os-dnscrypt-proxy: bootstrap_resolvers template incorrectly formats multiple comma-separated resolvers

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Description

The os-dnscrypt-proxy plugin template incorrectly generates the bootstrap_resolvers configuration when multiple comma-separated DNS servers are specified in the "Fallback Resolver" field. This causes dnscrypt-proxy to fail to start with a FATAL error.

The template at dns/dnscrypt-proxy/src/opnsense/service/templates/OPNsense/Dnscryptproxy/dnscrypt-proxy.toml line 98 generates:

bootstrap_resolvers = ['1.1.1.1:53,9.9.9.9:53']

But it should generate:

bootstrap_resolvers = ['1.1.1.1:53', '9.9.9.9:53']

The comma ends up inside the string instead of separating array elements, causing dnscrypt-proxy to reject it as an invalid IP address.

This appears to have been present since the fallback_resolver field was introduced. The same template correctly handles comma-separated values for listen_addresses (line 12), server_names (line 4), and relaylist (line 192) using a split/join pattern, but bootstrap_resolvers was not updated to use this pattern.

To reproduce:

1. Go to Services → DNSCrypt-Proxy → General
2. In "Fallback Resolver" field, enter multiple resolvers: 1.1.1.1:53,9.9.9.9:53
3. Click Save and Apply
4. Check service status - dnscrypt-proxy fails to start
5. Check /var/log/dnscrypt-proxy/dnscrypt-proxy.log for FATAL error

Expected behavior:

dnscrypt-proxy should start successfully and use both resolvers for bootstrapping DNS-over-HTTPS connections. Multiple bootstrap resolvers provide redundancy if one fails.

Screenshots:: N/A - CLI-based issue

Relevant log files:

[2026-01-23 04:32:27] [NOTICE] dnscrypt-proxy 2.1.5
[2026-01-23 04:32:27] [FATAL] Bootstrap resolver [1.1.1.1:53,9.9.9.9:53]: Host does not parse as IP '1.1.1.1:53,9.9.9.9:53'

Generated config (/usr/local/etc/dnscrypt-proxy/dnscrypt-proxy.toml):

bootstrap_resolvers = ['1.1.1.1:53,9.9.9.9:53']

XML config stores value correctly (/conf/config.xml):

<fallback_resolver>1.1.1.1:53,9.9.9.9:53</fallback_resolver>

Additional context

Root cause: Line 98 of the template uses:

bootstrap_resolvers = ['{{ OPNsense.dnscryptproxy.general.fallback_resolver }}']

Proposed fix: Change to match the pattern used elsewhere in the same template:

bootstrap_resolvers = [{{ "'" + ("','".join(OPNsense.dnscryptproxy.general.fallback_resolver.split(','))) + "'" }}]

Workaround: Users can use only a single bootstrap resolver (e.g., just 1.1.1.1:53) until this is fixed.

Environment

OPNsense 25.7.10 (amd64)
FreeBSD 14.3-RELEASE-p7

Hardware: QEMU/KVM Virtual Machine (Q35 + ICH9)
CPU: Intel Core i7-8550U @ 1.80GHz (4 cores)
Memory: 8 GB

Network Interfaces:
  - igb0 (WAN): Intel I211 Gigabit Network Connection (PCIe passthrough)
  - igb1: Intel I211 Gigabit Network Connection (PCIe passthrough)
  - vtnet0 (LAN): VirtIO Network Adapter

Plugins:
  - os-dnscrypt-proxy 1.16
  - dnscrypt-proxy 2.1.5_20