pyrox.dev
1#! /bin/sh -e
2
3url=
4rev=
5expHash=
6hashType=$NIX_HASH_ALGO
7deepClone=$NIX_PREFETCH_GIT_DEEP_CLONE
8leaveDotGit=$NIX_PREFETCH_GIT_LEAVE_DOT_GIT
9fetchSubmodules=
10builder=
11branchName=$NIX_PREFETCH_GIT_BRANCH_NAME
12
13if test -n "$deepClone"; then
14 deepClone=true
15else
16 deepClone=false
17fi
18
19if test "$leaveDotGit" != 1; then
20 leaveDotGit=
21else
22 leaveDotGit=true
23fi
24
25
26argi=0
27argfun=""
28for arg; do
29 if test -z "$argfun"; then
30 case $arg in
31 --out) argfun=set_out;;
32 --url) argfun=set_url;;
33 --rev) argfun=set_rev;;
34 --hash) argfun=set_hashType;;
35 --branch-name) argfun=set_branchName;;
36 --deepClone) deepClone=true;;
37 --no-deepClone) deepClone=false;;
38 --leave-dotGit) leaveDotGit=true;;
39 --fetch-submodules) fetchSubmodules=true;;
40 --builder) builder=true;;
41 *)
42 argi=$(($argi + 1))
43 case $argi in
44 1) url=$arg;;
45 2) rev=$arg;;
46 3) expHash=$arg;;
47 *) exit 1;;
48 esac
49 ;;
50 esac
51 else
52 case $argfun in
53 set_*)
54 var=$(echo $argfun | sed 's,^set_,,')
55 eval $var=$arg
56 ;;
57 esac
58 argfun=""
59 fi
60done
61
62usage(){
63 echo >&2 "syntax: nix-prefetch-git [options] [URL [REVISION [EXPECTED-HASH]]]
64
65Options:
66 --out path Path where the output would be stored.
67 --url url Any url understand by 'git clone'.
68 --rev ref Any sha1 or references (such as refs/heads/master)
69 --hash h Expected hash.
70 --deepClone Clone submodules recursively.
71 --no-deepClone Do not clone submodules.
72 --leave-dotGit Keep the .git directories.
73 --fetch-submodules Fetch submodules.
74 --builder Clone as fetchgit does, but url, rev, and out option are mandatory.
75"
76 exit 1
77}
78
79if test -z "$url"; then
80 usage
81fi
82
83
84init_remote(){
85 local url=$1
86 git init
87 git remote add origin $url
88 ( [ -n "$http_proxy" ] && git config http.proxy $http_proxy ) || true
89}
90
91# Return the reference of an hash if it exists on the remote repository.
92ref_from_hash(){
93 local hash=$1
94 git ls-remote origin | sed -n "\,$hash\t, { s,\(.*\)\t\(.*\),\2,; p; q}"
95}
96
97# Return the hash of a reference if it exists on the remote repository.
98hash_from_ref(){
99 local ref=$1
100 git ls-remote origin | sed -n "\,\t$ref, { s,\(.*\)\t\(.*\),\1,; p; q}"
101}
102
103# Fetch everything and checkout the right sha1
104checkout_hash(){
105 local hash="$1"
106 local ref="$2"
107
108 if test -z "$hash"; then
109 hash=$(hash_from_ref $ref)
110 fi
111
112 git fetch ${builder:+--progress} origin || return 1
113 git checkout -b $branchName $hash || return 1
114}
115
116# Fetch only a branch/tag and checkout it.
117checkout_ref(){
118 local hash="$1"
119 local ref="$2"
120
121 if "$deepClone"; then
122 # The caller explicitly asked for a deep clone. Deep clones
123 # allow "git describe" and similar tools to work. See
124 # http://thread.gmane.org/gmane.linux.distributions.nixos/3569
125 # for a discussion.
126 return 1
127 fi
128
129 if test -z "$ref"; then
130 ref=$(ref_from_hash $hash)
131 fi
132
133 if test -n "$ref"; then
134 # --depth option is ignored on http repository.
135 git fetch ${builder:+--progress} --depth 1 origin +"$ref" || return 1
136 git checkout -b $branchName FETCH_HEAD || return 1
137 else
138 return 1
139 fi
140}
141
142# Update submodules
143init_submodules(){
144 # Add urls into .git/config file
145 git submodule init
146
147 # list submodule directories and their hashes
148 git submodule status |
149 while read l; do
150 # checkout each submodule
151 local hash=$(echo $l | awk '{print substr($1,2)}')
152 local dir=$(echo $l | awk '{print $2}')
153 local name=$(
154 git config -f .gitmodules --get-regexp submodule\..*\.path |
155 sed -n "s,^\(.*\)\.path $dir\$,\\1,p")
156 local url=$(git config --get ${name}.url)
157
158 clone "$dir" "$url" "$hash" ""
159 done
160}
161
162clone(){
163 local top=$(pwd)
164 local dir="$1"
165 local url="$2"
166 local hash="$3"
167 local ref="$4"
168
169 cd $dir
170
171 # Initialize the repository.
172 init_remote "$url"
173
174 # Download data from the repository.
175 checkout_ref "$hash" "$ref" ||
176 checkout_hash "$hash" "$ref" || (
177 echo 1>&2 "Unable to checkout $hash$ref from $url."
