test/sharness: randomize api port workaround

we have a problem where initializing daemons with the same api port
often fails-- it hangs indefinitely. The proper solution is to make
ipfs pick an unused port for the api on startup, and then use that.
Unfortunately, ipfs doesnt yet know how to do this-- the api port
must be specified. Until ipfs learns how to do this, we must use
specific port numbers, which may still fail but less frequently
if we at least use different ones.

test/sharness/lib/test-lib.sh

@@ -125,6 +125,24 @@ test_config_set() {
 
 test_init_ipfs() {
 
+	# we have a problem where initializing daemons with the same api port
+	# often fails-- it hangs indefinitely. The proper solution is to make
+	# ipfs pick an unused port for the api on startup, and then use that.
+	# Unfortunately, ipfs doesnt yet know how to do this-- the api port
+	# must be specified. Until ipfs learns how to do this, we must use
+	# specific port numbers, which may still fail but less frequently
+	# if we at least use different ones.
+
+	# Using RANDOM like this is clearly wrong-- it samples with replacement
+	# and it doesnt even check the port is unused. this is a trivial stop gap
+	# until the proper solution is implemented.
+	apiport=$((RANDOM % 3000 + 5100))
+	ADDR_API="/ip4/127.0.0.1/tcp/$apiport"
+
+	# we set the Addresses.API config variable.
+	# the cli client knows to use it, so only need to set.
+	# todo: in the future, use env?
+
 	test_expect_success "ipfs init succeeds" '
 		export IPFS_PATH="$(pwd)/.go-ipfs" &&
 		ipfs init -b=1024 > /dev/null
@@ -134,6 +152,7 @@ test_init_ipfs() {
 		mkdir mountdir ipfs ipns &&
 		test_config_set Mounts.IPFS "$(pwd)/ipfs" &&
 		test_config_set Mounts.IPNS "$(pwd)/ipns" &&
+		test_config_set Addresses.API "$ADDR_API" &&
 		ipfs bootstrap rm --all ||
 		test_fsh cat "\"$IPFS_PATH/config\""
 	'
@@ -172,7 +191,6 @@ test_launch_ipfs_daemon() {
 	'
 
 	# we say the daemon is ready when the API server is ready.
-	ADDR_API="/ip4/127.0.0.1/tcp/5001"
 	test_expect_success "'ipfs daemon' is ready" '
 		IPFS_PID=$! &&
 		pollEndpoint -ep=/version -host=$ADDR_API -v -tout=1s -tries=60 2>poll_apierr > poll_apiout ||