Repository: oceanprotocol/ocean.py (language: python)

Issue:
Update developers.md for remote network testing
In commit https://github.com/oceanprotocol/ocean.py/commit/a4fb91153891e2b68be90d4a5a7558bbb44e14d4, we introduced testing of Ocean on a remote testnet (Mumbai). The tests need private keys that hold fake MATIC. But we don't want those keys to be public because bots might eat the fake MATIC. For the CI, we've already put Github Actions Secrets. But for local, we need to up the developers README, without making then public. That's the aim here.

TODO for this issue:
- [x] Make it easy to (a) grab the existing private keys - OPF only, or (b) generate more. 
  - (a) is via [private-keys repo](https://github.com/oceanprotocol/private-keys/blob/main/README.md), linked from developers.md
  - (b) is via a separate small README called get-test-MATIC.md. I'll be using it in in a revised-for-remote C2D README, and a simple publish-remote README. ([this issue](https://github.com/oceanprotocol/ocean.py/issues/909)
- [x] Add instructions to developers.md
Update developers.md for remote network testing
In commit https://github.com/oceanprotocol/ocean.py/commit/a4fb91153891e2b68be90d4a5a7558bbb44e14d4, we introduced testing of Ocean on a remote testnet (Mumbai). The tests need private keys that hold fake MATIC. But we don't want those keys to be public because bots might eat the fake MATIC. For the CI, we've already put Github Actions Secrets. But for local, we need to up the developers README, without making then public. That's the aim here.

TODO for this issue:
- [x] Make it easy to (a) grab the existing private keys - OPF only, or (b) generate more. 
  - (a) is via [private-keys repo](https://github.com/oceanprotocol/private-keys/blob/main/README.md), linked from developers.md
  - (b) is via a separate small README called get-test-MATIC.md. I'll be using it in in a revised-for-remote C2D README, and a simple publish-remote README. ([this issue](https://github.com/oceanprotocol/ocean.py/issues/909)
- [x] Add instructions to developers.md


Discussion / hints:

Fix patch:
diff --git a/README.md b/README.md
index 4488e5bda..f25676719 100644
--- a/README.md
+++ b/README.md
@@ -60,7 +60,8 @@ Here are flows to try out, from simple to specific detailed variants.
 
 ### Learn more
 
-- [Get test OCEAN](READMEs/get-test-OCEAN.md) - from rinkeby
+- [Get test OCEAN](READMEs/get-test-OCEAN.md) - from Rinkeby
+- [Get test MATIC](READMEs/get-test-MATIC.md) - from Mumbai
 - [Understand config parameters](READMEs/parameters.md) - envvars vs files
 - [Learn about off-chain services](READMEs/services.md) - Ocean Provider for data services, Aquarius metadata store
 - [Learn about wallets](READMEs/wallets.md) - on generating, storing, and accessing private keys
diff --git a/READMEs/developers.md b/READMEs/developers.md
index 5632519c2..249c00c36 100644
--- a/READMEs/developers.md
+++ b/READMEs/developers.md
@@ -70,7 +70,7 @@ In work console:
 #specify config file as an envvar
 export OCEAN_CONFIG_FILE=config.ini
 
-#set private keys of two accounts
+#set private keys of two local (ganache) accounts
 export TEST_PRIVATE_KEY1=0x8467415bb2ba7c91084d932276214b11a3dd9bdb2930fefa194b666dd8020b99
 export TEST_PRIVATE_KEY2=0x1d751ded5a32226054cd2e71261039b65afb9ee1c746d055dd699b1150a5befc
 
