我已在docker中启用了用户名称空间映射,并使用docker build来构建映像,但是当我对映像使用docker-compose时,它将失败,并显示以下消息。可能是什么原因?
db@vagrant:~/docker$ docker-compose up --build
Building db
Step 1/3 : FROM alpine:latest
---> e7d92cdc71fe
Step 2/3 : WORKDIR /app
---> Using cache
---> 1491149423a1
Step 3/3 : COPY 1.txt .
ERROR: Service 'db' failed to build: failed to copy files: failed to copy file: Container ID 65536 cannot be mapped to a host ID
[我的用户ID是由某些安装脚本生成的,导致UID的值大于65535。
db@vagrant:~/docker$ id
uid=65536(db) gid=1000(db) groups=1000(db),27(sudo),998(docker)
Docker configuration for namespace mapping
db@vagrant:~/docker$ cat /etc/docker/daemon.json
{
"userns-remap": "db"
}
db@vagrant:~/docker$ cat /etc/subuid /etc/subgid
db:100000:65536
db:100000:65536
Dockerfile内容(1.txt为空文件)
db@vagrant:~/docker$ cat Dockerfile
FROM alpine:latest
WORKDIR /app
COPY 1.txt .
docker-compose.yml文件内容
db@vagrant:~/docker$ cat docker-compose.yml
version: "2"
services:
db:
build:
context: .
dockerfile: Dockerfile
image: sirishkumar/test
docker build命令的输出
db@vagrant:~/docker$ docker build -t sirishkumar/test .
Sending build context to Docker daemon 3.584kB
Step 1/3 : FROM alpine:latest
latest: Pulling from library/alpine
c9b1b535fdd9: Pull complete
Digest: sha256:ab00606a42621fb68f2ed6ad3c88be54397f981a7b70a79db3d1172b11c4367d
Status: Downloaded newer image for alpine:latest
---> e7d92cdc71fe
Step 2/3 : WORKDIR /app
---> Running in 55f092b96268
Removing intermediate container 55f092b96268
---> 8af079e6a478
Step 3/3 : COPY 1.txt .
---> b3c14a691102
Successfully built b3c14a691102
Successfully tagged sirishkumar/test:latest
docker-compose的输出
db@vagrant:~/docker$ docker-compose up --build
Creating network "docker_default" with the default driver
Building db
Step 1/3 : FROM alpine:latest
latest: Pulling from library/alpine
c9b1b535fdd9: Pull complete
Digest: sha256:ab00606a42621fb68f2ed6ad3c88be54397f981a7b70a79db3d1172b11c4367d
Status: Downloaded newer image for alpine:latest
---> e7d92cdc71fe
Step 2/3 : WORKDIR /app
---> Running in fe39955aed1a
Removing intermediate container fe39955aed1a
---> fb23b8888f4a
Step 3/3 : COPY 1.txt .
ERROR: Service 'db' failed to build: failed to copy files: failed to copy file: Container ID 65536 cannot be mapped to a host ID
您有65,536个用户ID可以映射到您的docker用户名称空间:
db@vagrant:~/docker$ cat /etc/subuid /etc/subgid
db:100000:65536
db:100000:65536
然后您告诉docker将文件复制到该ID超出该范围(用户ID的起始位置为0)所拥有的容器中:
db@vagrant:~/docker$ id
uid=65536(db) gid=1000(db) groups=1000(db),27(sudo),998(docker)
您需要在主机上将您的用户ID设置为主机用户ID范围内(小于65536)。