Run oidc tests fully in docker

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

integration_common_test.go

@@ -316,3 +316,22 @@ func GetEnvBool(key string) (bool, error) {
 
 	return v, nil
 }
+
+func GetFirstOrCreateNetwork(pool *dockertest.Pool, name string) (dockertest.Network, error) {
+	networks, err := pool.NetworksByName(name)
+	if err != nil || len(networks) == 0 {
+
+		if _, err := pool.CreateNetwork(name); err == nil {
+			// Create does not give us an updated version of the resource, so we need to
+			// get it again.
+			networks, err := pool.NetworksByName(name)
+			if err != nil {
+				return dockertest.Network{}, err
+			}
+
+			return networks[0], nil
+		}
+	}
+
+	return networks[0], nil
+}