@@ -78,6 +78,15 @@ export TEST_PRIVATE_KEY2=0x1d751ded5a32226054cd2e71261039b65afb9ee1c746d055dd699
 export FACTORY_DEPLOYER_PRIVATE_KEY=0xc594c6e5def4bab63ac29eed19a134c130388f74f019bc74b8f4389df2837a58
 ```
 
+Some tests run on Mumbai (e.g. test_mumbai.py), which need fake MATIC. So you also need:
+```console
+#set private keys of two remote accounts
+export REMOTE_TEST_PRIVATE_KEY1=<your remote private key 1>
+export REMOTE_TEST_PRIVATE_KEY2=<your remote private key 2>
+```
+
+These keys aren't public because bots could eat the fake MATIC. You need to generate your own, and fill them with a faucet; [here's how](get-test-MATIC.md). (Or, [access-protected OPF keys](https://github.com/oceanprotocol/private-keys/blob/main/README.md)).
+
 ## 4. Test
 
 In work console:


Test patch:
diff --git a/READMEs/get-test-MATIC.md b/READMEs/get-test-MATIC.md
new file mode 100644
index 000000000..dada41534
--- /dev/null
+++ b/READMEs/get-test-MATIC.md
@@ -0,0 +1,54 @@
+<!--
+Copyright 2022 Ocean Protocol Foundation
+SPDX-License-Identifier: Apache-2.0
+-->
+
+# Get Test MATIC for Mumbai
+
+Mumbai is Polygon's testnet. It needs (fake) MATIC to pay gas for transactions.
+
+The READMEs use one or two remote accounts, with keys `REMOTE_TEST_PRIVATE_KEY1` and `REMOTE_TEST_PRIVATE_KEY2`. This README will show how to generate these keys, related addresses, and fill them with fake MATIC.
+
+### 1. Setup
+
+From [data-nfts-and-datatokens-flow](data-nfts-and-datatokens-flow.md), do:
+- [x] Setup : Prerequisites
+
+## 2. Create two new accounts
+
+In your console, run Python.
+```console
+python
+```
+
+In the Python console:
+
+```python
+from eth_account.account import Account
+account1 = Account.create()
+account2 = Account.create()
+
+print(f"""
+export REMOTE_TEST_PRIVATE_KEY1={account1.key.hex()}
+export REMOTE_TEST_PRIVATE_KEY2={account2.key.hex()}
+
+export ADDRESS1={account1.address}
+export ADDRESS2={account2.address}
+""")
+```
+
+Then, hit Ctrl-C to exit the Python console.
+
+Now, you have two mumbai accounts (address & private key). Same them somewhere safe, like a local file or a password manager. They actually work on any chain, not just Mumbai.
+
+The "export " is so that you can conveniently copy & paste them into a console, to set envvars for Ocean quickstarts or otherwise.
+
+## 3. Get (fake) MATIC
+
+Now, get Mumbai MATIC for each account, via a faucet:
+1. Go to https://faucet.polygon.technology/. Ensure you've selected "Mumbai" network and "MATIC" token.
+2. Request funds for ADDRESS1
+3. Request funds for ADDRESS2
+
+You could got fake ETH / MATIC / etc for these accounts in other chains, by going to a faucet for each respective chain.
+
diff --git a/READMEs/get-test-OCEAN.md b/READMEs/get-test-OCEAN.md
index 5b01e061c..440337408 100644
--- a/READMEs/get-test-OCEAN.md
+++ b/READMEs/get-test-OCEAN.md
@@ -9,15 +9,20 @@ As you develop on Ocean, you'll often need to use the OCEAN token. It's an ERC20
 
 Here, let's get some OCEAN for the Rinkeby testnet, and verify in Python that we have it.
 
-### First steps
+### Setup
 
-To get started with this guide, please refer to [data-nfts-and-datatokens-flow](data-nfts-and-datatokens-flow.md) and complete the following steps :
+From [data-nfts-and-datatokens-flow](data-nfts-and-datatokens-flow.md), do:
 - [x] Setup : Prerequisites
 - [x] Setup : Install the library from v4 sources
 
 ## Create a new address / key
 
-In a Python console:
+In your console, run Python.
+```console
+python
+```
+
+In the Python console:
 
 ```python
 from eth_account.account import Account