feat: Use exposed ports specified in image if it is not specified in ContainerRequest

[fiftin]

Relates to #343

Example:

# Dockerfile
EXPOSE 11211
CMD ["memcached"]

Old:

port := "11211/tcp"
rq := testcontainers.ContainerRequest{
	Image:        "memcached:1.6.10",
	ExposedPorts: []string{port},
	WaitingFor:   wait.ForListeningPort(nat.Port(port)),
}

New:

rq := testcontainers.ContainerRequest{
	Image:        "memcached:1.6.10",
	WaitingFor:   wait.ForListeningPort(""),
}

[fiftin]

I will be very grateful if you check my PR ASAP. I can not continue to work on the PR after Jul 13. Thank you!

[mdelapenya]

I added two small nits. The PR looks good to me. My only concern is about the call to the wait.ForListeningPort("") method with an empty string. Not sure if adding a new method, something like wait.ForExposedPort() would me it more usable though, but I'd like to hear your thoughts on it.

It's not a blocker for this PR, which I will approve once we discuss about it and find ourselves in a closed path.

[fiftin]

@mdelapenya ,

We have HostPortStrategy struct which has Port field. Method wait.ForListeningPort just instantiate this struct with provided port.

Yes, we can add method wait.ForExposedPort() but it would an alias for wait.ForListeningPort("").

[mdelapenya]

Yes, we can add method wait.ForExposedPort() but it would an alias for wait.ForListeningPort("").

I want it to be simple to use. I we have to do the mental effort of passing an empty string to wait for a port declared at the Dockerfile, then I think it would make it difficult to remember/easy to forget about it, unless the docs/tests are crystal clear. I think we are missing it in the docs, as you already added the example in the tests 👍

If you find it having the alias confusing, then it's OK to keep the method with the empty string, but well documented.

[codecov]

Codecov Report

Merging #468 (37e1e95) into main (28706cb) will increase coverage by 4.10%.
The diff coverage is 40.00%.

@@            Coverage Diff             @@
##             main     #468      +/-   ##
==========================================
+ Coverage   65.55%   69.65%   +4.10%     
==========================================
  Files          19       21       +2     
  Lines        1199     2040     +841     
==========================================
+ Hits          786     1421     +635     
- Misses        305      495     +190     
- Partials      108      124      +16     

Impacted Files	Coverage Δ
wait/wait.go	100.00% <ø> (ø)
wait/host_port.go	48.42% <15.00%> (-7.72%)	⬇️
docker.go	71.09% <90.00%> (+5.39%)	⬆️
container.go	80.72% <0.00%> (-6.52%)	⬇️
compose.go	74.04% <0.00%> (-2.73%)	⬇️
logger.go	100.00% <0.00%> (ø)
mounts.go	100.00% <0.00%> (ø)
testing.go	0.00% <0.00%> (ø)
wait/multi.go	0.00% <0.00%> (ø)
... and 14 more

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[fiftin]

Added wait.ForExposedPort.

[mdelapenya]

Last minute changes in docs, but other than that LGTM! Thanks @fiftin for your hard work here

[mdelapenya]

Thanks for your patience @fiftin!! It's merged now 🚀