1 files changed, 112 insertions, 0 deletions
diff --git a/binapigen/vppapi/util.go b/binapigen/vppapi/util.go
new file mode 100644
index 0000000..87f2e55
--- /dev/null
+++ b/binapigen/vppapi/util.go
@@ -0,0 +1,112 @@
+//  Copyright (c) 2020 Cisco and/or its affiliates.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at:
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+
+package vppapi
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	VPPVersionEnvVar = "VPP_VERSION"
+)
+
+// ResolveVPPVersion resolves version of the VPP for target directory.
+//
+// Version resolved here can be overriden by setting VPP_VERSION env var.
+func ResolveVPPVersion(apidir string) string {
+	// check env variable override
+	if ver := os.Getenv(VPPVersionEnvVar); ver != "" {
+		logrus.Debugf("VPP version was manually set to %q via %s env var", ver, VPPVersionEnvVar)
+		return ver
+	}
+
+	// assuming VPP package is installed
+	if path.Clean(apidir) == DefaultDir {
+		version, err := GetVPPVersionInstalled()
+		if err != nil {
+			logrus.Warnf("resolving VPP version from installed package failed: %v", err)
+		} else {
+			logrus.Debugf("resolved VPP version from installed package: %v", version)
+			return version
+		}
+	}
+
+	// check if inside VPP repo
+	repoDir, err := findGitRepoRootDir(apidir)
+	if err != nil {
+		logrus.Warnf("checking VPP git repo failed: %v", err)
+	} else {
+		logrus.Debugf("resolved git repo root directory: %v", repoDir)
+		version, err := GetVPPVersionRepo(repoDir)
+		if err != nil {
+			logrus.Warnf("resolving VPP version from version script failed: %v", err)
+		} else {
+			logrus.Debugf("resolved VPP version from version script: %v", version)
+			return version
+		}
+	}
+
+	// try to read VPP_VERSION file
+	data, err := ioutil.ReadFile(path.Join(repoDir, "VPP_VERSION"))
+	if err == nil {
+		return strings.TrimSpace(string(data))
+	}
+
+	logrus.Warnf("VPP version could not be resolved, you can set it manually using %s env var", VPPVersionEnvVar)
+	return ""
+}
+
+// GetVPPVersionInstalled retrieves VPP version of installed package using dpkg-query.
+func GetVPPVersionInstalled() (string, error) {
+	cmd := exec.Command("dpkg-query", "-f", "${Version}", "-W", "vpp")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return "", fmt.Errorf("dpkg-query command failed: %v\noutput: %s", err, out)
+	}
+	return strings.TrimSpace(string(out)), nil
+}
+
+const versionScriptPath = "./src/scripts/version"
+
+// GetVPPVersionRepo retrieves VPP version using script in repo directory.
+func GetVPPVersionRepo(repoDir string) (string, error) {
+	if _, err := os.Stat(versionScriptPath); err != nil {
+		return "", err
+	}
+	cmd := exec.Command(versionScriptPath)
+	cmd.Dir = repoDir
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return "", fmt.Errorf("version script failed: %v\noutput: %s", err, out)
+	}
+	return strings.TrimSpace(string(out)), nil
+}
+
+func findGitRepoRootDir(dir string) (string, error) {
+	cmd := exec.Command("git", "rev-parse", "--show-toplevel")
+	cmd.Dir = dir
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return "", fmt.Errorf("git command failed: %v\noutput: %s", err, out)
+	}
+	return strings.TrimSpace(string(out)), nil
+}