On Windows, the os/exec.{Command,CommandContext,LookPath} functions
resolve command names that have neither path separators nor file extension
(e.g., "git") by first looking in the current working directory before
looking in the PATH environment variable.
Go maintainers intended to match cmd.exe's historical behavior.
However, this is pretty much never the intended behavior and as an abundance of precaution
this patch prevents that when executing commands.
Example of commands that docker.exe may execute: `git`, `docker-buildx` (or other cli plugin), `docker-credential-wincred`, `docker`.
Note that this was prompted by the [Go 1.15.7 security fixes](https://blog.golang.org/path-security), but unlike in `go.exe`,
the windows path lookups in docker are not in a code path allowing remote code execution, thus there is no security impact on docker.
Signed-off-by: Tibor Vass <tibor@docker.com>
As pointed out in #1459, docker cli fails to detect that the input is a tarball,
in case it is generated by `git archive --format=tgz`.
This happens because `git archive` adds some metadata to the initial tar header,
and so it is more than 1 block (of 512 bytes) long, while we only provide 1 block
to archive/tar.Next() and it fails.
To fix, give it 2 blocks :)
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Historically, the Dockerfile had to be insde the build-context, because it was
sent as part of the build-context.
3f6dc81e10
added support for passing the Dockerfile through stdin, in which case the
contents of the Dockerfile is injected into the build-context.
This patch uses the same mechanism for situations where the location of the
Dockerfile is passed, and its path is outside of the build-context.
Before this change:
$ mkdir -p myproject/context myproject/dockerfiles && cd myproject
$ echo "hello" > context/hello
$ echo -e "FROM busybox\nCOPY /hello /\nRUN cat /hello" > dockerfiles/Dockerfile
$ docker build --no-cache -f $PWD/dockerfiles/Dockerfile $PWD/context
unable to prepare context: the Dockerfile (/Users/sebastiaan/projects/test/dockerfile-outside/myproject/dockerfiles/Dockerfile) must be within the build context
After this change:
$ mkdir -p myproject/context myproject/dockerfiles && cd myproject
$ echo "hello" > context/hello
$ echo -e "FROM busybox\nCOPY /hello /\nRUN cat /hello" > dockerfiles/Dockerfile
$ docker build --no-cache -f $PWD/dockerfiles/Dockerfile $PWD/context
Sending build context to Docker daemon 2.607kB
Step 1/3 : FROM busybox
---> 6ad733544a63
Step 2/3 : COPY /hello /
---> 9a5ae1c7be9e
Step 3/3 : RUN cat /hello
---> Running in 20dfef2d180f
hello
Removing intermediate container 20dfef2d180f
---> ce1748f91bb2
Successfully built ce1748f91bb2
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Tibor Vass
Sebastiaan van Stijn
Sam
Nao YONASHIRO
Kir Kolyshkin
Justyn Temme
Daniel Nephin
Vincent Demeester
Daniel Nephin