README

DOCKER-VOLUMES-AND-MANAGING-DATA

Bind Mount, Dev Container & Ts Node Dev Cheat Sheet

Bind Mound Syntax For

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For Git Bash

docker run -p 5000:5000 --name ts-container -w //app -v ts-docker-logs://app/logs -v "//$(pwd)"://app/ -v //app/node_modules --rm ts-docker

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For Powershell

docker run -p 5000:5000 --name ts-container -w //app -v ts-docker-logs://app/logs -v "${PWD}://app" -v //app/node_modules --rm ts-docker

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For CMD

docker run -p 5000:5000 --name ts-container -w //app -v ts-docker-logs://app/logs -v "%cd%"://app/ -v //app/node_modules --rm ts-docker

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ts-node-dev command for Docker Container

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ts-node-dev --respawn --transpile-only --poll src/server.ts

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First Open A .devcontainer folder in the root of the project
Inside the .devcontainer folder open a file named devcontainer.json and paste the following code
Change the json name, container names and file directories according to your project

{
  "name": "ts-container",
  "image": "node:20",
  "workspaceFolder": "/app",
  "mounts": [
    // Bind mount for your local project
    "source=/c/Projects/next-level/Docker/docker-with-typescipt-backend,target=/app,type=bind",

    // Named volume for logs (similar to: -v ts-docker-logs://app/logs)
    "source=ts-docker-logs,target=/app/logs,type=volume",

    // Anonymous volume for node_modules (similar to: -v //app/node_modules)
    "target=/app/node_modules,type=volume"
  ],
  "runArgs": [
    "--name",
    "ts-container",
    "-p",
    "5000:5000",
    "--rm" // Automatically remove the container after exiting VS Code
  ],
  "postCreateCommand": "npm install"
}

Bind Mount, Dev Container & Ts Node Dev Cheat Sheet:

https://find-saminravi99.notion.site/Bind-Mount-Dev-Container-Ts-Node-Dev-Cheat-Sheet-117c48b8ac8c804aabb5ed0f09bc69a9?pvs=4

GitHub Link:

https://github.com/Apollo-Level2-Web-Dev/docker-with-typescript-backend/tree/module-3

3-1 Understanding Data Categories

Primary Data

Data management means managing data in a way that ensures its availability, reliability, and security throughout its lifecycle. It involves processes and practices for collecting, storing, organizing, and maintaining data effectively.
Application Environment size (code+environment) is called Primary Data For Docker
Container has its own internal file system but the image has no file system. thats why image is read only and container is read write.
container has its own file system so we can do read write but the image has no file system so we can not do write to it.

Temporary Data

Temporary data refers to data that is generated or used temporarily during the operation of an application or system. This type of data is often volatile and may be deleted or overwritten once it is no longer needed.
In the context of Docker, temporary data can be managed using anonymous volumes or tmpfs mounts, which provide a way to store data that exists only for the duration of the container's lifecycle.
a temporary data can be image of a container or a container itself. if we delete the container the data will be deleted as well. but if we want to keep the data even after deleting the container we can use named volumes or bind mounts.

Permanent data

permanent data is stored in named volumes or bind mounts, while temporary data can be stored in anonymous volumes or tmpfs mounts. suppose we want to change code and directly add in container. the image is not gonna get the code. If we delete the container the changes will be deleted right? but we want the file is gonna be there even if we delete the container. so we use bind mount or named volume for that.
lets guess a scenario, we want to make some changes and push inside a container and we want the changes to be there even after deleting the container. so we can use bind mount or named volume for that. and if we want to keep the logs even after deleting the container we can use named volume for that. and if we want to keep the code even after deleting the container we can use bind mount for that.

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3-2 Analyzing A Real App

logger is a kind of thing that we can observe the application logs even after deployed in live. in the project we have used a package called winston for logging. and the system is made like that if any error occurs it will create a file based on the html file and save it permanently. we will see the error lits and debug in development phase

3-3 Dockerizing The New Updates Of The App

build and run the docker

docker build -t ts-docker:v1 .

docker run -p 5000:5000 --rm --name ts-docker-container ts-docker:v1

lets remove the container by stopping the container

docker container stop ts-docker-container

lets start the container again

docker run -p 5000:5000 --rm --name ts-docker-container ts-docker:v1

this will remove the container and will not be able to see the logs as well because the if we delete the container the logs will be deleted too because the file system is deleted.
this is a problem right? we will lose all the logs if we update the code and create a new container. to solve this problem we will use bind mount or named volume. we will use named volume for logs and bind mount for code.
if we run in attach mode we can see the logs in the terminal but if we run in detached mode we can not see the logs in the terminal. so we need to use named volume for logs and bind mount for code.

