Edits:

2019-11-26 - Updated with some new sane defaults..

Install ubuntu 18.04 and do the latest dist-upgrade dance.

sudo apt update; sudo apt -y dist-upgrade; sudo apt autoremove

install docker

sudo apt-get remove docker docker-engine docker.io

sudo apt-get install \
    apt-transport-https \
    ca-certificates \
    curl \
    software-properties-common

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

sudo add-apt-repository \
"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) \
stable"

sudo apt-get install docker-ce

install docker-compose

sudo curl -L https://github.com/docker/compose/releases/download/1.25.0/docker-compose-`uname -s`-`uname -m` -o /usr/local/bin/docker-compose

sudo chmod +x /usr/local/bin/docker-compose

Create user that runs librenms

sudo mkdir /opt/librenms ;\
sudo adduser librenms --disabled-password --home /opt/librenms --no-create-home --gecos '' ;\
sudo usermod -aG docker librenms ;\
sudo chown librenms:librenms /opt/librenms/ -R

install librenms docker-container

sudo su - librenms
mkdir ~/src ;\
cd ~/src ;\
git clone https://github.com/librenms/docker.git ;\
cp ~/src/docker/examples/traefik/.env ~/ ;\
cp ~/src/docker/examples/traefik/docker-compose.yml ~/ ;\
cp ~/src/docker/examples/traefik/librenms.env ~/

Edit some stuff..

Get id of librenms user

id -u librenms
1001 « This is the user ID

id -g librenms
1001 « This is group ID

Edit the the settings after your preferenses

vim .env

MYSQL_DATABASE=librenms
MYSQL_USER=librenms
MYSQL_PASSWORD=asupersecretpassword

SMTP_SERVER=smtp.example.com
SMTP_USERNAME=smtp@example.com
SMTP_PASSWORD=

TZ=Europe/Stockholm
PUID=1001
PGID=1001

vim docker-compose.yml

version: "3.5"

services:
  traefik:
    image: traefik:1.7-alpine
    container_name: traefik
    command:
      - "--logLevel=INFO"
      - "--defaultentrypoints=http,https"
      - "--entryPoints=Name:http Address::80 Redirect.EntryPoint:https"
      - "--entryPoints=Name:https Address::443 TLS"
      - "--docker"
      - "--docker.exposedbydefault=false"
      - "--docker.domain=yourdomain.local"
      - "--acme=false"
    ports:
      - target: 80
        published: 80
        protocol: tcp
      - target: 443
        published: 443
        protocol: tcp
    volumes:
      - "./acme.json:/acme.json"
      - "/var/run/docker.sock:/var/run/docker.sock"
      - "./certs/:/certs/"
    restart: always

  db:
    image: mariadb:10.2
    container_name: librenms_db
    command:
      - "mysqld"
      - "--sql-mode="
      - "--innodb-file-per-table=1"
      - "--lower-case-table-names=0"
      - "--character-set-server=utf8"
      - "--collation-server=utf8_unicode_ci"
    volumes:
      - "./db:/var/lib/mysql"
    environment:
      - "TZ=${TZ}"
      - "PUID=${PUID}"
      - "PGID=${PGID}"
      - "MYSQL_ALLOW_EMPTY_PASSWORD=yes"
      - "MYSQL_DATABASE=${MYSQL_DATABASE}"
      - "MYSQL_USER=${MYSQL_USER}"
      - "MYSQL_PASSWORD=${MYSQL_PASSWORD}"
    restart: always

  memcached:
    image: memcached:alpine
    container_name: librenms_memcached
    environment:
      - "TZ=${TZ}"
      - "PUID=${PUID}"
      - "PGID=${PGID}"
    restart: always

