Skip to content

feat(zrpc): add local kubeconfig fallback for k8s resolver #5383

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
tangentgo wants to merge 2 commits into
base: master
Choose a base branch
from
+121 −15
Open

feat(zrpc): add local kubeconfig fallback for k8s resolver #5383

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
dced64e
feat(zrpc): add local kubeconfig fallback for k8s resolver
Jan 22, 2026
2b527d6
feat(zrpc): add GOZERO_K8S_LOCAL_FALLBACK env check for kubeconfig fa…
Jan 30, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions go.mod
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -76,6 +76,7 @@ require (
github.com/grafana/pyroscope-go/godeltaprof v0.1.9 // indirect
github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0 // indirect
github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542 // indirect
github.com/imdario/mergo v0.3.6 // indirect
github.com/jackc/pgpassfile v1.0.0 // indirect
github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
github.com/jackc/puddle/v2 v2.2.2 // indirect
Expand All @@ -96,6 +97,7 @@ require (
github.com/prometheus/common v0.66.1 // indirect
github.com/prometheus/procfs v0.16.1 // indirect
github.com/rivo/uniseg v0.2.0 // indirect
github.com/spf13/pflag v1.0.5 // indirect
github.com/stretchr/objx v0.5.2 // indirect
github.com/xdg-go/pbkdf2 v1.0.0 // indirect
github.com/xdg-go/scram v1.1.2 // indirect
Expand Down
2 changes: 2 additions & 0 deletions go.sum
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -90,6 +90,8 @@ github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0 h1:bkypFPDjIYGfCYD5mRBvpqxfYX1
github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0/go.mod h1:P+Lt/0by1T8bfcF3z737NnSbmxQAppXMRziHUxPOC8k=
github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542 h1:2VTzZjLZBgl62/EtslCrtky5vbi9dd7HrQPQIx6wqiw=
github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542/go.mod h1:Ow0tF8D4Kplbc8s8sSb3V2oUCygFHVp8gC3Dn6U4MNI=
github.com/imdario/mergo v0.3.6 h1:xTNEAn+kxVO7dTZGu0CegyqKZmoWFI0rF8UxjlB2d28=
github.com/imdario/mergo v0.3.6/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
Expand Down
34 changes: 31 additions & 3 deletions zrpc/resolver/internal/kubebuilder.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,11 @@ package internal

import (
"context"
"errors"
"fmt"
"os"
"path/filepath"
"strings"
"time"

"github.com/zeromicro/go-zero/core/logx"
Expand All @@ -15,11 +19,14 @@ import (
"k8s.io/client-go/informers"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/rest"
"k8s.io/client-go/tools/clientcmd"
)

const (
resyncInterval = 5 * time.Minute
serviceSelector = "kubernetes.io/service-name="
resyncInterval = 5 * time.Minute
serviceSelector = "kubernetes.io/service-name="
localFallbackEnvKey = "GOZERO_K8S_LOCAL_FALLBACK"
localFallbackEnvValueTrue = "true"
)

type kubeResolver struct {
Expand Down Expand Up @@ -51,7 +58,28 @@ func (b *kubeBuilder) Build(target resolver.Target, cc resolver.ClientConn,

Copy link

Copilot AI Jan 22, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The fallback mechanism lacks documentation. Consider adding a comment before line 56 to explain the fallback behavior, such as: "Try in-cluster config first, then fall back to ~/.kube/config for local development." This would help developers understand the configuration loading strategy.

Suggested change
// Try in-cluster config first, then fall back to ~/.kube/config for local development.

