quarkusio/quarkus · error · IllegalArgumentException

Unable to resolve "${value}"

Error message

Unable to resolve "${value}"

What it means

InetAddressConverter.convert() parses a config value as a literal IP first, then falls back to InetAddress.getByName(value). If the name cannot be resolved (UnknownHostException), it throws IllegalArgumentException("Unable to resolve \"<value>\"").

Source

Thrown at core/runtime/src/main/java/io/quarkus/runtime/configuration/InetAddressConverter.java:36

@Priority(DEFAULT_QUARKUS_CONVERTER_PRIORITY)
public class InetAddressConverter implements Converter<InetAddress>, Serializable {

    private static final long serialVersionUID = 4539214213710330204L;

    @Override
    public InetAddress convert(String value) {
        value = value.trim();
        if (value.isEmpty()) {
            return null;
        }
        final InetAddress parsed = Inet.parseInetAddress(value);
        if (parsed != null) {
            return parsed;
        }
        try {
            return InetAddress.getByName(value);
        } catch (UnknownHostException e) {
            throw new IllegalArgumentException("Unable to resolve \"" + value + "\"", e);
        }
    }
}

View on GitHub (pinned to e1c734241f)

Solutions

1. Use a literal IP address instead of a hostname if DNS is unreliable.
2. Fix the hostname typo or add the entry to DNS//etc/hosts.
3. Ensure DNS is reachable in the runtime environment (container network, CoreDNS, resolv.conf).
4. If the property accepts multiple formats, confirm the value matches one exactly (try parsing with InetAddress.getByName locally).

Example fix

# before
quarkus.datasource.jdbc.host=db.internal   # unresolvable at startup
# after
quarkus.datasource.jdbc.host=10.0.0.5      # or fix DNS for db.internal

boolean isResolvable(String s) {
    if (s == null || s.isBlank()) return false;
    try {
        java.net.InetAddress.getByName(s.trim());
        return true;
    } catch (java.net.UnknownHostException e) { return false;
    }
}

java.net.InetAddress tryResolve(String s) {
    try { return (s == null || s.isBlank()) ? null : java.net.InetAddress.getByName(s.trim()); }
    catch (java.net.UnknownHostException e) { return null; }
}

try {
    // use converted InetAddress
} catch (IllegalArgumentException e) {
    if (e.getMessage().startsWith("Unable to resolve")) {
        log.errorf("Host unresolvable, falling back to loopback: %s", e.getMessage());
        addr = java.net.InetAddress.getLoopbackAddress();
    } else { throw e; }
}

When it happens

Trigger: Setting an IP/host-typed property with a hostname that DNS cannot resolve at startup, an invalid IP literal, or running in an environment without DNS/network access (containers, offline CI) where a hostname would be needed.

Common situations: Typo in hostname ('db.host.local' vs 'dbhost.local'); Docker/Kubernetes startup before the DNS entry exists; IPv6 literals needing brackets or wrong syntax; offline native-image container trying to resolve localhost aliases.

Related errors

• Failed to parse CIDR address "${value}"
• Unable to create Charset from: '${trimmedCharset}'
• Invalid duration: ${value}
• No SRV records available for host
• Unable to look up SRV record for host

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/c0cae0e83ad62e19. Report an issue: GitHub.