user errors.Wrap to give context to errors

Gopkg.toml

@@ -25,3 +25,7 @@
 [prune]
   go-tests = true
   unused-packages = true
+
+[[constraint]]
+  name = "github.com/pkg/errors"
+  version = "0.8.0"

apply/apply.go

@@ -12,6 +12,7 @@ import (
 	"github.com/chanzuckerberg/fogg/templates"
 	"github.com/chanzuckerberg/fogg/util"
 	"github.com/gobuffalo/packr"
+	"github.com/pkg/errors"
 	"github.com/spf13/afero"
 )
 
@@ -20,22 +21,22 @@ const rootPath = "terraform"
 func Apply(fs afero.Fs, configFile string, tmp *templates.T) error {
 	p, err := plan.Eval(fs, configFile)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "unable to evaluate plan")
 	}
 
 	e := applyRepo(fs, p, &tmp.Repo)
 	if e != nil {
-		return e
+		return errors.Wrap(e, "unable to apply repo")
 	}
 
 	e = applyAccounts(fs, p, &tmp.Account)
 	if e != nil {
-		return e
+		return errors.Wrap(e, "unable to apply accounts")
 	}
 
 	e = applyEnvs(fs, p, &tmp.Env, &tmp.Component)
 	if e != nil {
-		return e
+		return errors.Wrap(e, "unable to apply envs")
 	}
 
 	e = applyGlobal(fs, p.Global, &tmp.Global)
@@ -66,11 +67,11 @@ func applyAccounts(fs afero.Fs, p *plan.Plan, accountBox *packr.Box) (e error) {
 		path := fmt.Sprintf("%s/accounts/%s", rootPath, account)
 		e = fs.MkdirAll(path, 0755)
 		if e != nil {
-			return e
+			return errors.Wrap(e, "unable to make directories for accounts")
 		}
 		e = applyTree(accountBox, afero.NewBasePathFs(fs, path), accountPlan)
 		if e != nil {
-			return e
+			return errors.Wrap(e, "unable to apply templates to account")
 		}
 	}
 	return nil
@@ -81,21 +82,21 @@ func applyEnvs(fs afero.Fs, p *plan.Plan, envBox *packr.Box, componentBox *packr
 		path := fmt.Sprintf("%s/envs/%s", rootPath, env)
 		e = fs.MkdirAll(path, 0755)
 		if e != nil {
-			return e
+			return errors.Wrap(e, "unable to make directies for envs")
 		}
 		e := applyTree(envBox, afero.NewBasePathFs(fs, path), envPlan)
 		if e != nil {
-			return e
+			return errors.Wrap(e, "unable to apply templates to env")
 		}
 		for component, componentPlan := range envPlan.Components {
 			path := fmt.Sprintf("%s/envs/%s/%s", rootPath, env, component)
 			e = fs.MkdirAll(path, 0755)
 			if e != nil {
-				return e
+				return errors.Wrap(e, "unable to make directories for component")
 			}
 			e := applyTree(componentBox, afero.NewBasePathFs(fs, path), componentPlan)
 			if e != nil {
-				return e
+				return errors.Wrap(e, "unable to apply templates for component")
 			}
 		}
 	}
@@ -110,7 +111,7 @@ func applyTree(source *packr.Box, dest afero.Fs, subst interface{}) (e error) {
 
 			err := applyTemplate(sourceFile, dest, basename, subst)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "unable to apply template")
 			}
 
