[bitnami/redis] Fix Redis sentinel initialization with single replica

[Nepoxx]

Description

The get_service_ip function was called unconditionally during master initialization but only defined when external access is enabled. This caused single-replica Redis deployments to fail during startup when using the default internal-only configuration.

The fix makes the initialization logic consistent with the comparison logic by using get_full_hostname when external access is disabled.

Description of the change

This change fixes a conditional logic mismatch in the Redis chart's startup script template. The get_service_ip() function was being called unconditionally during master initialization (line 158) but was only defined when sentinel.externalAccess.enabled is true. This caused Redis containers to fail during startup in single-replica deployments using the default configuration where external access is disabled.

The fix adds the same conditional logic used in the comparison section to the initialization section, ensuring consistency between initialization and comparison phases.

Benefits

• Fixes Redis sentinel mode in single-replica deployments with default configuration
• Maintains compatibility with existing multi-replica deployments
• Ensures consistent conditional logic throughout the startup script
• No breaking changes to existing functionality

Possible drawbacks

None identified. The change only affects the problematic code path and maintains all existing behavior for configurations where external access is enabled.

Applicable issues

This addresses startup failures in single-replica Redis deployments where sentinel is unable to promote the replica to master due to undefined function calls.

Additional information

The issue occurs specifically when:

• replica.replicaCount: 1 (single replica)
• sentinel.externalAccess.enabled: false (default configuration)

The fix ensures the startup script works correctly in both external access and internal-only configurations.

Checklist

• Chart version bumped in Chart.yaml according to semver. This is not necessary when the changes only affect README.md files.
• Variables are documented in the values.yaml and added to the README.md using readme-generator-for-helm
• Title of the pull request follows this pattern [bitnami/<name_of_the_chart>] Descriptive title
• All commits signed off and in agreement of Developer Certificate of Origin (DCO)

Technical Details

Root Cause

The bug existed in /bitnami/redis/templates/scripts-configmap.yaml at line 158:

master_in_persisted_conf="$(get_service_ip "$SVC_NAME")"

This line called get_service_ip() unconditionally, but the function was only defined when:

{{- if and .Values.sentinel.externalAccess.enabled .Values.sentinel.externalAccess.service.loadBalancerIP }}

Fix Applied

Changed the unconditional call to use the same conditional logic as the comparison section:

{{- if and .Values.sentinel.externalAccess.enabled .Values.sentinel.externalAccess.service.loadBalancerIP }}
master_in_persisted_conf="$(get_service_ip "$SVC_NAME")"
{{- else }}
master_in_persisted_conf="$(get_full_hostname "$HOSTNAME")"
{{- end }}

Tested Scenarios

• ✅ Single replica with internal access (default)
• ✅ Multiple replicas with internal access
• ✅ Single/multiple replicas with external access

[gongomgra]

Hi @Nepoxx

Thanks for reporting this issue and for contributing with a solution! Can you please rebase your branch with updated main branch and fix the conflicts so we can merge your changes?

[gongomgra]

Thanks for your contribution!