Can't connect to local DNS name

[rodrigowbazevedo]

I have a local DNS alias in my /etc/hosts just named redis wich points to my Redis server when I try to create the client with the Factory::createClient using this DNS the React\Dns\Resolver\Resolver search for it in this server 8.8.8.8 (Google's DNS Server) and can't resolve because it's local.

[clue]

Hi @rodrigowbazevedo, are you sure you're running the latest versions? This should be supported as of #66. I've verified that this does indeed work locally.

[rodrigowbazevedo]

I'm using version 2.1 I'll update it to 2.2 and test again, Thanks.

[rodrigowbazevedo]

I updated my dependencies and I still get this error DNS Request did not return valid answer.

[clue]

I'd like to look into this and reproduce this locally. Can you show the output of composer info and your hosts file?

This library essentially passes the hostname to react/socket, which passes it to react/dns. Can you see if https://github.com/reactphp/dns/blob/master/examples/01-one.php works for you?

[rodrigowbazevedo]

The output of this script was IP for www.google.com: 216.58.202.100
I tried with localhost and got this output IP for localhost: 127.0.0.1
I tried with redis host and got React\Dns\RecordNotFoundException: DNS Request did not return valid answer.

My composer info

cboden/ratchet            v0.4.1  PHP WebSocket library
clue/ami-react            v0.4.0  Streaming, event-driven access to the Asterisk Manager Interface (AMI), built on top of ReactPHP
clue/redis-protocol       v0.3.1  A streaming redis wire protocol parser and serializer implementation in PHP
clue/redis-react          v2.2.0  Async Redis client implementation, built on top of ReactPHP
evenement/evenement       v3.0.1  Événement is a very simple event dispatching library for PHP
guzzlehttp/psr7           1.4.2   PSR-7 message implementation that also provides common utility methods
justinrainbow/json-schema 1.6.1   A library to validate a json schema.
pimple/pimple             v3.2.3  Pimple, a simple Dependency Injection Container
psr/container             1.0.0   Common Container Interface (PHP FIG PSR-11)
psr/http-message          1.0.1   Common interface for HTTP messages
ratchet/rfc6455           v0.2.3  RFC6455 WebSocket protocol handler
react/cache               v0.4.2  Async, Promise-based cache interface for ReactPHP
react/dns                 v0.4.12 Async DNS resolver for ReactPHP
react/event-loop          v0.4.3  Event loop abstraction layer that libraries can use for evented I/O.
react/promise             v2.5.1  A lightweight implementation of CommonJS Promises/A for PHP
react/promise-timer       v1.2.1  A trivial implementation of timeouts for Promises, built on top of ReactPHP.
react/socket              v0.8.9  Async, streaming plaintext TCP/IP and secure TLS socket server and client connections for ReactPHP
react/stream              v0.7.7  Event-driven readable and writable streams for non-blocking I/O in ReactPHP
seld/jsonlint             1.7.1   JSON Linter
symfony/http-foundation   v4.0.4  Symfony HttpFoundation Component
symfony/polyfill-mbstring v1.7.0  Symfony polyfill for the Mbstring extension
symfony/routing           v4.0.4  Symfony Routing Component
webmozart/assert          1.3.0   Assertions to validate method input/output with nice error messages.
webmozart/json            1.2.2   A robust JSON decoder/encoder with support for schema validation.
webmozart/path-util       2.3.0   A robust cross-platform utility for normalizing, comparing and modifying file paths.
zendframework/zend-config 3.1.0   provides a nested object property based user interface for accessing this configuration data within application...
zendframework/zend-stdlib 3.1.0

[clue]

The react/dns package uses the same handling for localhost as for any other hostname listed in the your hosts file. I wonder if there may be an issue in your hosts file, can you show (parts of) its contents?

[rodrigowbazevedo]

I'm using it inside a docker container with docker-compose, in older versions of docker-compose when you create a link between containers he puts the hostname inside /etc/hosts, but now I looked at it and he doesn't put the hostname inside /etc/hosts anymore, but if I ping the hostname it works... I don't know how... The hostname works well using with PDO for exemple...

[clue]

Interesting find. This sounds more like an issue with your environment and/or you may be affected by reactphp/socket#90. For now, you can explicitly pass your local DNS proxy address to the Connector or explicitly pass custom host mappings to Docker with the --add-host redis:10.1.2.3 flag (or extra_hosts with docker-compose).

See also https://docs.docker.com/engine/userguide/networking/default_network/dockerlinks/ and https://docs.docker.com/engine/userguide/networking/#embedded-dns-server for more details.

I hope this helps 👍

[rodrigowbazevedo]

Perfect I think using the docker embedded DNS server will work.

[clue]

This has been fixed via reactphp/socket#152 which has just been released https://github.com/reactphp/socket/releases/tag/v0.8.10 🎉 This means that this should now work out of the box if you update react/socket to v0.4.10.

Please report back if the problem persists 👍

[rodrigowbazevedo]

Great to know I'll test it!