README
¶
ssmconfig 
import "github.com/ianlopshire/go-ssm-config"
SSMConfig is a utility for loading configuration parameters from AWS SSM (Parameter Store) directly into a struct. This package is largely inspired by kelseyhightower/envconfig.
Motivation
This package was created to reduce the boilerplate code required when using Parameter Store to provide configuration to AWS Lambda functions. It should be suitable for additional applications.
Usage
Set some parameters in AWS Parameter Store:
| Name | Value | Type | Key ID |
|---|---|---|---|
| /exmaple_service/prod/debug | false | String | - |
| /exmaple_service/prod/port | 8080 | String | - |
| /exmaple_service/prod/user | Ian | String | - |
| /exmaple_service/prod/rate | 0.5 | String | - |
| /exmaple_service/prod/secret | zOcZkAGB6aEjN7SAoVBT | SecureString | alias/aws/ssm |
Write some code:
package main
import (
"fmt"
"log"
"time"
ssmconfig "github.com/ianlopshire/go-ssm-config"
)
type Config struct {
Debug bool `smm:"debug" default:"true"`
Port int `smm:"port"`
User string `smm:"user"`
Rate float32 `smm:"rate"`
Secret string `smm:"secret" required:"true"`
}
func main() {
var c Config
err := ssmconfig.Process("/example_service/prod/", &c)
if err != nil {
log.Fatal(err.Error())
}
format := "Debug: %v\nPort: %d\nUser: %s\nRate: %f\nSecret: %s\n"
_, err = fmt.Printf(format, c.Debug, c.Port, c.User, c.Rate, c.Secret)
if err != nil {
log.Fatal(err.Error())
}
}
Result:
Debug: false
Port: 8080
User: Ian
Rate: 0.500000
Secret: zOcZkAGB6aEjN7SAoVBT
Additional examples can be found in godoc.
Struct Tag Support
ssmconfig supports the use of struct tags to specify parameter name, default value, and required parameters.
type Config struct {
Param string `ssm:"param"`
RequiredParam string `ssm:"required_param" required:"true"`
DefaultParam string `ssm:"default_param" default:"foobar"`
}
The ssm tag is used to lookup the parameter in Parameter Store. It is joined to the base path passed into Process().
If the ssm tag is missing ssmconfig will ignore the struct field.
The default tag is used to set the default value of a parameter. The default value will only be set if Parameter Store
returns the parameter as invalid.
The required tag is used to mark a parameter as required. If Parameter Store returns a required parameter as invalid,
ssmconfig will return an error.
The behavior of using the default and required tags on the same struct field is currently undefined.
Supported Struct Field Types
ssmconfig supports these struct field types:
- string
- int, int8, int16, int32, int64
- bool
- float32, float64
More supported types may be added in the future.
Licence
MIT
Documentation
¶
Overview ¶
Package ssmconfig is a utility for loading configuration values from AWS SSM (Parameter Store) directly into a struct.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Process ¶
Process processes the config with a new default provider.
See Provider.Process() for full documentation.
Example ¶
package main
import (
"fmt"
"log"
ssmconfig "github.com/ianlopshire/go-ssm-config"
)
func main() {
// Assuming the following Parameter Store parameters:
//
// | Name | Value | Type | Key ID |
// | ---------------------------- | -------------------- | ------------ | ------------- |
// | /example_service/prod/debug | false | String | - |
// | /example_service/prod/port | 8080 | String | - |
// | /example_service/prod/user | Ian | String | - |
// | /example_service/prod/rate | 0.5 | String | - |
// | /example_service/prod/secret | zOcZkAGB6aEjN7SAoVBT | SecureString | alias/aws/ssm |
type Config struct {
Debug bool `smm:"debug" default:"true"`
Port int `smm:"port"`
User string `smm:"user"`
Rate float32 `smm:"rate"`
Secret string `smm:"secret" required:"true"`
}
var c Config
err := ssmconfig.Process("/example_service/prod/", &c)
if err != nil {
log.Fatal(err.Error())
}
format := "Debug: %v\nPort: %d\nUser: %s\nRate: %f\nSecret: %s\n"
_, err = fmt.Printf(format, c.Debug, c.Port, c.User, c.Rate, c.Secret)
if err != nil {
log.Fatal(err.Error())
}
}
Output:
Example (MultipleEnvironments) ¶
ExampleProcess_multipleEnvironments demonstrates how ssmcofig can be used to configure multiple environments.
