Add -c/--config flag

Signed-off-by: Andrew Keesler <akeesler@vmware.com>

cmd/placeholder-name/app/app.go

@@ -0,0 +1,70 @@
+/*
+Copyright 2020 VMware, Inc.
+SPDX-License-Identifier: Apache-2.0
+*/
+
+// Package app is the command line entry point for placeholder-name.
+package app
+
+import (
+	"io"
+	"log"
+	"net/http"
+
+	"github.com/spf13/cobra"
+
+	"github.com/suzerain-io/placeholder-name/pkg/handlers"
+)
+
+// App is an object that represents the placeholder-name application.
+type App struct {
+	cmd *cobra.Command
+
+	// runFunc runs the actual program, after the parsing of flags has been done.
+	//
+	// It is mostly a field for the sake of testing.
+	runFunc func(configPath string)
+}
+
+// New constructs a new App with command line args, stdout and stderr.
+func New(args []string, stdout, stderr io.Writer) *App {
+	a := &App{
+		runFunc: func(configPath string) {
+			addr := ":8080"
+			log.Printf("Starting server on %v", addr)
+			log.Fatal(http.ListenAndServe(addr, handlers.New()))
+		},
+	}
+
+	var configPath string
+	cmd := &cobra.Command{
+		Use: `placeholder-name`,
+		Long: `placeholder-name provides a generic API for mapping an external
+credential from somewhere to an internal credential to be used for
+authenticating to the Kubernetes API.`,
+		Run: func(cmd *cobra.Command, args []string) {
+			a.runFunc(configPath)
+		},
+		Args: cobra.NoArgs,
+	}
+
+	cmd.SetArgs(args)
+	cmd.SetOut(stdout)
+	cmd.SetErr(stderr)
+
+	cmd.Flags().StringVarP(
+		&configPath,
+		"config",
+		"c",
+		"placeholder-name.yaml",
+		"path to configuration file",
+	)
+
+	a.cmd = cmd
+
+	return a
+}
+
+func (a *App) Run() error {
+	return a.cmd.Execute()
+}

cmd/placeholder-name/app/app_test.go

@@ -0,0 +1,84 @@
+/*
+Copyright 2020 VMware, Inc.
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package app
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const knownGoodUsage = `Usage:
+  placeholder-name [flags]
+
+Flags:
+  -c, --config string   path to configuration file (default "placeholder-name.yaml")
+  -h, --help            help for placeholder-name
+`
+
+func TestCommand(t *testing.T) {
+	tests := []struct {
+		name string
+		args []string
+
+		wantConfigPath string
+	}{
+		{
+			name:           "NoArgsSucceeds",
+			args:           []string{},
+			wantConfigPath: "placeholder-name.yaml",
+		},
+		{
+			name: "OneArgFails",
+			args: []string{"tuna"},
+		},
+		{
+			name:           "ShortConfigFlagSucceeds",
+			args:           []string{"-c", "some/path/to/config.yaml"},
+			wantConfigPath: "some/path/to/config.yaml",
+		},
+		{
+			name:           "LongConfigFlagSucceeds",
+			args:           []string{"--config", "some/path/to/config.yaml"},
+			wantConfigPath: "some/path/to/config.yaml",
+		},
+		{
+			name: "OneArgWithConfigFlagFails",
+			args: []string{
+				"--config", "some/path/to/config.yaml",
+				"tuna",
+			},
+		},
+	}
+	for _, theTest := range tests {
+		test := theTest // please the linter :'(
+		t.Run(test.name, func(t *testing.T) {
+			expect := assert.New(t)
+
+			stdout := bytes.NewBuffer([]byte{})
+			stderr := bytes.NewBuffer([]byte{})
+
+			configPaths := make([]string, 0, 1)
+			runFunc := func(configPath string) {
+				configPaths = append(configPaths, configPath)
+			}
+
+			a := New(test.args, stdout, stderr)
+			a.runFunc = runFunc
+			err := a.Run()
+
+			if test.wantConfigPath != "" {
+				if expect.Equal(1, len(configPaths)) {
+					expect.Equal(test.wantConfigPath, configPaths[0])
+				}
+			} else {
+				expect.Error(err)
+				expect.Contains(stdout.String(), knownGoodUsage)
+			}
+		})
+	}
+}

cmd/placeholder-name/main.go

@@ -6,14 +6,13 @@ SPDX-License-Identifier: Apache-2.0
 package main
 
 import (
-	"log"
+	"os"
-	"net/http"
 
-	"github.com/suzerain-io/placeholder-name/pkg/handlers"
+	"github.com/suzerain-io/placeholder-name/cmd/placeholder-name/app"
 )
 
 func main() {
-	addr := ":8080"
+	if err := app.New(os.Args[1:], os.Stdout, os.Stderr).Run(); err != nil {
-	log.Printf("Starting server on %v", addr)
+		os.Exit(1)
-	log.Fatal(http.ListenAndServe(addr, handlers.New()))
+	}
 }

go.mod

@@ -4,6 +4,7 @@ go 1.14
 
 require (
 	github.com/golangci/golangci-lint v1.28.1
+	github.com/spf13/cobra v1.0.0
 	github.com/stretchr/testify v1.6.1
 	golang.org/x/tools v0.0.0-20200707134715-9e0a013e855f // indirect
 )

