wp redis cli hangs

Hey @ddyok,

Were you able to track this down?

WP Redis simply calls the equivalent of WP_CLI::launch(‘redis-cli’), which uses proc_open() under the hood.

Notably, the wp redis info command uses PhpRedis to fetch the relevant data, not the Redis CLI interface.

Here are a few questions that might help you debug further:

• What happens when you call redis-cli directly (with the relevant connection details)?
• If you use wp shell, what happens when you call WP_CLI::launch() with some other command?
• What system and shell are you on?

Hey Daniel,

>What happens when you call redis-cli

That works fine. So this not a very urgent matter. Maybe just to figure out what’s going on.

> wp shell, what happens when you call WP_CLI::launch()

wp> WP_CLI::launch()
PHP Fatal error: Uncaught ArgumentCountError: Too few arguments to function WP_CLI::launch(), 0 passed in phar:///usr/local/bin/wp/vendor/wp-cli/shell-command/src/WP_CLI/Shell/REPL.php(46) : eval()’d code on line 1 and at least 1 expected in phar:///usr/local/bin/wp/vendor/wp-cli/wp-cli/php/class-wp-cli.php:1029

Wonder what this is about? Trying to find out. I don’t know if it’s related to you.

> What system and shell are you on?

Linux 4.15.0-88-generic #88-Ubuntu SMPx86_64 x86_64 x86_64 GNU/Linux

with bash

Thank you.

Thanks for the update, @ddyok.

Given redis-cli works, and WP Redis simply calls WP-CLI functions, it seems like this issue is specific to WP-CLI and not WP Redis.

wp> WP_CLI::launch()
PHP Fatal error: Uncaught ArgumentCountError: Too few arguments to function WP_CLI::launch(), 0 passed in phar:///usr/local/bin/wp/vendor/wp-cli/shell-command/src/WP_CLI/Shell/REPL.php(46) : eval()’d code on line 1 and at least 1 expected in phar:///usr/local/bin/wp/vendor/wp-cli/wp-cli/php/class-wp-cli.php:1029

Wonder what this is about? Trying to find out. I don’t know if it’s related to you.

You’d need to pass a command as an argument to WP_CLI::launch(). Try WP_CLI::launch( 'echo "Hello World"' );

Also, can you share wp --info ?

@schlessera Have you seen WP_CLI::launch() hang in this manner before? Any ideas on how to debug further?

$ wp shell
wp> WP_CLI::launch( ‘echo “Hello World”‘ );
=> int(0)
wp> exit
$ wp –info
OS: Linux 4.15.0-88-generic #88-Ubuntu SMP Tue Feb 11 20:11:34 UTC 2020 x86_64
Shell: /bin/bash
PHP binary: /usr/bin/php7.2
PHP version: 7.2.24-0ubuntu0.18.04.3
php.ini used: /etc/php/7.2/cli/php.ini
WP-CLI root dir: phar://wp-cli.phar/vendor/wp-cli/wp-cli
WP-CLI vendor dir: phar://wp-cli.phar/vendor
WP_CLI phar path: /var/www/wordpress
WP-CLI packages dir:
WP-CLI global config:
WP-CLI project config:
WP-CLI version: 2.4.0

Huh.

Given that WP_CLI::launch( 'echo "Hello World"' ); works as expected, maybe it’s not WP-CLI after all.

Can you add var_dump( $cmd ); after this line and then, separately, try to run the command that’s dumped? I wonder whether there’s some way the command is formed that’s causing an issue on your system.

Added var_dump( $cmd ); to cli.php (line 34, after $cmd =), and it still hangs.

It didn’t print out the value of $cmd?

Nope, nothing was dumped.

Ok. Can you add var_dump() throughout that method to see where the execution hangs?

I just tested on my system. What I’ve seen so far:

– wp redis cli hangs on my system as well
– The command it tries to run on my system is redis-cli -h "'127.0.0.1'" -p "'6379'" -a "''" -n "0"
– If I run that comand manually, I get the following output:

Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
Could not connect to Redis at '127.0.0.1':0: nodename nor servname provided, or not known
not connected>

– This means Redis was not active on that site. So I used valet to enable Redis: valet redis enable => this one also hangs!

Given the above, my assumption is that Redis changed its CLI behavior (whether intentionally or not) and it doesn’t work as expected anymore.

• This reply was modified 5 years ago by Alain Schlesser.

Thanks @schlessera!

I’m embarrassed to admit… I guess I didn’t even test wp redis cli locally. As soon as I tried it (again?), I was able to reproduce the issue.

In debugging it further, it seems like the behavior of WP_CLI\Utils\esc_cmd() and WP_CLI::launch() have both changed since wp redis cli was written.

WP_CLI\Utils\esc_cmd( 'redis-cli -h "%s" -p "%s" -a "%s" -n "%d"' ), while somewhat incorrect, used to accommodate the double-quoting. I’ve removed the quotes and now it produces a singularly-quoted string as expected.

WP_CLI::launch() used array( STDIN, STDOUT, STDERR ) as the default $descriptorspec unless $return_detailed = true was provided. It looks like I accidentally broke this in 2014. I’m not sure why wp redis cli did work in 2016 but, regardless, switching back to proc_open( $cmd, array( STDIN, STDOUT, STDERR ), $pipes ); does the trick.

@ddyok I’ve just tagged WP Redis v0.8.3. Thanks for your help tracking this issue down!