cerulean herald
I want to write a quick demo example that matches closely to docker run hello-world
I tried dagger core container from --address=hello-world stdout:
✔ connect 0.5s
✔ loading type definitions 0.8s
✔ parsing command line arguments 0.0s
✔ container: Container! 0.0s
○ .from(address: "hello-world"): Container! 0.8s
✘ .stdout: String! 0.0s
! no command has been set: stdout requires an exec
patent tundra
Hello @cerulean herald, stdout returns the standard output of the last executed command. If no command has been executed, there is nothing to return. The error is to inform you of that explicitly.
cerulean herald
Hello <@1229425915675807797>, `stdout` returns the standard output of the last e...
That makes sense and maybe I'm misunderstanding docker run but the hello-world image prints to stdout immediately:
Because this image consists of nothing but a single static binary which prints some text to standard output, it can trivially be run as any arbitrary user (docker run --user $RANDOM:$RANDOM hello-world, for example).
So I'm not sure how I would get that stdout in dagger
patent tundra
In your example, what you want to do is execute that container's entrypoint with no argument. You can do that with dagger but we make it more explicit.
In dagger shell:
dagger <<.
container |
from hello-world |
with-exec "" --use-entrypoint |
stdout
.
Or using dagger core like you did:
dagger core container from --address=hello-world with-exec --use-entrypoint --args="" stdout
I personally prefer the shell syntax because it's more compact 🙂 But both work fine
As a one-liner: dagger -c 'container | from hello-world | with-exec "" --use-entrypoint | stdout'
cerulean herald
Yeah I agree, the shell example is much more concise, thank you very much