MultiChain Developer Q&A - Recent questions tagged docker

Docker issue connecting to genesis node

Wed, 05 Mar 2025 23:08:00 +0000

I have "rpcallowip=0.0.0.0/0" in my multichain.conf

docker images are able to ping and netcat displays the necessary port on genesis image as open..

Any idea on why they wont talk?

https://imgur.com/a/kdDiDPG

Multichain in Kubernetes

Wed, 13 Feb 2019 09:55:44 +0000

Hi,

I have deployed a master node in Kubernetes and I can join external (to the K8s cluster) client nodes, for instance, using Windows.

However, when I try to issue commands from the clients, and even from the master, I start to see lots of warning logs about massive peers and eventually the commands are not executed.

I presume everything is about the internal port openings that happen as part of the communication between nodes (the ports in the range of 30000 that I notice in the logs):

mchn: Sending minimal parameter set to 10.136.106.51:36906

Therefore, can you please let me know if these ports are configurable or can be somehow identified, so I can figure out how to manage them between inside and outside nodes to the K8s cluster?

Thanks!

Cannot connect to Multichain ran inside Docker

Thu, 13 Sep 2018 14:07:04 +0000

I have created a Dockerfile to run a blockchain within a Docker container. The chain is created successfully, and multichaind ran, which gives an output of:

Other nodes can connect to this node using:

multichaind dockChain2@172.17.0.2:5001

Listening for API requests on port 5002 (local only - see rpcallowip setting)

When trying to connect from another node the error received is -

Error: Couldn't connect to the seed node 172.17.0.2 on port 5001 - please check multichaind is running at that address and that your firewall settings allow incoming connections.

I have tried exposing port 5001 in docker, and using docker ps -a shows 0.0.0.0:5001->5001/tcp under PORTS.

Starting multichain and creating streams from script

Fri, 31 Aug 2018 18:08:30 +0000

I am trying to automate a creation of a multichain and also create/subscribe to a stream.

I wrote a bash script to run inside a docker container and the main elements of it are;

multichaind -txindex -printtoconsole -shrinkdebugfilesize $CHAINNAME

multichain-cli $CHAINNAME create stream test false
multichain-cli $CHAINNAME create stream user_data false
multichain-cli $CHAINNAME subscribe test
multichain-cli $CHAINNAME subscribe user_data

I pretty much copied it from here - https://github.com/Kunstmaan/docker-multichain/blob/master/master/runchain.sh

My problem is, once the multichain starts it doesn't go on to create the streams. I tried adding -daemon at the end of the start command but then the docker container just stops once it gets to the bottom of the script.

Any ideas how I can start up the multichain but also run the create stream commands, all being executed from a bash file

Connecting to docker instance that's running multichain

Sat, 12 May 2018 20:34:22 +0000

So I have a multichain instance running on a centos docker image. My main machine is Windows 10 and I can connect to my multichain node and run commands using the multichain-cli application.

Now I am writing a Java application that uses the MultiChainJavaAPI and I am getting an exception thrown when I try to connect and run any commands. The exception I get is;

MultichainException [
object=code :401,
reason=message : Authorization Required,
message=null,
cause=null
]

I was originally working on an Ubuntu VM, and did not have a problem, but I wasn't running the multichain server on Docker. Now I am running it on windows I am facing this issue.

Here is CLI output from my terminals to show all is working.

Docker Image

[root@e91ecb9e1ebf recordz_chain]# multichaind recordz_chain -daemon

MultiChain 1.0.4 Daemon (latest protocol 10010)

Starting up node...

Other nodes can connect to this node using:
multichaind recordz_chain@172.17.0.3:6471

Listening for API requests on port 6470 (local only - see rpcallowip setting)

Node ready.

Windows Machine

PS C:\Software\multichain-windows-1.0.4> .\multichaind.exe recordz_chain -daemon

MultiChain 1.0.4 Daemon (latest protocol 10010)

Other nodes can connect to this node using:
multichaind recordz_chain@192.168.99.1:6471

This host has multiple IP addresses, so from some networks:
multichaind recordz_chain@192.168.56.1:6471
multichaind recordz_chain@192.168.0.10:6471

Listening for API requests on port 6470 (local only - see rpcallowip setting)

Node ready.

Command From Windows Terminal

PS C:\Software\multichain-windows-1.0.4> .\multichain-cli.exe recordz_chain getinfo

{"method":"getinfo","params":[],"id":1,"chain_name":"recordz_chain"}

{
"version" : "1.0.4",
"nodeversion" : 10004901,
"protocolversion" : 10010,
"chainname" : "recordz_chain",
"description" : "MultiChain recordz_chain",
"protocol" : "multichain",
"port" : 6471,
"setupblocks" : 60,
"nodeaddress" : "recordz_chain@192.168.99.1:6471",
"burnaddress" : "1XXXXXXXLnXXXXXXiTXXXXXXTFXXXXXXWF5mxB",
"incomingpaused" : false,
"miningpaused" : false,
"walletversion" : 60000,
"balance" : 0.00000000,
"walletdbversion" : 2,
"reindex" : false,
"blocks" : 59,
"timeoffset" : 0,
"connections" : 2,
"proxy" : "",
"difficulty" : 0.00000006,
"testnet" : false,
"keypoololdest" : 1526140326,
"keypoolsize" : 2,
"paytxfee" : 0.00000000,
"relayfee" : 0.00000000,
"errors" : ""
}

I have the correct permissions setup and can communicate from my windows machine to my docker image, but when I am trying to run the application I get that error. I would have thought it was an issue with the API I am using, but I had this working before while on my Ubuntu VM, so I know its not the API.

