hub.docker.com »3.6.76. pw: 3..8

docker-compose.yml way as below:

image

Doing more Grand Project than earlier, using docker-compose

A. Problems faced & debug-how: So, when 404 error came on localhost:5000, I did docker-compose logs app

then it showed below error:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 791, in urlopen
    response = self._make_request(
               ^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 497, in _make_request
    conn.request(
  File "/usr/lib/python3/dist-packages/urllib3/connection.py", line 395, in request
    self.endheaders()
  File "/usr/lib/python3.12/http/client.py", line 1331, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "/usr/lib/python3.12/http/client.py", line 1091, in _send_output
    self.send(msg)
  File "/usr/lib/python3.12/http/client.py", line 1035, in send
    self.connect()
  File "/usr/lib/python3/dist-packages/docker/transport/unixconn.py", line 27, in connect
    sock.connect(self.unix_socket)
PermissionError: [Errno 13] Permission denied

is /usr/lib/python3.12/http/client.py referring to path inside container?

Chatgpt: So, /usr/lib/python3.12/http/client.py in the error message is not referring to a path inside the Docker container. It’s actually a path on your host machine (Ubuntu) where Python’s standard library files are located. Breakdown of the Error

This error occurs because:

PermissionError: [Errno 13] Permission denied: This indicates that a process on your host (not inside the container) is trying to access a Unix socket without the necessary permissions.

Docker Unix Socket: The line sock.connect(self.unix_socket) in docker/transport/unixconn.py shows that this process is trying to connect to Docker’s Unix socket (usually located at /var/run/docker.sock). The Unix socket allows the Docker client to communicate with the Docker daemon, and the permission error means the user trying to access it doesn’t have permission to use this socket.

Why This Happens in Docker Compose ? - In Docker Compose, if your application code (or some package it depends on) tries to interact with the Docker API or other Docker services, it needs permission to access the Docker socket. When running Docker commands or interacting with Docker from a process, permissions are required for /var/run/docker.sock

image

now, we can see above, docker-compose logs app RESULT is lot cleaner

B. Then after,

So, docker-compose.yml is LHS-of-3rd-pic-from-top and lets see how it compiles: image

yei mathi ko fig lai ramrari herema yo blog-post ko sabse tala ko schematicDgm le ni bujhauna nasalne kura bujhaux, schemticDgm bullshit hernai pardaina!

btw, dockerfile, app.py wa index.html kunai change garepaxi tesko effect dekhna docker-compose lai down garera feri up garna pardaina, just refresh gare hunxa; for deeper changes ko effect herna chai rarely matra garnu parna sakxa,

Then, how does app.py as client interacts w mysql server & also about how port expose is co-ordinated image

oh, btw: sudo docker-compose ps // to check if my container services are running image

sudo docker-compose down // if only I want to stop services n remove containers

&, Making docker image persistent on url -meaning I dont need to have sudo docker-compose up in my machine to come in browser, then look here even tho I have to find another way to put sudo docker-compose up everytime ON in cloud

more about entering inside specific container- in this case, postgres container

AFTER docker exec -it vivekproject2_db_1 bash

comes

root@999f799c7d38:/#

there I have to: psql -U django_user -d django_db

then comes django_db=#,

image

\q from exiting from postgresql-inside

docker exec -it ls -R /path/to/directory To find what files are generated inside the

docker exec -it vivekproject2_web_1 python manage.py makemigrations #NOTICE GAR web ma ho, db ma haina

docker exec -it vivekproject2_web_1 python manage.py migrate #le models.py ma va lai database ma actual table haru banaidini ho

_sometimes, docker-compose may build on cached image, so even tho 
just refreshing browser may help on simple changes like changing display text etc on html, 

but it maynot work for (for eg) if I update app.py, 
for that case, refreshing browser or 
even sudo docker-compose down n again sudo docker-compose up -d is NOT enough, 
for that sudo docker-compose down n sudo docker-compose up --build -d 

and when doing docker-compose down, we want to remove all images of containers' cache 
so that it does not docker-compose up from cache, then we should do:
sudo docker-compose down --rmi all_

u can skip looking at this below schematic dgm:

image

this below dgm is about segregating docker container for production ie. while developing stage from actual live one. so not very critical to know:

dockerWorkFlow