Config Manager

Package used for retrieving application settings from various sources.

Currently supported variable and secrets implementations:

<!-- "AWSSECRETS" // AWS Parameter Store prefix ParamStorePrefix ImplementationPrefix = "AWSPARAMSTR" // Azure Key Vault Secrets prefix AzKeyVaultSecretsPrefix ImplementationPrefix = "AZKVSECRET" // Hashicorp Vault prefix HashicorpVaultPrefix ImplementationPrefix = "VAULT" // GcpSecrets GcpSecretsPrefix ImplementationPrefix = "GCPSECRETS" -->

• 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 t