Dockerfile for microservices - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the Dockerfile line to specify the base image for a Node.js microservice.

Microservices

FROM [1]

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Amysql:8

Bpython:3.12

Cubuntu:latest

Dnode:18-alpine

Attempts:

3 left

💡 Hint

Common Mistakes

Using a base image for a different language or service like Python or MySQL.

Using a heavy base image when a lightweight one is preferred.

The FROM instruction sets the base image. For a Node.js microservice, node:18-alpine is a lightweight and common choice.

2fill in blank

medium

Complete the Dockerfile command to copy the application source code into the container.

Microservices

COPY [1] /app

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Apackage.json

B.

Cnode_modules

DDockerfile

Attempts:

3 left

💡 Hint

Common Mistakes

Copying only package.json without source files.

Copying node_modules which should be installed inside the container.

The COPY . /app command copies all files from the current directory into the container's /app folder.

3fill in blank

hard

Fix the error in the Dockerfile command to install dependencies using npm.

Microservices

RUN npm [1]

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Ainstall

Bstart

Cbuild

Dtest

Attempts:

3 left

💡 Hint

Common Mistakes

Using npm start which runs the app, not installs packages.

Using npm build which is not a standard npm command.

The RUN npm install command installs all dependencies listed in package.json.

4fill in blank

hard

Fill both blanks to expose the correct port and set the container's working directory.

Microservices

WORKDIR [1]
EXPOSE [2]

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A/app

B3000

C/usr/src/app

D8080

Attempts:

3 left

💡 Hint

Common Mistakes

Setting a working directory that doesn't match the copied files.

Exposing the wrong port that the app does not listen on.

WORKDIR /app sets the working directory inside the container. EXPOSE 3000 tells Docker the app listens on port 3000.

5fill in blank

hard

Fill the blanks to define the command that starts the Node.js microservice.

Microservices

CMD ["[1]", "[2]"]

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Anode

Bapp.js

Cserver.js

Dnpm

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'npm' as the first command in this JSON array format.

Using 'app.js' when the main file is 'server.js' or vice versa.

The CMD instruction defines the command to run the app. Usually, node server.js starts the service. Using npm here is incorrect for this format.