DataDog docker agent doesn't recieve logs from application container

Question

I have Golang app, it writes logs to Stdout with Logrus. I was trying to recreate this https://github.com/DataDog/docker-compose-example scenario, and replace python app with my app. But logs aren't coming to Datadog dashboad This is docker-compose I'm trying to make work

version: "3"
services:
  gos:
    build: goapp
    stdin_open: true
    ports:
      - "6000:6000"
    volumes:
      - /tmp/goapp:/tmp/goapp
      - ./goapp:/code
      - /var/run/docker.sock:/var/run/docker.sock
    environment:
      - DATADOG_HOST=datadog
  web:
    build: web
    command: python app.py
    ports:
     - "5000:5000"
    volumes:
     - ./web:/code # modified here to take into account the new app path
    links:
     - redis
    environment:
     - DATADOG_HOST=datadog # used by the web app to initialize the Datadog library
  redis:
    image: redis
  # agent section
  datadog:
    build: datadog
    links:
     - redis # ensures that redis is a host that the container can find
     - web # ensures that the web app can send metrics
    environment:
     - DD_API_KEY=34f-------63c
    volumes:
     - /var/run/docker.sock:/var/run/docker.sock
     - /proc/:/host/proc/:ro
     - /sys/fs/cgroup:/host/sys/fs/cgroup:ro

I also tried non-compose, but simple docker container installation for the agent by this https://docs.datadoghq.com/logs/log_collection/docker/?tab=containerinstallation instructions.

I run my golang app container with

docker run -v /var/run/docker.sock:/var/run/docker.sock:rw -d testgo

with Dockerfile

FROM golang:1.7.3
WORKDIR /go/src/github.com/alexellis/href-counter/
RUN go get -d -v github.com/Sirupsen/logrus
COPY app.go .
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

FROM alpine:latest  
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=0 /go/src/github.com/alexellis/href-counter/app .
EXPOSE 6000
LABEL "com.datadoghq.ad.logs"='[{"source": "goapp", "service": "webapp"}]'
CMD ["./app"] 

and DD agent can see app container ups and downs but receive no logs

Answer 1

it appears to me like you're missing a couple environment vars in your docker-compose datadog service configuration. And also the volume that adds the registry for tailing the logs from the docker socket. Maybe try something like this if you haven't?

  # agent section
  datadog:
    build: datadog
    links:
     - redis # ensures that redis is a host that the container can find
     - web # ensures that the web app can send metrics
    environment:
     - DD_API_KEY=34f-------63c
     - DD_LOGS_ENABLED=true
     - DD_LOGS_CONFIG_CONTAINER_COLLECT_ALL=true
     - DD_AC_EXCLUDE="name:datadog-agent"
    volumes:
     - /var/run/docker.sock:/var/run/docker.sock:ro
     - /proc/:/host/proc/:ro
     - /sys/fs/cgroup/:/host/sys/fs/cgroup:ro
     - /opt/datadog-agent/run:/opt/datadog-agent/run:rw

from there, if you still end up with trouble, you may want to reach out to support@datadoghq.com to ask for help. They're pretty quick to reply.