[PATCH 4/7] receive-pack: read env from execute-commands output

[Jiang Xin <worldhello.net@gmail.com>]

The “post-receive” hook may need the pull request ID generated by the
“execute-commands” hook.  The results can be passed between hooks by
environment variables.

Each line of the message received from the standard output of the
“execute-commands” in the key=value format is parsed as environment and
these variables will be sent to environment of the “post-receive” hook.

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
---
 builtin/receive-pack.c           | 42 +++++++++++++++--
 t/t5411-execute-commands-hook.sh | 79 ++++++++++++++++++++++++++++++++
 2 files changed, 117 insertions(+), 4 deletions(-)

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 241b1d4cfc..fd2f3ba80a 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -85,6 +85,7 @@ static const char *nonce_status;
 static long nonce_stamp_slop;
 static timestamp_t nonce_stamp_slop_limit;
 static struct ref_transaction *transaction;
+struct argv_array post_receive_env_array;
 
 static enum {
 	KEEPALIVE_NEVER = 0,
@@ -678,7 +679,9 @@ struct receive_hook_feed_state {
 };
 
 typedef int (*feed_fn)(void *, const char **, size_t *);
+typedef void (*stdout_handler_fn)(int out);
 static int run_and_feed_hook(const char *hook_name, feed_fn feed,
+			     stdout_handler_fn stdout_handler,
 			     struct receive_hook_feed_state *feed_state)
 {
 	struct child_process proc = CHILD_PROCESS_INIT;
@@ -713,9 +716,15 @@ static int run_and_feed_hook(const char *hook_name, feed_fn feed,
 
 	proc.argv = argv;
 	proc.in = -1;
-	proc.stdout_to_stderr = 1;
+	if (stdout_handler)
+		proc.out = -1;
+	else
+		proc.stdout_to_stderr = 1;
 	proc.trace2_hook_name = hook_name;
 
+	if (!strcmp(hook_name, "post-receive") && post_receive_env_array.argc > 0)
+		argv_array_pushv(&proc.env_array, post_receive_env_array.argv);
+
 	if (feed_state->push_options) {
 		int i;
 		for (i = 0; i < feed_state->push_options->nr; i++)
@@ -760,6 +769,10 @@ static int run_and_feed_hook(const char *hook_name, feed_fn feed,
 			break;
 	}
 	close(proc.in);
+
+	if (stdout_handler)
+		stdout_handler(proc.out);
+
 	if (use_sideband)
 		finish_async(&muxer);
 
@@ -817,7 +830,7 @@ static int run_receive_hook(struct command *commands,
 		return 0;
 	state.cmd = commands;
 	state.push_options = push_options;
-	status = run_and_feed_hook(hook_name, feed_receive_hook, &state);
+	status = run_and_feed_hook(hook_name, feed_receive_hook, NULL, &state);
 	strbuf_release(&state.buf);
 	return status;
 }
@@ -868,11 +881,29 @@ static int run_execute_commands_pre_receive_hook(struct command *commands,
 	state.cmd = commands;
 	state.push_options = push_options;
 	status = run_and_feed_hook("execute-commands--pre-receive",
-			feed_receive_hook, &state);
+			feed_receive_hook, NULL, &state);
 	strbuf_release(&state.buf);
 	return status;
 }
 
+
+static void prepare_post_receive_env(int in)
+{
+	struct strbuf stdout_buf = STRBUF_INIT;
+
+	while (strbuf_getwholeline_fd(&stdout_buf, in, '\n') != EOF) {
+		char *p = stdout_buf.buf + stdout_buf.len -1;
+		if (*p =='\n')
+			*p = '\0';
+		p = strchr(stdout_buf.buf, '=');
+		if (p == NULL)
+			continue;
+		argv_array_push(&post_receive_env_array, stdout_buf.buf);
+		strbuf_reset(&stdout_buf);
+	}
+	strbuf_release(&stdout_buf);
+}
+
 static int run_execute_commands_hook(struct command *commands,
 				     const struct string_list *push_options)
 {
@@ -889,7 +920,8 @@ static int run_execute_commands_hook(struct command *commands,
 		return 0;
 	state.cmd = commands;
 	state.push_options = push_options;
-	status = run_and_feed_hook("execute-commands", feed_receive_hook, &state);
+	status = run_and_feed_hook("execute-commands",
+			feed_receive_hook, prepare_post_receive_env, &state);
 	strbuf_release(&state.buf);
 	return status;
 }
@@ -2052,6 +2084,8 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
+	argv_array_init(&post_receive_env_array);
+
 	packet_trace_identity("receive-pack");
 
