Implement brotli encoder; improve validation of other encoders

6 files changed, 86 insertions, 5 deletions

diff --git a/cmd/caddy2/main.go b/cmd/caddy2/main.go
index 21b4f57..310b8c1 100644
--- a/cmd/caddy2/main.go
+++ b/cmd/caddy2/main.go
@@ -7,6 +7,7 @@ import (
 	_ "github.com/caddyserver/caddy2/modules/caddyhttp"
 	_ "github.com/caddyserver/caddy2/modules/caddyhttp/caddylog"
 	_ "github.com/caddyserver/caddy2/modules/caddyhttp/encode"
+	_ "github.com/caddyserver/caddy2/modules/caddyhttp/encode/brotli"
 	_ "github.com/caddyserver/caddy2/modules/caddyhttp/encode/gzip"
 	_ "github.com/caddyserver/caddy2/modules/caddyhttp/encode/zstd"
 	_ "github.com/caddyserver/caddy2/modules/caddyhttp/fileserver"
diff --git a/go.mod b/go.mod
index 9cb7e4f..b1cdb2a 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.12
 
 require (
 	github.com/DataDog/zstd v1.4.0 // indirect
+	github.com/andybalholm/brotli v0.0.0-20190430215306-5c318f9037cb // indirect
 	github.com/dustin/go-humanize v1.0.0
 	github.com/go-acme/lego v2.6.0+incompatible
 	github.com/google/go-cmp v0.3.0 // indirect
diff --git a/go.sum b/go.sum
index 61016a0..b9d96e1 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,7 @@
 github.com/DataDog/zstd v1.4.0 h1:vhoV+DUHnRZdKW1i5UMjAk2G4JY8wN4ayRfYDNdEhwo=
 github.com/DataDog/zstd v1.4.0/go.mod h1:1jcaCB/ufaK+sKp1NBhlGmpz41jOoPQ35bpF36t7BBo=
+github.com/andybalholm/brotli v0.0.0-20190430215306-5c318f9037cb h1:Qs8/an94NFS1x2nn7rSI+skKFuw/EGfEYAGS3w/p+jc=
+github.com/andybalholm/brotli v0.0.0-20190430215306-5c318f9037cb/go.mod h1:+lx6/Aqd1kLJ1GQfkvOnaZ1WGmLpMpbprPuIOOZX30U=
 github.com/cenkalti/backoff v2.1.1+incompatible h1:tKJnvO2kl0zmb/jA5UKAt4VoEVw1qxKWjE/Bpp46npY=
 github.com/cenkalti/backoff v2.1.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
@@ -9,6 +11,8 @@ github.com/dustin/go-humanize v1.0.0/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25Kn
 github.com/go-acme/lego v2.5.0+incompatible/go.mod h1:yzMNe9CasVUhkquNvti5nAtPmG94USbYxYrZfTkIn0M=
 github.com/go-acme/lego v2.6.0+incompatible h1:KxcEWOF5hKtgou4xIqPaXSRF9DoO4OJ90ndwdK6YH/k=
 github.com/go-acme/lego v2.6.0+incompatible/go.mod h1:yzMNe9CasVUhkquNvti5nAtPmG94USbYxYrZfTkIn0M=
+github.com/golang/gddo v0.0.0-20190419222130-af0f2af80721 h1:KRMr9A3qfbVM7iV/WcLY/rL5LICqwMHLhwRXKu99fXw=
+github.com/golang/gddo v0.0.0-20190419222130-af0f2af80721/go.mod h1:xEhNfoBDX1hzLm2Nf80qUvZ2sVwoMZ8d6IE2SrsQfh4=
 github.com/google/go-cmp v0.3.0 h1:crn/baboCvb5fXaQ0IJ1SGTsTVrWpDsCWC8EGETZijY=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/klauspost/compress v1.7.1-0.20190613161414-0b31f265a57b h1:LHpBANNM/cw1PAXJtKV9dgfp6ztOKfdGXcltGmqU9aE=
diff --git a/modules/caddyhttp/encode/brotli/brotli.go b/modules/caddyhttp/encode/brotli/brotli.go
new file mode 100644
index 0000000..3289f0c
--- /dev/null
+++ b/modules/caddyhttp/encode/brotli/brotli.go
@@ -0,0 +1,51 @@
+package caddybrotli
+
+import (
+	"fmt"
+
+	"github.com/andybalholm/brotli"
+	"github.com/caddyserver/caddy2"
+	"github.com/caddyserver/caddy2/modules/caddyhttp/encode"
+)
+
+func init() {
+	caddy2.RegisterModule(caddy2.Module{
+		Name: "http.encoders.brotli",
+		New:  func() interface{} { return new(Brotli) },
+	})
+}
+
+// Brotli can create brotli encoders. Note that brotli
+// is not known for great encoding performance.
+type Brotli struct {
+	Quality *int `json:"quality,omitempty"`
+}
+
+// Validate validates b's configuration.
+func (b Brotli) Validate() error {
+	if b.Quality != nil {
+		quality := *b.Quality
+		if quality < brotli.BestSpeed {
+			return fmt.Errorf("quality too low; must be >= %d", brotli.BestSpeed)
+		}
+		if quality > brotli.BestCompression {
+			return fmt.Errorf("quality too high; must be <= %d", brotli.BestCompression)
+		}
+	}
+	return nil
+}
+
+// NewEncoder returns a new brotli writer.
+func (b Brotli) NewEncoder() encode.Encoder {
+	quality := brotli.DefaultCompression
+	if b.Quality != nil {
+		quality = *b.Quality
+	}
+	return brotli.NewWriterLevel(nil, quality)
+}
+
+// Interface guards
+var (
+	_ encode.Encoding  = (*Brotli)(nil)
+	_ caddy2.Validator = (*Brotli)(nil)
+)
diff --git a/modules/caddyhttp/encode/gzip/gzip.go b/modules/caddyhttp/encode/gzip/gzip.go
index 0da5fc3..b08385a 100644
--- a/modules/caddyhttp/encode/gzip/gzip.go
+++ b/modules/caddyhttp/encode/gzip/gzip.go
@@ -3,6 +3,7 @@ package caddygzip
 import (
 	"compress/flate"
 	"compress/gzip" // TODO: consider using https://github.com/klauspost/compress/gzip
+	"fmt"
 
