Phase 2: The OBI Magic

1. Add the OBI Service

2 min

Add OBI to docker-compose.yaml

Exercise

Open docker-compose.yaml in your editor:

bash
cd ~/workshop/obi/02-obi-docker
docker-compose down
vim docker-compose.yaml #or editor of choice

Scroll to the very bottom of the file you’ll see a comment block that says PHASE 2. Paste the following block directly below that comment, keeping the 2-space indentation so it lines up with the other services (like frontend:, load-generator:, etc.):

yaml
  obi:
    image: otel/ebpf-instrument:main
    pid: host
    privileged: true
    network_mode: host
    volumes:
      - ./obi-config.yaml:/config/obi-config.yaml
      - /sys/fs/cgroup:/sys/fs/cgroup
    environment:
      OTEL_EBPF_CONFIG_PATH: /config/obi-config.yaml

Note: When pasting with vim using :set paste before pasting helps maintain formatting

Save the file.

Tip

Make sure obi: is indented 2 spaces (same level as frontend:, load-generator:, etc.). If it’s at the far left with no indentation, Docker Compose will reject it with Additional property obi is not allowed. It must be inside the services: block.

What Does Each Line Do?

Line	What it does	Why it matters
`image: otel/ebpf-instrument:main`	The OBI container image	This is the only thing you’re adding to your stack
`pid: host`	Shares the host’s PID namespace	OBI needs to see processes running in other containers
`privileged: true`	Grants kernel-level access	eBPF programs need to attach probes to kernel functions
`network_mode: host`	Shares the host’s network stack	Required for context propagation – OBI injects trace context at the network level
`volumes: ./obi-config.yaml:...`	Mounts the service discovery config	Tells OBI which processes to instrument and what to name them
`volumes: /sys/fs/cgroup:...`	Mounts the cgroup filesystem	OBI uses this to detect which processes are running inside containers
`OTEL_EBPF_CONFIG_PATH`	Points to the config file inside the container	Standard OBI env var for configuration

Start OBI

Docker Compose will detect that only the obi service is new and start it. Your existing services keep running.

docker-compose up -d

text
[+] Running 6/6
 ✔ Container 02-obi-docker-payment-service-1      Running
 ✔ Container 02-obi-docker-order-processor-1       Running
 ✔ Container 02-obi-docker-frontend-1              Running
 ✔ Container 02-obi-docker-splunk-otel-collector-1 Running
 ✔ Container 02-obi-docker-load-generator-1        Running
 ✔ Container 02-obi-docker-obi-1                   Started

1. Add the OBI Service

Add OBI to docker-compose.yaml #

What Does Each Line Do? #

Start OBI #

Add OBI to docker-compose.yaml

What Does Each Line Do?

Start OBI