178 exit 1
179 )
180
181 # Checkout linked sources.
182 if test -n "$fetchSubmodules"; then
183 init_submodules
184 fi
185
186 if [ -z "$builder" -a -f .topdeps ]; then
187 if tg help 2>&1 > /dev/null
188 then
189 echo "populating TopGit branches..."
190 tg remote --populate origin
191 else
192 echo "WARNING: would populate TopGit branches but TopGit is not available" >&2
193 echo "WARNING: install TopGit to fix the problem" >&2
194 fi
195 fi
196
197 cd $top
198}
199
200# Remove all remote branches, remove tags not reachable from HEAD, do a full
201# repack and then garbage collect unreferenced objects.
202make_deterministic_repo(){
203 local repo="$1"
204
205 # run in sub-shell to not touch current working directory
206 (
207 cd "$repo"
208 # Remove files that contain timestamps or otherwise have non-deterministic
209 # properties.
210 rm -rf .git/logs/ .git/hooks/ .git/index .git/FETCH_HEAD .git/ORIG_HEAD \
211 .git/refs/remotes/origin/HEAD .git/config
212
213 # Remove all remote branches.
214 git branch -r | while read branch; do
215 git branch -rD "$branch" >&2
216 done
217
218 # Remove tags not reachable from HEAD. If we're exactly on a tag, don't
219 # delete it.
220 maybe_tag=$(git tag --points-at HEAD)
221 git tag --contains HEAD | while read tag; do
222 if [ "$tag" != "$maybe_tag" ]; then
223 git tag -d "$tag" >&2
224 fi
225 done
226
227 # Do a full repack. Must run single-threaded, or else we lose determinism.
228 git config pack.threads 1
229 git repack -A -d -f
230 rm -f .git/config
231
232 # Garbage collect unreferenced objects.
233 git gc --prune=all
234 )
235}
236
237
238clone_user_rev() {
239 local dir="$1"
240 local url="$2"
241 local rev="${3:-HEAD}"
242
243 # Perform the checkout.
244 case "$rev" in
245 HEAD|refs/*)
246 clone "$dir" "$url" "" "$rev" 1>&2;;
247 *)
248 if test -z "$(echo $rev | tr -d 0123456789abcdef)"; then
249 clone "$dir" "$url" "$rev" "" 1>&2
250 else
251 echo 1>&2 "Bad commit hash or bad reference."
252 exit 1
253 fi;;
254 esac
255
256 local full_revision=$(cd $dir && (git rev-parse $rev 2> /dev/null || git rev-parse refs/heads/$branchName) | tail -n1)
257 echo "git revision is $full_revision"
258 echo "git human-readable version is $(cd $dir && (git describe $full_revision 2> /dev/null || git describe --tags $full_revision 2> /dev/null || echo -- none --))" >&2
259 echo "Commit date is $(cd $dir && git show --no-patch --pretty=%ci $full_revision)"
260
261 # Allow doing additional processing before .git removal
262 eval "$NIX_PREFETCH_GIT_CHECKOUT_HOOK"
263 if test -z "$leaveDotGit"; then
264 echo "removing \`.git'..." >&2
265 find $dir -name .git\* | xargs rm -rf
266 else
267 find $dir -name .git | while read gitdir; do
268 make_deterministic_repo "$(readlink -f "$gitdir/..")"
269 done
270 fi
271}
272
273if test -z "$branchName"; then
274 branchName=fetchgit
275fi
276
277if test -n "$builder"; then
278 test -n "$out" -a -n "$url" -a -n "$rev" || usage
279 mkdir $out
280 clone_user_rev "$out" "$url" "$rev"
281else
282 if test -z "$hashType"; then
283 hashType=sha256
284 fi
285
286 # If the hash was given, a file with that hash may already be in the
287 # store.
288 if test -n "$expHash"; then
289 finalPath=$(nix-store --print-fixed-path --recursive "$hashType" "$expHash" git-export)
290 if ! nix-store --check-validity "$finalPath" 2> /dev/null; then
291 finalPath=
292 fi
293 hash=$expHash
294 fi
295
296 # If we don't know the hash or a path with that hash doesn't exist,
297 # download the file and add it to the store.
298 if test -z "$finalPath"; then
299
300 tmpPath="$(mktemp -d "${TMPDIR:-/tmp}/git-checkout-tmp-XXXXXXXX")"
301 trap "rm -rf \"$tmpPath\"" EXIT
302
303 tmpFile="$tmpPath/git-export"
304 mkdir "$tmpFile"
305
306 # Perform the checkout.
307 clone_user_rev "$tmpFile" "$url" "$rev"
308
309 # Compute the hash.
310 hash=$(nix-hash --type $hashType $hashFormat $tmpFile)
311 if ! test -n "$QUIET"; then echo "hash is $hash" >&2; fi
312
313 # Add the downloaded file to the Nix store.
314 finalPath=$(nix-store --add-fixed --recursive "$hashType" $tmpFile)
315
316 if test -n "$expHash" -a "$expHash" != "$hash"; then
317 echo "hash mismatch for URL \`$url'"
318 exit 1
319 fi
320 fi
321
322 if ! test -n "$QUIET"; then echo "path is $finalPath" >&2; fi
323
324 echo $hash
325
326 if test -n "$PRINT_PATH"; then
327 echo $finalPath
328 fi
329fi