Copilot uses AI. Check for mistakes.
config, err := rest.InClusterConfig()
if err != nil {
return nil, err
// Check if local fallback is enabled via environment variable
if !strings.EqualFold(os.Getenv(localFallbackEnvKey), localFallbackEnvValueTrue) {
return nil, fmt.Errorf("not running in cluster and %s is not set to true: %w",
localFallbackEnvKey, err)
}

// Try to load kubeconfig from KUBECONFIG env or default path
kubeconfig := os.Getenv("KUBECONFIG")
if kubeconfig == "" {
home, errHome := os.UserHomeDir()
if errHome != nil {
return nil, errors.Join(err, errHome)
}
kubeconfig = filepath.Join(home, ".kube", "config")
}

localConfig, errLocal := clientcmd.BuildConfigFromFlags("", kubeconfig)
if errLocal != nil {
return nil, fmt.Errorf("k8s config load failed from %s: %w", kubeconfig,
errors.Join(err, errLocal))
}
config = localConfig
}

cs, err := kubernetes.NewForConfig(config)
Expand Down
98 changes: 86 additions & 12 deletions zrpc/resolver/internal/kubebuilder_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -15,20 +15,94 @@ func TestKubeBuilder_Scheme(t *testing.T) {
}

func TestKubeBuilder_Build(t *testing.T) {
t.Setenv("HOME", t.TempDir())
t.Setenv("KUBERNETES_SERVICE_HOST", "")
t.Setenv("KUBERNETES_SERVICE_PORT", "")
t.Setenv("GOZERO_K8S_LOCAL_FALLBACK", "true")

var b kubeBuilder
u, err := url.Parse(fmt.Sprintf("%s://%s", KubernetesScheme, "a,b"))
assert.NoError(t, err)
cc := &mockedClientConn{}

tests := []struct {
name string
input string
}{
{
name: "invalid host",
input: fmt.Sprintf("%s://%s", KubernetesScheme, "a,b"),
},
{
name: "bad endpoint format",
input: fmt.Sprintf("%s://%s:9100/a:b:c", KubernetesScheme, "a,b,c,d"),
},
}

for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
u, err := url.Parse(tt.input)
assert.NoError(t, err)

_, err = b.Build(resolver.Target{
URL: *u,
}, cc, resolver.BuildOptions{})
assert.Error(t, err)
})
}
}

func TestKubeBuilder_Build_LocalFallback(t *testing.T) {
tests := []struct {
name string
fallbackEnv string
kubeconfig string
errContains string
}{
{
name: "disabled when env not set",
fallbackEnv: "",
errContains: "GOZERO_K8S_LOCAL_FALLBACK",
},
{
name: "disabled when env is false",
fallbackEnv: "false",
errContains: "GOZERO_K8S_LOCAL_FALLBACK",
},
{
name: "enabled when env is true",
fallbackEnv: "true",
errContains: "k8s config load failed",
},
{
name: "use custom KUBECONFIG path",
fallbackEnv: "true",
kubeconfig: "/nonexistent/custom/kubeconfig",
errContains: "/nonexistent/custom/kubeconfig",
},
}

for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
t.Setenv("HOME", t.TempDir())
t.Setenv("KUBERNETES_SERVICE_HOST", "")
t.Setenv("KUBERNETES_SERVICE_PORT", "")
if tt.fallbackEnv != "" {
t.Setenv("GOZERO_K8S_LOCAL_FALLBACK", tt.fallbackEnv)
}
if tt.kubeconfig != "" {
t.Setenv("KUBECONFIG", tt.kubeconfig)
}

_, err = b.Build(resolver.Target{
URL: *u,
}, nil, resolver.BuildOptions{})
assert.Error(t, err)
var b kubeBuilder
cc := &mockedClientConn{}

u, err = url.Parse(fmt.Sprintf("%s://%s:9100/a:b:c", KubernetesScheme, "a,b,c,d"))
assert.NoError(t, err)
u, err := url.Parse(fmt.Sprintf("%s://my-service.default:8080", KubernetesScheme))
assert.NoError(t, err)

_, err = b.Build(resolver.Target{
URL: *u,
}, nil, resolver.BuildOptions{})
assert.Error(t, err)
_, err = b.Build(resolver.Target{
URL: *u,
}, cc, resolver.BuildOptions{})
assert.Error(t, err)
assert.Contains(t, err.Error(), tt.errContains)
})
}
}