rpk: attempt to print out Redpanda node's stderr on failure to start

[voutilad]

A working example of addressing #13023. It's not covering all possible failure paths and is really for an example of what I'm talking about in the issue.

$ ./linux-arm64/rpk container start
Waiting for the cluster to be ready...

Error: unable to dial: dial tcp 127.0.0.1:38135: connect: connection refused
Errors reported from the Docker container:
+ '[' '' = true ']'
+ exec /usr/bin/rpk redpanda start --node-id 0 --kafka-addr internal://0.0.0.0:9092,external://172.24.1.2:9093 --pandaproxy-addr internal://0.0.0.0:8082,external://172.24.1.2:35717 --schema-registry-addr 172.24.1.2:8081 --rpc-addr 172.24.1.2:33145 --advertise-kafka-addr internal://172.24.1.2:9092,external://127.0.0.1:38135 --advertise-pandaproxy-addr internal://172.24.1.2:8082,external://127.0.0.1:35717 --advertise-rpc-addr 172.24.1.2:33145 --mode dev-container
WARNING: This is a setup for development purposes only; in this mode your clusters may run unrealistically fast and data can be corrupted any time your computer shuts down uncleanly.
<libc++abi: terminating due to uncaught exception of type std::runtime_error: Could not setup Async I/O: Resource temporarily unavailable. The most common cause is not enough request capacity in /proc/sys/fs/aio-max-nr. Try increasing that number or reducing the amount of logical CPUs available for your application

Usage:
  rpk container start [flags]

Flags:
  -h, --help           Help for start
      --image string   An arbitrary container image to use (default "vectorized/redpanda:latest")
  -n, --nodes uint     The number of nodes to start (default 1)
      --pull           Force pull the container image used
      --retries uint   The amount of times to check for the cluster before considering it unstable and exiting (default 10)

Global Flags:
      --config string            Redpanda or rpk config file; default search paths are ~/.config/rpk/rpk.yaml, $PWD, and /etc/redpanda/redpanda.yaml
  -X, --config-opt stringArray   Override rpk configuration settings; '-X help' for detail or '-X list' for terser detail
      --profile string           rpk profile to use
  -v, --verbose                  Enable verbose logging

Backports Required

• none - not a bug fix
• none - this is a backport
• none - issue does not exist in previous branches
• none - papercut/not impactful enough to backport
• v23.2.x
• v23.1.x
• v22.3.x

Release Notes

• None

[r-vasquez]

Hey @voutilad , why is this a Draft? this seems awesome and helps with the debugging experience. Thanks!

(Just 2 small comments/nits, otherwise, LGTM)

[r-vasquez]

Wdyt of a similar chained error like in L369

Suggested change

	return nil, fmt.Errorf("%v\n%v", err, errInspect)
	return nil, fmt.Errorf("%v\nCould not inspect container: %v", err, errInspect)

[r-vasquez]

[nit] Just to keep with rest of the codebase

Suggested change

	errStr := ""
	var errStr string

[r-vasquez]

Hi @voutilad, as we talked, this can be closed in favor of #17780. I cherry-picked your commit and finished the PR there. Thanks a lot!