Add ability to generate png with inframap (#38)

The APIs for map generation via inframap are updated to support
generating png representations of the map using GraphViz's `dot` command.
For this purpose, graphviz is installed in the Docker image, and an
option struct is added to `api.InfraMap()`.

The command line interface is slightly refactored to allow for
tool-specific options in order to support this new feature.

The ability to generate png is available both via the command line and
the REST API. The /map endpoint will accept a "png" boolean attribute in
the JSON body.

Co-authored-by: Ido Perlmuter <ido.perlmuter@gofirefly.io>
Approved-by: Sefi Genis <sefi@gofirefly.io>

Dockerfile

@@ -14,7 +14,7 @@ RUN make -e build && make -e test
 RUN chmod +x ./bin/validiac
 
 FROM alpine:3.14
-RUN apk add -u ca-certificates git
+RUN apk add -u ca-certificates git graphviz
 COPY --from=0 /validiac/bin/* /validiac/bin/
 ENV HOME="/validiac/bin/"
 ENV BIN_PATH="/validiac/bin/"

backend/api/api.go

@@ -3,19 +3,25 @@ package api
 import (
 	"fmt"
 	"io/ioutil"
-    "os"
+	"os"
 )
 
+// Tool represents the name of a third-party tool support by validiac
 type Tool string
 
 const (
-	ToolTFLint    Tool = "tflint"
-	ToolTFSec     Tool = "tfsec"
+	// ToolTFLint represents the tflint tool
+	ToolTFLint Tool = "tflint"
+
+	// ToolTFSec represents the tfsec tool
+	ToolTFSec Tool = "tfsec"
+
+	// ToolInfracost represents the infracost tool
 	ToolInfracost Tool = "infracost"
-	ToolInframap  Tool = "inframap"
-)
 
-type ToolFunc func(in []byte) (out []byte, err error)
+	// ToolInframap represents the inframap tool
+	ToolInframap Tool = "inframap"
+)
 
 func asTempFile(dir, ext string, in []byte) (path string, err error) {
 	tmpfile, err := ioutil.TempFile(dir, fmt.Sprintf("validiac-*%s", ext))
@@ -48,9 +54,9 @@ func asTempDir(ext string, in []byte) (path string, err error) {
 }
 
 func getEnv(key, defaultValue string) string {
-    value := os.Getenv(key)
-    if len(value) == 0 {
-        return defaultValue
-    }
-    return value
+	value := os.Getenv(key)
+	if len(value) == 0 {
+		return defaultValue
+	}
+	return value
 }

backend/api/infracost.go

@@ -1,24 +1,37 @@
 package api
 
 import (
-    "fmt"
-    "github.com/thoas/go-funk"
-    "os"
-    "os/exec"
+	"fmt"
+	"os"
+	"os/exec"
+
+	"github.com/thoas/go-funk"
 )
 
 var InfraCostExec = getEnv("INFRACOST_EXEC", fmt.Sprintf("%s/infracost", BIN_PATH))
 
 func InfraCost(in []byte) ([]byte, error) {
-    var infraCostApiKey = funk.GetOrElse(os.Getenv("INFRACOST_API_KEY"), "infracost-api-key")
+	var infraCostApiKey = funk.GetOrElse(os.Getenv("INFRACOST_API_KEY"), "infracost-api-key")
 	path, err := asTempDir(".tf", in)
 	if err != nil {
 		return nil, err
 	}
 
 	defer os.Remove(path) // nolint: errcheck
 
-	cmd := exec.Command(InfraCostExec, "breakdown", "--path", path, "--terraform-parse-hcl", "--no-color", "--log-level=error")
-	cmd.Env = append(cmd.Env, fmt.Sprintf("INFRACOST_API_KEY=%s", infraCostApiKey), fmt.Sprintf("PATH=%s", os.Getenv("PATH")))
+	cmd := exec.Command(
+		InfraCostExec,
+		"breakdown",
+		"--path",
+		path,
+		"--terraform-parse-hcl",
+		"--no-color",
+		"--log-level=error",
+	)
+	cmd.Env = append(
+		cmd.Env,
+		fmt.Sprintf("INFRACOST_API_KEY=%s", infraCostApiKey),
+		fmt.Sprintf("PATH=%s", os.Getenv("PATH")),
+	)
 	return cmd.CombinedOutput()
 }

backend/api/inframap.go

@@ -1,20 +1,86 @@
 package api
 
 import (
-    "fmt"
-    "os"
-    "os/exec"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
 )
 
-var InfraMapExec = getEnv("INFRAMAP_EXEC",  fmt.Sprintf("%s/inframap", BIN_PATH))
+var InfraMapExec = getEnv("INFRAMAP_EXEC", fmt.Sprintf("%s/inframap", BIN_PATH))
 
