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Add New Environment Variables for Load Balancer Configuration #1052

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5804cf5
Add new env vars for load balancer config
M4t7e Oct 20, 2025
96ae9f4
Merge branch 'hetznercloud:main' into main
M4t7e Oct 27, 2025
33b6571
Use pointers and remove fallback to default value for public network
M4t7e Oct 27, 2025
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13 changes: 11 additions & 2 deletions docs/guides/load-balancer/configuration.md
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Original file line number Diff line number Diff line change
Expand Up @@ -6,8 +6,17 @@ Load Balancers are configured via Kubernetes [annotations](https://kubernetes.io

For convenience, you can set the following environment variables as cluster-wide defaults, so you don't have to set them on each load balancer service. If a load balancer service has the corresponding annotation set, it overrides the default.

- `HCLOUD_LOAD_BALANCERS_ALGORITHM_TYPE`
- `HCLOUD_LOAD_BALANCERS_DISABLE_IPV6`
- `HCLOUD_LOAD_BALANCERS_DISABLE_PRIVATE_INGRESS`
- `HCLOUD_LOAD_BALANCERS_DISABLE_PUBLIC_NETWORK`
- `HCLOUD_LOAD_BALANCERS_ENABLED`
- `HCLOUD_LOAD_BALANCERS_HEALTH_CHECK_INTERVAL`
- `HCLOUD_LOAD_BALANCERS_HEALTH_CHECK_RETRIES`
- `HCLOUD_LOAD_BALANCERS_HEALTH_CHECK_TIMEOUT`
- `HCLOUD_LOAD_BALANCERS_LOCATION` (mutually exclusive with `HCLOUD_LOAD_BALANCERS_NETWORK_ZONE`)
- `HCLOUD_LOAD_BALANCERS_NETWORK_ZONE` (mutually exclusive with `HCLOUD_LOAD_BALANCERS_LOCATION`)
- `HCLOUD_LOAD_BALANCERS_DISABLE_PRIVATE_INGRESS`
- `HCLOUD_LOAD_BALANCERS_PRIVATE_SUBNET_IP_RANGE`
- `HCLOUD_LOAD_BALANCERS_TYPE`
- `HCLOUD_LOAD_BALANCERS_USE_PRIVATE_IP`
- `HCLOUD_LOAD_BALANCERS_ENABLED`
- `HCLOUD_LOAD_BALANCERS_USES_PROXYPROTOCOL`
103 changes: 100 additions & 3 deletions internal/config/config.go
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Original file line number Diff line number Diff line change
Expand Up @@ -5,10 +5,12 @@ import (
"fmt"
"os"
"strconv"
"strings"
"time"

"k8s.io/klog/v2"

"github.com/hetznercloud/hcloud-go/v2/hcloud"
"github.com/hetznercloud/hcloud-go/v2/hcloud/exp/kit/envutil"
)

Expand All @@ -31,12 +33,20 @@ const (
hcloudNetworkDisableAttachedCheck = "HCLOUD_NETWORK_DISABLE_ATTACHED_CHECK"
hcloudNetworkRoutesEnabled = "HCLOUD_NETWORK_ROUTES_ENABLED"

