First Dockerhub public image

README.md

@@ -1,3 +1,44 @@
 # README
 
-This repository is a playground for practising docker based programming following [docker-development-youtube-series](https://github.com/marcel-dempers/docker-development-youtube-series)
+This repository is a playground for practising docker based programming following [docker-development-youtube-series](https://github.com/marcel-dempers/docker-development-youtube-series)
+
+## Three Problems for docker beginner
+
+1. Programmer need be able to navigate through windows/mac/linux OS using cmd line fluently:
+   1. `ls/dir` for list files
+   2. `cd` for move through file systems
+2. Working Directories
+   1. Show current working directory `echo $PWD`
+   2. Don't hardcode path to file in docker files
+3. Understand *docker volume* `docker run -v hostPath:containerPath`
+   1. e.g. `docker run -it -v $PWD:/work -w /work alpine:3.9 /bin/sh`
+
+## dockerfile
+
+Before bring up docker container, we need first create `dockerfile` to describe the image that we want to use to create containers.
+
+For different languages, `c#`, `golang` & `python` each has a separate dockerfile. Each describe the complete environment can be used to develop corresponding programs 
+
+## Docker compose
+
+`Compose` is an **orchestration** tool that used to spinning up multi-container distributed applications, it shipped with Docker by default. It's not ideal for large system setup, but great for development purpose and testing
+
+It's easy to define a multi-container app and accompanying services using **one single file**, and start it using single command. We can also build/push images to registry using `docker-compose`
+
+The compose file is `docker-compose.yaml` in PWD
+
+* Build image individually: `docker-compose build <service_name>`
+* Build all images: `docker-compose build`
+
+### Create & Push images built from docker-compose
+
+1. Create image using `docker-compose.yaml` & `Dockerfile`
+   1. Write `Dockerfile` and `docker-compose.yaml`
+   2. Create image: `docker-compose build first-public-dockerhub-image` where
+      1. `first-public-dockerhub-image` is the service name of the image
+2. Login Docker hub
+   1. `docker login`, without specify server address, it automatically connect to DockerHub
+   2. Enter Username & Password
+   3. Now computer has login DockerHub successfully
+3. Go to Docker hub, create the `first-public-dockerhub-image` repository
+4. Go to command line, push the image `docker push cruxligh/first-public-dockerhub-image`

docker-compose.yaml

@@ -0,0 +1,23 @@
+version: "3"
+services: 
+  csharp:
+    container_name: csharp # image name
+    image: <dockerhub account>/csharp_sdk:1.0.0
+    build:
+        context: ./c#
+  golang:
+    container_name: golang
+    image: <dockerhub account>/golang_sdk:1.0.0
+    build: ./golang
+  nodejs:
+    container_name: nodejs
+    image: <dockerhub account>/nodejs:1.0.0
+    build: ./nodejs
+  python:
+    container_name: python
+    image: <dockerhub account>/python:1.0.0
+    build: ./python
+  first-public-dockerhub-image:
+    container_name: first-public-dockerhub-image
+    image: cruxlight/first-public-dockerhub-image:latest
+    build: ./first-public-dockerhub-image

first-public-dockerhub-image/Dockerfile

@@ -0,0 +1,3 @@
+FROM busybox
+CMD echo "Hello world! This is my first Docker image."
+CMD echo "Some change"