Directory restructure (#1532)

Closes #1487
Closes #1427

Directory restructure in accordance with #1487. Also has temporary migration code to move the old directories into new structure.
Also extracts all default directory names and utility functions into a `directory` crate to avoid repetitio.

~Since `validator_definition.yaml` stores absolute paths, users will have to manually change the keystore paths or delete the file to get the validators picked up by the vc.~. `validator_definition.yaml` is migrated as well from the default directories.

Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Paul Hauner <paul@paulhauner.com>

book/src/key-management.md

@@ -40,12 +40,12 @@ keypairs. Creating a single validator looks like this:
 	- `lighthouse account validator create --wallet-name wally --wallet-password wally.pass --count 1`
 
 
-In step (1), we created a wallet in `~/.lighthouse/wallets` with the name
+In step (1), we created a wallet in `~/.lighthouse/{testnet}/wallets` with the name
 `wally`. We encrypted this using a pre-defined password in the
 `wally.pass` file. Then, in step (2), we created one new validator in the
-`~/.lighthouse/validators` directory using `wally` (unlocking it with
+`~/.lighthouse/{testnet}/validators` directory using `wally` (unlocking it with
 `wally.pass`) and storing the passwords to the validators voting key in
-`~/.lighthouse/secrets`.
+`~/.lighthouse/{testnet}/secrets`.
 
 Thanks to the hierarchical key derivation scheme, we can delete all of the
 aforementioned directories and then regenerate them as long as we remembered
@@ -63,14 +63,16 @@ There are three important directories in Lighthouse validator key management:
 
 - `wallets/`: contains encrypted wallets which are used for hierarchical
 	key derivation.
-	- Defaults to `~/.lighthouse/wallets`
+	- Defaults to `~/.lighthouse/{testnet}/wallets`
 - `validators/`: contains a directory for each validator containing
 	encrypted keystores and other validator-specific data.
-	- Defaults to `~/.lighthouse/validators`
+	- Defaults to `~/.lighthouse/{testnet}/validators`
 - `secrets/`: since the validator signing keys are "hot", the validator process
 	needs access to the passwords to decrypt the keystores in the validators
 	dir. These passwords are stored here.
-	- Defaults to `~/.lighthouse/secrets`
+	- Defaults to `~/.lighthouse/{testnet}/secrets`
+
+where `testnet` is the name of the testnet passed in the `--testnet` parameter (default is `medalla`).
 
 When the validator client boots, it searches the `validators/` for directories
 containing voting keystores. When it discovers a keystore, it searches the

book/src/validator-create.md

@@ -41,7 +41,7 @@ OPTIONS:
             The GWEI value of the deposit amount. Defaults to the minimum amount required for an active validator
             (MAX_EFFECTIVE_BALANCE)
         --secrets-dir <SECRETS_DIR>
-            The path where the validator keystore passwords will be stored. Defaults to ~/.lighthouse/secrets
+            The path where the validator keystore passwords will be stored. Defaults to ~/.lighthouse/{testnet}/secrets
 
     -s, --spec <TITLE>
             Specifies the default eth2 spec type. [default: mainnet]  [possible values: mainnet, minimal, interop]
@@ -53,7 +53,7 @@ OPTIONS:
             Path to directory containing eth2_testnet specs. Defaults to a hard-coded Lighthouse testnet. Only effective
             if there is no existing database.
         --validator-dir <VALIDATOR_DIRECTORY>
-            The path where the validator directories will be created. Defaults to ~/.lighthouse/validators
+            The path where the validator directories will be created. Defaults to ~/.lighthouse/{testnet}/validators
 
         --wallet-name <WALLET_NAME>                   Use the wallet identified by this name
         --wallet-password <WALLET_PASSWORD_PATH>
@@ -73,10 +73,12 @@ This command will:
 
 - Derive a single new BLS keypair from `wally`, updating it so that it generates a
     new key next time.
-- Create a new directory in `~/.lighthouse/validators` containing:
+- Create a new directory in `~/.lighthouse/{testnet}/validators` containing:
     - An encrypted keystore containing the validators voting keypair.
 	- An `eth1_deposit_data.rlp` assuming the default deposit amount (`32 ETH`
 		for most testnets and mainnet) which can be submitted to the deposit
 		contract for the medalla testnet. Other testnets can be set via the
 		`--testnet` CLI param.
-- Store a password to the validators voting keypair in `~/.lighthouse/secrets`.
+- Store a password to the validators voting keypair in `~/.lighthouse/{testnet}/secrets`.
+
+where `testnet` is the name of the testnet passed in the `--testnet` parameter (default is `medalla`).

book/src/validator-management.md

@@ -16,7 +16,7 @@ useful.
 ## Introducing the `validator_definitions.yml` file
 
 The `validator_definitions.yml` file is located in the `validator-dir`, which
-defaults to `~/.lighthouse/validators`. It is a
+defaults to `~/.lighthouse/{testnet}/validators`. It is a
 [YAML](https://en.wikipedia.org/wiki/YAML) encoded file defining exactly which
 validators the validator client will (and won't) act for.
 
@@ -92,7 +92,7 @@ name identical to the `voting_public_key` value.
 Lets assume the following directory structure:
 
 ```
-~/.lighthouse/validators
+~/.lighthouse/{testnet}/validators
 ├── john
 │   └── voting-keystore.json
 ├── sally
@@ -135,7 +135,7 @@ In order for the validator client to decrypt the validators, they will need to
 ensure their `secrets-dir` is organised as below:
 
 ```
-~/.lighthouse/secrets
+~/.lighthouse/{testnet}/secrets
 ├── 0xa5566f9ec3c6e1fdf362634ebec9ef7aceb0e460e5079714808388e5d48f4ae1e12897fed1bea951c17fa389d511e477
 ├── 0xaa440c566fcf34dedf233baf56cf5fb05bb420d9663b4208272545608c27c13d5b08174518c758ecd814f158f2b4a337
 └── 0x87a580d31d7bc69069b55f5a01995a610dd391a26dc9e36e81057a17211983a79266800ab8531f21f1083d7d84085007