Set up GCP Secrets Manager

Overview

Currently, the ZChains is concerned with keeping 2 major runtime secrets:

• The validator private key used by the node, if the node is a validator

• The networking private key used by libp2p, for participating and communicating with other peers

For additional information, please read through the Managing Private Keys Guide

The modules of the ZChains should not need to know how to keep secrets. Ultimately, a module should not care if a secret is stored on a far-away server or locally on the node's disk.

Everything a module needs to know about secret-keeping is knowing to use the secret, knowing which secrets to get or save. The finer implementation details of these operations are delegated away to the SecretsManager, which of course is an abstraction.

The node operator that's starting the ZChains can now specify which secrets manager they want to use, and as soon as the correct secrets manager is instantiated, the modules deal with the secrets through the mentioned interface - without caring if the secrets are stored on a disk or on a server.

This article details the necessary steps to get the ZChains up and running with GCP Secret Manager.

:::info previous guides It is highly recommended that before going through this article, articles on Local Setup and Cloud Setup are read. :::

Prerequisites

GCP Billing Account

In order to utilize GCP Secrets Manager, the user has to have Billing Account enabled on the GCP portal. New Google accounts on GCP platform are provided with some funds to get started, as a king of free trial. More info GCP docs

Secrets Manager API

The user will need to enable the GCP Secrets Manager API, before he can use it. This can be done via Secrets Manager API portal. More info: Configuring Secret Manger

GCP Credentials

Finally, the user needs to generate new credentials that will be used for authentication. This can be done by following the instructions posted here. The generated json file containing credentials, should be transferred to each node that needs to utilize GCP Secrets Manager.

Required information before continuing:

• Project ID (the project id defined on GCP platform)

• Credentials File Location (the path to the json file containing the credentials)

Step 1 - Generate the secrets manager configuration

In order for the ZChains to be able to seamlessly communicate with the GCP SM, it needs to parse an already generated config file, which contains all the necessary information for secret storage on GCP SM.

To generate the configuration, run the following command:

polygon-edge secrets generate --type gcp-ssm --dir <PATH> --name <NODE_NAME> --extra project-id=<PROJECT_ID>,gcp-ssm-cred=<GCP_CREDS_FILE>

Parameters present:

• PATH is the path to which the configuration file should be exported to. Default ./secretsManagerConfig.json

• NODE_NAME is the name of the current node for which the GCP SM configuration is being set up as. It can be an arbitrary value. Default polygon-edge-node

• PROJECT_ID is the ID of the project the user has defined in GCP console during account setup and Secrets Manager API activation.

• GCP_CREDS_FILE is the path to the json file containing credentials which will allow read/write access to the Secrets Manager.

:::caution Node names Be careful when specifying node names.

The ZChains uses the specified node name to keep track of the secrets it generates and uses on the GCP SM. Specifying an existing node name can have consequences of failing to write secret to GCP SM.

Secrets are stored on the following base path: projects/PROJECT_ID/NODE_NAME :::

Step 2 - Initialize secret keys using the configuration

Now that the configuration file is present, we can initialize the required secret keys with the configuration file set up in step 1, using the --config:

polygon-edge secrets init --config <PATH>

The PATH param is the location of the previously generated secrets manager param from step 1.

Step 3 - Generate the genesis file

The genesis file should be generated in a similar manner to the Local Setup and Cloud Setup guides, with minor changes.

Since GCP SM is being used instead of the local file system, validator addresses should be added through the --ibft-validator flag:

polygon-edge genesis --ibft-validator <VALIDATOR_ADDRESS> ...

Step 4 - Start the Polygon Edge client

Now that the keys are set up, and the genesis file is generated, the final step to this process would be starting the Polygon Edge with the server command.

The server command is used in the same manner as in the previously mentioned guides, with a minor addition - the --secrets-config flag:

polygon-edge server --secrets-config <PATH> ...

The PATH param is the location of the previously generated secrets manager param from step 1.