test: Add a set of tests for handling bad/invalid configs

This patch adds a set of tests to validate chasquid's handling of bad
and invalid configurations, to make sure we fail as expected.

test/t-20-bad_configs/run.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+
+set -e
+. "$(dirname "$0")/../util/lib.sh"
+
+init
+check_hostaliases
+
+mkdir -p .logs
+
+if chasquid --config_dir=doesnotexist > .chasquid-doesnotexist.out 2>&1; then
+	fail "chasquid should not start without a config"
+fi
+
+# Create this empty directory. We can't use a .keep file because that defeats
+# the purpose of the test.
+mkdir -p c-04-no_cert_dirs/certs/
+
+# Generate certs for the tests that need them.
+for i in c-05-no_addrs c-06-bad_maillog c-07-bad_domain_info \
+	c-08-bad_sts_cache c-09-bad_queue_dir ;
+do
+	CONFDIR=$i/ generate_certs_for testserver
+done
+
+for i in c-*; do
+	if chasquid --config_dir="$i" > ".chasquid-$i.out" 2>&1; then
+		echo "$i failed; output:"
+		echo
+		cat ".chasquid-$i.out"
+		echo
+		fail "$i: chasquid should not start with this invalid config"
+	fi
+
+	# Test that they failed as expected, and not by chance/unrelated error.
+	if ! tail -n 1 ".chasquid-$i.out" \
+	   | grep -q -E "$(cat "$i/.expected-error")"; then
+		echo "$i failed"
+		echo "expected last line to match:"
+		echo "    '$(cat "$i/.expected-error")'"
+		echo "got last line:"
+		echo "    '$(tail -n 1 ".chasquid-$i.out")'"
+		echo
+		fail "$i: chasquid did not fail as expected"
+	fi
+done
+
+success