upload-pack: test negotiation with changing repository

Add tests to check the behavior of fetching from a repository which changes between rounds of negotiation (for example, when different servers in a load-balancing agreement participate in the same stateless RPC negotiation). This forms a baseline of comparison to the ref-in-want functionality (which will be introduced to the client in subsequent commits), and ensures that subsequent commits do not change existing behavior. As part of this effort, a mechanism to substitute strings in a single HTTP response is added. Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Brandon Williams committed Jun 27, 2018 at 15:30 UTC 3374292e55564fa6107b31a63a5e5432cd8c2265
4 files changed +99
t/lib-httpd.sh
+1
@@ -132,6 +132,7 @@ prepare_httpd() {
132 cp "$TEST_PATH"/passwd "$HTTPD_ROOT_PATH"
133 install_script broken-smart-http.sh
134 install_script error.sh
135 + install_script apply-one-time-sed.sh
136
137 ln -s "$LIB_HTTPD_MODULE_PATH" "$HTTPD_ROOT_PATH/modules"
138
t/lib-httpd/apache.conf
+8
@@ -111,9 +111,14 @@ Alias /auth/dumb/ www/auth/dumb/
111 SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
112 SetEnv GIT_HTTP_EXPORT_ALL
113 </LocationMatch>
114 +<LocationMatch /one_time_sed/>
115 + SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
116 + SetEnv GIT_HTTP_EXPORT_ALL
117 +</LocationMatch>
118 ScriptAliasMatch /smart_*[^/]*/(.*) ${GIT_EXEC_PATH}/git-http-backend/$1
119 ScriptAlias /broken_smart/ broken-smart-http.sh/
120 ScriptAlias /error/ error.sh/
121 +ScriptAliasMatch /one_time_sed/(.*) apply-one-time-sed.sh/$1
122 <Directory ${GIT_EXEC_PATH}>
123 Options FollowSymlinks
124 </Directory>
@@ -123,6 +128,9 @@ ScriptAlias /error/ error.sh/
128 <Files error.sh>
129 Options ExecCGI
130 </Files>
131 +<Files apply-one-time-sed.sh>
132 + Options ExecCGI
133 +</Files>
134 <Files ${GIT_EXEC_PATH}/git-http-backend>
135 Options ExecCGI
136 </Files>
t/lib-httpd/apply-one-time-sed.sh new
+22
@@ -0,0 +1,22 @@
1 +#!/bin/sh
2 +
3 +# If "one-time-sed" exists in $HTTPD_ROOT_PATH, run sed on the HTTP response,
4 +# using the contents of "one-time-sed" as the sed command to be run. If the
5 +# response was modified as a result, delete "one-time-sed" so that subsequent
6 +# HTTP responses are no longer modified.
7 +#
8 +# This can be used to simulate the effects of the repository changing in
9 +# between HTTP request-response pairs.
10 +if [ -e one-time-sed ]; then
11 + "$GIT_EXEC_PATH/git-http-backend" >out
12 + sed "$(cat one-time-sed)" <out >out_modified
13 +
14 + if diff out out_modified >/dev/null; then
15 + cat out
16 + else
17 + cat out_modified
18 + rm one-time-sed
19 + fi
20 +else
21 + "$GIT_EXEC_PATH/git-http-backend"
22 +fi
t/t5703-upload-pack-ref-in-want.sh
+68
@@ -157,4 +157,72 @@ test_expect_success 'want-ref with ref we already have commit for' '
157 check_output
158 '
159
160 +. "$TEST_DIRECTORY"/lib-httpd.sh
161 +start_httpd
162 +
163 +REPO="$HTTPD_DOCUMENT_ROOT_PATH/repo"
164 +LOCAL_PRISTINE="$(pwd)/local_pristine"
165 +
166 +test_expect_success 'setup repos for change-while-negotiating test' '
167 + (
168 + git init "$REPO" &&
169 + cd "$REPO" &&
170 + >.git/git-daemon-export-ok &&
171 + test_commit m1 &&
172 + git tag -d m1 &&
173 +
174 + # Local repo with many commits (so that negotiation will take
175 + # more than 1 request/response pair)
176 + git clone "http://127.0.0.1:$LIB_HTTPD_PORT/smart/repo" "$LOCAL_PRISTINE" &&
177 + cd "$LOCAL_PRISTINE" &&
178 + git checkout -b side &&
179 + for i in $(seq 1 33); do test_commit s$i; done &&
180 +
181 + # Add novel commits to upstream
182 + git checkout master &&
183 + cd "$REPO" &&
184 + test_commit m2 &&
185 + test_commit m3 &&
186 + git tag -d m2 m3
187 + ) &&
188 + git -C "$LOCAL_PRISTINE" remote set-url origin "http://127.0.0.1:$LIB_HTTPD_PORT/one_time_sed/repo" &&
189 + git -C "$LOCAL_PRISTINE" config protocol.version 2
190 +'
191 +
192 +inconsistency () {
193 + # Simulate that the server initially reports $2 as the ref
194 + # corresponding to $1, and after that, $1 as the ref corresponding to
195 + # $1. This corresponds to the real-life situation where the server's
196 + # repository appears to change during negotiation, for example, when
197 + # different servers in a load-balancing arrangement serve (stateless)
198 + # RPCs during a single negotiation.
199 + printf "s/%s/%s/" \
200 + $(git -C "$REPO" rev-parse $1 | tr -d "\n") \
201 + $(git -C "$REPO" rev-parse $2 | tr -d "\n") \
202 + >"$HTTPD_ROOT_PATH/one-time-sed"
203 +}
204 +
205 +test_expect_success 'server is initially ahead - no ref in want' '
206 + git -C "$REPO" config uploadpack.allowRefInWant false &&
207 + rm -rf local &&
208 + cp -r "$LOCAL_PRISTINE" local &&
209 + inconsistency master 1234567890123456789012345678901234567890 &&
210 + test_must_fail git -C local fetch 2>err &&
211 + grep "ERR upload-pack: not our ref" err
212 +'
213 +
214 +test_expect_success 'server is initially behind - no ref in want' '
215 + git -C "$REPO" config uploadpack.allowRefInWant false &&
216 + rm -rf local &&
217 + cp -r "$LOCAL_PRISTINE" local &&
218 + inconsistency master "master^" &&
219 + git -C local fetch &&
220 +
221 + git -C "$REPO" rev-parse --verify "master^" >expected &&
222 + git -C local rev-parse --verify refs/remotes/origin/master >actual &&
223 + test_cmp expected actual
224 +'
225 +
226 +stop_httpd
227 +
228 test_done