DevOps Classroomnotes 26/Nov/2022

YAML/JSON

• Refer Here for yaml/json tutorial
• JSON files generally have extension of .json and yaml files have extension of .yaml or .yml
• Data in json/yaml is written in form of name/value pairs

<name>: <value>
        scalar
           number
           boolean
           text
        complex
           list/array 
           map/object

• Text

movie: "Wakanda forever"

yaml:
<name>: <value> ["<value>"]
movie: Wakanda forever

json
"name":"value"

"movie":"Wakanda forever" 

• number

price: 350.98

yaml:
<name>: <value> 
price: 350

json:
"<name>": <value>
"price": 350

• boolean:

is3D: true

yaml:
<name>: <value> [true/false/yes/no]
is3D: yes

json:
"<name>": <value> [true/false]
"is3D": true

• Complex – list
• json:
  • syntax: `’‘: [, … ,]
• Complex – map/object
  • syntax: {"<name1>": <value1>,.., "<namen>": <valuen> }
• Example – json:

{
    "name": "Wakanda Forever",
    "price": 350,
    "is3D": true,
    "actors": ["Wright", "Jordan", "Angela"]
}

• YAML

---
name: Wakanda Forever
price: 350
is3D: yes
actors:
  - Wright
  - Jordan
  - Angela

• JSON

{
    "movies": [
        {
            "name": "Wakanda Forever",
            "price": 350,
            "is3D": true,
            "actors": ["Wright", "Jordan", "Angela"]
        },
        {
            "name": "Kantara",
            "price": 350,
            "is3D": false,
            "actors": ["Rishab Shetty", "Kishore", "Achyut"]
        }
    ],
    "places": [
        {
            "name": "vizag",
            "spots": [  "RK Beach", "Rushi konda"  ] 
        },
        {
            "name": "Vijayawada",
            "spots": ["Kanaka durga temple", "Krishna river"]
        }
    ]
}

• YAML

---
movies:
  - name: Wakanda forever
    price: 350
    is3D: yes
    actors: 
      - Wright
      - Jordan
      - Angela
  - name: Kantara
    price: 350
    is3D: no
    actors:
      - Rishab
      - Kishore
      - Achyut
places:
  - name: Vizag
    spots:
      - RK Beach
      - Rushi konda
  - name: Vijayawada
    spots:
      - Kanaka durga temple
      - Krishna River

• In docker compose we create a file docker-compose.yml where we represent the multi container configuration as per our needs.
• Generally docker-compose is used for running a full system in developer environments.
• Docker-compose installation:
  • Install docker
  • On mac and windows once we install docker, docker-compose is part of the installation, so no need for any extra steps
  • on linux machines we need to install docker-compose separtely
  • For docker-compose on linux instances Refer Here
• The older versions the docker compose had docker-compose. Now docker compose is a plugin to docker, so it behaves like sub command (just like docker network, docker volume)
• Refer Here for the specification of the docker compose
• Refer Here for the latest yaml reference
• Refer Here for service configuration reference

Create a simple docker compose file to run a nginx container

• Refer Here for our first compose file with nginx container running on port 80 exposed to port 8081
  
• When we performed up docker compose has created a network
• lets destroy docker compose down
• Lets make changes in the docker compose file to create the network with the specifications provided by us.
• Refer Here for the network configuration
• Refer Here for the changes to add our own bridge network
  
• Lets add one more container which is mysql

docker container run -d --name mysql -e MYSQL_ROOT_PASSWORD=password -e MYSQL_DATABASE=test -e MYSQL_USER=directdevops -e MYSQL_PASSWORD=directdevops mysql:5.6

• for the changes done