Question

给出这个多阶段构建的小例子

<html>
<head>
    <title>Preload Images example</title>
</head>
<body>
<div><canvas id="myCanvas" width="960" height="400"></canvas></div>
<script src="https://code.createjs.com/1.0.0/easeljs.min.js"></script>
<script type="text/javascript" src="https://code.createjs.com/1.0.0/preloadjs.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript">
var canvas = document.getElementById("myCanvas");
var stage = new createjs.Stage(canvas);

var manifest;
var preload;
var progressText = new createjs.Text("", "20px Arial", "#dd4814");
progressText.x = 125 - progressText.getMeasuredWidth() / 2;
progressText.y = 20;
stage.addChild(progressText);
stage.update();


function setupManifest() {
    manifest = [ 
    {
        src: "https://s3.amazonaws.com/coursetro/stuff/mountains-clouds.jpg",
        id: "image1"
    }, 
    {
        src:  "https://s3.amazonaws.com/coursetro/stuff/adventure-alpine-alps-714258.jpg",
        id: "image2"
    },
    {
        src:  "https://s3.amazonaws.com/coursetro/stuff/170407220921-07-iconic-mountains-pitons-restricted.jpg",
        id: "image3"
    },
    {
        src:  "https://s3.amazonaws.com/coursetro/stuff/170407220916-04-iconic-mountains-matterhorn-restricted.jpg",
        id: "image4"
    }
    ];
}


function startPreload() {
    preload = new createjs.LoadQueue(true);
    preload.installPlugin(createjs.Sound);         
    preload.on("fileload", handleFileLoad);
    preload.on("progress", handleFileProgress);
    preload.on("complete", loadComplete);
    preload.on("error", loadError);
    preload.loadManifest(manifest);

}


function handleFileLoad(event) {
    console.log("loading: " + event.item.type);
    if(event.item.id == "image1"){

    }
}


function loadError(evt) {
    console.log("err",evt.text);
}
function handleFileProgress(event) {
    progressText.text = "loading " + (preload.progress*100|0) + " %";
    stage.update();
}
function loadComplete(event) {

}

setupManifest();
startPreload();
</script>

</body>
</html>

为什么这会在本地文件系统上生成3张图像？

FROM node:10 AS ui-build
WORKDIR /usr/src/app

FROM node:10 AS server-build
WORKDIR /root/

EXPOSE 3070

ENTRYPOINT ["node"]
CMD ["index.js"]

我希望有两个映像，即基础映像和服务器构建映像。我使用了标准的docker build命令，即

"<none>";"<none>";"58d63982fbef";"2020-04-15 17:53:14";"912MB"
"node";"10";"bd83fcefc19d";"2020-04-14 01:32:21";"912MB"
"test";"latest";"3913dd4d03b6";"2020-04-15 17:53:15";"912MB"

那么图像的哪一部分是空的，哪些是测试的？

我很困惑

Answer 1

Dockerfile中以FROM行开头的每个块都会创建一个新映像。如果使用docker build -t选项，则只有最后一个阶段会使用您指定的名称进行标记；其余的块将在<none>输出之类的地方显示为docker images。

# node:10 is a base image

# Not the final image, will appear as <none>:<none>
FROM node:10 AS ui-build
...

# The final image, will appear as test:latest (`docker build -t` option)
FROM node:10 AS server-build
...

您偶尔会看到Dockerfile，其中在以后的构建阶段中会重复使用基础映像，并且在docker images输出中根本不会显示该映像。

# Will be hidden because it has descendant images
FROM node:10 AS base
RUN apt-get update && apt-get upgrade

# Will appear as <none>:<none>
FROM base AS ui
...

# Will get the `docker build -t` tag
FROM base

Docker：多阶段构建会生成多个映像

1 个答案: