configmanager

README

Config Manager

Package used for retrieving application settings from various sources.

Currently supported variable and secrets implementations:

• AWS SecretsManager
  • Implementation Indicator: AWSSECRETS
• AWS ParameterStore
  • Implementation Indicator: AWSPARAMSTR
• AzureKeyvault Secrets
  • Implementation Indicator: AZKVSECRET
  • see Special consideration for AZKVSECRET around how to structure the token in this case.
• Azure TableStorage
  • Implementation Indicator: AZTABLESTORE
  • see Special consideration for AZTABLESTORE around how to structure the token in this case.
• Azure AppConfig
  • Implementation Indicator: AZAPPCONF
• GCP Secrets
  • Implementation Indicator: GCPSECRETS
• Hashicorp Vault
  • Implementation Indicator: VAULT
  • using the KvV2 engine endpoint
  • see special consideration hashivault

The main driver is to use component level configuration objects, if stored in a "namespaced" manner e.g. in AWS ParamStore as /nonprod/component-service-a/configVar, however this is not a requirement and the param name can be whatever. Though whilst using some sort of a organised manner it will be more straight forward to allow other services to consume certain secrets/params based on resource/access policies.

Beware size limitation with certain config/vault implementations. In which case it's best to split certain items up e.g. TLS certs /nonprod/component-service-a/pub-cert, /nonprod/component-service-a/private-cert, /nonprod/component-service-a/chain1-cert, etc...

Where configVar can be either a parseable string 'som3#!S$CRet' or a number 3306 or a parseable single level JSON object like {host: ..., pass: ...., port: ...} which can be returned whole or accessed via a key separator for a specific value.

Use cases

• Go API

  This can be leveraged from any application written in Go - on start up or at runtime. Secrets/Config items can be retrieved in "bulk" and parsed into a provided type, see here for examples.

  BREAKING CHANGE v2.x with the API (see examples)

  • generator.NewConfig() is no longer required.

    // initialise new configmanager instance
    cm := configmanager.New(context.TODO())
    // add additional config to apply on your tokens
    cm.Config.WithTokenSeparator("://")
    pm, err := cm.Retrieve([]string{"IMPLEMENTATION://token1", "IMPLEMENTATION://token2", "ANOTHER_IMPL://token1"})
    

  • RetrieveUnmarshalledFromYaml|RetrieveUnmarshalledFromJson|RetrieveMarshalledJson|RetrieveMarshalledYaml methods are now on the ConfigManager struct, see exampleRetrieveYamlMarshalled or exampleRetrieveYamlUnmarshalled in examples

• Kubernetes

  Avoid storing overly large configmaps and especially using secrets objects to store actual secrets e.g. DB passwords, 3rd party API creds, etc... By only storing a config file or a script containing only the tokens e.g. AWSSECRETS#/$ENV/service/db-config it can be git committed without writing numerous shell scripts, only storing either some interpolation vars like $ENV in a configmap or the entire configmanager token for smaller use cases.

• VMs

  VM deployments can function in a similar manner by passing in the contents or a path to the source config and the output path so that app at startup time can consume it.

CLI

ConfigManager comes packaged as a CLI for all major platforms, to see download/installation

For more detailed usage you can run -h with each subcommand and additional info can be found here

Token Config

The token is made up of the following parts:

An example token would look like this

AWSSECRETS#/path/to/my/key|lookup.Inside.Object[meta=data]

Implementation indicator

The AWSSECRETS the strategy identifier to choose the correct provider at runtime. Multiple providers can be referenced in a single run via a CLI or with the API.

This is not overrideable and must be exactly as it is in the provided list of providers.

Token Separator

The # symbol from the example token - used for separating the implementation indicator and the look up value.

The default is currently # - it will change to :// to allow for a more natural reading of the "token". you can achieve this behaviour now by either specifying the -s to the CLI or ConfigManager Go API.

cnf := generator.NewConfig().WithTokenSeparator("://")

Provider Secret/Config Path

The /path/to/my/key part from the example token is the actual path to the item in the backing store.

See the different special considerations per provider as it different providers will require different implementations.

Key Separator

THIS IS OPTIONAL

The | symbol from the example token is used to specify the key seperator.

If an item retrieved from a store is JSON parseable map it can be interrogated for further properties inside.

Look up key

THIS IS OPTIONAL

The lookup.Inside.Object from the example token is used to perform a lookup inside the retrieved item IF it is parseable into a map[string]any structure.

Given the below response from a backing store

{
	"lookup": {
		"Inside": {
			"Object": {
				"host": "db.internal",
				"port": 3306,
				"pass": "sUp3$ecr3T!",
			}
		}
	}
}

The value returned for the example token would be:

{
	"host": "db.internal",
	"port": 3306,
	"pass": "sUp3$ecr3T!",
}

See examples of working with files for more details.

Token Metadata Config

The [meta=data] from the example token - is the optional metadata about the target in the backing provider

IT must have this format [key=value] - IT IS OPTIONAL

The key and value would be provider specific. Meaning that different providers support different config, these values CAN be safely omitted configmanager would just use the defaults where applicable or not specify the additional

• Hashicorp Vault (VAULT)

  • iam_role - would be the value of an IAM role ARN to use with AWSClient Authentication.
  • version - is the version of the secret/configitem to get (should be in an integer format)

  e.g. VAULT://baz/bar/123|d88[role=arn:aws:iam::1111111:role/i-orchestration,version=1082313]

• Azure AppConfig (AZAPPCONF)

  • label - the label to use whilst retrieving the item
  • etag - etag value

  e.g. AZAPPCONF://baz/bar/123|d88[label=dev,etag=aaaaa1082313]

• GCP secrets, AWS SEcrets, AZ KeyVault (GCPSECRETS , AWSSECRETS, AZKVSECRET) they all support the version metadata property

  e.g. GCPSECRETS://baz/bar/123|d88[version=verUUID0000-1123zss]

Special considerations

This section outlines the special consideration in token construction on a per provider basis

Special consideration for AZKVSECRET

For Azure KeyVault the first part of the token needs to be the name of the vault.

Azure Go SDK (v2) requires the vault Uri on initializing the client

AZKVSECRET#/test-vault//token/1 ==> will use KeyVault implementation to retrieve the /token/1 from a test-vault.

AZKVSECRET#/test-vault/no-slash-token-1 ==> will use KeyVault implementation to retrieve the no-slash-token-1 from a test-vault.

The preceeding slash to the vault name is optional - AZKVSECRET#/test-vault/no-slash-token-1 and AZKVSECRET#test-vault/no-slash-token-1 will both identify the vault of name test-vault

Special consideration for AZTABLESTORE

The token itself must contain all of the following properties, so that it would look like this AZTABLESTORE://STORAGE_ACCOUNT_NAME/TABLE_NAME/PARTITION_KEY/ROW_KEY:

• Storage account name [STORAGE_ACCOUNT_NAME]
• Table Name [TABLE_NAME]

  • It might make sense to make this table global to the domain or project

• Partition Key [PARTITION_KEY]

  • This could correspond to the component/service name

• Row Key [ROW_KEY]

  • This could correspond to the property itself or a group of properties

  • e.g. AZTABLESTORE://globalconfigstorageaccount/domainXyz/serviceXyz/db => {"value":{"host":"foo","port":1234,"enabled":true}}

  • It will continue to work the same way with additional keyseparators inside values.

NOTE: if you store a more complex object inside a top level value property this will reduce the number of columns and normalize the table - THE DATA INSIDE THE VALUE MUST BE JSON PARSEABLE

All the usual token rules apply e.g. of keySeparator

AZTABLESTORE://account/app1Config/db/config => {host: foo.bar, port: 8891}

AZTABLESTORE://account/app1Config/db/config|host => foo.bar

Special consideration for HashicorpVault

For HashicorpVault the first part of the token needs to be the name of the mountpath. In Dev Vaults this is "secret", e.g.: VAULT://secret___demo/configmanager|test

or if the secrets are at another location: VAULT://another/mount/path__config/app1/db

The hardcoded separator cannot be modified and you must separate your mountPath with ___ (3x _) followed by the key to the secret.

AWS IAM auth to vault

when using Vault in AWS - you can set the value of the VAULT_TOKEN=aws_iam this will trigger the AWS Auth login as opposed to using the local token.

