Some notes about building docker image from Dockerfile
Dockerfile
simple example
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FROM alpine
# Step 2: Download and install dependency
RUN apk add --update redis
# Step 3: Tell the image what to do when it starts as container
CMD ["redis-server"]
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to run
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docker build -t dockerID/project:version(latest) .
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Alternatively, docker commit could be used.
- In terminal 1,
docker run -it alpine sh
- Inside the container , run
apk add --update redis
- Open terminal 2,
docker ps get the container id
- run
docker commit -c 'CMD ["redis-server"]' containerid
Copy building files
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COPY ./(in host relative to build context) ./(inside container)
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Port Mapping
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docker run -p localhost_port:port_inside_container <imagename>
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Specifying Working Directory
Minimizing Cache Busting and Rebuilds
Make sure there are less change possible in the previous steps
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# Specify a base image
FROM node:alpine
WORKDIR /usr/app
# Less change in the previous steps
COPY ./package.json ./
RUN npm install
COPY ./ ./
# Default command
CMD ["npm", "start"]
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Docker Compose
docker-compose.yml
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version: "3"
services:
redis-server:
image: "redis"
node-app:
restart: on-failure[always/no/unless-stopped]
build: .
ports:
- "4001:8081"
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Same network will be created for services.
in redis, refer other services just by name.
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const client = redis.createClient({
host: "redis-server",
port: 6379, // default
});
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Command
Launch
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docker-compose up
docker-compose up --build
docker-compose up -d // in background
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Stop
Status