  rrdcached:
    image: crazymax/rrdcached
    container_name: librenms_rrdcached
    volumes:
      - "./librenms/rrd:/data/db"
      - "./rrd-journal:/data/journal"
    environment:
      - "TZ=${TZ}"
      - "PUID=${PUID}"
      - "PGID=${PGID}"
      - "LOG_LEVEL=LOG_INFO"
      - "WRITE_TIMEOUT=1800"
      - "WRITE_JITTER=1800"
      - "WRITE_THREADS=4"
      - "FLUSH_DEAD_DATA_INTERVAL=3600"
    restart: always

  smtp:
    image: juanluisbaptiste/postfix
    container_name: librenms_smtp
    volumes:
      - "/etc/localtime:/etc/localtime:ro"
    environment:
      - "SERVER_HOSTNAME=librenms.yourdomain.local"
      - "SMTP_SERVER=${SMTP_SERVER}"
      - "SMTP_USERNAME=${SMTP_USERNAME}"
      - "SMTP_PASSWORD=${SMTP_PASSWORD}"
    restart: always

  librenms:
    image: librenms/librenms:latest
    container_name: librenms
    domainname: yourdomain.local
    hostname: librenms
    depends_on:
      - db
      - memcached
      - rrdcached
      - smtp
    volumes:
      - "./librenms:/data"
    labels:
      - "traefik.enable=true"
      - "traefik.backend=librenms"
      - "traefik.port=8000"
      - "traefik.frontend.rule=Host:librenms.yourdomain.local"
    environment:
      - "TZ=${TZ}"
      - "PUID=${PUID}"
      - "PGID=${PGID}"
      - "DB_HOST=db"
      - "DB_NAME=${MYSQL_DATABASE}"
      - "DB_USER=${MYSQL_USER}"
      - "DB_PASSWORD=${MYSQL_PASSWORD}"
      - "DB_TIMEOUT=60"
    env_file:
      - "./librenms.env"
    restart: always

  cron:
    image: librenms/librenms:latest
    container_name: librenms_cron
    domainname: yourdomain.local
    hostname: librenms
    depends_on:
      - librenms
    volumes:
      - "./librenms:/data"
    environment:
      - "TZ=${TZ}"
      - "PUID=${PUID}"
      - "PGID=${PGID}"
      - "DB_HOST=db"
      - "DB_NAME=${MYSQL_DATABASE}"
      - "DB_USER=${MYSQL_USER}"
      - "DB_PASSWORD=${MYSQL_PASSWORD}"
      - "DB_TIMEOUT=60"
      - "SIDECAR_CRON=1"
    env_file:
      - "./librenms.env"
    restart: always

  syslog-ng:
    image: librenms/librenms:latest
    container_name: librenms_syslog
    domainname: yourdomain.local
    hostname: librenms
    depends_on:
      - librenms
    ports:
      - target: 514
        published: 514
        protocol: tcp
      - target: 514
        published: 514
        protocol: udp
    volumes:
      - "./librenms:/data"
    environment:
      - "TZ=${TZ}"
      - "PUID=${PUID}"
      - "PGID=${PGID}"
      - "DB_HOST=db"
      - "DB_NAME=${MYSQL_DATABASE}"
      - "DB_USER=${MYSQL_USER}"
      - "DB_PASSWORD=${MYSQL_PASSWORD}"
      - "DB_TIMEOUT=60"
      - "SIDECAR_SYSLOGNG=1"
    env_file:
      - "./librenms.env"
    restart: always

Fix selfsigned cert and enter the correct FQDN when prompted.

mkdir ~/certs ;\
cd ~/certs ;\
openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout cert.key -out cert.crt

cd ~

start the containers

docker-compose up -d
docker-compose logs -f

Browse to your fqdn of the host https://librenms.yourdomain.local and login with librenms/librenms

If your default user [librenms/librenms] dont workm ,create an admin user (my default user always go bork)

docker exec -it --user librenms `docker container list | grep docker_app | awk {'print $1'}` php adduser.php admin password 10 admin@example.com

DONE

More information about this containersetup here » [https://github.com/librenms/docker]

And at last do not forget your well earned Coffee.

Install librenms in docker on ubuntu 18.04

DONE