go.sum

@@ -41,8 +41,10 @@ github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc
 github.com/coreos/etcd v3.3.13+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
 github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
+github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e h1:Wf6HqHfScWJN9/ZjdUKyjop4mf3Qdd+1TvvltAvM3m8=
 github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
 github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
+github.com/cpuguy83/go-md2man/v2 v2.0.0 h1:EoUDS0afbrsXAZ9YQ9jdu/mZ2sXgT1/2yyNng4PGlyM=
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
@@ -100,10 +102,12 @@ github.com/gofrs/flock v0.7.1/go.mod h1:F1TvTiK9OcQqauNUHlbJvyl9Qa1QvF/gOUDKA14j
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.2.1 h1:/s5zKNz0uPFCZ5hddgPdo2TK2TVrUNMn0OOX8/aZMTE=
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
+github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b h1:VKtxabqXZkF25pY9ekfRL6a582T4P37/31XEstQ5p58=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/mock v1.2.0/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
+github.com/golang/mock v1.3.1 h1:qGJ6qTW+x6xX/my+8YUVl4WNpX9B7+/l2tRsHGZ7f2s=
 github.com/golang/mock v1.3.1/go.mod h1:sBzyDLLjw3U8JLTeZvSv8jJB+tU5PVekmnlKIyFUx0Y=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
@@ -177,6 +181,7 @@ github.com/hashicorp/go-uuid v1.0.0/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/b
 github.com/hashicorp/go-uuid v1.0.1/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/bN7x4byOro=
 github.com/hashicorp/go.net v0.0.1/go.mod h1:hjKkEWcCURg++eb33jQU7oqQcI9XDCnUzHA0oac0k90=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
+github.com/hashicorp/golang-lru v0.5.1 h1:0hERBMJE1eitiLkihrMvRVBYAkpHzc/J3QdDN+dAcgU=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
@@ -298,6 +303,7 @@ github.com/quasilyte/regex/syntax v0.0.0-20200407221936-30656e2c4a95/go.mod h1:r
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/rogpeppe/go-internal v1.5.2/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
+github.com/russross/blackfriday/v2 v2.0.1 h1:lPqVAte+HuHNfhJ/0LC98ESWRz8afy9tM/0RK8m9o+Q=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
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@@ -313,6 +319,7 @@ github.com/shurcooL/go v0.0.0-20180423040247-9e1955d9fb6e h1:MZM7FHLqUHYI0Y/mQAt
 github.com/shurcooL/go v0.0.0-20180423040247-9e1955d9fb6e/go.mod h1:TDJrrUr11Vxrven61rcy3hJMUqaf/CLWYhHNPmT14Lk=
 github.com/shurcooL/go-goon v0.0.0-20170922171312-37c2f522c041 h1:llrF3Fs4018ePo4+G/HV/uQUqEI1HMDjCeOf2V6puPc=
 github.com/shurcooL/go-goon v0.0.0-20170922171312-37c2f522c041/go.mod h1:N5mDOmsrJOB+vfqUK+7DmDyjhSLIIBnXo9lvZJj3MWQ=
+github.com/shurcooL/sanitized_anchor_name v1.0.0 h1:PdmoCO6wvbs+7yrJyMORt4/BmY5IYyJwS/kOiWx8mHo=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/sirupsen/logrus v1.6.0 h1:UBcNElsrwanuuMsnGSlYmtmgbb23qDR5dG+6X6Oo89I=
@@ -377,8 +384,10 @@ github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
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 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+go.etcd.io/bbolt v1.3.2 h1:Z/90sZLPOeCy2PwprqkFa25PdkusRzaj9P8zm/KNyvk=
 go.etcd.io/bbolt v1.3.2/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
+go.opencensus.io v0.22.0 h1:C9hSCOW830chIVkdja34wa6Ky+IzWllkUinR+BtRZd4=
 go.opencensus.io v0.22.0/go.mod h1:+kGneAE2xo2IficOXnaByMWTGM9T73dGwxeWcUqIpI8=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
@@ -429,6 +438,7 @@ golang.org/x/net v0.0.0-20190522155817-f3200d17e092/go.mod h1:HSz+uSET+XFnRR8LxR
 golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e h1:3G+cUijn7XD+S4eJFddp53Pv7+slrESplyjG25HgL+k=
 golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/net v0.0.0-20200625001655-4c5254603344 h1:vGXIOMxbNfDTk/aXCmfdLgkrSV+Z2tcbze+pEc3v5W4=
 golang.org/x/net v0.0.0-20200625001655-4c5254603344/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
@@ -440,7 +450,9 @@ golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e h1:vcxGaoTs7kV8m5Np9uUNQin4BrLOthgV7252N8V+FwY=
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208 h1:qwRHBd0NqMbJxfbotnDhm2ByMI1Shq4Y6oRJo21SGJA=
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
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@@ -533,10 +545,12 @@ google.golang.org/genproto v0.0.0-20190502173448-54afdca5d873/go.mod h1:VzzqZJRn
 google.golang.org/genproto v0.0.0-20190801165951-fa694d86fc64/go.mod h1:DMBHOl98Agz4BDEuKkezgsaosCRResVns1a3J2ZsMNc=
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 google.golang.org/genproto v0.0.0-20190911173649-1774047e7e51/go.mod h1:IbNlFCBrqXvoKpeg0TB2l7cyZUmoaFKYIwrEpbDKLA8=
+google.golang.org/genproto v0.0.0-20191108220845-16a3f7862a1a h1:Ob5/580gVHBJZgXnff1cZDbG+xLtMVE5mDRTe+nIsX4=
 google.golang.org/genproto v0.0.0-20191108220845-16a3f7862a1a/go.mod h1:n3cpQtvxv34hfy77yVDNjmbRyujviMdxYliBSkLhpCc=
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