From 6c42f0d976d7cec3a6c5924c22174e4874b90973 Mon Sep 17 00:00:00 2001
From: Fmar <_@fmar.link>
Date: Tue, 5 Mar 2024 11:21:25 +0100
Subject: [PATCH] add max-htlc-fee-rate

---
 .../workflows/build_max-htlc-fee-rate.yaml    | 28 ++++++++
 max-htlc-fee-rate/Dockerfile                  | 16 +++++
 max-htlc-fee-rate/README.md                   | 14 ++++
 max-htlc-fee-rate/run.sh                      | 67 +++++++++++++++++++
 4 files changed, 125 insertions(+)
 create mode 100644 .github/workflows/build_max-htlc-fee-rate.yaml
 create mode 100644 max-htlc-fee-rate/Dockerfile
 create mode 100644 max-htlc-fee-rate/README.md
 create mode 100755 max-htlc-fee-rate/run.sh

diff --git a/.github/workflows/build_max-htlc-fee-rate.yaml b/.github/workflows/build_max-htlc-fee-rate.yaml
new file mode 100644
index 0000000..b2cbc87
--- /dev/null
+++ b/.github/workflows/build_max-htlc-fee-rate.yaml
@@ -0,0 +1,28 @@
+name: Build s3-lastmodified-checker
+on:
+  workflow_dispatch:
+  push:
+    paths:
+      - 'max-htlc-fee-rate**'
+    branches:
+      - master
+    tags:        
+      - '*'
+jobs:
+  build:
+    env:
+      REGISTRY: ghcr.io
+      IMAGENAME: max-htlc-fee-rate
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+      name: Check out code
+    - name: Docker build
+      uses: mr-smithers-excellent/docker-build-push@v5
+      with:
+        image: ${{ env.IMAGENAME }}
+        registry: ${{ env.REGISTRY }}
+        directory: s3-lastmodified-checker
+        dockerfile: s3-lastmodified-checker/Dockerfile
+        username: ${{ github.repository_owner }}
+        password: ${{ secrets.GITHUB_TOKEN }}
diff --git a/max-htlc-fee-rate/Dockerfile b/max-htlc-fee-rate/Dockerfile
new file mode 100644
index 0000000..3821d1b
--- /dev/null
+++ b/max-htlc-fee-rate/Dockerfile
@@ -0,0 +1,16 @@
+FROM alpine:latest
+
+# Update package repository and install bash and jq
+RUN apk update && apk add --no-cache \
+    bash \
+    jq
+
+RUN apk add --no-cache curl && \
+    curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl" && \
+    chmod +x kubectl && \
+    mv kubectl /usr/local/bin/
+
+ADD run.sh /scripts/
+RUN chmod 755 /scripts/run.sh
+
+ENTRYPOINT ["/scripts/run.sh"]
diff --git a/max-htlc-fee-rate/README.md b/max-htlc-fee-rate/README.md
new file mode 100644
index 0000000..80f94ce
--- /dev/null
+++ b/max-htlc-fee-rate/README.md
@@ -0,0 +1,14 @@
+# max-htlc-fee-rate
+Script for setting max_htlc & fee_rate on each channel in a LND node
+
+## Basic usage
+
+```sh
+$ docker run -e LND_DEPLOYMENT=alby-mainnet-lnd-2 -e MAX_FEE_RATE=2000 -e MAX_HTLC_SIZE_MSAT=15000000000 ghcr.io/getalby/max-htlc-fee-rate
+```
+
+## Environment variables
+
+* `LND_DEPLOYMENT` - name of the deployment of LND, e.g. 'alby-mainnet-lnd-2'
+* `MAX_FEE_RATE` - max fee rate to apply for each channel, this max will be for channels with full remote liquidity
+* `MAX_HTLC_SIZE_MSAT` - max_htlc in msats to be set on each channel
diff --git a/max-htlc-fee-rate/run.sh b/max-htlc-fee-rate/run.sh
new file mode 100755
index 0000000..d0b4908
--- /dev/null
+++ b/max-htlc-fee-rate/run.sh
@@ -0,0 +1,67 @@
+#!/bin/bash
+
+if [ -z "${LND_DEPLOYMENT}" ]; then
+    echo "LND_DEPLOYMENT environment variable is not set. Please set it before running this script."
