Docker version 24.0.2
Ubuntu (WSL) 22.04
WSL version: 2.1.5.0
I have two unrelated docker projects both displaying cURL error 7 messages when upgrading from PHP 8.0 to PHP 8.1 and later. Both projects are WordPress stacks with reverse proxies, one is more complex with Apache which I’ll omit, the other is very simple with Nginx see details below.
Up to WordPress PHP 8.0 I experienced the following two WordPress Site Health check errors:
REST API Endpoint: https://wordpress.localhost/index.php?rest_route=%2Fwp%2Fv2%2Ftypes%2Fpost&context=edit
REST API Response: (http_request_failed) cURL error 7: Failed to connect to wordpress.localhost port 443 after 0 ms: Couldn't connect to server
The loopback request to your site failed, this means features relying on them are not currently working as expected.
Error: cURL error 7: Failed to connect to wordpress.localhost port 443 after 0 ms: Couldn't connect to server (http_request_failed)
These were both resolved by adding the following to the wordpress service in docker compose:
extra_hosts:
- wordpress.localhost:172.17.0.1
Unfortunately with PHP 8.1 and later in Nginx and Apache the same errors are back.
If I execute:
docker exec -it wordpress bash
then
curl -Lv http://wordpress.localhost
there are no errors but if I execute the same command for ssl:
curl -Lv https://wordpress.localhost
I get the following error:
* Trying 127.0.0.1:443...
* connect to 127.0.0.1 port 443 failed: Connection refused
* Trying [::1]:443...
* Immediate connect fail for ::1: Cannot assign requested address
* Failed to connect to wordpress.localhost port 443 after 0 ms: Couldn't connect to server
* Closing connection 0
curl: (7) Failed to connect to wordpress.localhost port 443 after 0 ms: Couldn't connect to server
If I roll back WordPress to PHP 8.0 and execute the same cURL command in the same container:
curl -Lv https//wordpress.localhost
the error is different:
* Trying 172.17.0.1:443...
* Connected to wordpress.localhost (172.17.0.1) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
* CAfile: /etc/ssl/certs/ca-certificates.crt
* CApath: /etc/ssl/certs
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
* TLSv1.3 (IN), TLS handshake, Certificate (11):
* TLSv1.3 (OUT), TLS alert, unknown CA (560):
* SSL certificate problem: unable to get local issuer certificate
* Closing connection 0
curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: https://curl.se/docs/sslcerts.html
curl failed to verify the legitimacy of the server and therefore could not
establish a secure connection to it. To learn more about this situation and
how to fix it, please visit the web page mentioned above.
root@71dcc56b92f6:/var/www/html#
I notice PHP 8.1 attempts to connect to 127.0.0.1 and PHP 8.0 to 172.17.0.1.
I can cURL both my projects from Ubuntu (WSL) without any errors using:
curl -Lv https://wordpress.localhost
Everything else appears correct and there are no SSL errors in the browser or elsewhere so it feels like an internal docker networking issue with SSL and reverse proxies. My project is public on GitHub here.
My Docker Compose YAML:
name: lemp
services:
mariadb:
image: mariadb:11.2.3-jammy
container_name: mariadb
restart: always
expose:
- 3306
volumes:
- lemp_db_data:/var/lib/mysql
environment:
MARIADB_DATABASE: rds_mysql
MARIADB_USER: wpress
MARIADB_PASSWORD: wpress_247x
MARIADB_ROOT_PASSWORD: root_wpress_247x
networks:
- nginx
wordpress:
depends_on:
- mariadb
image: wordpress:6.4.1-php8.1
container_name: wordpress
restart: unless-stopped
expose:
- 80
- 443
extra_hosts:
- wordpress.localhost:172.17.0.1
environment:
WORDPRESS_DB_HOST: mariadb
WORDPRESS_DB_USER: wpress
WORDPRESS_DB_PASSWORD: wpress_247x
WORDPRESS_DB_NAME: rds_mysql
WORDPRESS_DEBUG: 1
WORDPRESS_CONFIG_EXTRA: |
define( 'WP_DEBUG_DISPLAY', true );
define( 'WP_DEBUG_LOG', true );
networks:
- nginx
nginx:
image: nginx:1.25.2
container_name: nginx
restart: unless-stopped
depends_on:
- wordpress
ports:
- 80:80
- 443:443
volumes:
- ./nginx/conf.d/default.conf:/etc/nginx/conf.d/default.conf
- ./nginx/ssl/my_wpress_site.crt:/etc/nginx/my_wpress_site.crt
- ./nginx/ssl/my_wpress_site.key:/etc/nginx/my_wpress_site.key
- /var/log/nginx:/var/log/nginx
networks:
- nginx
volumes:
lemp_db_data:
external: true
networks:
nginx:
name: nginx
My Nginx default.conf:
server {
listen 80;
listen [::]:80;
server_name wordpress.localhost;
location / {
access_log off;
return 301 https://$server_name$request_uri;
proxy_set_header X-Forwarded-Proto http;
}
}
server {
listen 443 ssl;
listen [::]:443 ssl;
server_name wordpress.localhost;
access_log /var/log/nginx/wordpress-443-access.log main;
error_log /var/log/nginx/wordpress-443-error.log debug;
ssl_certificate /etc/nginx/my_wpress_site.crt;
ssl_certificate_key /etc/nginx/my_wpress_site.key;
location / {
proxy_pass http://wordpress;
proxy_redirect off;
proxy_read_timeout 90;
proxy_connect_timeout 90;
proxy_set_header X-Forwarded-Proto https;
}
}
I am not a programmer so I’m having to learn everything as I go along but I’m finding this last part difficult to resolve.
I worded it badly but I figured out it was probably a library bundled in the WordPress PHP version and probably cURL or OpenSSL, your solution should be ideal.