AIT SAD 2022

# Workshop: Postgres

# Situation 1: without volume

  • create Postgres container
docker run -d -e POSTGRES_PASSWORD=1234 postgres:14.1
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  • go inside container
docker ps
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output

CONTAINER ID   IMAGE                      COMMAND                  CREATED          STATUS          PORTS                    NAMES
407e03ea3d60   postgres:14.1              "docker-entrypoint.s…"   6 seconds ago    Up 2 seconds    5432/tcp                 youthful_driscoll
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2
docker exec -it 407 bash
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psql -U postgres
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  • create db
CREATE DATABASE mydb;
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  • list db
\l
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output




 







                                 List of databases
   Name    |  Owner   | Encoding |  Collate   |   Ctype    |   Access privileges
-----------+----------+----------+------------+------------+-----------------------
 mydb      | postgres | UTF8     | en_US.utf8 | en_US.utf8 |
 postgres  | postgres | UTF8     | en_US.utf8 | en_US.utf8 |
 template0 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
 template1 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
(4 rows)
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  • use db
\c mydb
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  • create table
CREATE TABLE users(
    name VARCHAR(50) PRIMARY KEY,
    age INT NOT NULL
);
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\dt
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output




 


         List of relations
 Schema | Name  | Type  |  Owner
--------+-------+-------+----------
 public | users | table | postgres
(1 row)
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  • insert a user
INSERT INTO users (name, age)
VALUES ('Chaky', 22);
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2
SELECT * FROM users;
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output



 


 name  | age
-------+-----
 Chaky |  22
(1 row)
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  • exit from psql
exit
1
  • exit from container
exit
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  • remove container
docker rm 407 -f
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  • make sure that our data already gone
docker run -d -e POSTGRES_PASSWORD=1234 postgres:14.1
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output

95036a5a81525b5bab2feb5aec44dff76b936af20094d835c675b873272c3fbb
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  • next
docker exec -it 950 bash
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psql -U postgres
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  • list databases
\l
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output

                                 List of databases
   Name    |  Owner   | Encoding |  Collate   |   Ctype    |   Access privileges
-----------+----------+----------+------------+------------+-----------------------
 postgres  | postgres | UTF8     | en_US.utf8 | en_US.utf8 |
 template0 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
 template1 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
(3 rows)
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  • exit and remove container
exit
exit
docker rm 950 -f
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# Situation 2: with volume

  • create Postgres container
docker run -d -e POSTGRES_PASSWORD=1234 -v postgres-volume:/var/lib/postgresql/data postgres:14.1
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output

e2d46d3faafe2790f5db67335d8566e153ffca857d667a5513b53271adc844de
1
  • list volume
docker volume ls
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output

DRIVER    VOLUME NAME
local     postgres-volume
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2
  • create database, table and insert data
docker exec -it e2d bash
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psql -U postgres
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CREATE DATABASE mydb;
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\c mydb
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CREATE TABLE users(
    name VARCHAR(50) PRIMARY KEY,
    age INT NOT NULL
);
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INSERT INTO users (name, age)
VALUES ('Chaky', 22);
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2
SELECT * FROM users;
1

output



 


 name  | age
-------+-----
 Chaky |  22
(1 row)
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  • remove container and create again
exit
exit
docker rm e2d -f
docker run -d -e POSTGRES_PASSWORD=1234 -v postgres-volume:/var/lib/postgresql/data postgres:14.1
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output

d556ada570b54aec1de343b04ff762104c7cda82aee2da6f1dd840274d5a7d4f
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  • go inside container
docker exec -it d55 bash
psql -U postgres
\c mydb
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SELECT * FROM users;
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output



 


 name  | age
-------+-----
 Chaky |  22
(1 row)
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  • remove container, volume, and finish this lab
exit
exit
docker rm d55 -f
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docker volume rm postgres-volume
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