devnet

Gossamer Devnet

Docker container and Docker Compose for a Gossamer Devnet currently with three authority nodes running the westend chain with keys alice, bob and charlie.

Requirements

• Docker Compose

Running the Devnet

From the Gossamer root run the following commands to run the devnet

# will rebuild the containers based on the current code
docker-compose up --abort-on-container-exit --build 

# will run the devnet without rebuilding
docker-compose up --abort-on-container-exit

# destroys the devnet
docker-compose down

optional: you can add the flag -f followed by the path to the docker-compose.yml file

NOTE: The devnet is not stateful, so subsequent runs will start from the genesis block.

Prometheus Datadog Integration

All Prometheus metrics from the nodes are piped to Datadog. You can set up your own dashboard and add additional tags by modifying the Dockerfiles. Currently the metrics are prefixed with gossamer.local.devnet and are tagged (Prometheus label) with a key tag for alice, bob, and charlie.

For metrics to be piped to Datadog, you will require a Datadog API key. Please contact Elizabeth or myself (Tim) for access to datadog if you don't already have it.

The Datadog API key must be an environment variable on your own machine, which Docker Compose will pick up and inject when building the node images.

export $DD_API_KEY=YourKey

Files

Dockerfiles

There are four Dockerfiles used in the devnet.

• alice.Dockerfile is the lead node.
• bob.Dockerfile is used for both bob and charlie and shares the same genesis as alice Dockerfile .
• substrate_alice.Dockerfile is the alice node initiated with explicit node key to keep a deterministic peer id (the same used by gossamer alice node)
• substrate_bob.Dockerfile is used for bob and charlie and shares the same genesis as alice Dockerfile .

NOTE:: It is possible to use the substrate alice node with the bob and charlie gossamer nodes or any combination of these since the nodes in the network contain different keys

cmd/update-dd-agent-confd

A command line app to create a confd.yml file used by the Datadog agent when piping metrics to Datadog. It's used in the both alice.Dockerfile and bob.Dockerfile to create specific confd.yml files.

alice.node.key

This key is injected in alice.Dockerfile so it uses the same public key for the bootnodes param in bob.Dockerfile.

docker-compose.yml

The Docker Compose file. Specifies the IP addresses of all the nodes.

ECS Fargate Deployment

The docker-compose.yml file within devnet/gssmr-ecs folder uses Docker Compose ECS plugin to deploy and update an existing AWS ECS Cluster using the Fargate launch type running a Gossamer devnet with 3 services corresponding to the 3 keys used alice, bob, and charlie.

Deployment

Currently deployment is handled via a github workflow. Pushing the devnet branch will initiate the deploy process. Steps are outlined in /.github/workflows/devnet.yml.

At a high level, images for the alice, bob and charlie correspond to ECS services under the same name. The docker images are built based on the latest commit on the devnet branch. These images are pushed to ECR. A specific type of Docker context is required to use the ECS plugin. Deploying and updating is as simple as:

docker context create ecs gssmr-ecs --from-env
docker context use gssmr-ecs
docker compose up

Prometheus to Datadog

Prometheus metrics are automatically piped to Datadog. All metrics from the ECS devnet are prefixed with gossamer.ecs.devnet.