Use go v1.15

Cleanup and Makefile

.github/workflows/build.yaml

@@ -7,7 +7,7 @@ jobs:
   build:
     strategy:
       matrix:
-        go-version: [1.13.x]
+        go-version: [1.15.x]
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
     steps:
@@ -16,10 +16,7 @@ jobs:
       - name: Set env
         run: echo ::set-env name=RELEASE_VERSION::${GITHUB_REF:10}
       - name: Build
-        run: docker build \
+        run: docker build -t tomwright/mermaid-server:latest -t tomwright/mermaid-server:${{ env.RELEASE_VERSION }} -f Dockerfile .
-          -t tomwright/mermaid-server:latest \
-          -t tomwright/mermaid-server:${{ env.RELEASE_VERSION }} \
-          -f Dockerfile .
       - name: Login
         run: echo ${{ secrets.DOCKER_PASS }} | docker login -u${{ secrets.DOCKER_USER }} --password-stdin
       - name: Push

.github/workflows/test.yaml

@@ -4,7 +4,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.13.x]
+        go-version: [1.15.x]
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
     steps:

Dockerfile

@@ -1,5 +1,5 @@
 # This stage builds the go executable.
-FROM golang:1.13-buster as go
+FROM golang:1.15-buster as go
 
 WORKDIR /root
 COPY ./ ./

Makefile

@@ -0,0 +1,21 @@
+DOCKER_IMAGE=tomwright/mermaid-server:latest
+CONTAINER_NAME=mermaid-server
+
+docker-image:
+	docker build -t ${DOCKER_IMAGE} .
+
+docker-run:
+	docker run -d --name ${CONTAINER_NAME} -p 80:80 ${DOCKER_IMAGE}
+
+docker-stop:
+	docker stop ${CONTAINER_NAME} || true
+
+docker-rm:
+	make docker-stop
+	docker rm ${CONTAINER_NAME} || true
+
+docker-logs:
+	docker logs -f ${CONTAINER_NAME}
+
+docker-push:
+	docker push ${DOCKER_IMAGE}

README.md

@@ -22,6 +22,8 @@ go run cmd/app/main.go --mermaid=./mermaidcli/node_modules/.bin/mmdc --in=./in -
 
 ### Diagram creation
 
+Use the query param 'type' to change between 'png' and 'svg' defaults to 'svg'.
+
 #### POST
 
 Send a CURL request to generate a diagram via `POST`:

go.mod

@@ -1,5 +1,5 @@
 module github.com/tomwright/mermaid-server
 
-go 1.13
+go 1.15
 
 require github.com/tomwright/lifetime v1.0.0

internal/diagram.go

@@ -10,11 +10,12 @@ import (
 )
 
 // NewDiagram returns a new diagram.
-func NewDiagram(description []byte) *Diagram {
+func NewDiagram(description []byte, imgType string) *Diagram {
 	return &Diagram{
 		description: []byte(strings.TrimSpace(string(description))),
 		lastTouched: time.Now(),
 		mu:          &sync.RWMutex{},
+		imgType:     imgType,
 	}
 }
 
@@ -30,6 +31,8 @@ type Diagram struct {
 	mu *sync.RWMutex
 	// lastTouched is the time that the diagram was last used.
 	lastTouched time.Time
+	// the type of image to generate svg or png
+	imgType string
 }
 
 // Touch updates the last touched time of the diagram.
@@ -55,7 +58,7 @@ func (d *Diagram) ID() (string, error) {
 
 	encoded := base64.StdEncoding.EncodeToString(d.description)
 	hash := md5.Sum([]byte(encoded))
-	d.id = hex.EncodeToString(hash[:])
+	d.id = hex.EncodeToString(hash[:]) + d.imgType
 
 	return d.id, nil
 }

internal/generator.go

@@ -79,7 +79,7 @@ func (c cachingGenerator) generate(diagram *Diagram) error {
 	}
 
 	inPath := fmt.Sprintf("%s/%s.mmd", c.inPath, id)
-	outPath := fmt.Sprintf("%s/%s.svg", c.outPath, id)
+	outPath := fmt.Sprintf("%s/%s.%s", c.outPath, id, diagram.imgType)
 
 	if err := ioutil.WriteFile(inPath, diagram.description, 0644); err != nil {
 		return fmt.Errorf("could not write to input file [%s]: %w", inPath, err)

internal/http.go

@@ -22,12 +22,20 @@ func writeJSON(rw http.ResponseWriter, value interface{}, status int) {
 	}
 }
 
-func writeSVG(rw http.ResponseWriter, data []byte, status int) {
+func writeImage(rw http.ResponseWriter, data []byte, status int, imgType string) error {
-	rw.Header().Set("Content-Type", "image/svg+xml")
+	switch imgType {
+	case "png":
+		rw.Header().Set("Content-Type", "image/png")
+	case "svg":
+		rw.Header().Set("Content-Type", "image/svg+xml")
+	default:
+		return fmt.Errorf("unhandled image type: %s", imgType)
+	}
 	rw.WriteHeader(status)
 	if _, err := rw.Write(data); err != nil {
-		panic("could not write bytes to response: " + err.Error())
+		return fmt.Errorf("could not write image bytes: %w", err)
 	}
+	return nil
 }
 
 func writeErr(rw http.ResponseWriter, err error, status int) {
@@ -41,59 +49,72 @@ func writeErr(rw http.ResponseWriter, err error, status int) {
 // URLParam is the URL parameter getDiagramFromGET uses to look for data.
 const URLParam = "data"
 
