Cannot connect to dockerised ganache-cli:latest

[tim-hm]

• I asked about this on gitter: [x]
• Link to my question on gitter: link

Expected Behavior

When sending an RPC call to ganache I should get a valid response:

• Request: curl -X POST --data '{"jsonrpc":"2.0","method":"web3_clientVersion","params":[],"id":67}' localhost:8545
• Expected Reply: {"id":67,"jsonrpc":"2.0","result":"EthereumJS TestRPC/v2.1.5/ethereum-js"}

Current Behavior

• curl -X POST --data '{"jsonrpc":"2.0","method":"web3_clientVersion","params":[],"id":67}' localhost:8545 returns: curl: (52) Empty reply from server
• I invoked a shell inside the docker container and the above curl command successfully returns: {"id":67,"jsonrpc":"2.0","result":"EthereumJS TestRPC/v2.1.5/ethereum-js"}

Steps to Reproduce (for bugs)

0. Tried on MacOs and Ubuntu
1. docker run --rm -it -p 8545:8545 trufflesuite/ganache-cli:latest
2. curl -X POST --data '{"jsonrpc":"2.0","method":"web3_clientVersion","params":[],"id":67}' localhost:8545

Context

Your Environment

• Version used: Ganache CLI v6.1.6 (ganache-core: 2.1.5)
• Version of Truffle/Remix/Other tools used: N/A
• NodeJS Version: [ ] 6.x, [ ] 7.x (unsupported), [ ] 8.x, [ ] 9.x: N/A
• Operating System and version (include distro if Linux): Fails on Ubuntu 16.04.4 LTS (GNU/Linux 4.4.0-116-generic x86_64) and MacOS 10.13.5
• Docker: Docker version 17.12.1-ce, build 7390fc6 (Ubuntu) and 18.03.1-ce-mac65 (24312)

[GarethOates]

I managed to get this working by running the following:

docker run -d -p 8545:8545 trufflesuite/ganache-cli:latest -h 0.0.0.0

For some reason having the ganache-cli server listening on host 0.0.0.0 instead of the loopback address 127.0.0.1 allowed me to connect. Could this be due to some networking changes in Docker?

[tim-hm]

Can confirm that @GarethOates's solution works

[fasmat]

I'm experiencing the same issue, setting the default host of 0.0.0.0 did not help. Running docker on macOS, the port seems to be not exposed at all from the image

[GarethOates]

@fasmat Did you try the command as I wrote above? Have you tried disabling any local firewall's that might be blocking you from connecting to the container?

docker run -d -p 8545:8545 trufflesuite/ganache-cli:latest -h 0.0.0.0

[fasmat]

@GarethOates

Yes thats the command i'm starting the container with. It's running in the background:

docker ps 
CONTAINER ID        IMAGE                             COMMAND                  CREATED             STATUS              PORTS                    NAMES
80a13b8964f9        trufflesuite/ganache-cli:latest   "node ./build/cli.no…"   34 seconds ago      Up 34 seconds       0.0.0.0:8545->8545/tcp   trusting_ride

but no one is listening on 8545 according to lsof, no firewall is running.

[GarethOates]

Very strange! It works for myself and the CI build we run daily using those exact settings.

[GarethOates]

What is the configuration in your truffle.js file? Maybe there's something misconfigured there? It's specifying the correct port etc?

[fasmat]

I think my issue is that I'm running my docker on macos and bridged networking doesn't seem to work here :-/

[GarethOates]

I'm running on MacOS as well and it's working. Did you do something manual to the dockervm to make it use bridged mode or is that the default? If it's default, then I assume mine is also in bridged mode.

[tim-hm]

I'm also running on MacOS and the workaround works for me. What happens when you invoke a shell inside the container and use the curl command in my original post?

[fasmat]

@GarethOates @tim-hm
I investigated a little bit further this weekend, I had several issues that contributed to my problem:

Using the -h 0.0.0.0 flag allowed me to curl from one docker container to the container running ganache with success. Curl resolved ganache:8545 to docker_ganache_1.docker_default:8545. Using the full domain name I was also able to access ganache from within another docker container running a small test application (with the short domain name it did not work).

From my host machine I still cannot connect to ganache, neither with localhost:8545, 0.0.0.0:8545, ganache:8545 nor docker_ganache_1.docker_default:8545. Well at least when I'm connected to the wifi at my office, at my home wifi it did work ONCE with ganache:8545, but I cannot reproduce what I did different when it did work.

This seems like a docker / network configuration issue on my side and not directly related to the initial issue. But still thanks for helping :)

[mikeseese]

Hey everyone! I'm sorry for the delay on this one :(

A little background: per the discussion on trufflesuite/ganache#529, we decided to change the default to 127.0.0.1 as it is a minor security issue to let anyone on your network access your RPC port.

The reason this got messed up for Docker is because Docker acts as another computer on the network, which would mean you'd need to specify the specific ip address, or wildcard (0.0.0.0) for you to be able to bind to the port.

I apologize for the hindsight on this. I think it makes complete sense for the Docker instance to open the port completely (as this is just how you use Docker).

I will submit a fix that should auto use the -h 0.0.0.0 in the Docker file, but you seem to have figured out how to get it working in the meantime.