 's/ /%20/g' <<<$arg2)
info "clone request for $uri"

# scan the domain and projet parts of the uri
if [[ $uri =~ ^(.+://)?(.+@)?([^:/]+)(:[0-9]+)?(/.+)$ ]]; then
    domain=${BASH_REMATCH[3]}
    project=${BASH_REMATCH[5]}
    # info "sheme ${BASH_REMATCH[1]} user ${BASH_REMATCH[2]} domain ${BASH_REMATCH[3]} port ${BASH_REMATCH[4]} path ${BASH_REMATCH[5]}"
elif [[ $uri =~ ^(.+@)?([^:/]+):(.+)$ ]]; then
    domain=${BASH_REMATCH[2]}
    project=${BASH_REMATCH[3]}
    # info "sheme - user ${BASH_REMATCH[1]} domain ${BASH_REMATCH[2]} port - path ${BASH_REMATCH[3]}"
else
    error "Bad uri $uri"
fi

# enter the cachedir
if [[ ! -d $GIT_CACHE_DIR ]]; then
    mkdir -p $GIT_CACHE_DIR || error "can't create $GIT_CACHE_DIR"
fi
cd $GIT_CACHE_DIR

# create the domain/ip root directories
ip=$(dig +short $domain)
[[ -z "$ip" ]] && error "can't resolve ip for $domain"

if [[ ! -d $ip ]]; then
    mkdir -p $ip || error "can't create $(pwd)/$ip"
fi
ln -sf $ip $domain

# try to fetch if cached and remove on error
gcdir=$(pwd)/$domain/${project%.git}.git
if [[ -d $gcdir ]]; then
    cd $gcdir
    info "cache hit - refreshing cache from $uri"
    # remove the tags to fetch them (for syncing with deleted tags)
    git tag -l 2>/dev/null | xargs git tag -d >&/dev/null
    # fetch with prune (for syncing with deleted branches)
    #git fetch --prune --progress origin +refs/heads/*:refs/remotes/origin/* +refs/changes/*:refs/changes/* >&2 || { rm -rf $gcdir; info "Fetching cached repo failed"; }
    git fetch --prune --progress >&2 || { rm -rf $gcdir; info "Fetching cached repo failed"; }
    log "clone => fetch : $domain/${project%.git}"
fi

# if not cached or had fetch error, clone
if [[ ! -d $gcdir ]]; then
    dir=$(dirname $gcdir)
    [[ -d $dir ]] || mkdir -p $dir || error "can't create directory $dir"
    cd $dir
    edir="$(basename $gcdir)"
    if [[ -n "$GIT_CACHE_SERVER_PRIMARY" ]]; then
	# clone from a git-cache (chaining)
        export GIT_CACHE_SERVER="$GIT_CACHE_SERVER_PRIMARY"
        info "cache miss - chain-cloning $uri into $gcdir through $GIT_CACHE_SERVER"
        git-cclone "$uri" "$edir" --mirror >&2 || { rm -rf $gcdir; error "chain-cloning failure"; }
        log "clone => cclone : $domain/${project%.git}"
    else
	# direct clone
        info "cache miss - cloning $uri into $gcdir"
        git clone --progress --mirror "$uri" "$edir" >&2 || { rm -rf $gcdir; error "cloning failure"; }
        log "clone => clone : $domain/${project%.git}"
    fi
fi

echo "$gcdir"
exit 0