From b5f0f62f70d9cc6029df9b51b2978567b7572e6b Mon Sep 17 00:00:00 2001
From: Sagar Muchhal <muchhals@vmware.com>
Date: Wed, 16 Sep 2020 18:28:12 -0700
Subject: [PATCH] Allows relative paths for kubeconfig and argsfile

Signed-off-by: Sagar Muchhal <muchhals@vmware.com>
---
 starlark/crashd_config.go |  6 ++++++
 starlark/kube_config.go   |  6 ++++++
 util/args.go              | 11 +++++++++++
 util/path.go              | 22 ++++++++++++++++++++++
 util/path_test.go         | 27 +++++++++++++++++++++++++++
 5 files changed, 72 insertions(+)
 create mode 100644 util/path.go
 create mode 100644 util/path_test.go

diff --git a/starlark/crashd_config.go b/starlark/crashd_config.go
index d52f1eb1..9a93527e 100644
--- a/starlark/crashd_config.go
+++ b/starlark/crashd_config.go
@@ -10,6 +10,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"github.com/vmware-tanzu/crash-diagnostics/ssh"
+	"github.com/vmware-tanzu/crash-diagnostics/util"
 	"go.starlark.net/starlark"
 	"go.starlark.net/starlarkstruct"
 )
@@ -77,6 +78,11 @@ func crashdConfigFn(thread *starlark.Thread, _ *starlark.Builtin, args starlark.
 		thread.SetLocal(identifiers.sshAgent, agent)
 	}
 
+	workdir, err := util.ExpandPath(workdir)
+	if err != nil {
+		return starlark.None, err
+	}
+
 	cfgStruct := starlarkstruct.FromStringDict(starlark.String(identifiers.crashdCfg), starlark.StringDict{
 		"workdir":       starlark.String(workdir),
 		"gid":           starlark.String(gid),
diff --git a/starlark/kube_config.go b/starlark/kube_config.go
index d2742630..c414c492 100644
--- a/starlark/kube_config.go
+++ b/starlark/kube_config.go
@@ -7,6 +7,7 @@ import (
 	"fmt"
 
 	"github.com/pkg/errors"
+	"github.com/vmware-tanzu/crash-diagnostics/util"
 	"go.starlark.net/starlark"
 	"go.starlark.net/starlarkstruct"
 )
@@ -51,6 +52,11 @@ func KubeConfigFn(_ *starlark.Thread, _ *starlark.Builtin, args starlark.Tuple,
 		path = pathStr.GoString()
 	}
 
+	path, err := util.ExpandPath(path)
+	if err != nil {
+		return starlark.None, err
+	}
+
 	structVal := starlarkstruct.FromStringDict(starlark.String(identifiers.kubeCfg), starlark.StringDict{
 		"path": starlark.String(path),
 	})
diff --git a/util/args.go b/util/args.go
index 0ea47f20..3302b646 100644
--- a/util/args.go
+++ b/util/args.go
@@ -14,7 +14,18 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// ReadArgsFile parses the args file and populates the map with the contents
+// of that file. The parsing follows the following rules:
+// * each line should contain only a single key=value pair
+// * lines starting with # are ignored
+// * empty lines are ignored
+// * any line not following the above patterns are ignored with a warning message
 func ReadArgsFile(path string, args map[string]string) error {
+	path, err := ExpandPath(path)
+	if err != nil {
+		return err
+	}
+
 	file, err := os.Open(path)
 	if err != nil {
 		return errors.Wrap(err, fmt.Sprintf("args file not found: %s", path))
diff --git a/util/path.go b/util/path.go
new file mode 100644
index 00000000..fe731816
--- /dev/null
+++ b/util/path.go
@@ -0,0 +1,22 @@
+// Copyright (c) 2020 VMware, Inc. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package util
+
+import (
+	"os"
+	"path/filepath"
+)
+
+// ExpandPath converts the file path to include the home directory when prefixed with `~`.
+func ExpandPath(path string) (string, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+
+	if path[0] == '~' {
+		path = filepath.Join(home, path[1:])
+	}
+	return path, nil
+}
diff --git a/util/path_test.go b/util/path_test.go
new file mode 100644
index 00000000..676b3f0d
--- /dev/null
+++ b/util/path_test.go
@@ -0,0 +1,27 @@
+// Copyright (c) 2020 VMware, Inc. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package util
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("ExpandPath", func() {
+
+	It("returns the same path when input does not contain ~", func() {
+		input := "/foo/bar"
+		path, err := ExpandPath(input)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(path).To(Equal(input))
+	})
+
+	It("replaces the ~ with home directory path", func() {
+		input := "~/foo/bar"
+		path, err := ExpandPath(input)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(path).NotTo(Equal(input))
+		Expect(path).NotTo(ContainSubstring("~"))
+	})
+})