Lab #15: Logs Command

The docker-compose logs command help to see the service logs.

Pre-requisite:

Tested Infrastructure

Platform	Number of Instance	Reading Time
Play with Docker	1	5 min

Pre-requisite

Create an account with DockerHub
Open PWD Platform on your browser
Click on Add New Instance on the left side of the screen to bring up Alpine OS instance on the right side

Assignment

Create a docker-compose.yml file
Bringing up the containers
Checking Service logs
Follow log output
Checking last two line logs

Create a docker-compose.yml file

version: '3.7'
services:
  #Nginx Service
   webserver:
     image: nginx:alpine
     container_name: Nginx
     restart: unless-stopped
     ports:
       - "80:80"
       - "443:443"
   dbserver:
     image: mysql:5.7
     container_name: Mysqldb
     restart: unless-stopped
     ports:
       - "3306:3306"
     environment:
       MYSQL_ROOT_PASSWORD: Pa$$w0rd
       MYSQL_USER: test
       MYSQL_PASSWORD: Pa$$w0rd123
       MYSQL_DATABASE: test 
     volumes:
       - db_data:/var/lib/mysql
volumes:
  db_data:

Bringing up the containers

$ docker-compose up -d

Checking container status

$ docker-compose ps
 Name               Command             State                    Ports                  
----------------------------------------------------------------------------------------
Mysqldb   docker-entrypoint.sh mysqld   Up      0.0.0.0:3306->3306/tcp, 33060/tcp       
Nginx     nginx -g daemon off;          Up      0.0.0.0:443->443/tcp, 0.0.0.0:80->80/tcp   

Checking Service logs

$ docker-compose logs
Attaching to Mysqldb, Nginx
Mysqldb      | Initializing database
Mysqldb      | 2019-10-04T08:45:43.926007Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
Mysqldb      | 2019-10-04T08:45:44.832102Z 0 [Warning] InnoDB: New log files created, LSN=45790
Mysqldb      | 2019-10-04T08:45:44.942095Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
Mysqldb      | 2019-10-04T08:45:45.017777Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: 5acfb862-e683-11e9-bee0-0242ac130003.

Follow log output

Access the nginx while check the logs, to see live logs.

$ docker-compose logs -f webserver
Attaching to Nginx
Nginx        | 172.18.0.1 - - [04/Oct/2019:08:48:42 +0000] "GET / HTTP/1.1" 200 612 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.90 Safari/537.36" "-"

Checking last two line logs for a service

$ docker-compose logs  --tail="2"  webserver
Attaching to Nginx
Nginx        | 2019/10/04 08:48:43 [error] 7#7: *1 open() "/usr/share/nginx/html/favicon.ico" failed (2: No such file or directory), client: 172.18.0.1, server: localhost, request: "GET /favicon.ico HTTP/1.1", host: "ip172-18-0-46-bmbfiuol9uvg00c4s2s0-80.direct.labs.play-with-docker.com", referrer: "http://ip172-18-0-46-bmbfiuol9uvg00c4s2s0-80.direct.labs.play-with-docker.com/"
Nginx        | 172.18.0.1 - - [04/Oct/2019:08:48:43 +0000] "GET /favicon.ico HTTP/1.1" 404 555 "http://ip172-18-0-46-bmbfiuol9uvg00c4s2s0-80.direct.labs.play-with-docker.com/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.90 Safari/537.36" "-"

Contributor

Savio Mathew

Next » Lab #16: Port Command