Course 31 - Dive Into Docker | Episode 7: Building, Running, and Syncing Flask Applications

In this lesson, you’ll learn about: Docker CLI workflows, container management, live development, and debugging techniques1. Image Management & Docker CLI WorkflowYou start by working with Docker image lifecycle operations:🔹 Build Imagesdocker build -t myapp:1.0 .Uses Dockerfile instructionsLeverages layer caching → faster rebuilds🔹 Tagging Imagesdocker tag myapp:1.0 username/myapp:1.0Used for version controlPrepares image for sharing🔹 DockerHub WorkflowLogin → docker loginPush → docker pushPull → docker pull👉 Enables sharing across machines and teams2. Running & Managing Containers🔹 Core Run Flagsdocker run -it -p 5000:5000 -e FLASK_APP=app.py myapp FlagPurpose-itInteractive terminal-pPort mapping-eEnvironment variables🔹 Detached Modedocker run -d myappRuns container in backgroundFrees terminal🔹 Monitoring Containersdocker logs → view logsdocker stats → live performance metrics🔹 Restart Policiesdocker run --restart on-failure myappAutomatically restarts crashed containersImproves reliability in production3. Live Development with Volumes🔹 Volume Mountingdocker run -v $(pwd):/app myappSyncs local code into containerEnables real-time updates🔹 Flask Live ReloadSet:FLASK_DEBUG=1Automatically reloads server on file changes4. Debugging & Container Access🔹 Enter Running Containerdocker exec -it container_id bashInspect filesystemRun debugging commands🔹 Run One-Off CommandsRun testsCheck logsInspect environment5. Platform Compatibility Issues⚠️ File Watch Issues (Windows/Mac)Inotify may not work properly in some environments✅ Solution:Use slim Python images instead of Alpine👉 Improves:File syncingStability of live reload6. File Permissions HandlingFiles created inside containers may become root-ownedFix by aligning:container userhost userKey TakeawaysDocker builds are faster using layer cachingImages are portable via DockerHubContainers can be:interactive (-it)background (-d)Volumes enable real-time developmentdocker exec is essential for debuggingOS differences can affect file syncingBig PictureYou’re now operating at a professional Docker workflow level:Building and publishing imagesRunning production-like containersDebugging live systemsDeveloping without rebuild delaysYou can listen and download our episodes for free on more than 10 different platforms:https://linktr.ee/cybercode_academy