 	argc = parse_options(argc, argv, prefix, options, receive_pack_usage, 0);
diff --git a/t/t5411-execute-commands-hook.sh b/t/t5411-execute-commands-hook.sh
index 0bf14e702d..1907d0619d 100755
--- a/t/t5411-execute-commands-hook.sh
+++ b/t/t5411-execute-commands-hook.sh
@@ -454,4 +454,83 @@ test_expect_success "cannot push mixed references (declined)" '
 	test_cmp expect actual
 '
 
+test_expect_success "new execute-commands and post-receive hooks (environments in output)" '
+	## execute-commands hook
+	mv $bare/hooks/execute-commands $bare/hooks/execute-commands.ok &&
+	cat >$bare/hooks/execute-commands <<-EOF &&
+	#!/bin/sh
+
+	printf >&2 "execute: execute-commands\n"
+
+	if test \$# -gt 0 && test "\$1" = "--pre-receive"
+	then
+		printf >&2 ">> pre-receive mode\n"
+	else
+		printf "GIT_VAR1=var1\n"
+		printf "GIT_VAR2=var2\n"
+		printf "AGIT_VAR1=foo\n"
+		printf "AGIT_VAR2=bar\n"
+	fi
+
+	while read old new ref
+	do
+		printf >&2 ">> old: \$old, new: \$new, ref: \$ref.\n"
+	done
+
+	for k in GIT_VAR1 GIT_VAR2 AGIT_VAR1 AGIT_VAR2
+	do
+		if test -n "\$(eval echo \\"\\\$\$k\")"
+		then
+			printf >&2 ">> has env: \$k=\$(eval echo \\"\\\$\$k\").\n"
+		fi
+	done
+	EOF
+	chmod a+x $bare/hooks/execute-commands &&
+
+	## post-receive hook
+	mv $bare/hooks/post-receive $bare/hooks/post-receive.ok &&
+	cat >$bare/hooks/post-receive <<-EOF &&
+	#!/bin/sh
+
+	printf >&2 "execute: post-receive hook\n"
+
+	while read old new ref
+	do
+		printf >&2 ">> old: \$old, new: \$new, ref: \$ref.\n"
+	done
+
+	for k in GIT_VAR1 GIT_VAR2 AGIT_VAR1 AGIT_VAR2
+	do
+		if test -n "\$(eval echo \\"\\\$\$k\")"
+		then
+			printf >&2 ">> has env: \$k=\$(eval echo \\"\\\$\$k\").\n"
+		fi
+	done
+	EOF
+	chmod a+x $bare/hooks/post-receive
+'
+
+test_expect_success "push and show environments" '
+	(
+		cd work &&
+		git push origin \
+			HEAD:refs/for/master/my/topic
+	) >out 2>&1 &&
+	grep "^remote:" out | sed -e "s/  *\$//g" >actual &&
+	cat >expect <<-EOF &&
+	remote: execute: execute-commands
+	remote: >> pre-receive mode
+	remote: >> old: 0000000000000000000000000000000000000000, new: ce858e653cdbf70f9955a39d73a44219e4b92e9e, ref: refs/for/master/my/topic.
+	remote: execute: execute-commands
+	remote: >> old: 0000000000000000000000000000000000000000, new: ce858e653cdbf70f9955a39d73a44219e4b92e9e, ref: refs/for/master/my/topic.
+	remote: execute: post-receive hook
+	remote: >> old: 0000000000000000000000000000000000000000, new: ce858e653cdbf70f9955a39d73a44219e4b92e9e, ref: refs/for/master/my/topic.
+	remote: >> has env: GIT_VAR1=var1.
+	remote: >> has env: GIT_VAR2=var2.
+	remote: >> has env: AGIT_VAR1=foo.
+	remote: >> has env: AGIT_VAR2=bar.
+	EOF
+	test_cmp expect actual
+'
+
 test_done
-- 
2.25.1.362.g51ebf55b93