I did find this answer - https://www.multichain.com/qa/2444/running-multichain-docker-unable-connect-external-service

I applied the solution of changing the defaulted password to a shorter one, just 'password' and restarted the multichain server and my windows connection to it. I also updated the password in my java application but still getting the same result.

I'm out of ideas now. Any help would be much appreciated

Savoir: No JSON object could be decoded

Sat, 03 Mar 2018 22:18:42 +0000

Hi,

I have not been able to use Savoir to make api calls to my multichain node. The node is running in a docker container and I have included rpcallowip of my computer from which I am trying make api calls using python and savoir.

First, making the standard getinfo() call raises "No handlers could be found for logger "Savoir". This is odd. The final error raised is "No JSON object could be decoded".

How can this problem be solved? Many thanks!!

No handlers could be found for logger "Savoir"
Traceback (most recent call last):
File "test_savoir.py", line 10, in <module>
    result=api.listassets()
File "/home/helio/blockchain/multichain/savoir/Savoir/Savoir.py", line 65, in __call__
    log.error("Json: %s" % r.json())
File "/usr/local/lib/python2.7/dist-packages/requests/models.py", line 885, in json
    return complexjson.loads(self.text, **kwargs)
File "/usr/lib/python2.7/json/__init__.py", line 339, in loads
    return _default_decoder.decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 364, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python2.7/json/decoder.py", line 382, in raw_decode
    raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded

Run a node per docker container

Fri, 02 Mar 2018 13:54:23 +0000

Is it possible to run a node per container and make them discover each other? Currently, I have made a Dockerfile:
```

FROM ubuntu:16.04

WORKDIR /

ADD . /multichain

RUN apt-get update
RUN apt-get -y install build-essential libtool autotools-dev automake pkg-config libssl-dev libevent-dev bsdmainutils
RUN apt-get -y install libboost-all-dev
RUN apt-get -y install git
RUN apt-get -y install software-properties-common
RUN add-apt-repository ppa:bitcoin/bitcoin
RUN apt-get update
RUN apt-get -y install libdb4.8-dev libdb4.8++-dev

WORKDIR /multichain

RUN ./autogen.sh
RUN ./configure
RUN make

RUN cp src/multichain-util /usr/local/bin/
RUN cp src/multichaind /usr/local/bin/
RUN cp src/multichain-cli /usr/local/bin/

```
But since the `IP` and `port` of the chain are created randomly upon chain initialization, I cannot know what port and IP to expose when I run the containers.

Multichain CLI error - error: no response from server

Thu, 30 Nov 2017 12:22:38 +0000

I start a node (master-node) that initializes a chain via docker. I also initialized other nodes (slaves), and connect to the master-node chain. "anyone-can-connect" is made true so no permissions are required. It connects successfully ("Node started" message is shown) and I can see the data directory for each node.

I can connect multichain-cli (on my host machine ) to the master node and I can run commands such as getinfo.

When I try to connect to the slave nodes, and run a command, it says "error: no response from server".

Both docker containers are running.

Onboarding / Automating Node deployment

Thu, 18 May 2017 11:23:24 +0000

Hi MC-Team,

would be great if you consider a better onboarding experience for new nodes that should join a existing network.

The problem here is (mainly when using docker, or other ways to automate nodes joining a network) that it is quite awkward at the moment to onboard a node.

When a node cannot join a network it just exits with a message.

To automate this I had to do a lot of scripting like:
- grep the account address (to hand it over to some node in the network for granting)
- start an additional rest service on the instance just to be able to query the account address from outside because the node immediately stops when not able (allowed) to connect
- hard to get the account address without again trying to connect and grep from the error message if you missed it
- do a bash for loop trying to connect every minute and see if permission were granted

I think dockerization of MultiChain and something like Multichain as a Service offerings need a better handling in this case.

Maybe the node can keep running and tries connect polling itself?

Maybe when it keeps running it has a minimal json rpc interface that allows to query:
- the generated MC account
- some information that are available event without connectivity to another network (e.g. which network it wants to join etc...)

Greetings,

Alex

Running Multichain in a docker container

Sat, 13 May 2017 16:09:38 +0000

I am trying to setup multichain in a docker container. It works fine till I shutdown the machine, but on reboot, the mining is not happening and block count remains static even after restart of the docker container.

I have tried pausing mining and then stopping the node. And after machine restart and docker container restart, set the mining flag to resumed but the block count doesn't increase.

Is this not supposed to work or is there some alternative for this?

Multichain & Docker: peer discovery not working

Thu, 23 Mar 2017 20:33:50 +0000

Hi.

Is it possible to tell Multichain what ip and port it should exchange as endpoint information to other nodes?

The peer discovery and exchange does not work when running inside a docker container since it seems that the nodes exchange the wrong ip address and port that is not accessible form outside the container because the container ip != public ip and the container p2p port != the external mapped p2p port.

I can connect nodes manually but it seems they cannot share node information to get fully connected.

What is the parameter -externalip for example?

Greetings,

Alex

Connecting a node via a hostname defined in /etc/hosts?

Wed, 30 Dec 2015 07:46:48 +0000

For development I'm trying to use a docker cluster to have a master node and several slave nodes. The master node starts perfectly and is running (on port 7447).

On the slave nodes connecting also runs perfectly when using:

multichaind dockerchain@172.17.42.5:7447

I've got no real indication on the IP address of the master node but docker-compose exposes in /etc/hosts on the slave nodes:

172.17.42.5 masternode

So i've tried running "multichaind dockerchain@masternode:7447", but it gives me

...
mchn: Could not establish connection with seed node - timeout
...
Error: Couldn't connect to the seed node masternode on port 7447 - please check multichaind is running at that address and that your firewall settings allow incoming connections.

Now strangely enough, if i first connect using the IP address, then the masternode version works as well.

What am I missing here?