Compression parameters ignored
Open
Nobody has claimed this yet.
- Dominant language
- Go
- Stars
- 10.3k
- Forks
- 1.5k
- Avg merge
- 1d 23h
- Merged PRs (30d)
- 48
Description
The compression algorithm parameters are completely ignored when using buildx to build and push an image. This is despite following the example command in the compression documentation. The size and media type in the manifest remain the same regardless of the compression algorithm I choose.
It appears the compression parameters are not being read at all because if I provide invalid values (e.g. a non-numeric compression-level) I do not get an error.
I have tested on both WSL (Ubuntu) and Windows. The below sequence of commands demonstrates the problem.
BuildKit version
PS C:\Users\usrname> docker buildx ls
NAME/NODE DRIVER/ENDPOINT STATUS BUILDKIT PLATFORMS
default docker
\_ default \_ default running v0.15.2 linux/amd64, linux/amd64/v2, linux/amd64/v3, linux/arm64, linux/riscv64, linux/ppc64le, linux/s390x, linux/386, linux/mips64le, linux/mips64, linux/arm/v7, linux/arm/v6
desktop-linux* docker
\_ desktop-linux \_ desktop-linux running v0.15.2 linux/amd64, linux/amd64/v2, linux/amd64/v3, linux/arm64, linux/riscv64, linux/ppc64le, linux/s390x, linux/386, linux/mips64le, linux/mips64, linux/arm/v7, linux/arm/v6
Dockerfile
PS C:\Users\usrname> cat Dockerfile
FROM alpine
ARG ID
RUN cp /bin/busybox /home
Build and push image compressed with gzip
PS C:\Users\usrname> docker buildx build --build-arg ID=gzip --output type=image,name=usrname/dummy:gzip,push=true,compression=gzip .
[+] Building 23.7s (7/7) FINISHED docker:desktop-linux
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 85B 0.0s
=> [internal] load metadata for docker.io/library/alpine:latest 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> CACHED [1/2] FROM docker.io/library/alpine:latest 0.0s
=> [2/2] RUN cp /bin/busybox /home 0.3s
=> exporting to image 0.0s
=> => exporting layers 0.0s
=> => writing image sha256:2d1df90518de65637f7798eed87f30ad75a547e0e6d30d6acc5b5547731afc3e 0.0s
=> => naming to docker.io/usrname/dummy:gzip 0.0s
=> pushing usrname/dummy:gzip with docker 17.3s
=> => pushing layer e2696caccd8d 7.9s
=> => pushing layer 94e5f06ff8e3 15.6s
Build and push image compressed with zstd
PS C:\Users\usrname> docker buildx build --build-arg ID=zstd --output type=image,name=usrname/dummy:zstd,push=true,compression=zstd .
[+] Building 23.0s (7/7) FINISHED docker:desktop-linux
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 85B 0.0s
=> [internal] load metadata for docker.io/library/alpine:latest 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> CACHED [1/2] FROM docker.io/library/alpine:latest 0.0s
=> [2/2] RUN cp /bin/busybox /home 0.2s
=> exporting to image 0.0s
=> => exporting layers 0.0s
=> => writing image sha256:e211987a585928034e89c408c7cdc6f15a77a2e6b45b4616cec10f0e5dfab665 0.0s
=> => naming to docker.io/usrname/dummy:zstd 0.0s
=> pushing usrname/dummy:zstd with docker 17.0s
=> => pushing layer 7b5d89f5975c 7.7s
=> => pushing layer 94e5f06ff8e3 15.8s
Build and push uncompressed image
PS C:\Users\usrname> docker buildx build --build-arg ID=uncompressed --output type=image,name=usrname/dummy:uncompressed,push=true,compression=uncompressed .
[+] Building 23.4s (7/7) FINISHED docker:desktop-linux
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 85B 0.0s
=> [internal] load metadata for docker.io/library/alpine:latest 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> CACHED [1/2] FROM docker.io/library/alpine:latest 0.0s
=> [2/2] RUN cp /bin/busybox /home 0.2s
=> exporting to image 0.0s
=> => exporting layers 0.0s
=> => writing image sha256:d8e8715782f9d17423d267590c2ac74dda8743621a5910a067ffdf3073fde711 0.0s
=> => naming to docker.io/usrname/dummy:uncompressed 0.0s
=> pushing usrname/dummy:uncompressed with docker 17.1s
=> => pushing layer b2ffd68f6199 7.9s
=> => pushing layer 94e5f06ff8e3 15.8s
Manifest for gzip image
PS C:\Users\usrname> docker manifest inspect usrname/dummy:gzip
{
"schemaVersion": 2,
"mediaType": "application/vnd.docker.distribution.manifest.v2+json",
"config": {
"mediaType": "application/vnd.docker.container.image.v1+json",
"size": 939,
"digest": "sha256:2d1df90518de65637f7798eed87f30ad75a547e0e6d30d6acc5b5547731afc3e"
},
"layers": [
{
"mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
"size": 3623844,
"digest": "sha256:ec99f8b99825a742d50fb3ce173d291378a46ab54b8ef7dd75e5654e2a296e99"
},
{
"mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
"size": 513591,
"digest": "sha256:958ef0a9c069b82a13223ae4be9b6bfaeebdfa4070dc7045135b3c1db199da1a"
}
]
}
Manifest for zstd image
PS C:\Users\usrname> docker manifest inspect usrname/dummy:zstd
{
"schemaVersion": 2,
"mediaType": "application/vnd.docker.distribution.manifest.v2+json",
"config": {
"mediaType": "application/vnd.docker.container.image.v1+json",
"size": 939,
"digest": "sha256:e211987a585928034e89c408c7cdc6f15a77a2e6b45b4616cec10f0e5dfab665"
},
"layers": [
{
"mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
"size": 3623844,
"digest": "sha256:ec99f8b99825a742d50fb3ce173d291378a46ab54b8ef7dd75e5654e2a296e99"
},
{
"mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
"size": 513590,
"digest": "sha256:d3792e8213e6ac1b7362242f6d4ca227bafa11bb3ad1836d86e483c46fb7d137"
}
]
}
Manifest for uncompressed image
PS C:\Users\usrname> docker manifest inspect usrname/dummy:uncompressed
{
"schemaVersion": 2,
"mediaType": "application/vnd.docker.distribution.manifest.v2+json",
"config": {
"mediaType": "application/vnd.docker.container.image.v1+json",
"size": 955,
"digest": "sha256:d8e8715782f9d17423d267590c2ac74dda8743621a5910a067ffdf3073fde711"
},
"layers": [
{
"mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
"size": 3623844,
"digest": "sha256:ec99f8b99825a742d50fb3ce173d291378a46ab54b8ef7dd75e5654e2a296e99"
},
{
"mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
"size": 513589,
"digest": "sha256:4b50faf70afcaad978d835f74ac88d589952c2e9e2e9454ed84db9c3c2ca7b65"
}
]
}
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the issue with the documented buildx commands using gzip, zstd, uncompressed, and an invalid compression level, then inspect the buildx image-export and push path. Done means compression and compression-level affect the pushed manifest as expected, and invalid values produce an error; compare the resulting manifests with docker manifest inspect.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- docker, go
- Domain
- build-system, cli
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100