Support mounting host file/directory to devservices containers

[Eng-Fouad]

Description

Testcontainers has API to copy/mount file/directory to containers:

continer.withCopyFileToContainer(MountableFile.forHostPath("/mappable-resource/"), directoryInContainer);

See: Testcontainers for Java: Files and volumes

---

One possible usage is to add Keycloak extension to Keycloak devservices by copying the extension jar files to /opt/keycloak/providers.

Implementation ideas

It can be added to app configurations, something like:

quarkus.keycloak.devservices.mount=./extension/jars:/opt/keycloak/providers

[quarkus-bot]

/cc @geoand (devservices), @stuartwdouglas (devservices)

[geoand]

I think it makes sense. WDYT @sberyozkin?

[sberyozkin]

@geoand Sure, makes sense

@Eng-Fouad As far as the Keycloak dev service is concerned,

FYI, in this PR, https://github.com/quarkusio/quarkus/pull/36508/files#diff-67404a43520250b1ebd5a0c945e070e60d70d4a3ba06b15e3fac747f820320ccR541

I'm attempting to attach a specific classpath or file system file to a required container location (there, a generated policy jar has to be copied), can that help with your requirements ? Note I'm using 2 maps there, one creates aliases to the local resources, another maps these aliases to container locations - I'm not 100% sure having a single Map to map for ex a Windows path to the container resource can work without resorting to various escape tricks...

[Eng-Fouad]

@geoand Sure, makes sense

@Eng-Fouad As far as the Keycloak dev service is concerned,

FYI, in this PR, https://github.com/quarkusio/quarkus/pull/36508/files#diff-67404a43520250b1ebd5a0c945e070e60d70d4a3ba06b15e3fac747f820320ccR541

I'm attempting to attach a specific classpath or file system file to a required container location (there, a generated policy jar has to be copied), can that help with your requirements ? Note I'm using 2 maps there, one creates aliases to the local resources, another maps these aliases to container locations - I'm not 100% sure having a single Map to map for ex a Windows path to the container resource can work without resorting to various escape tricks...

Yes, this seems what I am looking for.

[sberyozkin]

@Eng-Fouad OK, thanks, let me have that PR fix this issue on its completion.
I guess we will be easily able to map the whole directories if it will be necessary as a follow up to that PR