Kubernetes node bootstrap token manager

Manager for Node bootstrap tokens for Kubernetes.

Supports currently Azure cloud provider (more cloud provider support -> please submit PR).

Azure:

• Stores token in Keyvault as secret
• (re)creates token inside Kubernetes and ensures it existence
• Manages renewal if token is going to be expired

Configuration

Usage:
  kube-bootstrap-token-manager [OPTIONS]

Application Options:
      --log.debug                                      debug mode [$LOG_DEBUG]
      --log.devel                                      development mode [$LOG_DEVEL]
      --log.json                                       Switch log output to json format [$LOG_JSON]
      --bootstraptoken.id-template=                    Template for token ID for bootstrap tokens (default: {{.Date}}) [$BOOTSTRAPTOKEN_ID_TEMPLATE]
      --bootstraptoken.name=                           Name for bootstrap tokens (default: bootstrap-token-%s) [$BOOTSTRAPTOKEN_NAME]
      --bootstraptoken.label=                          Label for bootstrap tokens (default: webdevops.kubernetes.io/bootstraptoken-managed) [$BOOTSTRAPTOKEN_LABEL]
      --bootstraptoken.namespace=                      Namespace for bootstrap tokens (default: kube-system) [$BOOTSTRAPTOKEN_NAMESPACE]
      --bootstraptoken.type=                           Type for bootstrap tokens (default: bootstrap.kubernetes.io/token) [$BOOTSTRAPTOKEN_TYPE]
      --bootstraptoken.usage-bootstrap-authentication= Usage bootstrap authentication for bootstrap tokens (default: true) [$BOOTSTRAPTOKEN_USAGE_BOOTSTRAP_AUTHENTICATION]
      --bootstraptoken.usage-bootstrap-signing=        usage bootstrap signing for bootstrap tokens (default: true) [$BOOTSTRAPTOKEN_USAGE_BOOTSTRAP_SIGNING]
      --bootstraptoken.auth-extra-groups=              Auth extra groups for bootstrap tokens (default: system:bootstrappers:worker,system:bootstrappers:ingress) [$BOOTSTRAPTOKEN_AUTH_EXTRA_GROUPS]
      --bootstraptoken.expiration=                     Expiration (time.Duration) for bootstrap tokens (default: 8760h) [$BOOTSTRAPTOKEN_EXPIRATION]
      --bootstraptoken.token-length=                   Length of the random token string for bootstrap tokens (default: 16) [$BOOTSTRAPTOKEN_TOKEN_LENGTH]
      --bootstraptoken.token-runes=                    Runes which should be used for the random token string for bootstrap tokens (default: abcdefghijklmnopqrstuvwxyz0123456789)
                                                       [$BOOTSTRAPTOKEN_TOKEN_RUNES]
      --sync.time=                                     Sync time (time.Duration) (default: 1h) [$SYNC_TIME]
      --sync.recreate-before=                          Time duration (time.Duration) when token should be recreated (default: 2190h) [$SYNC_RECREATE_BEFORE]
      --sync.full                                      Sync also previous tokens (full sync) [$SYNC_FULL]
      --cloud-provider=[azure]                         Cloud provider [$CLOUD_PROVIDER]
      --azure.keyvault.url=                            URL of Keyvault to sync token [$AZURE_KEYVAULT_URL]
      --azure.keyvault.secret=                         Name of Keyvault secret to sync token (default: kube-bootstrap-token) [$AZURE_KEYVAULT_SECRET]
      --dry-run                                        Dry run (do not apply to nodes) [$DRY_RUN]
      --server.bind=                                   Server address (default: :8080) [$SERVER_BIND]
      --server.timeout.read=                           Server read timeout (default: 5s) [$SERVER_TIMEOUT_READ]
      --server.timeout.write=                          Server write timeout (default: 10s) [$SERVER_TIMEOUT_WRITE]

Help Options:
  -h, --help                                           Show this help message

for Azure API authentication (using ENV vars) see following documentations:

• https://github.com/webdevops/go-common/blob/main/azuresdk/README.md
• https://docs.microsoft.com/en-us/azure/developer/go/azure-sdk-authentication

Metrics

(see :8080/metrics)

Metric	Description
bootstraptoken_token_info	Info about current token
bootstraptoken_token_expiration	Expiration time (unix timestamp) of token
bootstraptoken_sync_status	Status if sync was successfull
bootstraptoken_sync_time	Timestamp of last sync
bootstraptoken_sync_count	Counter of sync

AzureTracing metrics

see armclient tracing documentation

Settings

Environment variable	Example	Description
METRIC_AZURERM_API_REQUEST_BUCKETS	1, 2.5, 5, 10, 30, 60, 90, 120	Sets buckets for azurerm_api_request histogram metric
METRIC_AZURERM_API_REQUEST_ENABLE	false	Enables/disables azurerm_api_request_* metric
METRIC_AZURERM_API_REQUEST_LABELS	apiEndpoint, method, statusCode	Controls labels of azurerm_api_request_* metric
METRIC_AZURERM_API_RATELIMIT_ENABLE	false	Enables/disables azurerm_api_ratelimit metric
METRIC_AZURERM_API_RATELIMIT_AUTORESET	false	Enables/disables azurerm_api_ratelimit autoreset after fetch

azurerm_api_request label	Status	Description
apiEndpoint	enabled by default	hostname of endpoint (max 3 parts)
routingRegion	enabled by default	detected region for API call, either routing region from Azure Management API or Azure resource location
subscriptionID	enabled by default	detected subscriptionID
tenantID	enabled by default	detected tenantID (extracted from jwt auth token)
resourceProvider	enabled by default	detected Azure Management API provider
method	enabled by default	HTTP method
statusCode	enabled by default	HTTP status code

Kubernetes deployment

see deployment