docker build is the command used to build a Docker image. It allows you to create an image based on a Dockerfile. In the docker build command, there are two commonly used options -t and -f, which have different effects.
-
'-t' option:
The '-t' option is used to specify the name and label of the built image. The format is <image_name>:. This option allows you to give the image an easily identifiable name and version label, making it easier to manage and use the image later.
Example:docker build -t myapp:latest .
This command will build the Dockerfile in the current directory, and name the built image myapp and label it latest. -
'-f' option:
The -f option is used to specify the path to the Dockerfile to use. By default, Docker will look for a file named Dockerfile in the current directory to build the image. However, if you have multiple Dockerfiles, or wish to use Dockerfiles in different paths, you can use the -f option to specify the file path to use.
Example:docker build -t myapp:latest -f path/to/Dockerfile .
This command will search for the Dockerfile in path/to/Dockerfile and build an image named myapp with the label latest based on it.
To sum up, docker build -t is used to specify the name and label of the built image, while docker build -f is used to specify the path of the Dockerfile to be used. These two options can be used together or separately, depending on your build needs.
Specific examples:
docker build -f Package_Dockerfile -t 192.168.18.49:5000/my_server .
This command is used in the process of building an image using Docker. The specific parameters and meanings are as follows:
docker build: This is the command used to build a Docker image.-f Package_Dockerfile: This option is used to specify the path of the Dockerfile to use. In this case, Docker will use a file named Package_Dockerfile as the configuration file for building the image.-t 192.168.18.49:5000/my_server: This option is used to specify the name and label of the built image. Here, the image will be named 192.168.18.49:5000/my_server, where 192.168.18.49:5000 is a private Docker Registry address, and my_server is the label of the image..: This point indicates that Docker will look for the Dockerfile file in the current directory and execute the build.
Taken together, this command means: use the file named Package_Dockerfile as the build configuration, build an image named 192.168.18.49:5000/my_server, and use the contents of the current directory as the build context. The image will be built and identified as 192.168.18.49:5000/my_server, and it can be pushed to the private Docker Registry at 192.168.18.49:5000.