Docker Compose Deployment

dynamic_deploy.sh provides a containerized multi-node environment for developing and testing ChronoLog without physical cluster hardware. It generates a Docker Compose file at runtime, starts the containers, configures SSH between them, and deploys the pre-built ChronoLog services across the cluster — following the same SSH-based approach as the multi-node deployment. Unlike the single-node and multi-node bare-metal scripts, this workflow handles the full lifecycle from image launch through service startup in one step. The script is located at CI/docker/dynamic_deploy.sh in the repository.

Prerequisites

Requirement	Notes
Docker Engine	Must be running and reachable
Docker Compose v2	docker compose (not docker-compose) must be on PATH
docker group membership	Current user must be able to run docker without sudo

Docker Image

All containers use ghcr.io/grc-iit/chronolog:v2.5.0 (or ghcr.io/grc-iit/chronolog:latest). The image provides:

• Ubuntu 24.04 base
• Spack package manager with pre-installed dependencies (MPICH, Mochi/Thallium, etc.)
• grc-iit user account
• ChronoLog pre-installed at $CHRONOLOG_HOME (/home/grc-iit/chronolog-release-install/chronolog/)
• OpenSSH server for inter-container SSH (started automatically by the container entrypoint)

ChronoLog is pre-built and ready to deploy — no compilation is needed inside the containers.

Container Layout

The script assigns each container a fixed role based on its index. For a deployment with K keepers, G graphers, and P players the total container count is N = 1 + K + G + P.

Container	Hostname	Role
chronolog-c1	c1	ChronoVisor
chronolog-c2 ... chronolog-c(K+1)	c2 ... c(K+1)	ChronoKeeper x K
chronolog-c(K+2) ... chronolog-c(K+G+1)	c(K+2) ... c(K+G+1)	ChronoGrapher x G
chronolog-c(K+G+2) ... chronolog-c(N)	c(K+G+2) ... c(N)	ChronoPlayer x P

All containers are connected to the chronolog_net bridge network and mount the same shared_home Docker volume at /home/grc-iit. This shared volume is automatically populated with the image contents (including the ChronoLog installation) on first use, making the installed binaries and libraries visible to all containers.

Script Options

Flag	Default	Constraint	Description
-n	4	>= 2; must equal 1 + K + G + P	Total number of containers
-k	1	>= 1	Number of ChronoKeeper containers
-g	1	>= 1	Number of ChronoGrapher containers
-p	1	>= 1	Number of ChronoPlayer containers

The script exits with an error if -n does not equal 1 + k + g + p.

Deployment Steps

Running dynamic_deploy.sh performs the following steps in order:

1. Generate dynamic-compose.yaml — writes a Compose file that defines one service per container (c1...cN), all sharing shared_home and chronolog_net.
2. Start containers — runs docker compose -f dynamic-compose.yaml up -d; containers c2...cN depend on c1.
3. SSH key setup on c1 — generates an RSA 4096-bit key pair under /home/grc-iit/.ssh/, copies the public key to authorized_keys, and scans host keys for all containers into known_hosts. Sets correct permissions on the .ssh directory.
4. Restart SSH on all containers — ensures the SSH daemon is running and accepts the newly configured keys.
5. Generate host files — writes one hostname per line into ~/chronolog-release-install/chronolog/conf/:
   • hosts_visor — c1
   • hosts_keeper — c2 ... c(K+1)
   • hosts_grapher — c(K+2) ... c(K+G+1)
   • hosts_player — c(K+G+2) ... c(N)
   • hosts_clients and hosts_all — all containers
6. Deploy — runs deploy_cluster.sh with the host files generated in step 5. ChronoLog processes are started across all containers via SSH, matching the multi-node deployment flow.

Examples

Default 4-container deployment (1 ChronoVisor, 1 ChronoKeeper, 1 ChronoGrapher, 1 ChronoPlayer):

cd CI/docker
./dynamic_deploy.sh

8-container deployment with 3 keepers, 2 graphers, and 2 players:

cd CI/docker
./dynamic_deploy.sh -n 8 -k 3 -g 2 -p 2

Stopping

Bring down the containers:

docker compose -f CI/docker/dynamic-compose.yaml down

To also remove the shared_home volume (required when upgrading to a new ChronoLog image version):

docker compose -f CI/docker/dynamic-compose.yaml down -v

note

dynamic-compose.yaml is generated at runtime in the CI/docker/ directory. A static 4-node reference file is available at CI/docker/distributed.docker-compose.yaml if you need a fixed, pre-defined topology without running the generation script.