生产力

如何用Docker容器部署应用

自从用了Docker之后，部署应用真的是简单很多，再也不用单独安装很多依赖。

谢现实

— 4 min read
如何用Docker容器部署应用

近期部署大模型的应用如Dify AI，Flowise等，发现很多应用是用Docker部署的，相比源码部署要简单很多。Dify的安装只需要4步：

# Clone the Dify source code to your local machine:
git clone https://github.com/langgenius/dify.git

# Navigate to the Docker directory in the Dify source code
cd dify/docker

# Copy the environment configuration file
cp .env.example .env

# Start the Docker containers
docker compose up -d

同样Flowise的安装也只需要4 步：

# Clone the Flowise source code to your local machine:
git clone https://github.com/FlowiseAI/Flowise.git

# Navigate to the Docker directory in the Dify source code
cd Flowise/docker

# Copy the environment configuration file
cp .env.example .env

# Start the Docker containers
docker compose up -d

什么是Docker？

Docker is a tool that is used to automate the deployment of applications in lightweight containers so that applications can work efficiently in different environments in isolation.

Docker本质是上一种Container Orchestration System，能够把每个软件独立安装与运行在一个容器里面。类似的产品还有Kubernetes，Openshift。使用Docker不仅从能够解决部署应用的兼容性问题，而且还能提升部署的效率。比如在Mac上安装一个PostgreSQL的数据库，常规的安装步骤如下：

# Install PostgreSQL
brew install postgresql

# Start PostgreSQL as a background service
brew services start postgresql

# Access the PostgreSQL shell
psql postgres

# Create a new user
CREATE USER myuser WITH PASSWORD 'mypassword'

# Give the user superuser privileges
ALTER USER myuser WITH SUPERUSER;

# Exit the shell
\q

如果使用Docker，安装步骤可以简化为一个指令：

docker run --name my-postgres \
  -e POSTGRES_USER=myuser \
  -e POSTGRES_PASSWORD=mypassword \
  -e POSTGRES_DB=mydatabase \
  -p 5432:5432 \
  -d postgres

Docker常用的命令有哪些？

1. Running a Container

Docker最常用的命令是运行一个容器。根据官方文档的描述：The docker run command runs a command in a new container, pulling the image if needed and starting the container. 命令格式如下：

docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

• IMAGE specifies the Docker image to use, optionally with a tag or digest to specify the version.
• COMMAND and ARG... are optional commands and arguments to run inside the container, overriding the default image command.

完全了解这个命令会非常复杂，建议运行具体的容器时，通过ChatGPT查找相应的命令。例如以下回复：

docker run command

Here’s a quick reference to the docker run command — with examples for different common use cases:

1. Run a container interactively

docker run -it ubuntu bash

  • -i: Interactive
  • -t: Allocate a pseudo-TTY
  • ubuntu: Image name
  • bash: Command to run inside

2. Run a container in the background (detached)

docker run -d nginx

  • -d: Detached mode (runs in background)

3. Map ports

docker run -p 8080:80 nginx

  • Maps port 80 inside the container to port 8080 on your host

4. Mount a volume

docker run -v /host/path:/container/path ubuntu

  • Mounts a host directory into the container

5. Assign a name

docker run --name my-container nginx

6. Auto-remove container on exit

docker run --rm ubuntu

运行了容器之后，可以通过docker ps来查看运行的容器。In docker ps, the ps stands for “process status” — just like the traditional Linux/Unix ps command that shows running processes.

💡
Docker 中的 容器（Container） 和 镜像（Image） 是两个核心概念，它们的关系可以理解为：镜像是模版，容器是运行中的实例。

2. Managing Docker Images

Docker运行一个容器的时候经常要拉取镜像。如果你需要管理Docker本地的镜像，可以通过docker image命令：

Common docker image Subcommands and Their Functions

  • docker image ls (or docker images): Lists all Docker images available locally, showing details like repository, tag, image ID, creation date, and size.
  • docker image pull: Downloads an image from a Docker registry to the local system.
  • docker image push: Uploads an image from the local system to a Docker registry.
  • docker image rm: Removes one or more images from the local system.
  • docker image inspect: Displays detailed metadata and configuration information about one or more images.
  • docker image build: Builds a new image from a Dockerfile.
  • docker image save: Saves one or more images to a tar archive.
  • docker image load: Loads an image from a tar archive or STDIN.
  • docker image tag: Creates a new tag for an existing image.
  • docker image prune: Removes unused images to free up disk space.
  • docker image history: Shows the history of an image’s layers.
  • docker image import: Imports an image from a tarball to create a filesystem image.

Read more