ContainerImage.Pinniped/internal/downward/downward.go
Ryan Richard c6c2c525a6 Upgrade the linter and fix all new linter warnings
Also fix some tests that were broken by bumping golang and dependencies
in the previous commits.

Note that in addition to changes made to satisfy the linter which do not
impact the behavior of the code, this commit also adds ReadHeaderTimeout
to all usages of http.Server to satisfy the linter (and because it
seemed like a good suggestion).
2022-08-24 14:45:55 -07:00

81 lines
2.4 KiB
Go

// Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
// Package downward implements a client interface for interacting with Kubernetes "downwardAPI" volumes.
// See https://kubernetes.io/docs/tasks/inject-data-application/downward-api-volume-expose-pod-information/.
package downward
import (
"bytes"
"fmt"
"io"
"os"
"path/filepath"
"strconv"
"strings"
"go.pinniped.dev/internal/plog"
)
// PodInfo contains pod metadata about the current pod.
type PodInfo struct {
// Namespace where the current pod is running.
Namespace string
// Name of the current pod.
Name string
// Labels of the current pod.
Labels map[string]string
}
// Load pod metadata from a downwardAPI volume directory.
func Load(directory string) (*PodInfo, error) {
var result PodInfo
ns, err := os.ReadFile(filepath.Join(directory, "namespace"))
if err != nil {
return nil, fmt.Errorf("could not load namespace: %w", err)
}
result.Namespace = strings.TrimSpace(string(ns))
name, err := os.ReadFile(filepath.Join(directory, "name"))
if err != nil {
plog.Warning("could not read 'name' downward API file")
} else {
result.Name = strings.TrimSpace(string(name))
}
labels, err := os.ReadFile(filepath.Join(directory, "labels"))
if err != nil {
return nil, fmt.Errorf("could not load labels: %w", err)
}
result.Labels, err = parseMap(labels)
if err != nil {
return nil, fmt.Errorf("could not parse labels: %w", err)
}
return &result, nil
}
// parseMap parses the key/value format emitted by the Kubernetes Downward API for pod labels and annotations.
// See https://kubernetes.io/docs/tasks/inject-data-application/downward-api-volume-expose-pod-information/.
// See https://github.com/kubernetes/kubernetes/blob/4b2cb072dba10227083b16731f019f096c581787/pkg/fieldpath/fieldpath.go#L28.
func parseMap(input []byte) (map[string]string, error) {
result := map[string]string{}
for _, line := range bytes.Split(input, []byte("\n")) {
line = bytes.TrimSpace(line)
if len(line) == 0 {
continue
}
parts := bytes.SplitN(line, []byte("="), 2)
if len(parts) != 2 {
return nil, fmt.Errorf("expected 2 parts, found %d: %w", len(parts), io.ErrShortBuffer)
}
value, err := strconv.Unquote(string(parts[1]))
if err != nil {
return nil, fmt.Errorf("invalid quoted value: %w", err)
}
result[string(parts[0])] = value
}
return result, nil
}