 	"github.com/caddyserver/caddy2"
 	"github.com/caddyserver/caddy2/modules/caddyhttp/encode"
@@ -20,17 +21,37 @@ type Gzip struct {
 	Level int `json:"level,omitempty"`
 }
 
-// NewEncoder returns a new gzip writer.
-func (g Gzip) NewEncoder() encode.Encoder {
-	if g.Level <= flate.NoCompression {
+// Provision provisions g's configuration.
+func (g *Gzip) Provision(ctx caddy2.Context) error {
+	if g.Level == 0 {
 		g.Level = defaultGzipLevel
 	}
+	return nil
+}
+
+// Validate validates g's configuration.
+func (g Gzip) Validate() error {
+	if g.Level < flate.NoCompression {
+		return fmt.Errorf("quality too low; must be >= %d", flate.NoCompression)
+	}
 	if g.Level > flate.BestCompression {
-		g.Level = flate.BestCompression
+		return fmt.Errorf("quality too high; must be <= %d", flate.BestCompression)
 	}
+	return nil
+}
+
+// NewEncoder returns a new gzip writer.
+func (g Gzip) NewEncoder() encode.Encoder {
 	writer, _ := gzip.NewWriterLevel(nil, g.Level)
 	return writer
 }
 
 // Informed from http://blog.klauspost.com/gzip-performance-for-go-webservers/
 var defaultGzipLevel = 5
+
+// Interface guards
+var (
+	_ encode.Encoding    = (*Gzip)(nil)
+	_ caddy2.Provisioner = (*Gzip)(nil)
+	_ caddy2.Validator   = (*Gzip)(nil)
+)
diff --git a/modules/caddyhttp/encode/zstd/zstd.go b/modules/caddyhttp/encode/zstd/zstd.go
index 6afe53e..eb66ad8 100644
--- a/modules/caddyhttp/encode/zstd/zstd.go
+++ b/modules/caddyhttp/encode/zstd/zstd.go
@@ -1,4 +1,4 @@
-package caddystd
+package caddyzstd
 
 import (
 	"github.com/caddyserver/caddy2"
@@ -21,3 +21,6 @@ func (z Zstd) NewEncoder() encode.Encoder {
 	writer, _ := zstd.NewWriter(nil)
 	return writer
 }
+
+// Interface guard
+var _ encode.Encoding = (*Zstd)(nil)