hcloudLoadBalancersAlgorithmType = "HCLOUD_LOAD_BALANCERS_ALGORITHM_TYPE"
hcloudLoadBalancersDisableIPv6 = "HCLOUD_LOAD_BALANCERS_DISABLE_IPV6"
hcloudLoadBalancersDisablePrivateIngress = "HCLOUD_LOAD_BALANCERS_DISABLE_PRIVATE_INGRESS"
hcloudLoadBalancersDisablePublicNetwork = "HCLOUD_LOAD_BALANCERS_DISABLE_PUBLIC_NETWORK"
hcloudLoadBalancersEnabled = "HCLOUD_LOAD_BALANCERS_ENABLED"
hcloudLoadBalancersHealthCheckInterval = "HCLOUD_LOAD_BALANCERS_HEALTH_CHECK_INTERVAL"
hcloudLoadBalancersHealthCheckRetries = "HCLOUD_LOAD_BALANCERS_HEALTH_CHECK_RETRIES"
hcloudLoadBalancersHealthCheckTimeout = "HCLOUD_LOAD_BALANCERS_HEALTH_CHECK_TIMEOUT"
hcloudLoadBalancersLocation = "HCLOUD_LOAD_BALANCERS_LOCATION"
hcloudLoadBalancersNetworkZone = "HCLOUD_LOAD_BALANCERS_NETWORK_ZONE"
hcloudLoadBalancersDisablePrivateIngress = "HCLOUD_LOAD_BALANCERS_DISABLE_PRIVATE_INGRESS"
hcloudLoadBalancersPrivateSubnetIPRange = "HCLOUD_LOAD_BALANCERS_PRIVATE_SUBNET_IP_RANGE"
hcloudLoadBalancersType = "HCLOUD_LOAD_BALANCERS_TYPE"
hcloudLoadBalancersUsePrivateIP = "HCLOUD_LOAD_BALANCERS_USE_PRIVATE_IP"
hcloudLoadBalancersDisableIPv6 = "HCLOUD_LOAD_BALANCERS_DISABLE_IPV6"
hcloudLoadBalancersUsesProxyProtocol = "HCLOUD_LOAD_BALANCERS_USES_PROXYPROTOCOL"

hcloudMetricsEnabled = "HCLOUD_METRICS_ENABLED"
hcloudMetricsAddress = "HCLOUD_METRICS_ADDRESS"
Expand Down Expand Up @@ -76,12 +86,20 @@ type InstanceConfiguration struct {
}

type LoadBalancerConfiguration struct {
AlgorithmType hcloud.LoadBalancerAlgorithmType
DisablePublicNetwork *bool
Enabled bool
HealthCheckInterval time.Duration
HealthCheckRetries int
HealthCheckTimeout time.Duration
IPv6Enabled bool
Location string
NetworkZone string
PrivateIngressEnabled bool
PrivateIPEnabled bool
IPv6Enabled bool
PrivateSubnetIPRange string
ProxyProtocolEnabled *bool
Type string
}

type NetworkConfiguration struct {
Expand Down Expand Up @@ -188,12 +206,66 @@ func Read() (HCCMConfiguration, error) {
errs = append(errs, err)
}

cfg.LoadBalancer.ProxyProtocolEnabled, err = getEnvBoolPtr(hcloudLoadBalancersUsesProxyProtocol)
if err != nil {
errs = append(errs, err)
}

disableIPv6, err := getEnvBool(hcloudLoadBalancersDisableIPv6, false)
if err != nil {
errs = append(errs, err)
}
cfg.LoadBalancer.IPv6Enabled = !disableIPv6 // Invert the logic, as the env var is prefixed with DISABLE_.

if subnetRange, ok := os.LookupEnv(hcloudLoadBalancersPrivateSubnetIPRange); ok {
cfg.LoadBalancer.PrivateSubnetIPRange = subnetRange
}
Comment on lines +220 to +222
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We could use net.ParseCIDR in the Validate function to check if the format is correct.


if algorithmType, ok := os.LookupEnv(hcloudLoadBalancersAlgorithmType); ok {
alg, parseErr := parseLoadBalancerAlgorithmType(algorithmType)
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I think we are mixing Read and Validate in this call. Could you please move the arg type validation into Validate.