-func InfraMap(in []byte) ([]byte, error) {
+type InfraMapOpts struct {
+	Png bool
+}
+
+func InfraMap(in []byte, opts InfraMapOpts) ([]byte, error) {
 	path, err := asTempFile("", "", in)
 	if err != nil {
 		return nil, err
 	}
 
 	defer os.Remove(path) // nolint: errcheck
 
-	return exec.Command(InfraMapExec, "generate", "--raw", "--show-icons=true", "--connections=false", "--clean=false", path).CombinedOutput()
+	args := []string{
+		"generate",
+		"--show-icons=true",
+		"--connections=false",
+		"--clean=false",
+	}
+
+	if !opts.Png {
+		args = append(args, "--raw")
+	}
+
+	cmd := exec.Command(InfraMapExec, append(args, path)...)
+
+	if opts.Png {
+		// get a pipe of stdout, we're going to pipe output to dot (from graphviz)
+		stdout, err := cmd.StdoutPipe()
+		if err != nil {
+			return nil, fmt.Errorf("failed getting stdout pipe of inframap: %w", err)
+		}
+
+		if err = cmd.Start(); err != nil {
+			return nil, fmt.Errorf("failed starting inframap: %w", err)
+		}
+
+		dot := exec.Command("dot", "-Tpng")
+		stdin, err := dot.StdinPipe()
+		if err != nil {
+			return nil, fmt.Errorf("failed getting stdin pipe for dot: %w", err)
+		}
+
+		var pipeErr error
+
+		go func() {
+			defer stdin.Close()
+
+			// copy from inframap's stdout to dot's stdin
+			r := io.TeeReader(stdout, stdin)
+			if _, err := io.ReadAll(r); err != nil {
+				pipeErr = fmt.Errorf("failed reading from inframap: %w", err)
+				return
+			}
+
+			// wait for inframap to exit
+			if err = cmd.Wait(); err != nil {
+				pipeErr = fmt.Errorf("inframap failed: %w", err)
+				return
+			}
+		}()
+
+		out, err := dot.CombinedOutput()
+		if err != nil {
+			return nil, fmt.Errorf("dot failed: %w", err)
+		}
+
+		if pipeErr != nil {
+			return nil, pipeErr
+		}
+
+		return out, nil
+	}
+
+	return cmd.CombinedOutput()
 }

backend/api/tflint.go

@@ -1,58 +1,58 @@
 package api
 
 import (
-    "fmt"
-    "github.com/hashicorp/hcl2/hcl/hclsyntax"
-    "github.com/hashicorp/hcl2/hclparse"
-    "github.com/thoas/go-funk"
-    "os"
-    "os/exec"
-    "strings"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/hashicorp/hcl2/hcl/hclsyntax"
+	"github.com/hashicorp/hcl2/hclparse"
+	"github.com/thoas/go-funk"
 )
 
 var TFLintExec = getEnv("TFLINT_EXEC", fmt.Sprintf("%s/tflint", BIN_PATH))
 var TFLintConfig = getEnv("TFLINT_config", fmt.Sprintf("%s/.tflint.hcl", BIN_PATH))
 
 func TFLint(in []byte) ([]byte, error) {
-    path, err := asTempDir(".tf", in)
-    if err != nil {
-        return nil, err
-    }
+	path, err := asTempDir(".tf", in)
+	if err != nil {
+		return nil, err
+	}
 
-    defer os.RemoveAll(path)
+	defer os.RemoveAll(path)
 
 	err, hasAWS, hasAzure, hasGoogle := extractActiveProviders(in)
     if err != nil{
         return nil, err
     }
 
-    var args = []string{}
-    //Adding config args if one of the providers is enabled
-    if hasAWS||hasAzure||hasGoogle{
-        args = append(args, fmt.Sprintf("--config=%s", TFLintConfig))
-    }
+	var args = []string{}
+	//Adding config args if one of the providers is enabled
+	if hasAWS || hasAzure || hasGoogle {
+		args = append(args, fmt.Sprintf("--config=%s", TFLintConfig))
+	}
 
-    if hasAWS{
-        args = append(args, "--enable-plugin=aws")
-    }
+	if hasAWS {
+		args = append(args, "--enable-plugin=aws")
+	}
 
-    if hasAzure{
-        args = append(args, "--enable-plugin=azurerm")
-    }
+	if hasAzure {
+		args = append(args, "--enable-plugin=azurerm")
+	}
 
-    if hasGoogle{
-        args = append(args, "--enable-plugin=google")
-    }
+	if hasGoogle {
+		args = append(args, "--enable-plugin=google")
+	}
 
-    args = append(args, path)
-    args = append(args, "--no-color")
-    args = append(args, "--force")
+	args = append(args, path)
+	args = append(args, "--no-color")
+	args = append(args, "--force")
 	return exec.Command(TFLintExec, args...).CombinedOutput()
 }
 
 func tflintInit() ([]byte, error) {
-    var cmd = exec.Command(TFLintExec, "--init", "-c", TFLintConfig)
-    return cmd.CombinedOutput()
+	return exec.Command(TFLintExec, "--init", "-c", TFLintConfig).CombinedOutput()
 }
 
 func extractActiveProviders(hcl []byte) (error, bool, bool, bool) {

backend/api/tfsec.go

@@ -1,8 +1,8 @@
 package api
 
 import (
-    "fmt"
-    "os"
+	"fmt"
+	"os"
 	"os/exec"
 )