cli: hint client flags in the output of cockroach start

[knz]

Fixes #14325.
Requested by @sploiselle.

When one starts a node with the --host/--advertise flag, all future
clients commands require the same value in --host. However, there is
no in-app messaging that communicates this requirement, nor is there a
command that you can run to find out what the --host flag was set to.

Ditto for --certs-dir.

This patch enhances the situation by announcing the command prefix to
use for client commands in the output of cockroach start. For
example:

% ./cockroach start --certs-dir=certs --host=localhost
CockroachDB node starting [...]
...
client flags:        ./cockroach --host=localhost --port=26257 --certs-dir=certs
...

% ./cockroach start --certs-dir=certs --host=localhost --advertise-host=kenax
CockroachDB node starting [...]
...
client flags:        ./cockroach --host=kenax --port=26257 --certs-dir=certs
...

Release note (cli change): cockroach start now informs the user of
which command-line flags to use to access the newly started node in
client commands (e.g. cockroach quit etc.).

[cockroach-teamcity]

This change is 

[petermattis]

modulo nit.

Reviewable status: complete! 0 of 0 LGTMs obtained (and 1 stale)

---

pkg/cli/start.go, line 569 at r1 (raw file):

			fmt.Fprintf(tw, "webui:\t%s\n", serverCfg.AdminURL())
			fmt.Fprintf(tw, "sql:\t%s\n", pgURL)
			fmt.Fprintf(tw, "client cmd:\t%s\n", clientFlags())

Nit: the commit message says client flags, but here you have client cmd. I wonder if this should be cli flags. @piyush-singh ?

[piyush-singh]

I agree with cli flags to eliminate any ambiguity.

[knz]

Done.

Used the word "client" because "cli flag" would be inclusive of "cockroach start".

[petermattis]

Used the word "client" because "cli flag" would be inclusive of "cockroach start".

client feels confusing to me because I think of the client application. console flags? We could bike shed this all day.

[knz]

What do you want me to do here?

• cli flags is incorrect because other commands (cockroach gen, cockroach debug etc) cannot use the flags
• console flags is confusing because the flags work also when used in scripts in a non-interactive fashion
• terminal flags ditto

Now consider this: I used client flags: but I also placed the word ./cockroach directly to the right of it. This is a reminder we're talking about CockroachDB client commands, not anything else. Is that reminder insufficient?

[petermattis]

What do you want me to do here?

I'm not thrilled with any of the options. client flags is fine for now given the problems with the other options.

[a-robinson]

Reviewed 1 of 1 files at r2.
Reviewable status: complete! 0 of 0 LGTMs obtained (and 1 stale)

---

pkg/cli/start.go, line 794 at r2 (raw file):

	flags := []string{
		os.Args[0],
		"--host=" + serverAdvertiseHost,

If I just run cockroach start without specifying --host or --advertise-host, won't serverAdvertiseHost be empty? I'd think we'd want to omit --host in such cases (or always use localhost or the hostname or something)..

[a-robinson]

Reviewable status: complete! 0 of 0 LGTMs obtained (and 2 stale)

---

pkg/cli/start.go, line 794 at r2 (raw file):

Previously, a-robinson (Alex Robinson) wrote…

If I just run cockroach start without specifying --host or --advertise-host, won't serverAdvertiseHost be empty? I'd think we'd want to omit --host in such cases (or always use localhost or the hostname or something)..

Although I guess that's ok, so nevermind.

[a-robinson]

Reviewable status: complete! 1 of 0 LGTMs obtained (and 1 stale)

[knz]

@a-robinson good catch I wasn't looking at the right var to generate the flags. Fixed.

[a-robinson]

Reviewed 1 of 1 files at r3.
Reviewable status: complete! 0 of 0 LGTMs obtained (and 2 stale)

[knz]

thanks!

bors r+

[craig]

Build succeeded

• GitHub CI (Cockroach)