When I start redis:3.2.6-alpine Container with command redis-server, no save-option are set: CONFIG GET * returns me an empty string after "save" (line 130). But as I understand, via default the should be a save option set: https://raw.githubusercontent.com/antirez/redis/3.0/redis.conf
Nevertheless, I tried to start the container with command redis-server --save "900 1 300 10" but same result.
I had to create my own redis docker image and add my custom redis.conf to get it to work, but it should also be possible with command options.