Deploying to Deno Deploy - Step-by-Step Execution

Concept Flow - Deploying to Deno Deploy

Write Deno app code

↓

Test locally with deno run

↓

Push code to GitHub repo

↓

Create Deno Deploy project

↓

Deno Deploy builds and deploys

↓

App is live on Deno Deploy URL

This flow shows how you write your Deno app, test it locally, then deploy it by connecting your GitHub repo to Deno Deploy, which builds and hosts your app.

Execution Sample

Deno

import { serve } from "https://deno.land/std@0.177.0/http/server.ts";

serve(() => new Response("Hello from Deno Deploy!"));

A simple Deno server that responds with a greeting message when deployed.

Execution Table

Step	Action	Evaluation	Result
1	Import serve function	Imports HTTP server from Deno standard library	serve function ready to use
2	Call serve with handler	Handler function passed; server listens for incoming requests	Server starts listening on default port
3	Request received	Handler runs	Response "Hello from Deno Deploy!" sent
4	Push code to GitHub	Code uploaded	Ready for deployment
5	Deno Deploy builds	Build succeeds	App deployed and live
6	Access app URL	Browser requests app	Displays "Hello from Deno Deploy!"
7	End	No more steps	Deployment complete

💡 Deployment completes after app is live and responding on Deno Deploy URL

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 5	Final
serve	undefined	function imported	function imported	function imported	function imported
handler response	undefined	handler function passed	Response object created and sent	Response object created and sent	Response object created and sent
deployment status	not started	not started	not started	built and deployed	live

Key Moments - 3 Insights

Why do we push code to GitHub before deploying to Deno Deploy?

Deno Deploy connects to your GitHub repo to fetch your code and build it automatically, as shown in execution_table step 4 and 5.

What happens when the serve function is called?

It starts an HTTP server that listens for requests and runs the handler function to respond, as seen in execution_table step 2 and 3.

How do we know the app is live after deployment?

Accessing the app URL returns the expected response, confirming deployment success (execution_table step 6).

Visual Quiz - 3 Questions

Look at the execution_table, what is the result after step 3?

A Response "Hello from Deno Deploy!" sent

B Server starts listening on default port

C Code uploaded to GitHub

D App deployed and live

💡 Hint

Check the 'Result' column for step 3 in the execution_table

At which step does Deno Deploy build and deploy the app?

A Step 2

B Step 5

C Step 4

D Step 6

💡 Hint

Look for 'Deno Deploy builds' in the 'Action' column of execution_table

If you skip pushing code to GitHub, what changes in the deployment flow?

A The app will deploy but show errors

B The server will start locally anyway

C Deno Deploy cannot fetch your code to build

D The app URL will be different

💡 Hint

Refer to key_moments about why pushing code to GitHub is necessary

Concept Snapshot

Deploying to Deno Deploy:
1. Write your Deno app using serve from std library.
2. Test locally with 'deno run'.
3. Push code to GitHub.
4. Connect GitHub repo to Deno Deploy.
5. Deno Deploy builds and hosts your app.
6. Access your app via the provided URL.

Full Transcript

Deploying to Deno Deploy involves writing a Deno app, testing it locally, then pushing the code to a GitHub repository. Deno Deploy connects to this repository, builds the app, and hosts it live. The serve function from Deno's standard library creates an HTTP server that responds to requests. After deployment, accessing the app URL shows the app running live. This process ensures your code is safely stored and automatically deployed by Deno Deploy.

Practice

1. What is the main purpose of deno deploy in Deno?

easy

A. To run Deno scripts locally without internet

B. To install Deno on your computer

C. To create a new Deno project template

D. To publish your Deno app online as a serverless function

Solution

1. Step 1: Understand the command purpose

   deno deploy is used to publish apps online, not for local installs or running scripts.

2. Step 2: Match the description to the command

   Publishing as serverless functions matches the description of deno deploy.

3. Final Answer:

   To publish your Deno app online as a serverless function -> Option D

4. Quick Check:

   deno deploy = publish app online [OK]

Hint: Remember: deploy means publish online [OK]

Common Mistakes:

• Confusing deploy with install
• Thinking deploy runs code locally
• Assuming deploy creates projects

2. Which of the following is the correct command to deploy a Deno project located in the current folder?

easy

A. deno deploy --install

B. deno deploy .

C. deno run deploy

D. deno start deploy

Solution

1. Step 1: Identify the correct deploy syntax

   The command deno deploy . tells Deno to deploy the current folder project.

2. Step 2: Check other options for correctness

   Options B, C, and D are invalid commands for deployment.

3. Final Answer:

   deno deploy . -> Option B

4. Quick Check:

   Deploy current folder = deno deploy . [OK]

Hint: Use dot (.) to deploy current folder [OK]

Common Mistakes:

• Using deno run instead of deno deploy
• Adding wrong flags like --install
• Using deno start which is not a Deno command

3. Given this command run in your terminal: deno deploy https://github.com/user/myapp, what will happen?

medium

A. Deno will deploy the app from the GitHub repo URL as a serverless app

B. Deno will clone the repo locally but not deploy

C. Deno will throw a syntax error because URLs are not allowed

D. Deno will run the app locally without deploying

Solution

1. Step 1: Understand deploying from a repo URL

   Deno Deploy supports deploying directly from GitHub repo URLs.

2. Step 2: Analyze the command behavior

   The command deploys the app serverlessly from the given URL, no local clone or syntax error occurs.

3. Final Answer:

   Deno will deploy the app from the GitHub repo URL as a serverless app -> Option A

4. Quick Check:

   Deploy from URL = deploy serverless app [OK]

Hint: Deploy accepts GitHub URLs directly [OK]

Common Mistakes:

• Thinking deploy clones repo locally
• Assuming URLs cause syntax errors
• Confusing deploy with local run

4. You run deno deploy myapp but get an error saying "No such file or directory". What is the most likely cause?

medium

A. You forgot to install Deno before deploying

B. The internet connection is down

C. The folder or file named 'myapp' does not exist in the current directory

D. You need to run deno run myapp first

Solution

1. Step 1: Interpret the error message

   "No such file or directory" means the path 'myapp' is missing locally.

2. Step 2: Match error to cause

   Since deploy expects a valid path or URL, missing folder causes this error.

3. Final Answer:

   The folder or file named 'myapp' does not exist in the current directory -> Option C

4. Quick Check:

   Missing folder = No such file error [OK]

Hint: Check folder exists before deploying [OK]

Common Mistakes:

• Assuming Deno is not installed
• Blaming internet connection for local file errors
• Confusing deploy with run command

5. You want to deploy a Deno app that uses environment variables securely on Deno Deploy. Which approach is best?

hard

A. Set environment variables in Deno Deploy dashboard and access them via Deno.env.get()

B. Hardcode environment variables in your source code before deploying

C. Pass environment variables as command line arguments to deno deploy

D. Store environment variables in a local .env file and deploy it with your app

Solution

1. Step 1: Understand environment variable best practices

   Hardcoding or deploying .env files risks exposing secrets publicly.

2. Step 2: Use Deno Deploy features

   Deno Deploy dashboard allows secure environment variable setup accessed by Deno.env.get().

3. Final Answer:

   Set environment variables in Deno Deploy dashboard and access them via Deno.env.get() -> Option A

4. Quick Check:

   Secure env vars = dashboard + Deno.env.get() [OK]

Hint: Use dashboard for env vars, not code files [OK]

Common Mistakes:

• Hardcoding secrets in code
• Uploading .env files publicly
• Trying to pass env vars via deploy command