Add "DOCKER_TLS_CERTDIR" for https://github.com/docker-library/docker/pull/166

For images which don't support this feature, this will be a no-op.

test/tests/docker-dind/run.sh

@@ -10,6 +10,7 @@ cid="$(
 	docker run -d -it \
 		--privileged \
 		--name "$cname" \
+		-e DOCKER_TLS_CERTDIR=/certs -v /certs \
 		"$image"
 )"
 trap "docker rm -vf $cid > /dev/null" EXIT
@@ -17,6 +18,7 @@ trap "docker rm -vf $cid > /dev/null" EXIT
 docker_() {
 	docker run --rm -i \
 		--link "$cname":docker \
+		-e DOCKER_TLS_CERTDIR=/certs --volumes-from "$cname:ro" \
 		--entrypoint docker-entrypoint.sh \
 		"$image" \
 		"$@"

test/tests/docker-registry-push-pull/run.sh

@@ -37,6 +37,7 @@ dcid="$(
 		--privileged \
 		--link "$rcid":"$rhostname" \
 		--name "$dcname" \
+		-e DOCKER_TLS_CERTDIR=/certs -v /certs \
 		"$dockerImage" \
 		--insecure-registry "$rnamespace"
 )"
@@ -45,6 +46,7 @@ trap "docker rm -vf $rcid $dcid > /dev/null" EXIT
 docker_() {
 	docker run --rm -i \
 		--link "$dcid":docker \
+		-e DOCKER_TLS_CERTDIR=/certs --volumes-from "$dcid:ro" \
 		--entrypoint docker-entrypoint.sh \
 		"$dockerImage" \
 		"$@"