Default compression (none) in 0.47.0 breaks docker engine build API version 2 (buildkit) #1886
Description
Since version 0.47.0, in a project where the following buildOptions are specified:
<buildOptions>
<version>2</version>
</buildOptions>(see https://docs.docker.com/reference/api/engine/version/v1.51/#tag/Image/operation/ImageBuild)
will cause the image build to fail with:
[ERROR] DOCKER> Unable to build image [my-image] : "dockerfile parse error on line 1: unknown instruction: ./PaxHeaders.X/(...)
The same exact setup works in both 0.46.0 and 0.45.0 (didn't check earlier).
AFAICT the issue sees to be the tar archive format, in 0.46.0 the hex dump shows something like this:
00000000 63 74 78 2f 00 00 00 00 00 00 00 00 00 00 00 00 |ctx/............|
00000000 63 74 78 2f 00 00 00 00 00 00 00 00 00 00 00 00 |ctx/............|
(ctx is the name of the assembly and the dir under which all files referenced by the Dockerfile are located)
while in 0.47.0 it shows this:
00000000 2e 2f 50 61 78 48 65 61 64 65 72 73 2e 58 2f 63 |./PaxHeaders.X/c|
00000000 2e 2f 50 61 78 48 65 61 64 65 72 73 2e 58 2f 63 |./PaxHeaders.X/c|
00000010 74 78 5f 00 00 00 00 00 00 00 00 00 00 00 00 00 |tx_.............|
00000010 74 78 5f 00 00 00 00 00 00 00 00 00 00 00 00 00 |tx_.............|
Not sure where ./PaxHeaders.X/ comes from (related to tar format?) but the docker API doesn't seem to like/support it (I can open/extract the tar file manually just fine though, so maybe this is a limitation of the docker API?).
I experimented with it a bit and found the following workarounds (either works):
- Setting
compressionto anything other thannone - Setting the assembly
modeto anything other than the default (dir)
So it definitely seems related to changes that affect the tar file creation between 0.46.0 and 0.47.0