package main
import (
"fmt"
"log"
"os"
ssmconfig "github.com/ianlopshire/go-ssm-config"
)
func main() {
// Assuming the following Parameter Store parameters:
//
// | Name | Value | Type | Key ID |
// | ---------------------------- | -------------------- | ------------ | ------------- |
// | /example_service/prod/debug | false | String | - |
// | /example_service/prod/port | 8080 | String | - |
// | /example_service/prod/user | Ian | String | - |
// | /example_service/prod/rate | 0.5 | String | - |
// | /example_service/prod/secret | zOcZkAGB6aEjN7SAoVBT | SecureString | alias/aws/ssm |
// | ---------------------------- | -------------------- | ------------ | ------------- |
// | /example_service/test/debug | true | String | - |
// | /example_service/test/port | 8080 | String | - |
// | /example_service/test/user | Ian | String | - |
// | /example_service/test/rate | 0.9 | String | - |
// | /example_service/test/secret | TBVoAS7NjEa6BGAkZcOz | SecureString | alias/aws/ssm |
type Config struct {
Debug bool `smm:"debug" default:"true"`
Port int `smm:"port"`
User string `smm:"user"`
Rate float32 `smm:"rate"`
Secret string `smm:"secret" required:"true"`
}
// An environment variable is used to set the config path. In this example it would be
// set to `/example_service/test/` for test and `/example_service/prod/` for
// production.
configPath := os.Getenv("CONFIG_PATH")
var c Config
err := ssmconfig.Process(configPath, &c)
if err != nil {
log.Fatal(err.Error())
}
format := "Debug: %v\nPort: %d\nUser: %s\nRate: %f\nSecret: %s\n"
_, err = fmt.Printf(format, c.Debug, c.Port, c.User, c.Rate, c.Secret)
if err != nil {
log.Fatal(err.Error())
}
}
Output:
Types ¶
type Provider ¶
Provider is a ssm configuration provider.
func (*Provider) Process ¶
Process loads config values from smm (parameter store) into c. Encrypted parameters will automatically be decrypted. c must be a pointer to a struct.
The `ssm` tag is used to lookup the parameter in Parameter Store. It is joined to the provided base path. If the `ssm` tag is missing the struct field will be ignored.
The `default` tag is used to set the default value of a parameter. The default value will only be set if Parameter Store returns the parameter as invalid.
The `required` tag is used to mark a parameter as required. If Parameter Store returns a required parameter as invalid an error will be returned.
The behavior of using the `default` and `required` tags on the same struct field is currently undefined.
Example ¶
package main
import (
"fmt"
"log"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/aws/aws-sdk-go/service/ssm"
ssmconfig "github.com/ianlopshire/go-ssm-config"
)
func main() {
// Assuming the following Parameter Store parameters:
//
// | Name | Value | Type | Key ID |
// | ---------------------------- | -------------------- | ------------ | ------------- |
// | /example_service/prod/debug | false | String | - |
// | /example_service/prod/port | 8080 | String | - |
// | /example_service/prod/user | Ian | String | - |
// | /example_service/prod/rate | 0.5 | String | - |
// | /example_service/prod/secret | zOcZkAGB6aEjN7SAoVBT | SecureString | alias/aws/ssm |
type Config struct {
Debug bool `smm:"debug" default:"true"`
Port int `smm:"port"`
User string `smm:"user"`
Rate float32 `smm:"rate"`
Secret string `smm:"secret" required:"true"`
}
sess, err := session.NewSession()
if err != nil {
log.Fatal(err)
}
provider := &ssmconfig.Provider{
SSM: ssm.New(sess),
}
var c Config
err = provider.Process("/example_service/prod/", &c)
if err != nil {
log.Fatal(err.Error())
}
format := "Debug: %v\nPort: %d\nUser: %s\nRate: %f\nSecret: %s\n"
_, err = fmt.Printf(format, c.Debug, c.Port, c.User, c.Rate, c.Secret)
if err != nil {
log.Fatal(err.Error())
}
}
Output:
Source Files