+    exit 1
+fi
+
+if [ -z "${MAX_FEE_RATE}" ]; then
+    echo "MAX_FEE_RATE environment variable is not set. Please set it before running this script."
+    exit 1
+fi
+
+if [ -z "${MAX_HTLC_SIZE_MSAT}" ]; then
+    echo "MAX_HTLC_SIZE_MSAT environment variable is not set. Please set it before running this script."
+    exit 1
+fi
+
+# Continue with the existing script logic
+echo "Using MAX_HTLC_SIZE_MSAT: $MAX_HTLC_SIZE_MSAT"
+
+# Get the LND Pod
+lnd2Pod=$(kubectl get pods -n mainnet | grep $LND_DEPLOYMENT | awk '{print $1}' | grep -v backup)
+echo "Using LND Pod: $lnd2Pod"
+
+# Get our node's public key
+ourNodePub=$(kubectl exec $lnd2Pod -n mainnet -c $LND_DEPLOYMENT -- lncli getinfo | jq -r '.identity_pubkey')
+echo "Our Node Public Key: $ourNodePub"
+
+# Get a list of all channels with channel_point and chan_id
+channels=$(kubectl exec $lnd2Pod -n mainnet -c $LND_DEPLOYMENT -- lncli listchannels | jq -r '.channels[] | "\(.channel_point) \(.chan_id) \(.capacity) \(.remote_balance) \(.local_constraints.max_pending_amt_msat) \(.peer_alias)"')
+
+while IFS= read -r line; do
+    read -r channel_point chan_id capacity remote_balance max_pending_amt_msat peer_alias <<<$(echo $line | awk '{print $1, $2, $3, $4, $5, $6}')
+    # Since peer_alias can contain spaces, it might be split across multiple fields. Reconstruct it if necessary.
+    peer_alias=$(echo $line | cut -d' ' -f6-)
+
+    # Fetch channel info using chan_id
+    chanInfo=$(kubectl exec $lnd2Pod -n mainnet -c $LND_DEPLOYMENT -- lncli getchaninfo --chan_id $chan_id)
+
+    # Determine which node we are (node1 or node2), extract policy details
+    node1_pub=$(echo "$chanInfo" | jq -r '.node1_pub')
+    policyPath=".node1_policy"
+    if [[ "$ourNodePub" != "$node1_pub" ]]; then
+        policyPath=".node2_policy"
+    fi
+
+    fee_base_msat=$(echo "$chanInfo" | jq -r "$policyPath.fee_base_msat")
+    existing_fee_rate_milli_msat=$(echo "$chanInfo" | jq -r "$policyPath.fee_rate_milli_msat")
+    time_lock_delta=$(echo "$chanInfo" | jq -r "$policyPath.time_lock_delta")
+
+    # Adjusting MAX_HTLC_SIZE_MSAT based on max_pending_amt_msat using bc
+    adjusted_max_htlc_size_msat=$(echo "if ($MAX_HTLC_SIZE_MSAT > $max_pending_amt_msat) $max_pending_amt_msat else $MAX_HTLC_SIZE_MSAT" | bc)
+
+    # Calculate fee_rate_ppm based on local_balance/capacity ratio
+    remote_balance_ratio=$((remote_balance *100/ capacity))
+    # Adjust fee_rate_ppm calculation as needed based on your desired logic
+    # Here we set a basic example that scales linearly with the local_balance_ratio
+    if [ "$existing_fee_rate_milli_msat" -eq 0 ]; then
+        fee_rate_ppm=0
+    else
+        fee_rate_ppm=$((remote_balance_ratio * $MAX_FEE_RATE / 100 + 10))
+    fi
+
+    echo "Updating channel with peer $peer_alias (remote balance ratio of ${remote_balance_ratio}%), setting fee rate -> $fee_rate_ppm ppm , max HTLC -> $adjusted_max_htlc_size_msat"
+    kubectl exec $lnd2Pod -n mainnet -c $LND_DEPLOYMENT -- lncli updatechanpolicy --chan_point $channel_point --max_htlc_msat $adjusted_max_htlc_size_msat --base_fee_msat $fee_base_msat --fee_rate_ppm $fee_rate_ppm --time_lock_delta $time_lock_delta
+
+done <<< "$channels"