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| # Intro to DevOps - Week 2 Project Starter Code | ||
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| # Goal | ||
| ## Containerize two Flask web services and use Docker Compose to orchestrate them | ||
| ### For our week 2 project, we will be containerizing two Flask apps, one generates a Random Quote, and the other service consumes this and displays it on a neat front end. | ||
| ### Then we shall be using Docker Swarm to orchestrate the services to achieve our end goal. This exercise will help us understand a real-world use case of Docker and Docker Swarm better. | ||
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| ## Prerequisites | ||
| <br> Basic knowledge of programming and APIs is needed. </br> | ||
| <br> The tutorial on how to start a Docker Container is here - https://docs.docker.com/language/python/build-images/ </br> | ||
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| ## Environment Setup - Things needed to run Project 2 | ||
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| Install Docker Desktop from here - https://docs.docker.com/desktop/. | ||
| Choose the distribution of your choice but we will be using Windows. | ||
| Docker compose, the CLI tools come along with Docker Desktop. | ||
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| Download the starter file from here - (https://github.com/sb2nov/corise-zignite-devops-cc) | ||
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| Test if Docker is installed by running the following command in the terminal | ||
| ``` | ||
| docker run hello-world | ||
| ``` | ||
| If everything is installed right you get a response 'Hello from Docker! We are all good to go, let's start off our Week 2 project then! | ||
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| # Steps | ||
| Download or Clone the repo https://github.com/sb2nov/corise-zignite-devops-cc/tree/starter_code | ||
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| Create a Docker File within the cloned Repository | ||
| ``` | ||
| vim Dockerfile | ||
| ``` | ||
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| The Python application directory structure should now look like the following: | ||
| ``` | ||
| quote_gen | ||
| |____ static | ||
| |____ templates | ||
| |____ app.py | ||
| |____ requirements.txt | ||
| |____ Dockerfile | ||
| ``` | ||
| ``` | ||
| quote_disp | ||
| |____ static | ||
| |____ templates | ||
| |____ app.py | ||
| |____ requirements.txt | ||
| |____ Dockerfile | ||
| ``` | ||
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| Let's create a basic container in each of the directories | ||
| ``` | ||
| FROM python:3.8-slim-buster | ||
| COPY . /app | ||
| WORKDIR /app | ||
| RUN pip install -r requirements.txt | ||
| ENTRYPOINT [ "python" ] | ||
| CMD [ "app.py" ] | ||
| ``` | ||
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| Let's see what each of these commands means - | ||
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| <br> FROM python - gets a Python distribution from Docker Images </br> | ||
| <br> WORKDIR Changes the working directory </br> | ||
| <br> COPY Copies the content of Workdir into a new directory </br> | ||
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| Build the Docker Images - | ||
| ``` | ||
| cd quote_gen | ||
| ``` | ||
| ``` | ||
| docker build --tag quote-gen-service . | ||
| ``` | ||
| ``` | ||
| cd quote_disp | ||
| ``` | ||
| ``` | ||
| docker build --tag quote-disp-service . | ||
| ``` | ||
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| Run Docker Container | ||
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| With the Docker images created, let’s get the containers up and running | ||
| ``` | ||
| cd quote_gen | ||
| docker run --name quote-gen-container -p 84:84 quote-gen-service | ||
| ``` | ||
| ``` | ||
| cd quote_disp | ||
| docker run --name quote-disp-container -p 85:85 quote-disp-service | ||
| ``` | ||
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| Let’s run docker container ls to get a list of containers created | ||
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| Create Docker Network | ||
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| ``` | ||
| docker network create quote-network | ||
| ``` | ||
| and running the followng command | ||
| ``` | ||
| docker network inspect quote-network | ||
| ``` | ||
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| Let's add our containers to the quote-network | ||
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| ``` | ||
| docker network connect quote-network quote-gen-container | ||
| docker network connect quote-network quote-disp-container | ||
| docker network inspect quote-network | ||
| ``` | ||
| You see the following output - | ||
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| ``` | ||
| [ | ||
| { | ||
| "Name": "quote-network", | ||
| "Id": "999c81eb87c4b687921ea474abd1e59875447a96d2477ae190dcccc40f882d8a", | ||
| "Created": "2023-04-24T04:45:15.9081804Z", | ||
| "Scope": "local", | ||
| "Driver": "bridge", | ||