if parseErr != nil {
errs = append(errs, fmt.Errorf("failed to parse %s: %w", hcloudLoadBalancersAlgorithmType, parseErr))
} else {
cfg.LoadBalancer.AlgorithmType = alg
}
}

if interval, ok := os.LookupEnv(hcloudLoadBalancersHealthCheckInterval); ok {
d, parseErr := time.ParseDuration(interval)
if parseErr != nil {
errs = append(errs, fmt.Errorf("failed to parse %s: %w", hcloudLoadBalancersHealthCheckInterval, parseErr))
} else {
cfg.LoadBalancer.HealthCheckInterval = d
}
}
Comment on lines +233 to +240
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Suggested change
if interval, ok := os.LookupEnv(hcloudLoadBalancersHealthCheckInterval); ok {
d, parseErr := time.ParseDuration(interval)
if parseErr != nil {
errs = append(errs, fmt.Errorf("failed to parse %s: %w", hcloudLoadBalancersHealthCheckInterval, parseErr))
} else {
cfg.LoadBalancer.HealthCheckInterval = d
}
}
cfg.LoadBalancer.HealthCheckInterval, err = getEnvDuration(hcloudLoadBalancersHealthCheckInterval)
if err != nil {
errs = append(errs, err)
}

We already have a util function for this. If errs is not empty, HCCM won't continue and throw an error. So the if-else is not necessary here.


if timeout, ok := os.LookupEnv(hcloudLoadBalancersHealthCheckTimeout); ok {
d, parseErr := time.ParseDuration(timeout)
if parseErr != nil {
errs = append(errs, fmt.Errorf("failed to parse %s: %w", hcloudLoadBalancersHealthCheckTimeout, parseErr))
} else {
cfg.LoadBalancer.HealthCheckTimeout = d
}
}
Comment on lines +242 to +249
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Suggested change
if timeout, ok := os.LookupEnv(hcloudLoadBalancersHealthCheckTimeout); ok {
d, parseErr := time.ParseDuration(timeout)
if parseErr != nil {
errs = append(errs, fmt.Errorf("failed to parse %s: %w", hcloudLoadBalancersHealthCheckTimeout, parseErr))
} else {
cfg.LoadBalancer.HealthCheckTimeout = d
}
}
cfg.LoadBalancer.HealthCheckTimeout, err = getEnvDuration(hcloudLoadBalancersHealthCheckTimeout)
if err != nil {
errs = append(errs, err)
}

Same here


if retries, ok := os.LookupEnv(hcloudLoadBalancersHealthCheckRetries); ok {
v, parseErr := strconv.Atoi(retries)
if parseErr != nil {
errs = append(errs, fmt.Errorf("failed to parse %s: %w", hcloudLoadBalancersHealthCheckRetries, parseErr))
} else {
cfg.LoadBalancer.HealthCheckRetries = v
}
}
Comment on lines +251 to +258
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@lukasmetzner lukasmetzner Oct 30, 2025 •
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Suggested change
if retries, ok := os.LookupEnv(hcloudLoadBalancersHealthCheckRetries); ok {
v, parseErr := strconv.Atoi(retries)
if parseErr != nil {
errs = append(errs, fmt.Errorf("failed to parse %s: %w", hcloudLoadBalancersHealthCheckRetries, parseErr))
} else {
cfg.LoadBalancer.HealthCheckRetries = v
}
}
cfg.LoadBalancer.HealthCheckRetries, err = strconv.Atoi(os.Getenv(hcloudLoadBalancersHealthCheckRetries))
if err != nil {
errs = append(errs, err)
}

Same here


cfg.LoadBalancer.DisablePublicNetwork, err = getEnvBoolPtr(hcloudLoadBalancersDisablePublicNetwork)
if err != nil {
errs = append(errs, err)
}

if lbType, ok := os.LookupEnv(hcloudLoadBalancersType); ok {
cfg.LoadBalancer.Type = lbType
}
Comment on lines +265 to +267
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Suggested change
if lbType, ok := os.LookupEnv(hcloudLoadBalancersType); ok {
cfg.LoadBalancer.Type = lbType
}
cfg.LoadBalancer.Type = os.Getenv(hcloudLoadBalancersType)

cfg.LoadBalancer.Type is of type string and therefore will be initialized as an empty string. os.Getenv will return an empty string when the env is not set.


