[PATCH v1] travis-ci: retry if Git for Windows CI returns HTTP error 502 or 503

[Lars Schneider <larsxschneider@gmail.com>]

The Git for Windows CI web app sometimes returns HTTP errors of
"502 bad gateway" or "503 service unavailable" [1]. Wait a little and
retry the request if this happens.

[1] https://docs.microsoft.com/en-in/azure/app-service-web/app-service-web-troubleshoot-http-502-http-503

Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
---

Hi,

this should make the Git for Windows build a bit more stable. We saw
a few 502's recently. E.g. https://travis-ci.org/git/git/jobs/226669324

I did not add any checks to avoid an endless loop because TravisCI would
shutdown the worker if there is no output for more than 10min. Therefore
I think we don't need to handle this case ourselves.

Cheers,
Lars

Notes:
    Base Ref: next
    Web-Diff: https://github.com/larsxschneider/git/commit/b57ebf31ab
    Checkout: git fetch https://github.com/larsxschneider/git travisci/win-retry-v1 && git checkout b57ebf31ab

 ci/run-windows-build.sh | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/ci/run-windows-build.sh b/ci/run-windows-build.sh
index e043440799..7a9aa9c6a7 100755
--- a/ci/run-windows-build.sh
+++ b/ci/run-windows-build.sh
@@ -15,6 +15,8 @@ COMMIT=$2
 gfwci () {
 	local CURL_ERROR_CODE HTTP_CODE
 	exec 3>&1
+	while test -z $HTTP_CODE
+	do
 	HTTP_CODE=$(curl \
 		-H "Authentication: Bearer $GFW_CI_TOKEN" \
 		--silent --retry 5 --write-out '%{HTTP_CODE}' \
@@ -22,6 +24,16 @@ gfwci () {
 		"https://git-for-windows-ci.azurewebsites.net/api/TestNow?$1" \
 	)
 	CURL_ERROR_CODE=$?
+		# The GfW CI web app sometimes returns HTTP errors of
+		# "502 bad gateway" or "503 service unavailable".
+		# Wait a little and retry if it happens. More info:
+		# https://docs.microsoft.com/en-in/azure/app-service-web/app-service-web-troubleshoot-http-502-http-503
+		if test $HTTP_CODE -eq 502 || test $HTTP_CODE -eq 503
+		then
+			sleep 10
+			HTTP_CODE=
+		fi
+	done
 	if test $CURL_ERROR_CODE -ne 0
 	then
 		return $CURL_ERROR_CODE

base-commit: 1ea7e62026c5dde4d8be80b2544696fc6aa70121
--
2.12.2