| "EnableIPv6": false, | ||
| "IPAM": { | ||
| "Driver": "default", | ||
| "Options": {}, | ||
| "Config": [ | ||
| { | ||
| "Subnet": "172.19.0.0/16", | ||
| "Gateway": "172.19.0.1" | ||
| } | ||
| ] | ||
| }, | ||
| "Internal": false, | ||
| "Attachable": false, | ||
| "Ingress": false, | ||
| "ConfigFrom": { | ||
| "Network": "" | ||
| }, | ||
| "ConfigOnly": false, | ||
| "Containers": { | ||
| "2636f9d91e5468029981d499fc7e0b46a204d8fc3b16e5e7e6e912651ce8dd4a": { | ||
| "Name": "quote-disp-container", | ||
| "EndpointID": "a4eb7320b1585b43a10499a73059e8f50fb8d5e33f9aee433b1b7e5e0b1dee85", | ||
| "MacAddress": "02:42:ac:13:00:03", | ||
| "IPv4Address": "172.19.0.3/16", | ||
| "IPv6Address": "" | ||
| }, | ||
| "557e1ff9f220704ad9f76d94ebe5d3c433dc20ed44798831af6f2bfe68176583": { | ||
| "Name": "quote-gen-container", | ||
| "EndpointID": "191f2b22ec8a92256d47b152a06eeaeead9f05a13799f48d43d9c5410daceebb", | ||
| "MacAddress": "02:42:ac:13:00:02", | ||
| "IPv4Address": "172.19.0.2/16", | ||
| "IPv6Address": "" | ||
| } | ||
| }, | ||
| "Options": {}, | ||
| "Labels": {} | ||
| } | ||
| ] | ||
| ``` | ||
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| Let's see if the dockers are communicating | ||
| ``` | ||
| StatusCode : 200 | ||
| StatusDescription : OK | ||
| Content : <link rel="stylesheet" href="/static/css/style.css"> | ||
| <title>Docker App Quote </title> | ||
| <div class="screen"> | ||
| <div class="screen-image"></div> | ||
| <div class="screen-overlay"></div> | ||
| <div class="screen-... | ||
| RawContent : HTTP/1.1 200 OK | ||
| Connection: close | ||
| Content-Length: 503 | ||
| Content-Type: text/html; charset=utf-8 | ||
| Date: Mon, 24 Apr 2023 04:51:36 GMT | ||
| Server: Werkzeug/2.2.3 Python/3.8.16 | ||
| <link rel="stylesheet" hre... | ||
| Forms : {} | ||
| Headers : {[Connection, close], [Content-Length, 503], [Content-Type, text/html; charset=utf-8], [Date, Mon, 24 Apr | ||
| 2023 04:51:36 GMT]...} | ||
| Images : {} | ||
| InputFields : {} | ||
| Links : {@{innerHTML=; innerText=; outerHTML=<A class=link href="https://youtube.com/@Hyperplexed" | ||
| target=_blank></A>; outerText=; tagName=A; class=link; href=https://youtube.com/@Hyperplexed; | ||
| target=_blank}} | ||
| ParsedHtml : mshtml.HTMLDocumentClass | ||
| RawContentLength : 503 | ||
| ``` | ||
| They seem to be working! | ||
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| Let's create a Docker Compose Manifest to orchestrate our services | ||
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| ``` | ||
| version: "3.7" | ||
| services: | ||
| web1: | ||
| build: ./quote_gen | ||
| container_name: gen | ||
| ports: | ||
| - "5000:5000" | ||
| web2: | ||
| build: ./quote_disp | ||
| container_name: disp | ||
| expose: | ||
| - "5000" | ||
| ports: | ||
| - "5001:5000" | ||
| depends_on: | ||
| - web1 | ||
| ``` | ||
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| Let's understand the commands in our Compose YAML file - | ||
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| version: - Compose file versions that run our Docker Compose | ||
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| services: the components or services that run within the docker-compose manifest | ||
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| Eg - Our website is a service, we can have a database service or a unit testing service, an application server, etc | ||
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| Under service, we have our website - service name, build - looks for a docker image, context - specifies where to look | ||
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| ports: -80:80 | ||
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| Run Docker Compose | ||
| ``` | ||
| docker-compose up | ||
| ``` | ||
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| ``` | ||
| [+] Running 3/3 | ||
| - Network corise-zignite-devops-cc_default Created 0.8s | ||
| - Container gen Created 0.6s | ||
| - Container disp Created 0.1s | ||
| Attaching to disp, gen | ||
| gen | * Serving Flask app 'app' | ||
| gen | * Debug mode: on | ||
| gen | WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead. | ||
| gen | * Running on all addresses (0.0.0.0) | ||
| gen | * Running on http://127.0.0.1:5000 | ||
| gen | * Running on http://172.26.0.2:5000 | ||
| gen | Press CTRL+C to quit | ||
| gen | * Restarting with stat | ||
| gen | * Debugger is active! | ||
| gen | * Debugger PIN: 930-011-562 | ||
| disp | * Serving Flask app 'app' | ||
| disp | * Debug mode: on | ||
| disp | WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead. | ||
| disp | * Running on all addresses (0.0.0.0) | ||
| disp | * Running on http://127.0.0.1:5000 | ||
| disp | * Running on http://172.26.0.3:5000 | ||
| disp | Press CTRL+C to quit | ||
| disp | * Restarting with stat | ||
| disp | * Debugger is active! | ||
| disp | * Debugger PIN: 112-266-209 | ||
| ``` | ||
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| ## You can find a link to the Docker Compose tutorial https://docs.docker.com/compose/gettingstarted/ |