1 files changed, 116 insertions, 0 deletions
diff --git a/pkg/config/redis.go b/pkg/config/redis.go
new file mode 100644
index 0000000..38571e3
--- /dev/null
+++ b/pkg/config/redis.go
@@ -0,0 +1,116 @@
+package config
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"github.com/go-redis/redis/v8"
+	"github.com/icinga/icingadb/pkg/backoff"
+	"github.com/icinga/icingadb/pkg/icingaredis"
+	"github.com/icinga/icingadb/pkg/logging"
+	"github.com/icinga/icingadb/pkg/retry"
+	"github.com/icinga/icingadb/pkg/utils"
+	"github.com/pkg/errors"
+	"go.uber.org/zap"
+	"net"
+	"strings"
+	"time"
+)
+
+// Redis defines Redis client configuration.
+type Redis struct {
+	Host       string              `yaml:"host"`
+	Port       int                 `yaml:"port" default:"6380"`
+	Password   string              `yaml:"password"`
+	TlsOptions TLS                 `yaml:",inline"`
+	Options    icingaredis.Options `yaml:"options"`
+}
+
+type ctxDialerFunc = func(ctx context.Context, network, addr string) (net.Conn, error)
+
+// NewClient prepares Redis client configuration,
+// calls redis.NewClient, but returns *icingaredis.Client.
+func (r *Redis) NewClient(logger *logging.Logger) (*icingaredis.Client, error) {
+	tlsConfig, err := r.TlsOptions.MakeConfig(r.Host)
+	if err != nil {
+		return nil, err
+	}
+
+	var dialer ctxDialerFunc
+	dl := &net.Dialer{Timeout: 15 * time.Second}
+
+	if tlsConfig == nil {
+		dialer = dl.DialContext
+	} else {
+		dialer = (&tls.Dialer{NetDialer: dl, Config: tlsConfig}).DialContext
+	}
+
+	options := &redis.Options{
+		Dialer:      dialWithLogging(dialer, logger),
+		Password:    r.Password,
+		DB:          0, // Use default DB,
+		ReadTimeout: r.Options.Timeout,
+		TLSConfig:   tlsConfig,
+	}
+
+	if strings.HasPrefix(r.Host, "/") {
+		options.Network = "unix"
+		options.Addr = r.Host
+	} else {
+		options.Network = "tcp"
+		options.Addr = net.JoinHostPort(r.Host, fmt.Sprint(r.Port))
+	}
+
+	c := redis.NewClient(options)
+
+	opts := c.Options()
+	opts.PoolSize = utils.MaxInt(32, opts.PoolSize)
+	opts.MaxRetries = opts.PoolSize + 1 // https://github.com/go-redis/redis/issues/1737
+	c = redis.NewClient(opts)
+
+	return icingaredis.NewClient(c, logger, &r.Options), nil
+}
+
+// dialWithLogging returns a Redis Dialer with logging capabilities.
+func dialWithLogging(dialer ctxDialerFunc, logger *logging.Logger) ctxDialerFunc {
+	// dial behaves like net.Dialer#DialContext,
+	// but re-tries on common errors that are considered retryable.
+	return func(ctx context.Context, network, addr string) (conn net.Conn, err error) {
+		err = retry.WithBackoff(
+			ctx,
+			func(ctx context.Context) (err error) {
+				conn, err = dialer(ctx, network, addr)
+				return
+			},
+			retry.Retryable,
+			backoff.NewExponentialWithJitter(1*time.Millisecond, 1*time.Second),
+			retry.Settings{
+				Timeout: 5 * time.Minute,
+				OnError: func(_ time.Duration, _ uint64, err, lastErr error) {
+					if lastErr == nil || err.Error() != lastErr.Error() {
+						logger.Warnw("Can't connect to Redis. Retrying", zap.Error(err))
+					}
+				},
+				OnSuccess: func(elapsed time.Duration, attempt uint64, _ error) {
+					if attempt > 0 {
+						logger.Infow("Reconnected to Redis",
+							zap.Duration("after", elapsed), zap.Uint64("attempts", attempt+1))
+					}
+				},
+			},
+		)
+
+		err = errors.Wrap(err, "can't connect to Redis")
+
+		return
+	}
+}
+
+// Validate checks constraints in the supplied Redis configuration and returns an error if they are violated.
+func (r *Redis) Validate() error {
+	if r.Host == "" {
+		return errors.New("Redis host missing")
+	}
+
+	return r.Options.Validate()
+}