Add MakeReadClient for creating a redis reader (letsencrypt#5814)

andygabby · web-flow · commit 6184ad5365eb · 2021-11-25T12:16:01.000-07:00
Add a function to create and return a read only redis client.
diff --git a/rocsp/config/rocsp_config.go b/rocsp/config/rocsp_config.go
@@ -103,3 +103,38 @@ func MakeClient(c *RedisConfig, clk clock.Clock) (*rocsp.WritingClient, error) {
 	})
 	return rocsp.NewWritingClient(rdb, timeout, clk), nil
 }
+
+func MakeReadClient(c *RedisConfig, clk clock.Clock) (*rocsp.Client, error) {
+	password, err := c.PasswordConfig.Pass()
+	if err != nil {
+		return nil, fmt.Errorf("loading password: %w", err)
+	}
+
+	tlsConfig, err := c.TLS.Load()
+	if err != nil {
+		return nil, fmt.Errorf("loading TLS config: %w", err)
+	}
+
+	timeout := c.Timeout.Duration
+
+	rdb := redis.NewClusterClient(&redis.ClusterOptions{
+		Addrs:     c.Addrs,
+		Username:  c.Username,
+		Password:  password,
+		TLSConfig: tlsConfig,
+
+		MaxRetries:      c.MaxRetries,
+		MinRetryBackoff: c.MinRetryBackoff.Duration,
+		MaxRetryBackoff: c.MaxRetryBackoff.Duration,
+		DialTimeout:     c.DialTimeout.Duration,
+		ReadTimeout:     c.ReadTimeout.Duration,
+
+		PoolSize:           c.PoolSize,
+		MinIdleConns:       c.MinIdleConns,
+		MaxConnAge:         c.MaxConnAge.Duration,
+		PoolTimeout:        c.PoolTimeout.Duration,
+		IdleTimeout:        c.IdleTimeout.Duration,
+		IdleCheckFrequency: c.IdleCheckFrequency.Duration,
+	})
+	return rocsp.NewClient(rdb, timeout, clk), nil
+}
diff --git a/rocsp/rocsp.go b/rocsp/rocsp.go
@@ -64,17 +64,14 @@ func MakeMetadataKey(serial string) string {
 
 // Client represents a read-only Redis client.
 type Client struct {
-	prefix  string
 	rdb     *redis.ClusterClient
 	timeout time.Duration
 	clk     clock.Clock
 }
 
 // NewClient creates a Client. The timeout applies to all requests, though a shorter timeout can be
 // applied on a per-request basis using context.Context.
-// The prefix is used to simulate different Redis clusters for different purposes - for instance
-// integration testing and unittesting.
-func NewClient(rdb *redis.ClusterClient, prefix string, timeout time.Duration, clk clock.Clock) *Client {
+func NewClient(rdb *redis.ClusterClient, timeout time.Duration, clk clock.Clock) *Client {
 	return &Client{
 		rdb:     rdb,
 		timeout: timeout,