The Hashicorp Vault functions in the same exact way as the other implementations. It will retrieve the JSON object and can be looked up within it by using a key separator.

Go API

Examples

Help

• More implementations should be easily added with a specific implementation under the strategy interface

  • see add additional providers

• maybe run as cron in the background to perform a periodic sync in case values change?

Documentation

Index

• Constants
• Variables
• func FindTokens(input string) []string
• type ConfigManager
  • func New(ctx context.Context) *ConfigManager
  • func (c *ConfigManager) GeneratorConfig() *config.GenVarsConfig
  • func (c *ConfigManager) Retrieve(tokens []string) (generator.ParsedMap, error)
  • func (cm *ConfigManager) RetrieveMarshalledJson(input any) error
  • func (cm *ConfigManager) RetrieveMarshalledYaml(input any) error
  • func (c *ConfigManager) RetrieveUnmarshalledFromJson(input []byte, output any) error
  • func (c *ConfigManager) RetrieveUnmarshalledFromYaml(input []byte, output any) error
  • func (c *ConfigManager) RetrieveWithInputReplaced(input string) (string, error)
  • func (c *ConfigManager) WithGenerator(generator generateAPI) *ConfigManager

Constants

const (
	TERMINATING_CHAR string = `[^\'\"\s\n\\\,]`
)

Variables

var ErrEnvSubst = errors.New("envsubst enabled and errored on")

Functions

func FindTokens

func FindTokens(input string) []string

FindTokens extracts all replaceable tokens from a given input string

Types

type ConfigManager

type ConfigManager struct {
	Config *config.GenVarsConfig
	// contains filtered or unexported fields
}

func New

func New(ctx context.Context) *ConfigManager

New returns an initialised instance of ConfigManager Uses default config for:

``` outputPath = "" keySeparator = "|" tokenSeparator = "://" ```

Calling cm.Config.WithXXX() will overwrite the generator config

func (*ConfigManager) GeneratorConfig

func (c *ConfigManager) GeneratorConfig() *config.GenVarsConfig

GeneratorConfig Returns the gettable generator config

func (*ConfigManager) Retrieve

func (c *ConfigManager) Retrieve(tokens []string) (generator.ParsedMap, error)

Retrieve gets a rawMap from a set implementation will be empty if no matches found

func (*ConfigManager) RetrieveMarshalledJson

func (cm *ConfigManager) RetrieveMarshalledJson(input any) error

RetrieveMarshalledJson

It marshalls an input pointer value of a type with appropriate struct tags in JSON marshalls it into a string and runs the appropriate token replacement. and fills the same pointer value with the replaced fields.

This is useful for when you have another tool or framework already passing you a known type. e.g. a CRD Spec in kubernetes - where you POSTed the json/yaml spec with tokens in it but now want to use them with tokens replaced for values in a stateless way.

Enables you to store secrets in CRD Specs and other metadata your controller can use

func (*ConfigManager) RetrieveMarshalledYaml

func (cm *ConfigManager) RetrieveMarshalledYaml(input any) error

RetrieveMarshalledYaml

Same as RetrieveMarshalledJson

func (*ConfigManager) RetrieveUnmarshalledFromJson

func (c *ConfigManager) RetrieveUnmarshalledFromJson(input []byte, output any) error

RetrieveUnmarshalledFromJson It accepts an already marshalled byte slice and pointer to the value type. It fills the type with the replaced

func (*ConfigManager) RetrieveUnmarshalledFromYaml

func (c *ConfigManager) RetrieveUnmarshalledFromYaml(input []byte, output any) error

RetrieveUnmarshalledFromYaml

Same as RetrieveUnmarshalledFromJson

func (*ConfigManager) RetrieveWithInputReplaced

func (c *ConfigManager) RetrieveWithInputReplaced(input string) (string, error)

RetrieveWithInputReplaced parses given input against all possible token strings using regex to grab a list of found tokens in the given string and returns the replaced string

func (*ConfigManager) WithGenerator

func (c *ConfigManager) WithGenerator(generator generateAPI) *ConfigManager

WithGenerator replaces the generator instance