Registry resource unavailable

Description

The platform does not start. In response to the command to start the platform, an error shown below appears:

# vm start
2024/01/31 21:41:16 Running command 'docker-compose -f /opt/ispsystem/vm/docker-compose.yaml up -d --remove-orphans --timeout 20'
Pulling clickhouse_server (docker-registry.ispsystem.com/team/vm/clickhouse:0.0.4)...
Get "https://docker-registry.ispsystem.com/v2/": dial tcp: lookup docker-registry.ispsystem.com on [::1]:53: read udp [::1]:60454->[::1]:53: read: connection refused
exit status 1

The error means that the server cannot access the registry-1.docker.io resource where the containers required for the start are located. In most cases, the error occurs if no DNS servers are specified in the /etc/resolv.conf file.

Solution

To solve the problem:

Connect to the server with the platform via SSH.
Check the availability of registry-1.docker.io:
```
ping registry-1.docker.io
```
If there is no response, make sure that the /etc/resolv.conf file contains entries as follows:
```
nameserver <IP address of DNS server>
```
If the IP address of the systemd-resolved local service (127.0.0.53) is specified as the DNS server, check that the DNS server addresses are specified in /etc/systemd/resolved.conf:
```
DNS=<list_servers>
```
If there are no entries, add them to the /etc/systemd/resolved.conf file.
An example of entries
```
# Generated by NetworkManager
nameserver <IP address of DNS server>
```
Start the platform:
```
vm start
```