cfg.Network.NameOrID = os.Getenv(hcloudNetwork)
disableAttachedCheck, err := getEnvBool(hcloudNetworkDisableAttachedCheck, false)
if err != nil {
Expand Down Expand Up @@ -270,6 +342,22 @@ func getEnvBool(key string, defaultValue bool) (bool, error) {
return b, nil
}

// getEnvBoolPtr returns a pointer to the boolean parsed from the environment variable with the given key.
// Returns nil if the env var is unset.
func getEnvBoolPtr(key string) (*bool, error) {
v, ok := os.LookupEnv(key)
if !ok {
return nil, nil
}

b, err := strconv.ParseBool(v)
if err != nil {
return nil, fmt.Errorf("failed to parse %s: %w", key, err)
}

return &b, nil
}

// getEnvDuration returns the duration parsed from the environment variable with the given key and a potential error
// parsing the var. Returns false if the env var is unset.
func getEnvDuration(key string) (time.Duration, error) {
Expand All @@ -285,3 +373,12 @@ func getEnvDuration(key string) (time.Duration, error) {

return b, nil
}

func parseLoadBalancerAlgorithmType(value string) (hcloud.LoadBalancerAlgorithmType, error) {
v := strings.ToLower(strings.TrimSpace(value))
alg := hcloud.LoadBalancerAlgorithmType(v)
if alg == hcloud.LoadBalancerAlgorithmTypeRoundRobin || alg == hcloud.LoadBalancerAlgorithmTypeLeastConnections {
return alg, nil
}
return "", fmt.Errorf("unsupported value %q", value)
}
17 changes: 17 additions & 0 deletions internal/config/config_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@ import (
"github.com/stretchr/testify/assert"

"github.com/hetznercloud/hcloud-cloud-controller-manager/internal/testsupport"
"github.com/hetznercloud/hcloud-go/v2/hcloud"
)

func TestRead(t *testing.T) {
Expand Down Expand Up @@ -123,6 +124,14 @@ failed to read ROBOT_PASSWORD_FILE: open /tmp/hetzner-password: no such file or
"HCLOUD_TOKEN", "jr5g7ZHpPptyhJzZyHw2Pqu4g9gTqDvEceYpngPf79jN_NOT_VALID_dzhepnahq",
"HCLOUD_ENDPOINT", "https://api.example.com",
"HCLOUD_DEBUG", "true",
"HCLOUD_LOAD_BALANCERS_PRIVATE_SUBNET_IP_RANGE", "10.1.0.0/24",
"HCLOUD_LOAD_BALANCERS_USES_PROXYPROTOCOL", "true",
"HCLOUD_LOAD_BALANCERS_ALGORITHM_TYPE", "least_connections",
"HCLOUD_LOAD_BALANCERS_HEALTH_CHECK_INTERVAL", "30s",
"HCLOUD_LOAD_BALANCERS_HEALTH_CHECK_TIMEOUT", "5s",
"HCLOUD_LOAD_BALANCERS_HEALTH_CHECK_RETRIES", "5",
"HCLOUD_LOAD_BALANCERS_DISABLE_PUBLIC_NETWORK", "true",
"HCLOUD_LOAD_BALANCERS_TYPE", "lb21",
},
want: HCCMConfiguration{
HCloudClient: HCloudClientConfiguration{
Expand All @@ -140,6 +149,14 @@ failed to read ROBOT_PASSWORD_FILE: open /tmp/hetzner-password: no such file or
Enabled: true,
PrivateIngressEnabled: true,
IPv6Enabled: true,
PrivateSubnetIPRange: "10.1.0.0/24",
ProxyProtocolEnabled: hcloud.Ptr(true),
AlgorithmType: hcloud.LoadBalancerAlgorithmTypeLeastConnections,
HealthCheckInterval: 30 * time.Second,
HealthCheckTimeout: 5 * time.Second,
HealthCheckRetries: 5,
DisablePublicNetwork: hcloud.Ptr(true),
Type: "lb21",
},
},
wantErr: nil,
Expand Down
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