Docker image from existing Rails/Unicorn/MySQL app

Question

I am new to Docker and experimenting by creating an image from an existing Rails/Unicorn/MySQL app. My files are below and the image successfully creates but I'm unclear if things are actually working properly as I can't access the traditional Unicorn localhost URL, or the boot2docker IP.

So my question is, how do I access a Unicorn server locally on OSX with a Docker image running?

Dockerfile

# Dockerfile
FROM seapy/rails-nginx-unicorn

# Publish port 8080
EXPOSE 8080

CMD ["bundle", "exec","unicorn", "-p", "8080"]

Docker Image Run Command

docker run --name games-app --link test-mysql:mysql -p 8080 -d -e SECRET_KEY_BASE=test sample_rails_games_app

Docker PS Output

docker ps
CONTAINER ID        IMAGE                    COMMAND                CREATED             STATUS              PORTS                     NAMES
cf9c45d62763        sample_rails_games_app   "bundle exec unicorn   17 minutes ago      Up 17 minutes       0.0.0.0:32777->8080/tcp   games-app
93485cb7bcca        mysql                    "/entrypoint.sh mysq   6 hours ago         Up 6 hours          3306/tcp                  test-mysql

If I try to hit localhost:8080 or http://192.168.59.103:8080/ I am getting a Gateway Timeout: can't connect to remote host

Docker Logs Output

docker logs cf9c45d62763
I, [2015-07-30T22:44:44.941674 #1]  INFO -- : listening on addr=0.0.0.0:8080 fd=9
I, [2015-07-30T22:44:44.941927 #1]  INFO -- : worker=0 spawning...
I, [2015-07-30T22:44:44.944000 #1]  INFO -- : master process ready
I, [2015-07-30T22:44:44.944836 #8]  INFO -- : worker=0 spawned pid=8
I, [2015-07-30T22:44:44.945103 #8]  INFO -- : Refreshing Gem list
I, [2015-07-30T22:44:46.729708 #8]  INFO -- : worker=0 ready

I have also tried the boot2docker workarounds from here to no avail: https://github.com/boot2docker/boot2docker/blob/master/doc/WORKAROUNDS.md

Any guidance is greatly appreciated.

Answer 1

You have to use the eth1 address of your boot2docker vm.

Run from a shell:

boot2docker ssh

and then

ifconfig eth1
docker@boot2docker:~$ ifconfig eth1
eth1      Link encap:Ethernet  HWaddr 08:00:27:69:53:F6
          inet addr:192.168.59.103  Bcast:192.168.59.255  Mask:255.255.255.0
          inet6 addr: fe80::a00:27ff:fe69:53f6/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:170143 errors:0 dropped:0 overruns:0 frame:0
          TX packets:98176 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:107722766 (102.7 MiB)  TX bytes:13713741 (13.0 MiB)

docker@boot2docker:~$

192.168.59.103 is the address you want to use from your mac. The port depends on what port your are forwarding. For example in this case:

$ docker ps
CONTAINER ID        IMAGE               COMMAND                CREATED              STATUS              PORTS                   NAMES
2e1d63d6928a        f6ac7e4116f3        "/usr/sbin/sshd -D -   3 hours ago         Up About an hour    0.0.0.0:32771->22/tcp   mad_jones
104f730aa7da        f6ac7e4116f3        "/usr/sbin/sshd -D -   3 hours ago         Up About an hour    0.0.0.0:32770->22/tcp   reverent_almeida

it's either 32771 or 32770. In this example it's an sshd server running by in your case it would be your unicorn which would be port 32777 So I think you are connecting to the right address but you need to connect to 32777 instead.

Hope it helps.