feat(agent)!: add support for mTLS authentication in gRPC server (#54)

* refactor(fancontroller): improve fan controller validation logic and error handling for temperature steps

* refactor(agent): restructure gRPC server implementation by moving it to a new api package for better organization and maintainability

* feat(agent): implement gRPC server for managing compute blade agents and add graceful shutdown support
refactor(agent): restructure agent code by moving API logic to a dedicated file and improving error handling
fix(agent): update logging messages for clarity and consistency across the agent's operations
chore(agent): remove unused API code and consolidate event handling logic for better maintainability
style(agent): improve code formatting and organization for better readability and adherence to conventions

* feat(agent): add support for TLS configuration in gRPC server

* feat(api): add gRPC server authentication

* fix

* feat(config): add listen mode configuration to support tcp or unix sockets
feat(agent): implement listen mode in gRPC service to allow flexible socket types
feat(bladectl): enhance configuration loading and add support for TLS credentials
fix(bladectl): improve error handling for gRPC connection and event emission
style(logging): change log level from Warn to Info for better clarity in logs

* add logging middleware + fixes

* fix remote-connection to gRPC API Server

debugging the SAN issues took the soul out of me... And then the stupid
mistake in cmd_root where I didn't construct the TLS credentials
correctly... Oh dear...

* cleanup

* cleanup

* cleanup commands

* cleanup

* make README.md nicer

* Update cmd/agent/main.go

Co-authored-by: Matthias Riegler <github@m4tbit.de>

* Update cmd/bladectl/cmd_root.go

Co-authored-by: Matthias Riegler <github@m4tbit.de>

* move bladectl config into correct directory

* fix bugs

* // FIXME: No dead code

* nit: code style

* nit(YAGNI): you aint gonna need it. Don't make life harder than it needs to be

* nit(YAGNI): you aint gonna need it. Don't make life harder than it needs to be

* nit(YAGNI): you aint gonna need it. Don't make life harder than it needs to be

* nit(cmd_identify)

---------

Co-authored-by: Matthias Riegler <github@m4tbit.de>

pkg/smartfanunit/commands.go

@@ -3,19 +3,29 @@ package smartfanunit
 import (
 	"errors"
 
-	"github.com/uptime-induestries/compute-blade-agent/pkg/hal/led"
-	"github.com/uptime-induestries/compute-blade-agent/pkg/smartfanunit/proto"
+	"github.com/uptime-industries/compute-blade-agent/pkg/hal/led"
+	"github.com/uptime-industries/compute-blade-agent/pkg/smartfanunit/proto"
 )
 
+// Blade -> FanUnit communication
 const (
-	// Blade -> FanUnit
+	// CmdSetFanSpeedPercent sets the fan speed as a percentage, sent from the blade to the fan unit.
 	CmdSetFanSpeedPercent proto.Command = 0x01
-	CmdSetLED             proto.Command = 0x02
 
-	// FanUnit -> Blade, sent in regular intervals
-	NotifyButtonPress        proto.Command = 0xa1
+	// CmdSetLED represents the command to set the LED color, sent from the blade to the fan unit.
+	CmdSetLED proto.Command = 0x02
+)
+
+// FanUnit -> Blade, sent in regular intervals
+const (
+	// NotifyButtonPress represents a command sent from the fan unit to indicate a button press event.
+	NotifyButtonPress proto.Command = 0xa1
+
+	// NotifyAirFlowTemperature represents a command sent from the fan unit to report the current air flow temperature.
 	NotifyAirFlowTemperature proto.Command = 0xa2
-	NotifyFanSpeedRPM        proto.Command = 0xa3
+
+	// NotifyFanSpeedRPM is a command used to report the current fan speed in RPM from the fan unit to the blade.
+	NotifyFanSpeedRPM proto.Command = 0xa3
 )
 
 var ErrInvalidCommand = errors.New("invalid command")
@@ -93,7 +103,7 @@ type AirFlowTemperaturePacket struct {
 func (p *AirFlowTemperaturePacket) Packet() proto.Packet {
 	return proto.Packet{
 		Command: NotifyAirFlowTemperature,
-		Data:    proto.Data(float32To24Bit(p.Temperature)),
+		Data:    float32To24Bit(p.Temperature),
 	}
 }
 

pkg/smartfanunit/emc2101/emc2101.go

@@ -1,4 +1,4 @@
-// This is a driver for the EMC2101 fan controller
+// Package emc2101 is a driver for the EMC2101 fan controller
 // Based on https://ww1.microchip.com/downloads/en/DeviceDoc/2101.pdf
 package emc2101
 
@@ -57,7 +57,6 @@ func (e *emc2101) updateReg(regAddr, setMask, clearMask uint8) error {
 		return nil
 	}
 
-
 	return e.bus.Tx(e.Address, []byte{regAddr, toWrite}, nil)
 }
 
@@ -74,10 +73,10 @@ func (e *emc2101) Init() error {
 	}
 
 	/*
-	0x3 0b100
-	0x4b 0b11111
-	0x4a 0b100000
-	0x4a 0b100000
+		0x3 0b100
+		0x4b 0b11111
+		0x4a 0b100000
+		0x4a 0b100000
 	*/
 
 	// Configure fan spin up to ignore tach input
@@ -126,7 +125,7 @@ func (e *emc2101) FanRPM() (float32, error) {
 		return 0, err
 	}
 
-	var tachCount int = int(high[0])<<8 | int(low[0])
+	var tachCount = int(high[0])<<8 | int(low[0])
 
 	return float32(5400000) / float32(tachCount), nil
 }

pkg/smartfanunit/helpers.go

@@ -1,6 +1,6 @@
 package smartfanunit
 
-import "github.com/uptime-induestries/compute-blade-agent/pkg/smartfanunit/proto"
+import "github.com/uptime-industries/compute-blade-agent/pkg/smartfanunit/proto"
 
 func float32To24Bit(val float32) proto.Data {
 	// Convert float32 to number with 3 bytes (0.1 precision)

pkg/smartfanunit/proto/proto.go

@@ -78,7 +78,7 @@ func WritePacket(_ context.Context, w io.Writer, packet Packet) error {
 // ReadPacket reads a packet from an io.Reader with escaping.
 // This is blocking and drops invalid bytes until a valid packet is received.
 func ReadPacket(ctx context.Context, r io.Reader) (Packet, error) {
-	buffer := []uint8{}
+	var buffer []uint8
 
 	started := false
 	escaped := false

pkg/smartfanunit/proto/proto_test.go

@@ -6,7 +6,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-	"github.com/uptime-induestries/compute-blade-agent/pkg/smartfanunit/proto"
+	"github.com/uptime-industries/compute-blade-agent/pkg/smartfanunit/proto"
 )
 
 func TestWritePacket(t *testing.T) {

pkg/smartfanunit/smartfanunit.go

@@ -1,11 +1,11 @@
 package smartfanunit
 
 import (
-	"github.com/uptime-induestries/compute-blade-agent/pkg/smartfanunit/proto"
+	"github.com/uptime-industries/compute-blade-agent/pkg/smartfanunit/proto"
 )
 
 const (
-	Baudrate = 115200
+	BaudRate = 115200
 )
 
 func MatchCmd(cmd proto.Command) func(any) bool {