concordia/docker

Concordia Dockerized

This page provides information about the provided docker images, their configuration and supported deployment strategies.

TLDR: head down to Putting it all together/Scripts for a quick setup.

Services

Concordia requires at the minimum two services to work, a blockchain and a rendezvous server.

Additionally, the Concordia application code must be provided to the user. Currently, the only way of distributing the application code is via a webserver as a web application.

Ganache

Ganache is a personal blockchain software used during development. It is a very convenient way of developing and testing dApps. More information can be found in the project's website.

Note that any other Ethereum compliant blockchain can be used.

Rendezvous

Concordia uses a distributed database to store forum data. A rendezvous server is needed in order for users to discover peers in the network and get access to the data.

Application

The Concordia application is a React app that handles interactions with the contracts and the distributed database used.

Docker images

This repository provides docker images to easily setup (and destroy) instances of all required services Concordia. Furthermore, we provide an image that builds the contracts and handles their migration to the blockchain in use.

Ganache

The Dockerfile is provided in the path ./ganache. The image makes use of the environment variables described below.

Environment variable	Default value	Usage
ACCOUNTS_NUMBER	10	Set the number of accounts generated
ACCOUNTS_ETHER	100	Set the amount of ETH assigned to each account
MNEMONIC	NaN	The mnemonic phrase sued as a seed for deterministic account generation
HOST	0.0.0.0	The hostname to listen on
PORT	8545	The port to listen on
NETWORK_ID	5778	The network id used to identify ganache

Note that the Ganache instance running inside the container will save the generated blockchain keys in the path /home/ganache_keys/keys.json. If you need to access the keys (eg for getting a private key and importing in Metamask) you can mount a volume to this path to have easier access.

Also, the database used by Ganache for storing blockchain information is placed in the path /home/ganache_db/. You can maintain the blockchain state between runs by mounting a volume to the database path. To do that, add the docker flag -v host/absolute/path/to/ganache_db:/home/ganache_db.

Rendezvous

The rendezvous server used here is js-libp2p-webrtc-star. The server listens on port 9090. More information can be found on the github page of the project here.

Contracts

This is a provision system that compiles and deploys the contracts to any Ethereum blockchain.

A Dockerfile is provided in the path ./concordia-contracts that will build the contracts used by Concordia and handle their deployment to any Ethereum network defined using env-vars upon container run. Dockerfile contains three useful stages, described in the table below.

Stage name	Entrypoint	Usage
compile	Exits immediately	Compiles the contracts
test	Runs contract tests	Compiles contracts and runs tests using blockchain defined by env vars
runtime	Migrates contracts	Compiles contracts and migrates to the blockchain defined by env vars. Does not run tests

The image makes use of the environment variables described below.

Environment variable	Default value	Usage
MIGRATE_NETWORK	develop	Set the network where the contracts will be deployed/tested (set this to "env" unless you know what you're doing)
DEPLOY_CHAIN_HOST	NaN	Set the hostname of the blockchain network that will be used for deployment (requires network to be "env")
DEPLOY_CHAIN_PORT	NaN	Set the port of the blockchain network that will be used for deployment (requires network to be "env")
TEST_CHAIN_HOST	NaN	Set the hostname of the blockchain network that will be used for testing (requires network to be "env")
TEST_CHAIN_PORT	NaN	Set the port of the blockchain network that will be used for testing (requires network to be "env")

You can find the contract artifacts in the directory /usr/src/concordia/packages/concordia-contracts/build/ inside the image.

Attention: make sure the targeted blockchain is up and running before trying to migrate the contracts.

Application

The Dockerfile provided in the path ./concordia-application builds the application for production and serves the resulting build using an nginx server. Dockerfile contains two useful stages, described in the table below.

Stage name	Entrypoint	Usage
test	Runs tests	Fetches npm packages and runs tests
runtime	Serves application	Builds for production and serves it through nginx

The image makes use of the environment variables described below.

Environment variable	Default value	Usage
REACT_APP_RENDEZVOUS_HOST	127.0.0.1	Set the hostname of the rendezvous server
REACT_APP_RENDEZVOUS_PORT	9090	Set the port of the rendezvous server

Attention: this image will copy the contract artifacts from the directory /packages/concordia-contracts/build. The image is bound the these artifacts after build. If the contracts change or get re-deployed the image must be re-built to use the new artifacts.

Attention: make sure the contracts have been deployed before building this image. Also, make sure the rendezvous server is up and running.

Docker Compose

A docker-compose file also is provided. The docker-compose handles the lifecycle of the Ganache and Rendezvous server containers.

Putting it all together

You can find some ready to use scripts for common scenarios like dev deploys and testing in the ./docker directory. These scripts are documented in the following chapters.

Makefile targets

Concordia uses blockchain and other distributed technologies. There are a number of ways to set up a running instance of this application.

This chapter will guide you through simple setups for testing and production that depend on local blockchain (ganache) instances which do not require real ETH to work or have any other charges.

Testing the contracts

Build the ganache image and spin up a blockchain for testing:

make build-ganache run-ganache-test

Build the testing stage of the contracts image:

make build-contracts-tests

Run the tests:

make run-contracts-tests

The results should be printed in the terminal, but are also available in the directory ./reports/contracts.

Testing the application

Build the testing stage of the application image:

make build-app-tests

Run the test:

make run-app-tests

The results should be printed in the terminal, but are also available in the directory ./reports/app.

Production

Just run the target:

make run

And you' re done! Head to localhost:7777 and voilà, a working Concordia instance appears! The blockchain is exposed in the address localhost:8545.

Tip: the accounts (private keys) generated by Ganache are available in the file ./volumes/ganache_keys/keys.json.

Note that the make run command might take several minutes to execute (depending on your system). What happens under the hood is that:

• the ganache image is built
• blockchain and rendezvous server containers are started
• migration stage of the contracts image is built
• the contracts are deployed to the blockchain:
• the application image is built and then deployed

Env Files

Targets in the Makefile make use of env files suffixed by .docker located in the directory ./env. Using this environment variables, you can change various configuration options of the testing/production deploys.

Targets suffixed with host-chain will try to use a blockchain and rendezvous server running in the host machine. They use the --net=host docker option and get the required environment variables from different env files, ./env/contracts.env and ./env/concordia.env (notice these env files don't include the .docker). These env files do not exist by default. The values set will largely depend on how you choose to run services in your system (which ports you use etc.), so be sure to create them before running any host-chain target. Luckily example files are provided.