apache/pulsar · error · RuntimeException

Kubernetes does not allow upper case jobNames.

Error message

Kubernetes does not allow upper case jobNames.

What it means

KubernetesRuntime.doChecks() validates the derived job name because Kubernetes resource names must be RFC-1123 DNS labels (lowercase). If the job name (derived from tenant/namespace/function names or an overridden job name) contains uppercase characters, a RuntimeException is thrown before any k8s call.

Source

Thrown at pulsar-functions/runtime/src/main/java/org/apache/pulsar/functions/runtime/kubernetes/KubernetesRuntime.java:1164

        final String jobNameBase = String.format("%s-%s-%s", tenant, namespace, functionName);
        final String jobName = "pf-" + jobNameBase;
        final String convertedJobName = toValidPodName(jobName);
        if (jobName.equals(convertedJobName)) {
            return jobName;
        }
        // toValidPodName may cause naming collisions, add a short hash here to avoid it
        final String shortHash = DigestUtils.sha1Hex(jobNameBase).toLowerCase().substring(0, 8);
        return convertedJobName + "-" + shortHash;
    }
    @VisibleForTesting
    String getServiceUrl(String jobName, String jobNamespace, int instanceId) {
        String suffix = isNotBlank(kubernetesServiceDomainSuffix) ? kubernetesServiceDomainSuffix : "svc.cluster.local";
        return String.format("%s-%d.%s.%s.%s", jobName, instanceId, jobName, jobNamespace, suffix);
    }
    public static void doChecks(FunctionDetails functionDetails, String overridenJobName) {
        final String jobName = createJobName(functionDetails, overridenJobName);
        if (!jobName.equals(jobName.toLowerCase())) {
            throw new RuntimeException("Kubernetes does not allow upper case jobNames.");
        }
        final Matcher matcher = VALID_POD_NAME_REGEX.matcher(jobName);
        if (!matcher.matches()) {
            throw new RuntimeException("Kubernetes only admits lower case and numbers. "
                    + "(jobName=" + jobName + ")");
        }
        if (jobName.length() > maxJobNameSize) {
            throw new RuntimeException("Kubernetes job name size should be less than " + maxJobNameSize);
        }
    }
}

View on GitHub (pinned to 820761864e)

Solutions

1. Rename the function using only lowercase letters, numbers, and '-'.
2. If using an overridden job name, change it to lowercase.
3. Where renaming is impossible, configure a sanitized/translated job name (the runtime normally translates invalid chars — check the name isn't bypassing translation).

Example fix

// before
functions create --name MyFunction ...
// after
functions create --name my-function ...

String jobName = tenant + "-" + namespace + "-" + functionName;
if (!jobName.equals(jobName.toLowerCase())) {
    throw new IllegalArgumentException("Function/job name must be lowercase for Kubernetes: " + jobName);
}

static boolean isValidK8sName(String name) {
    return name != null && name.equals(name.toLowerCase());
}

try {
    functions.create(request);
} catch (RuntimeException e) {
    if (e.getMessage().contains("upper case jobNames")) {
        log.error("Rename function to lowercase: {}", e.getMessage());
    }
    throw e;
}

When it happens

Trigger: Function metadata (tenant, namespace, name) or the overridden job name contains uppercase letters, producing a jobName like "MyFunction"; doChecks() rejects it via jobName.equals(jobName.toLowerCase()).

Common situations: Users create functions with CamelCase names; cluster-level custom job name overrides include capitals; older clients allowed names Kubernetes rejects.

Related errors

• Kubernetes only admits lower case and numbers. (jobName=%s)
• Invalid value for BROKER_CLIENT_TRUST_CERTS_SECRET_NAME. Exp
• Invalid value for SERVICE_ACCOUNT_TOKEN_EXPIRATION_SECONDS.
• Invalid value for SERVICE_ACCOUNT_TOKEN_AUDIENCE. Expected a
• Failed to create service for function %s

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/d6111170c0ad504f. Report an issue: GitHub.