git-annex/doc/special_remotes/external/git-annex-remote-ipfs
Joey Hess 18d326cb6f
external protocol VERSION 2
Support VERSION 2 in the external special remote protocol, which is
identical to VERSION 1, but avoids external remote programs neededing to
work around the above bug. External remote program that support
exporttree=yes are recommended to be updated to send VERSION 2.

Sponsored-by: Kevin Mueller on Patreon
2023-03-28 17:00:08 -04:00

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#!/bin/sh
# This is a git-annex external special remote program,
# which adds experimental ipfs support to git-annex.
#
# Install in PATH as git-annex-remote-ipfs
#
# Copyright 2015 Joey Hess; licenced under the GNU GPL version 3 or higher.
set -e
# use ipfs: as a prefix to indicate when an "url" is really stored in ipfs
isipfsurl () {
echo "$1" | egrep -q "^ipfs:"
}
# convert an ipfs: url to an address that the ipfs client understands
urltoaddress () {
echo "$1" | sed -e 's/^ipfs://'
}
addresstourl () {
echo "ipfs:$1"
}
# Gets a VALUE response and stores it in $RET
getvalue () {
read resp
# Tricky POSIX shell code to split first word of the resp,
# preserving all other whitespace
case "${resp%% *}" in
VALUE)
RET="$(echo "$resp" | sed 's/^VALUE \?//')"
;;
*)
RET=""
;;
esac
}
# Get a list of all known ipfs addresses for a key,
# storing it in a temp file.
getaddrs () {
key="$1"
tmp="$2"
echo GETURLS "$key"
getvalue
while [ -n "$RET" ]; do
if isipfsurl "$RET"; then
echo "$RET" >> "$tmp"
fi
getvalue
done
}
# This has to come first, to get the protocol started.
echo VERSION 2
while read line; do
set -- $line
case "$1" in
INITREMOTE)
echo INITREMOTE-SUCCESS
;;
PREPARE)
echo PREPARE-SUCCESS
;;
CLAIMURL)
url="$2"
if isipfsurl "$url"; then
echo CLAIMURL-SUCCESS
else
echo CLAIMURL-FAILURE
fi
;;
CHECKURL)
url="$2"
# TODO if size of file can be quickly determined
# (without downloading it) return the size
# instead of UNKNOWN
echo CHECKURL-CONTENTS UNKNOWN "$(urltoaddress "$url")"
;;
TRANSFER)
op="$2"
key="$3"
shift 3
file="$@"
case "$op" in
STORE)
addr=$(ipfs add -q "$file" </dev/null) || true
if [ -z "$addr" ]; then
echo TRANSFER-FAILURE STORE "$key" "ipfs add failed"
else
echo "SETURIPRESENT" "$key" "$(addresstourl "$addr")"
echo TRANSFER-SUCCESS STORE "$key"
fi
;;
RETRIEVE)
addrtmp=$(mktemp)
getaddrs "$key" "$addrtmp"
addr="$(urltoaddress "$(head "$addrtmp")")" || true
rm -f "$addrtmp"
if [ -z "$addr" ]; then
echo TRANSFER-FAILURE RETRIEVE "$key" "no known ipfs address for this key"
else
if ! ipfs get --output="$file" "$addr" >&2 </dev/null; then
echo TRANSFER-FAILURE RETRIEVE "$key" "failed downloading ipfs $addr"
else
echo TRANSFER-SUCCESS RETRIEVE "$key"
fi
fi
;;
esac
;;
CHECKPRESENT)
key="$2"
echo CHECKPRESENT-FAILURE "$key"
;;
REMOVE)
key="$2"
echo REMOVE-FAILURE "$key" "cannot remove content from ipfs (instead, run ipfs gc to clear your local ipfs cache)"
;;
*)
echo UNSUPPORTED-REQUEST
;;
esac
done