docker run -p 5000:5000 --name ts-docker-container ts-docker:v1

do not auto remove container while stopping
stop the container

docker container stop ts-docker-container

start the container again in attach mode

docker container start --attach ts-docker-container

now the error logs will be there because we are running in attach mode and we can see the logs in the terminal but if we run in detached mode we can not see the logs in the terminal. so we need to use named volume for logs and bind mount for code.
in normal mode running it wil run in detach mode
lets delete all the container

docker container prune

as the container is deleted the logs will not be existing
this is still a problem.
we will solve this problem by using named volume for logs and bind mount for code.

3-4 Introduction To Docker Volumes

Problems of logs deletion after container deletion is solved by docker Volumes.

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Volumes are stored in a part of the host filesystem which is managed by docker. and we can use the volume in multiple containers as well. and we can also backup and restore the volumes. and we can also share the volumes between different containers. and we can also use the volumes in swarm mode as well. its like a folder of host machine which is mapped with container.

what we want to do ? the logs file never be deleted even after the container is deleted. the thing is a specific folder we want to store from the container.

here is the twist .

COPY . .

this is connected to the image build. and the volume work is connected with container.
we were used to take files from the host machine and store in container now we can also do something like copy from the container and keep in host machine.
we basically use docker VLOLUME

VOLUME ["/app/logs"]
# we are telling that bro hook the folder name of the container with the host machine(docker will handle it)

work of COPY .. is connected with image build
work of VOLUME[] is connected with container

FROM node:20

WORKDIR /app

COPY package.json .

RUN npm install

COPY . .

VOLUME ["/app/logs"]
# we are telling that bro hook the folder name of the container with the host machine

EXPOSE 5000

CMD ["npm", "run", "dev"]

now do the docker build and run the container

docker build -t ts-docker:v1 .

docker run -p 5000:5000 --rm --name ts-docker-container ts-docker:v1

even after adding volume the logs will be removed after deleting the container. lets solve this with named volume

3-5 Named Volumes & Removing Anonymous Volumes

The system will be like if any file changes in local machine then the changes will be reflected in the container and if any file changes in the container then the changes will be reflected in the local machine. and we can also use the same volume in multiple containers as well. and we can also backup and restore the volumes. and we can also share the volumes between different containers. and we can also use the volumes in swarm mode as well.

we need to know.

by default docker handles where it will keep the file in the local machine after the container is deleted.
we can also use bind mount (full control) for this purpose but bind mount is not recommended for production because it can cause performance issues. Its like we will connect container with our codebase and we will directly add the code in the container and we will directly see the changes in the container.

Volumes are two types

Anonymous volumes : These are created automatically by Docker when a container is run with a volume that doesn't have a name.
Named volumes : These are created explicitly by the user and can be reused across multiple containers.

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here is a twist. if we use named volumes the volume do not get connected with container so even if the container is deleted the volume will not be deleted. but if we use anonymous volumes the volume get connected with container so if the container is deleted the volume will also be deleted. so we need to use named volumes for logs and bind mount for code.
fo named volumes we need to the docker file like

FROM node:20

WORKDIR /app

COPY package.json .

RUN npm install

COPY . .

# VOLUME ["/app/logs"]
# anonymus volumes
# we are telling that bro hook the folder name of the container with the host machine

EXPOSE 5000

CMD ["npm", "run", "dev"]

but we will tell the named volume in docker run command like

docker run -p 5000:5000 --name ts-docker-container --rm -v ts-docker-logs:/app/logs  ts-docker:v2

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here the -v ts-docker-logs:/app/logs is the named volume and ts-docker:v2 is the image name. and we are telling that bro hook the folder name of the container with the host machine(docker will handle it) and we are also telling that if any file changes in local machine then the changes will be reflected in the container and if any file changes in the container then the changes will be reflected in the local machine. and we can also use the same volume in multiple containers as well. and we can also backup and restore the volumes. and we can also share the volumes between different containers. and we can also use the volumes in swarm mode as well.
in the docker file mentioning volumes will be always anonymous volumes.

Boomed !!!!! The Log remains even after deleting the container by using the named volume.

if we want we vcn remove the anonymous volume we can use the command

ts-docker-logs

# or 

docker volume prune