feat: Fully featured Go client for the secrets service.

pkg/secretsclient/cli.go

@@ -0,0 +1,149 @@
+package secretsclient
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+)
+
+type Client interface {
+	GetString(key string) (string, error)
+	PutString(key string, val string) error
+
+	GetStringArr(key string) ([]string, error)
+	PutStringArr(key string, val []string) error
+
+	GetStringMap(key string) (map[string]string, error)
+	PutStringMap(key string, val map[string]string) error
+
+	Delete(key string) error
+}
+
+func New(base, ca, cert, certKey string) (Client, error) {
+	h, err := newMTLSClient(ca, cert, certKey)
+	if err != nil {
+		return nil, err
+	}
+	return &client{
+		base: base,
+		h:    h,
+	}, nil
+}
+
+type client struct {
+	base string
+	h    *http.Client
+}
+
+func (c *client) GetString(key string) (string, error) {
+	res, err := c.get(key)
+	if err != nil {
+		return "", err
+	}
+	return string(res), nil
+}
+
+func (c *client) PutString(key, val string) error {
+	return c.put(key, []byte(val))
+}
+
+func (c *client) GetStringArr(key string) ([]string, error) {
+	arrBytes, err := c.get(key)
+	if err != nil {
+		return nil, err
+	}
+
+	var res []string
+	err = json.Unmarshal(arrBytes, &res)
+	if err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+func (c *client) PutStringArr(key string, val []string) error {
+	arrBytes, err := json.Marshal(val)
+	if err != nil {
+		return err
+	}
+	return c.put(key, arrBytes)
+}
+
+func (c *client) GetStringMap(key string) (map[string]string, error) {
+	mapBytes, err := c.get(key)
+	if err != nil {
+		return nil, err
+	}
+
+	var res map[string]string
+	err = json.Unmarshal(mapBytes, &res)
+	if err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+func (c *client) PutStringMap(key string, val map[string]string) error {
+	mapBytes, err := json.Marshal(val)
+	if err != nil {
+		return err
+	}
+	return c.put(key, mapBytes)
+}
+
+func (c *client) get(key string) ([]byte, error) {
+	res, err := c.h.Get(c.urlFromKey(key))
+	if err != nil {
+		return nil, err
+	}
+	if res.StatusCode != http.StatusOK {
+		return nil, errors.New("request did not succeed")
+	}
+	val, err := io.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+
+	return val, nil
+}
+
+func (c *client) put(key string, val []byte) error {
+	body := bytes.NewBuffer(val)
+	req, err := http.NewRequest("PUT", c.urlFromKey(key), body)
+	if err != nil {
+		return err
+	}
+	res, err := c.h.Do(req)
+	if err != nil {
+		return err
+	}
+	if res.StatusCode != http.StatusOK {
+		return errors.New("request did not succeed")
+	}
+	return nil
+}
+
+func (c *client) Delete(key string) error {
+	req, err := http.NewRequest("DELETE", c.urlFromKey(key), nil)
+	if err != nil {
+		return err
+	}
+
+	res, err := c.h.Do(req)
+	if err != nil {
+		return err
+	}
+	if res.StatusCode != http.StatusOK {
+		return errors.New("request did not succeed")
+	}
+	return nil
+}
+
+func (c *client) urlFromKey(key string) string {
+	b64Key := base64.RawURLEncoding.EncodeToString([]byte(key))
+	return c.base + "?key=" + b64Key
+}

pkg/secretsclient/http.go

@@ -0,0 +1,38 @@
+package secretsclient
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"net/http"
+	"os"
+	"time"
+)
+
+func newMTLSClient(ca, cert, key string) (*http.Client, error) {
+	caPEMBytes, err := os.ReadFile(ca)
+	if err != nil {
+		return nil, err
+	}
+	caPool := x509.NewCertPool()
+	if !caPool.AppendCertsFromPEM(caPEMBytes) {
+		return nil, errors.New("could create a ca pool from file")
+	}
+
+	cliCert, err := tls.LoadX509KeyPair(cert, key)
+	if err != nil {
+		return nil, fmt.Errorf("could not load client cert/key: %w", err)
+	}
+
+	return &http.Client{
+		// TODO: Tune other params.
+		Timeout: 10 * time.Second,
+		Transport: &http.Transport{
+			TLSClientConfig: &tls.Config{
+				RootCAs:      caPool,
+				Certificates: []tls.Certificate{cliCert},
+			},
+		},
+	}, nil
+}