Docker Mastery: Section 6 - docker compose

• section6-52, 53

Udemy

• Docker Mastery: with Kubernetes +Swarm from a Docker Captain

• GitHub: udemy-docker-mastery

• 講師的YouTube

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Docker Compose

• Why: configure relationships between containers
• Why: save our docker container run settings in easy-to-read file
• Why: create one-liner developer environment startups
• Comprised of 2 separate but related things
• #1. YAML-formatted file that describes our solution options for:
  • containers
  • networks
  • volumes
• #2. A CLI tool docker-compose used for local dev/test automation with those YAML files

docker-compose.yml

• Compose YAML format has it’s oen versions: 1, 2, 2.1, 3, 3.1
• YAML file can be used with docker-compose command for local docker automation or..
• With docker directly in production wiht Swarm(as of v1.13)
• docker-compose --help

• docker-compose.yml is default filesname, but any can be used with docker-compose -f

• template.yml

  • yml 檔案，空格必須兩個或四個

     version: '3.1'  # if no version is specificed then v1 is assumed. Recommend v2 minimum
          
     services:  # containers. same as docker run
       servicename: # a friendly name. this is also DNS name inside network
         image: # Optional if you use build:
         command: # Optional, replace the default CMD specified by the image
         environment: # Optional, same as -e in docker run
         volumes: # Optional, same as -v in docker run
       servicename2:
          
     volumes: # Optional, same as docker volume create
          
     networks: # Optional, same as docker network create
    

• https://yaml.org/refcard.html

• https://yaml.org/start.html

docker-compose Documentation

• https://docs.docker.com/compose/compose-file/

dokcer-compose CLI

• CLI tool comes with Docker for Windows/Mac, but separate download for Linux
• Not a production-grade tool but ideal for local development and test
• Two most common commands are
  • docker-compose up # setup volumes/networks and start all comtainers
  • docker-compose down # stop all containers and remove cont/vol/net
• If all your porjects had a Dockerfile and docker-compose.yml then new developer onboarding would be:
  • git clone github.com/some/sofware
  • docker-compse up

docker-compose cli

• 主要兩個檔案

  • nginx.conf

     server {
           
     	listen 80;
           
     	location / {
           
     		proxy_pass         http://web;
     		proxy_redirect     off;
     		proxy_set_header   Host $host;
     		proxy_set_header   X-Real-IP $remote_addr;
     		proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
     		proxy_set_header   X-Forwarded-Host $server_name;
           
     	}
     }
    

  • docker-compose.yml

     version: '3'
           
     services:
       proxy:
         image: nginx:1.13 # this will use the latest version of 1.13.x
         ports:
           - '80:80' # expose 80 on host and sent to 80 in container
         volumes:
           - ./nginx.conf:/etc/nginx/conf.d/default.conf:ro # ro: read only
       web:
         image: httpd  # this will use httpd:latest
    

• docker-compose up

PS E:\Udemy\Docker Mastery\udemy-docker-mastery\compose-sample-2> docker-compose up
Creating network "compose-sample-2_default" with the default driver
Creating compose-sample-2_proxy_1 ... done                                                                                                             Creating compose-sample-2_web_1   ... done                                                                                                             Attaching to compose-sample-2_web_1, compose-sample-2_proxy_1
web_1    | AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 172.21.0.2. Set the 'ServerName' directive globally to suppress this message
web_1    | AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 172.21.0.2. Set the 'ServerName' directive globally to suppress this message
web_1    | [Wed Jan 15 09:59:44.121799 2020] [mpm_event:notice] [pid 1:tid 140154876986496] AH00489: Apache/2.4.41 (Unix) configured -- resuming normal operations
web_1    | [Wed Jan 15 09:59:44.121878 2020] [core:notice] [pid 1:tid 140154876986496] AH00094: Command line: 'httpd -D FOREGROUND'

• docker-compose up -d ：　背景執行

PS E:\Udemy\Docker Mastery\udemy-docker-mastery\compose-sample-2> docker-compose up -d
Starting compose-sample-2_proxy_1 ... done                                                                                                           Starting compose-sample-2_web_1   ... done       

• dokcer-compose ps : 看用　docker-compsoe 指令跑的有那些

PS E:\Udemy\Docker Mastery\udemy-docker-mastery\compose-sample-2> docker-compose ps
系統找不到指定的路徑。
          Name                   Command          State         Ports
----------------------------------------------------------------------------
compose-sample-2_proxy_1   nginx -g daemon off;   Up      0.0.0.0:80->80/tcp
compose-sample-2_web_1     httpd-foreground       Up      80/tcp

• docker-compse top

PS E:\Udemy\Docker Mastery\udemy-docker-mastery\compose-sample-2> docker-compose top
compose-sample-2_proxy_1
系統找不到指定的路徑。
 PID    USER   TIME                    COMMAND
----------------------------------------------------------------
11356   root   0:00   nginx: master process nginx -g daemon off;
11607   101    0:00   nginx: worker process

compose-sample-2_web_1
系統找不到指定的路徑。
 PID    USER   TIME        COMMAND
----------------------------------------
11357   root   0:00   httpd -DFOREGROUND
11613   bin    0:00   httpd -DFOREGROUND
11614   bin    0:00   httpd -DFOREGROUND
11615   bin    0:00   httpd -DFOREGROUND

• docker-compose down

PS E:\Udemy\Docker Mastery\udemy-docker-mastery\compose-sample-2> docker-compose down
Stopping compose-sample-2_proxy_1 ... done                                                                                                           Stopping compose-sample-2_web_1   ... done                                                                                                         Removing compose-sample-2_proxy_1 ... done                                                                                                       Removing compose-sample-2_web_1   ... done                                                                                                     Removing network compose-sample-2_default