 			//     if dest.endswith('.tf'):
@@ -129,7 +130,7 @@ func applyTree(source *packr.Box, dest afero.Fs, subst interface{}) (e error) {
 			log.Printf("copying %s", path)
 			e = afero.WriteReader(dest, path, sourceFile)
 			if e != nil {
-				return e
+				return errors.Wrap(e, "unable to copy file")
 			}
 		}
 		return nil
@@ -143,7 +144,7 @@ func touchFile(dest afero.Fs, path string) error {
 		log.Printf("touching %s", path)
 		_, err = dest.Create(path)
 		if err != nil {
-			return err
+			return errors.Wrap(err, "unable to touch file")
 		}
 	} else {
 		log.Printf("skipping touch on existing file %s", path)
@@ -157,7 +158,7 @@ func createFile(dest afero.Fs, path string, sourceFile io.Reader) error {
 		log.Printf("creating %s", path)
 		err = afero.WriteReader(dest, path, sourceFile)
 		if err != nil {
-			return err
+			return errors.Wrap(err, "unable to create file")
 		}
 	} else {
 		log.Printf("skipping create on existing file %s", path)
@@ -173,7 +174,7 @@ func applyTemplate(sourceFile io.Reader, dest afero.Fs, path string, overrides i
 	log.Printf("templating %s", path)
 	writer, err := dest.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0755)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "unable to open file")
 	}
 	t := util.OpenTemplate(sourceFile)
 	return t.Execute(writer, overrides)

config/config.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"io/ioutil"
 
+	"github.com/pkg/errors"
 	"github.com/spf13/afero"
 )
 
@@ -110,21 +111,21 @@ func InitConfig(project, region, bucket, awsProfile, owner string) *Config {
 
 func ReadConfig(f io.Reader) (*Config, error) {
 	c := &Config{}
-	b, err := ioutil.ReadAll(f)
-	if err != nil {
-		return nil, err
+	b, e := ioutil.ReadAll(f)
+	if e != nil {
+		return nil, errors.Wrap(e, "unable to read config")
 	}
-	err2 := json.Unmarshal(b, c)
-	if err2 != nil {
-		return nil, err2
+	e = json.Unmarshal(b, c)
+	if e != nil {
+		return nil, errors.Wrap(e, "unable to parse json config file")
 	}
 	return c, nil
 }
 
 func FindAndReadConfig(fs afero.Fs, configFile string) (*Config, error) {
-	f, err := fs.Open(configFile)
-	if err != nil {
-		return nil, err
+	f, e := fs.Open(configFile)
+	if e != nil {
+		return nil, errors.Wrap(e, "unable to open config file")
 	}
 	reader := io.ReadCloser(f)
 	defer reader.Close()

init/init.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 
 	"github.com/chanzuckerberg/fogg/config"
+	"github.com/pkg/errors"
 	prompt "github.com/segmentio/go-prompt"
 	"github.com/spf13/afero"
 )
@@ -21,11 +22,11 @@ func userPrompt() (string, string, string, string, string) {
 func writeConfig(fs afero.Fs, config *config.Config) error {
 	json, e := json.MarshalIndent(config, "", "  ")
 	if e != nil {
-		return e
+		return errors.Wrap(e, "unable to marshal json")
 	}
-	configFile, e2 := fs.Create("fogg.json")
-	if e2 != nil {
-		return e2
+	configFile, e := fs.Create("fogg.json")
+	if e != nil {
+		return errors.Wrap(e, "unable to create config file fogg.json")
 	}
 	_, e3 := configFile.Write(json)
 	return e3

util/version.go

@@ -3,23 +3,25 @@ package util
 import (
 	"fmt"
 	"strconv"
+
+	"github.com/pkg/errors"
 )
 
 var (
-	Version  = "undefined"
-	GitSha   = "undefined"
-	Release  = "false"
-	Dirty    = "true"
+	Version = "undefined"
+	GitSha  = "undefined"
+	Release = "false"
+	Dirty   = "true"
 )
 
 func VersionString() (string, error) {
 	release, e := strconv.ParseBool(Release)
 	if e != nil {
-		return "", e
+		return "", errors.Wrapf(e, "unable to parse version release field %s", Release)
 	}
 	dirty, e := strconv.ParseBool(Dirty)
 	if e != nil {
-		return "", e
+		return "", errors.Wrapf(e, "unable to parse version dirty field %s", Dirty)
 	}
 	return versionString(Version, GitSha, release, dirty), nil
 }