ci: add regression test for boot race condition

If two instances start up at the same time, they end up with different
keys on both ends. Test this with different delays of 2 (working), 1
(flaky) and 0 (broken) seconds.

Signed-off-by: Paul Spooren <mail@aparcar.org>

.ci/boot_race/a.toml

@@ -0,0 +1,14 @@
+public_key = "rp-a-public-key"
+secret_key = "rp-a-secret-key"
+listen = ["127.0.0.1:9999"]
+verbosity = "Verbose"
+
+[api]
+listen_path = []
+listen_fd = []
+stream_fd = []
+
+[[peers]]
+public_key = "rp-b-public-key"
+endpoint = "127.0.0.1:9998"
+key_out = "rp-b-key-out.txt"

.ci/boot_race/b.toml

@@ -0,0 +1,14 @@
+public_key = "rp-b-public-key"
+secret_key = "rp-b-secret-key"
+listen = ["127.0.0.1:9998"]
+verbosity = "Verbose"
+
+[api]
+listen_path = []
+listen_fd = []
+stream_fd = []
+
+[[peers]]
+public_key = "rp-a-public-key"
+endpoint = "127.0.0.1:9999"
+key_out = "rp-a-key-out.txt"

.ci/boot_race/run.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+
+iterations="$1"
+sleep_time="$2"
+config_a="$3"
+config_b="$4"
+
+PWD="$(pwd)"
+EXEC="$PWD/target/release/rosenpass"
+
+i=0
+while [ "$i" -ne "$iterations" ]; do
+	echo "=> Iteration $i"
+
+	# flush the PSK files
+	echo "A" >rp-a-key-out.txt
+	echo "B" >rp-b-key-out.txt
+
+	# start the two instances
+	echo "Starting instance A"
+	"$EXEC" exchange-config "$config_a" &
+	PID_A=$!
+	sleep "$sleep_time"
+	echo "Starting instance B"
+	"$EXEC" exchange-config "$config_b" &
+	PID_B=$!
+
+	# give the key exchange some time to complete
+	sleep 3
+
+	# kill the instances
+	kill $PID_A
+	kill $PID_B
+
+	# compare the keys
+	if cmp -s rp-a-key-out.txt rp-b-key-out.txt; then
+		echo "Keys match"
+	else
+		echo "::warning title=Key Exchange Race Condition::The key exchange resulted in different keys. Delay was ${sleep_time}s."
+		# TODO: set this to 1 when the race condition is fixed
+		exit 0
+	fi
+
+	# give the instances some time to shut down
+	sleep 2
+
+	i=$((i + 1))
+done