Support casing for environmental keys

Makefile

@@ -1,2 +1,5 @@
 build:
-	bash build.sh
+	bash build.sh
+
+test:
+	go test .

README.md

@@ -33,6 +33,8 @@ $ export DB_USERNAME=$'Username'
 $ export DB_PASSWORD=$'SecretPassword'
 ```
 
+### Optional Flags
+*Recursive*
 You can also pass the `--recursive` flag.  When specified, aws-env will recursively fetch parameters starting from the base path specified in 
 `AWS_ENV_PATH`.  For the exported environment variables, any `/` characters from sub-paths will be converted to `_` characters.  For example:
 
@@ -47,7 +49,27 @@ $ aws ssm put-parameter --name /prod/my-app/db1/DB_PASSWORD --value "OtherSecret
 $ export db0_DB_PASSWORD=$'SecretPassword'
 $ export db1_DB_PASSWORD=$'OtherSecretPassword'
 ```
+*Case*
+You can also pass `--case <upper|lower>` to convert the ENV **KEY** to upper or lower case
 
+With the following parameters:
+```
+$ aws ssm put-parameter --name /prod/my-app/db_password --value "SecretPassword" --type SecureString --key-id "alias/aws/ssm0" --region us-west-2
+```
+
+`eval $(AWS_ENV_PATH=/prod/my-app/ AWS_REGION=us-west-2 ./aws-env --case upper)` will output:
+```
+$ export DB_PASSWORD=$'SecretPassword'
+```
+
+```
+$ aws ssm put-parameter --name /prod/my-app/DB_PASSWORD --value "SecretPassword" --type SecureString --key-id "alias/aws/ssm0" --region us-west-2
+```
+
+`eval $(AWS_ENV_PATH=/prod/my-app/ AWS_REGION=us-west-2 ./aws-env --case lower)` will output:
+```
+$ export db_password=$'SecretPassword'
+```
 ## Example Dockerfile
 
 ```

aws-env.go

@@ -1,14 +1,20 @@
 package main
 
 import (
+	"flag"
 	"fmt"
-	"github.com/aws/aws-sdk-go/aws"
-	"github.com/aws/aws-sdk-go/aws/session"
-	"github.com/aws/aws-sdk-go/service/ssm"
 	"log"
 	"os"
 	"strings"
-        "flag"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/ssm"
+)
+
+const (
+	upper = "upper"
+	lower = "lower"
 )
 
 func main() {
@@ -17,13 +23,19 @@ func main() {
 		return
 	}
 
-        recursivePtr := flag.Bool("recursive", false, "recursively process parameters on path")
-        flag.Parse()
+	recursivePtr := flag.Bool("recursive", false, "recursively process parameters on path")
+	convertCase := flag.String("case", upper, "Converts ENV Key to upper or lower case")
+	flag.Parse()
+
+	if *convertCase == upper || *convertCase == lower {
+	} else {
+		log.Fatal("Unsupported case option. Must be 'upper' or 'lower'")
+	}
 
 	sess := CreateSession()
 	client := CreateClient(sess)
 
-	ExportVariables(client, os.Getenv("AWS_ENV_PATH"), *recursivePtr, "")
+	ExportVariables(client, os.Getenv("AWS_ENV_PATH"), *recursivePtr, *convertCase, "")
 }
 
 func CreateSession() *session.Session {
@@ -34,12 +46,12 @@ func CreateClient(sess *session.Session) *ssm.SSM {
 	return ssm.New(sess)
 }
 
-func ExportVariables(client *ssm.SSM, path string, recursive bool, nextToken string) {
-        input := &ssm.GetParametersByPathInput{
-                Path:           &path,
-                WithDecryption: aws.Bool(true),
-                Recursive: aws.Bool(recursive),
-        }
+func ExportVariables(client *ssm.SSM, path string, recursive bool, convertCase string, nextToken string) {
+	input := &ssm.GetParametersByPathInput{
+		Path:           &path,
+		WithDecryption: aws.Bool(true),
+		Recursive:      aws.Bool(recursive),
+	}
 
 	if nextToken != "" {
 		input.SetNextToken(nextToken)
@@ -52,20 +64,26 @@ func ExportVariables(client *ssm.SSM, path string, recursive bool, nextToken str
 	}
 
 	for _, element := range output.Parameters {
-		PrintExportParameter(path, element)
+		PrintExportParameter(path, element, convertCase)
 	}
 
 	if output.NextToken != nil {
-		ExportVariables(client, path, recursive, *output.NextToken)
+		ExportVariables(client, path, recursive, convertCase, *output.NextToken)
 	}
 }
 
-func PrintExportParameter(path string, parameter *ssm.Parameter) {
+func PrintExportParameter(path string, parameter *ssm.Parameter, convertCase string) {
 	name := *parameter.Name
 	value := *parameter.Value
 
 	env := strings.Replace(strings.Trim(name[len(path):], "/"), "/", "_", -1)
 	value = strings.Replace(value, "\n", "\\n", -1)
 
+	switch convertCase {
+	case upper:
+		env = strings.ToUpper(env)
+	case lower:
+		env = strings.ToLower(env)
+	}
 	fmt.Printf("export %s=$'%s'\n", env, value)
 }

aws-env_test.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"testing"
+
+	"github.com/aws/aws-sdk-go/service/ssm"
+)
+
+type testCaseSlice struct {
+	Name        string
+	Value       string
+	Path        string
+	ConvertCase string
+
+	ExpectedValue string
+}
+
+func TestPrintExportParamater(t *testing.T) {
+	testCases := []testCaseSlice{
+		{
+			Name:        "/production/mysql_password",
+			Value:       "passwerd",
+			Path:        "/production",
+			ConvertCase: "upper",
+
+			ExpectedValue: "export MYSQL_PASSWORD=$'passwerd'\n",
+		},
+		{
+
+			Name:        "/production/mysql_password",
+			Value:       "passwerd",
+			Path:        "/production",
+			ConvertCase: "lower",
+
+			ExpectedValue: "export mysql_password=$'passwerd'\n",
+		},
+	}
+	for _, testCase := range testCases {
+
+		fakeSSM := &ssm.Parameter{
+			Name:  &testCase.Name,
+			Value: &testCase.Value,
+		}
+
+		old := os.Stdout // keep backup of the real stdout
+		r, w, _ := os.Pipe()
+		os.Stdout = w
+
+		PrintExportParameter(testCase.Path, fakeSSM, testCase.ConvertCase)
+		outC := make(chan string)
+		// copy the output in a separate goroutine so printing can't block indefinitely
+		go func() {
+			var buf bytes.Buffer
+			io.Copy(&buf, r)
+			outC <- buf.String()
+		}()
+
+		// back to normal state
+		w.Close()
+		os.Stdout = old // restoring the real stdout
+		out := <-outC
+
+		if out != testCase.ExpectedValue {
+			t.Errorf("Action: %scase failed.  We expected: %s. But we got: %s.", testCase.ConvertCase, testCase.ExpectedValue, out)
+		}
+	}
+}