-func getDiagramFromGET(rw http.ResponseWriter, r *http.Request) *Diagram {
+func getDiagramFromGET(r *http.Request, imgType string) (*Diagram, error) {
 	if r.Method != http.MethodGet {
-		writeErr(rw, fmt.Errorf("expected HTTP method GET"), http.StatusBadRequest)
+		return nil, fmt.Errorf("expected HTTP method GET")
-		return nil
 	}
 
 	queryVal := strings.TrimSpace(r.URL.Query().Get(URLParam))
 	if queryVal == "" {
-		writeErr(rw, fmt.Errorf("missing data"), http.StatusBadRequest)
+		return nil, fmt.Errorf("missing data")
-		return nil
 	}
 	data, err := url.QueryUnescape(queryVal)
 	if err != nil {
-		writeErr(rw, fmt.Errorf("could not read query param: %s", err), http.StatusBadRequest)
+		return nil, fmt.Errorf("could not read query param: %s", err)
-		return nil
 	}
 
 	// Create a diagram from the description
-	d := NewDiagram([]byte(data))
+	d := NewDiagram([]byte(data), imgType)
-	return d
+	return d, nil
 }
 
-func getDiagramFromPOST(rw http.ResponseWriter, r *http.Request) *Diagram {
+func getDiagramFromPOST(r *http.Request, imgType string) (*Diagram, error) {
 	if r.Method != http.MethodPost {
-		writeErr(rw, fmt.Errorf("expected HTTP method POST"), http.StatusBadRequest)
+		return nil, fmt.Errorf("expected HTTP method POST")
-		return nil
 	}
 	// Get description from request body
 	bytes, err := ioutil.ReadAll(r.Body)
 	if err != nil {
-		writeErr(rw, fmt.Errorf("could not read body: %s", err), http.StatusInternalServerError)
+		return nil, fmt.Errorf("could not read body: %s", err)
-		return nil
 	}
 
 	// Create a diagram from the description
-	d := NewDiagram(bytes)
+	d := NewDiagram(bytes, imgType)
-	return d
+	return d, nil
 }
 
+const URLParamImageType = "type"
+
 // generateHTTPHandler returns a HTTP handler used to generate a diagram.
 func generateHTTPHandler(generator Generator) func(rw http.ResponseWriter, r *http.Request) {
 	return func(rw http.ResponseWriter, r *http.Request) {
 		var diagram *Diagram
 
+		imgType := r.URL.Query().Get(URLParamImageType)
+
+		switch imgType {
+		case "png", "svg":
+		case "":
+			imgType = "svg"
+		default:
+			writeErr(rw, fmt.Errorf("unsupported image type (%s) use svg or png", imgType), http.StatusBadRequest)
+			return
+		}
+
+		var err error
 		switch r.Method {
 		case http.MethodGet:
-			diagram = getDiagramFromGET(rw, r)
+			diagram, err = getDiagramFromGET(r, imgType)
 		case http.MethodPost:
-			diagram = getDiagramFromPOST(rw, r)
+			diagram, err = getDiagramFromPOST(r, imgType)
 		default:
 			writeErr(rw, fmt.Errorf("unexpected HTTP method %s", r.Method), http.StatusBadRequest)
 			return
 		}
+		if err != nil {
+			writeErr(rw, err, http.StatusBadRequest)
+			return
+		}
 		if diagram == nil {
 			writeErr(rw, fmt.Errorf("could not create diagram"), http.StatusInternalServerError)
 			return
@@ -112,6 +133,8 @@ func generateHTTPHandler(generator Generator) func(rw http.ResponseWriter, r *ht
 			writeErr(rw, fmt.Errorf("could not read diagram bytes: %s", err), http.StatusInternalServerError)
 			return
 		}
-		writeSVG(rw, diagramBytes, http.StatusOK)
+		if err := writeImage(rw, diagramBytes, http.StatusOK, imgType); err != nil {
+			writeErr(rw, fmt.Errorf("could not write diagram: %w", err), http.StatusInternalServerError)
+		}
 	}
 }

mermaidcli/package-lock.json

@@ -59,9 +59,9 @@
       "integrity": "sha512-mLQ4i2QO1ytvGWFWmcngKO//JXAQueZvwEKtjgQFM4jIK0kU+ytMfplL8j+n5mspOfjHwoAg+9yhb7BwAHm36g=="
     },
     "bl": {
-      "version": "4.0.2",
+      "version": "4.0.3",
-      "resolved": "https://registry.npmjs.org/bl/-/bl-4.0.2.tgz",
+      "resolved": "https://registry.npmjs.org/bl/-/bl-4.0.3.tgz",
-      "integrity": "sha512-j4OH8f6Qg2bGuWfRiltT2HYGx0e1QcBTrK9KAHNMwMZdQnDZFk0ZSYIpADjYCB3U12nicC5tVJwSIhwOWjb4RQ==",
+      "integrity": "sha512-fs4G6/Hu4/EE+F75J8DuN/0IpQqNjAdC7aEQv7Qt8MHGUH7Ckv2MwTEEeN9QehD0pfIDkMI1bkHYkKy7xHyKIg==",
       "requires": {
         "buffer": "^5.5.0",
         "inherits": "^2.0.4",