Errno::EADDRNOTAVAIL - LogStashLogger not connecting to Logstash - Ruby on Rails - ruby-on-rails

Question

I've been fighting on getting the logs to work on a Dockerized Rails 5.1.5 application with the ELK (Elasticsearch Logstash Kibana) stack (which is Dockerized as well). I've been having problems on setting it up. I haven't been able to send a single log to logstash from Rails.
The current problem is:
ERROR -- : [LogStashLogger::Device::TCP] Errno::EADDRNOTAVAIL - Cannot
assign requested address - connect(2) for "localhost" port 5228
At first, I thought there was a problem with my current ELK configuration. After days spent, I finally figured out that ELK was working correctly by sending a dummy .log file through the nc command using Ubuntu for Win10, and it worked 🎉🎉🎉🎉 !!!
Now that I know the problem is with Rails, I've been trying a different set of combinations, but I still haven't gotten it to work:
I checked that the configuration from Logstash is correctly accepting TCP, and is the right port.
Changed to a different port, both in Logstash and Rails.
I'm currently using Docker-Compose V3. I initialized ELK first, and then Rails (but the problem still creeped in)
Switched between UDP and TCP.
Did not specified a codec in the logstash.conf.
Specified the json_lines codec in the logstash.conf
I've tried specifying a link between logstash and rails in docker-compose.yml (Even though it's deprecated for docker-compose v3)
I've tried bringing them together through a networkin docker-compose.
I've tried specifying a depends_on logstash in the rails app in docker-compose.
I'm running out of ideas:
Here's the logging config (Right now it's in development.rb):
config.log_level = :debug
config.lograge.enabled = true
config.lograge.formatter = Lograge::Formatters::Logstash.new
config.logger = LogStashLogger.new(type: :tcp, host: 'localhost', port: 5228)
The logstash conf:
input {
tcp {
port => 5228
codec => json_lines
}
}
## Add your filters / logstash plugins configuration here
output {
elasticsearch {
hosts => ["elasticsearch:9200"]
}
}
And last, but not least, here's the Docker-compose:
version: '3'
services:
db:
# This specifies a MySQL image that will be created with root privileges
# Note that MYSQL_ROOT_PASSWORD is Mandatory!
# We specify the 5.7.21'th version of MySQL from the docker repository.
# We are using mariadb because there's an apparent problem with permissions.
# See: https://github.com/docker-library/mysql/issues/69
image: mariadb:10.3.5
restart: always
environment:
MYSQL_ROOT_PASSWORD: "rootPassword"
MYSQL_USER: "ruby"
MYSQL_PASSWORD: "userPassword"
MYSQL_DATABASE: "dev"
ports:
- "3306:3306"
volumes:
- db-data:/var/lib/mysql/data
- ./db/rails_.sql:/docker-entrypoint-initdb.d/rails_.sql
elasticsearch:
image: docker.elastic.co/elasticsearch/elasticsearch:6.2.3
container_name: elasticsearch
environment:
- cluster.name=docker-cluster
- bootstrap.memory_lock=true
- "ES_JAVA_OPTS=-Xms512m -Xmx512m"
ulimits:
memlock:
soft: -1
hard: -1
volumes:
- elasticsearch:/usr/share/elasticsearch/data
ports:
- 9200:9200
networks:
- elk
logstash:
container_name: logstash
image: docker.elastic.co/logstash/logstash:6.2.3
volumes:
- ./elk/logstash/config/logstash.yml:/usr/share/logstash/config/logstash.yml
- ./elk/logstash/pipeline/logstash.conf:/etc/logstash/conf.d/logstash.conf
command: logstash -f /etc/logstash/conf.d/logstash.conf
ports:
- "5050:5050"
- "5228:5228"
environment:
- "ES_JAVA_OPTS=-Xms512m -Xmx512m"
networks:
- elk
depends_on:
- elasticsearch
kibana:
image: docker.elastic.co/kibana/kibana:6.2.3
volumes:
- ./elk/kibana/config/kibana.yml:/usr/share/kibana/config/kibana.yml
ports:
- "5601:5601"
networks:
- elk
depends_on:
- elasticsearch
app:
depends_on:
- db
environment:
RAILS_ENV: development
LOGSTASH_HOST: localhost
SECRET_MYSQL_HOST: 'db'
SECRET_MYSQL_DATABASE: 'dev'
SECRET_MYSQL_USERNAME: 'ruby'
SECRET_MYSQL_PASSWORD: 'userPassword'
command: bash -c "rm -f tmp/pids/server.pid && bundle exec rails s -p 3001 -b '0.0.0.0'"
stdin_open: true
tty: true
links:
- db
- logstash
volumes:
- "./:/var/www/rails"
ports:
- "3001:3001"
expose:
- "3001"
networks:
- elk
db-data:
driver: local
elasticsearch:
driver: local
networks:
elk:
driver: bridge
Any help is greatly appreciated 😊

Answer 1

By default Compose sets up a single network for your app. Each
container for a service joins the default network and is both
reachable by other containers on that network, and discoverable by
them at a hostname identical to the container name.
According to the docker-compose.yaml file, logstash container is accessible on logstash:5228 from other containers, so logging config on app container should be changed to:
config.log_level = :debug
config.lograge.enabled = true
config.lograge.formatter = Lograge::Formatters::Logstash.new
config.logger = LogStashLogger.new(type: :tcp, host: 'logstash', port: 5228, formatter: :json_lines, sync: true))
Check that logstash.conf is like this:
input {
tcp {
port => 5228
codec => json_lines
}
}
## Add your filters / logstash plugins configuration here
output {
elasticsearch {
hosts => ["elasticsearch:9200"]
}
}