store name of stage inside metadata/labels

[tobwen]

summary

When building images with named multiple stages, the name isn't stored anywhere. Making the name available in metadata (for example in labels) would make developing and debugging way easier.

example

podman build -t stages_demo - <<EOF
# stage 1
FROM alpine AS findme
RUN echo "hello" >> /podman.txt

# stage 2
FROM findme AS release
RUN echo "world" >> /podman.txt
EOF

[1/2] STEP 1/2: FROM alpine AS findme
[1/2] STEP 2/2: RUN echo "hello" >> /podman.txt
--> c54f74d6cc9
[2/2] STEP 1/2: FROM c54f74d6cc97487a1116841a2b2d380a387a38d111bb7b28116ed4d3f2110251 AS release
[2/2] STEP 2/2: RUN echo "world" >> /podman.txt
[2/2] COMMIT stages_demo
--> 9669170f524
Successfully tagged localhost/stages_demo:latest
9669170f5249c48ef090de9748c20781956d97304972f19818c91399a3be32ab

test

Neither findme, nor release can be found.

# docker image inspect c54f74d6cc97487a1116841a2b2d380a387a38d111bb7b28116ed4d3f2110251 | grep -i findme; echo $?
1

# docker image inspect 9669170f5249c48ef090de9748c20781956d97304972f19818c91399a3be32ab | grep -i findme; echo $?
1

# docker image inspect c54f74d6cc97487a1116841a2b2d380a387a38d111bb7b28116ed4d3f2110251 | grep -i release; echo $?
1

# docker image inspect 9669170f5249c48ef090de9748c20781956d97304972f19818c91399a3be32ab | grep -i release; echo $?
1

[flouthoc]

Could you please create an issue on buildah repo github.com/containers/buildah :)

[rhatdan]

I transferred the discussion and then created an issue out of it.