html: rework docs about operation, pledging etc.
[girocco.git] / cgi / snapshot.cgi
blobcad8ee669fe2d76d7aed21a2260c1afae0e1d65b
1 #!/bin/sh
3 # snapshot.cgi -- throttle snapshot requests
4 # Copyright (C) 2015,2017 Kyle J. McKay. All rights reserved.
5 # License GPLv2+: GNU GPL version 2 or later.
6 # www.gnu.org/licenses/gpl-2.0.html
7 # This is free software: you are free to change and redistribute it.
8 # There is NO WARRANTY, to the extent permitted by law.
10 set -e
12 . @basedir@/shlib.sh
14 # Set to non-empty to throttle if the initial throttle service connect fails
15 throttle_on_connect_fail=1
17 # Supplemental message to be included in the throttle result
18 throttle_msg=\
19 'Ravenous roving robots are probably greedily chowing down on our services
20 right now.
22 We are valiantly trying to fight them off to improve service availability.'
24 hdrout()
26 _kw="$1"
27 shift
28 printf '%s: %s\r\n' "$_kw" "$*"
31 errorhdrsct()
33 _ct="$1"; shift
34 printf '%s\r\n' "Status: $1 $2"
35 printf '%s\r\n' "Expires: Fri, 01 Jan 1980 00:00:00 GMT"
36 printf '%s\r\n' "Pragma: no-cache"
37 printf '%s\r\n' "Cache-Control: no-cache,max-age=0,must-revalidate"
38 [ -z "$3" ] || printf '%s\r\n' "$3"
39 printf '%s\r\n' "Content-Type: $_ct"
40 printf '\r\n'
43 errorhdrs()
45 errorhdrsct 'text/plain; charset=utf-8; format=fixed' "$@"
48 msglines()
50 [ $# -le 0 ] || printf '%s\n' "$@"
53 methodnotallowed()
55 errorhdrs 405 "Method Not Allowed" "Allow: GET"
56 [ $# -gt 0 ] || set -- "Method Not Allowed"
57 msglines "$@"
58 exit 0
61 forbidden()
63 errorhdrs 403 Forbidden
64 [ $# -gt 0 ] || set -- "Forbidden"
65 msglines "$@"
66 exit 0
69 notfound()
71 errorhdrs 404 "Not Found"
72 [ $# -gt 0 ] || set -- "Not Found"
73 msglines "$@"
74 exit 0
77 # Snapshots are too expensive to allow HEAD
78 [ "$REQUEST_METHOD" = "GET" ] || methodnotallowed
80 # The project must be valid
81 suffix="${PATH_INFO#*.git/}"
82 project="${PATH_INFO%/"$suffix"}"
83 project="${project#/}"
84 [ -n "$project" ] || forbidden
85 case "$suffix" in snapshot|snapshot/*) :;; *) forbidden; esac
86 suffix="${suffix#snapshot}"
87 suffix="${suffix#/}"
89 # Perform some basic sanity checking
90 if [ -z "$suffix" ]; then
91 # Must have an "h=" argument
92 case "&$QUERY_STRING&" in *[\&\;]"h="[!\&\;]*) :;; *) forbidden; esac
94 case "$suffix" in [!A-Za-z0-9_]*) forbidden; esac
95 case "/$project/" in *"/../"*|*"/./"*|*"/_"*|*"//"*) forbidden; esac
96 is_git_dir "$cfg_reporoot/$project" || notfound
98 # Give the 'bots indigestion
99 sleep 5
101 # Attempt to trigger a SIGPIPE if the connection has already been closed
102 hdrout "X-Project" "${project%.git}"
103 sleep 1
104 hdrout "X-Snapshot" "${suffix:-$QUERY_STRING}"
105 sleep 1
107 # Off to the races
108 projname="${project%.git}"
109 "$cfg_basedir/bin/throttle" ${throttle_on_connect_fail:+-t} -c snapshot \
110 -d "$projname" -m "$throttle_msg" "$cfg_cgiroot/gitweb.cgi"
111 exit 0