Silent mode?

[slimtoolkit]

Silent mode?

[kcq]

Yes :-) You can use the "--continue-after" build option. The "probe" value is good when you use the HTTP probe feature to interact with your image. That way DockerSlim will wait for the probe to finish and then it'll continue minifying the image. You can use a "timeout" instead. It defaults to 60 seconds, but you can specify a custom timeout by passing the number of seconds you want to wait. You can also signals if you pick the "signal" value. Send the USR1 signal to the DockerSlim process.

Soon there'll be an HTTP server mode too, so you'll be able to control DockerSlim using HTTP API calls.

[vraravam]

How can i specify the timeout value? An example of this would be greatly appreciated!

I'm currently invoking like this: docker-slim build --continue-after=timeout my-api --http-probe-off - but, im unable to figure out how to specify a timeout value less than 60 secs. Ideally, i would prefer no timeout

[kcq]

The command should look something like this docker-slim build --continue-after=30 --http-probe-off my-api. I assume my-api is a containerized CLI app. It makes sense to have a mode to continue once the app exits without waiting any extra time.

[vraravam]

Thanks @kcq - I was trying with a value of 0 (intending for fully non-interactive mode, but that reverts back to waiting for user input. Instead, 1 works perfectly fine!

my-app is an image for a java springboot application whose ENTRYPOINT is java -jar ... so, it'll not exit per se

[kcq]

@vraravam you don't want to turn off http probing then because one way or another the app needs to have a chance to fully initialize, which may take a bit longer than usual because the app is traced. With the default http probe (which you get if you don't set any extra params) your app will get pinged with GET / and the probe will keep trying until it gets a response or it runs out of the number of retries it uses. If your springboot app has a different root path you'll want to specify a custom http probe command like this --http-probe-cmd /your/app/api/root/path.

[vraravam]

Thanks for the explanations @kcq - but, while building the image, i fail to understand why i need the app to fully initialize. Could you please elaborate? I can understand if running, but, while building?

[kcq]

@vraravam the build command in docker-slim performs static and dynamic analysis on the target container images and it ends up creating an ephemeral container to do the dynamic analysis and that's where the probes are used.

[vraravam]

sorry to belabor the point, but what's the use of dynamic analysis? Is it for cases where the app writes files to some disk location or other similar functionality?

[kcq]

Dynamic analysis is necessary to understand the containerized application and what it needs. The information collected during dynamic analysis is augmented with the information collected with static analysis and all that is used to generate the minified image. Without that information you'll have to use a lot of the --include-*** parameters to explicitly declare what you want to keep when it comes to the system dependencies.