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Add host.docker.internal DNS resolution for containerized gateway #174

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Merged
lpcox merged 2 commits into from
Jan 11, 2026
Merged

Add host.docker.internal DNS resolution for containerized gateway #174

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05699ee
Initial plan
Copilot Jan 11, 2026
99f2716
Add host.docker.internal DNS resolution to container entrypoint
Copilot Jan 11, 2026
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50 changes: 50 additions & 0 deletions run_containerized.sh
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Original file line number Diff line number Diff line change
Expand Up @@ -236,6 +236,53 @@ set_docker_api_version() {
log_info "Set DOCKER_API_VERSION=$DOCKER_API_VERSION for $arch"
}

# Detect host IP and configure host.docker.internal DNS mapping
configure_host_dns() {
log_info "Detecting host IP for container networking..."

local HOST_IP=""

# Method 1: Try to get the primary network interface IP (not loopback)
HOST_IP=$(ip -4 addr show 2>/dev/null | grep -oP '(?<=inet\s)\d+(\.\d+){3}' | grep -v '^127\.' | head -1)
if [ -n "$HOST_IP" ]; then
log_info "Method 1 (primary interface): $HOST_IP"
fi

# Method 2: Try default gateway IP
if [ -z "$HOST_IP" ]; then
HOST_IP=$(ip route 2>/dev/null | grep default | awk '{print $3}' | head -1)
if [ -n "$HOST_IP" ]; then
log_info "Method 2 (default gateway): $HOST_IP"
fi
fi

# Method 3: Try docker0 bridge IP
if [ -z "$HOST_IP" ]; then
HOST_IP=$(ip addr show docker0 2>/dev/null | grep 'inet ' | awk '{print $2}' | cut -d/ -f1)
if [ -n "$HOST_IP" ]; then
log_info "Method 3 (docker0 bridge): $HOST_IP"
fi
fi

# Method 4: Last resort - common Docker bridge IP
if [ -z "$HOST_IP" ]; then
HOST_IP="172.17.0.1"
log_info "Method 4 (fallback): $HOST_IP"
fi

log_info "Using host IP: $HOST_IP"

# Add host.docker.internal mapping to /etc/hosts
# Check if the entry already exists to avoid duplicates
if ! grep -q "host.docker.internal" /etc/hosts 2>/dev/null; then
log_info "Adding host.docker.internal mapping to /etc/hosts"
echo "$HOST_IP host.docker.internal" >> /etc/hosts
log_info "DNS mapping configured: $HOST_IP -> host.docker.internal"
else
log_info "host.docker.internal already exists in /etc/hosts"
fi
}

# Build command line arguments
build_command_args() {
local host="${MCP_GATEWAY_HOST:-0.0.0.0}"
Expand Down Expand Up @@ -285,6 +332,9 @@ main() {
validate_log_directory_mount "$CONTAINER_ID"
fi

# Configure DNS for host.docker.internal
configure_host_dns

# Build command
FLAGS=$(build_command_args)
CMD="./awmg"
Expand Down