我有docker多级构建,例如:
FROM golang:1.7.3
WORKDIR /go/src/github.com/alexellis/href-counter/
RUN go get -d -v golang.org/x/net/html
COPY app.go .
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .
FROM alpine:latest
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=0 /go/src/github.com/alexellis/href-counter/app .
CMD ["./app"]
比我有cloudbuild.yml:
steps:
- name: 'gcr.io/cloud-builders/docker'
args: ['pull', 'gcr.io/$PROJECT_ID/app:$BRANCH_NAME']
- name: 'gcr.io/cloud-builders/docker'
args: ['pull', 'gcr.io/$PROJECT_ID/app:latest']
- name: 'gcr.io/cloud-builders/docker'
args: [
'build',
'--cache-from', 'gcr.io/$PROJECT_ID/app:latest',
'--cache-from', 'gcr.io/$PROJECT_ID/app:$BRANCH_NAME',
'--build-arg', 'COMMIT_HASH=$COMMIT_SHA',
'-t', 'gcr.io/$PROJECT_ID/app:$COMMIT_SHA',
'-f', 'config/dockerfiles/app.dockerfile',
'.'
]
- name: 'gcr.io/cloud-builders/docker'
args: ["tag", "gcr.io/$PROJECT_ID/app:$COMMIT_SHA", "gcr.io/$PROJECT_ID/app:$BRANCH_NAME"]
- name: 'gcr.io/cloud-builders/docker'
args: ["tag", "gcr.io/$PROJECT_ID/app:$COMMIT_SHA", "gcr.io/$PROJECT_ID/app:latest"]
images: [
'gcr.io/$PROJECT_ID/app:$COMMIT_SHA',
'gcr.io/$PROJECT_ID/app:$BRANCH_NAME',
'gcr.io/$PROJECT_ID/app:latest'
]
现在我想要不仅缓存生成的图像,还要缓存构建器步骤。例如,在go中我使用dep构建的/ vendor,并且想要缓存这些依赖项。我如何通过谷歌云平台取得最简单的成绩?我认为我的问题主要是码头工具,但仍然存在。
答案 0 :(得分:5)
构建器映像需要分别构建和标记。您需要从构建阶段推送该映像,并在下一个构建中将其用作缓存。为此,更方便地命名您的构建阶段。
FROM golang:1.7.3 as builder
WORKDIR /go/src/github.com/alexellis/href-counter/
RUN go get -d -v golang.org/x/net/html
COPY app.go .
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .
FROM alpine:latest
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=builder /go/src/github.com/alexellis/href-counter/app .
CMD ["./app"]
在您的cloudbuild.yaml
中,您需要知道应拉哪个图像才能更好地使用缓存,并将该决定“存储”在某个地方。我将向您展示如何通过存储在文件中来完成此操作。
将逻辑放在一个构建步骤中会更容易:
steps:
- name: 'gcr.io/cloud-builders/docker'
entrypoint: 'bash'
args:
- '-c'
- |
mkdir tmp
(docker pull gcr.io/$PROJECT_ID/app:$BRANCH_NAME && echo "$BRANCH_NAME" > tmp/base) ||
echo "master" > tmp/base
docker pull "us.gcr.io/$PROJECT_ID/app-builder:$(cat tmp/base)" || true
docker pull "us.gcr.io/$PROJECT_ID/app:$(cat tmp/base)" || true
docker build \
--cache-from "gcr.io/$PROJECT_ID/app-builder:$(cat tmp/base)" \
-t us.gcr.io/$PROJECT_ID/app-builder:$BRANCH_NAME \
-t us.gcr.io/$PROJECT_ID/app-builder:$COMMIT_SHA \
-t us.gcr.io/$PROJECT_ID/app-builder:latest \
--build-arg COMMIT_HASH=$COMMIT_SHA \
-f config/dockerfiles/app.dockerfile \
--target builder \
.
docker build \
--cache-from "gcr.io/$PROJECT_ID/app-builder:$COMMIT_SHA" \
--cache-from "gcr.io/$PROJECT_ID/app:$(cat tmp/base)" \
-t us.gcr.io/$PROJECT_ID/app:$BRANCH_NAME \
-t us.gcr.io/$PROJECT_ID/app:$COMMIT_SHA \
-t us.gcr.io/$PROJECT_ID/app:latest \
--build-arg COMMIT_HASH=$COMMIT_SHA \
-f config/dockerfiles/app.dockerfile \
.
images: [
'gcr.io/$PROJECT_ID/app-builder:$COMMIT_SHA',
'gcr.io/$PROJECT_ID/app-builder:$BRANCH_NAME',
'gcr.io/$PROJECT_ID/app-builder:latest',
'gcr.io/$PROJECT_ID/app:$COMMIT_SHA',
'gcr.io/$PROJECT_ID/app:$BRANCH_NAME',
'gcr.io/$PROJECT_ID/app:latest'
]
该脚本在tag
内创建tmp/
文件,因此Docker忽略此目录或文件(将其放在.dockerignore
上非常重要)。
请注意,我避免将--cache-from
与两个图像一起使用。这是因为在我的实验中,由于构建使用的是最旧的映像作为缓存,因此我使缓存无效。还要注意,第一个docker build
命令具有一个--target
参数。这是在告诉Docker仅在该阶段结束之前进行构建。
我将默认图像更改为master
,因为它可以保证基本图像是稳定的,并且与您的分支没有太大差异,从而提高了性能。在我的示例中,latest
标签是不必要的。