Add tink-agent binary (#762)

_Depends on #734_

This PR adds the tink-agent binary to that includes minimal configuration to enable launching an agent with connectivity over gRPC to a server.

Author: mergify[bot]

Makefile

@@ -49,7 +49,7 @@ help: ## Print this help
 VERSION ?= $(shell git rev-parse --short HEAD)
 
 # Define all the binaries we build for this project that get packaged into containers.
-BINARIES := tink-server tink-worker tink-controller virtual-worker
+BINARIES := tink-server tink-agent tink-worker tink-controller virtual-worker
 
 .PHONY: build
 build: $(BINARIES) ## Build all tink binaries. Cross build by setting GOOS and GOARCH.

cmd/tink-agent/Dockerfile

@@ -0,0 +1,10 @@
+FROM alpine:3.15
+
+ARG TARGETOS
+ARG TARGETARCH
+
+RUN apk add --no-cache --update --upgrade ca-certificates
+
+COPY bin/tink-agent-${TARGETOS}-${TARGETARCH} /usr/bin/tink-agent
+
+ENTRYPOINT ["/usr/bin/tink-agent"]

cmd/tink-agent/main.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"os"
+
+	"github.com/tinkerbell/tink/internal/cli"
+)
+
+func main() {
+	if err := cli.NewAgent().Execute(); err != nil {
+		os.Exit(-1)
+	}
+}

internal/agent/run.go

@@ -26,13 +26,13 @@ func (agent *Agent) run(ctx context.Context, wflw workflow.Workflow, events even
 	log := agent.Log.WithValues("workflow_id", wflw.ID)
 
 	workflowStart := time.Now()
-	log.Info("Start workflow")
+	log.Info("Starting workflow")
 
 	for _, action := range wflw.Actions {
 		log := log.WithValues("action_id", action.ID, "action_name", action.Name)
 
 		actionStart := time.Now()
-		log.Info("Start action")
+		log.Info("Starting action")
 
 		started := event.ActionStarted{
 			ActionID:   action.ID,
@@ -79,10 +79,10 @@ func (agent *Agent) run(ctx context.Context, wflw workflow.Workflow, events even
 			return
 		}
 
-		log.Info("Finish action", "duration", time.Since(actionStart).String())
+		log.Info("Finished action", "duration", time.Since(actionStart).String())
 	}
 
-	log.Info("Finish workflow", "duration", time.Since(workflowStart).String())
+	log.Info("Finished workflow", "duration", time.Since(workflowStart).String())
 }
 
 func extractReason(log logr.Logger, err error) string {

internal/cli/agent.go

@@ -0,0 +1,59 @@
+package cli
+
+import (
+	"fmt"
+
+	"github.com/go-logr/zapr"
+	"github.com/spf13/cobra"
+	"github.com/tinkerbell/tink/internal/agent"
+	"github.com/tinkerbell/tink/internal/agent/runtime"
+	"github.com/tinkerbell/tink/internal/agent/transport"
+	"github.com/tinkerbell/tink/internal/proto/workflow/v2"
+	"go.uber.org/zap"
+	"google.golang.org/grpc"
+)
+
+// NewAgent builds a command that launches the agent component.
+func NewAgent() *cobra.Command {
+	var opts struct {
+		AgentID        string
+		TinkServerAddr string
+	}
+
+	// TODO(chrisdoherty4) Handle signals
+	cmd := cobra.Command{
+		Use: "tink-agent",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			zl, err := zap.NewProduction()
+			if err != nil {
+				return fmt.Errorf("init logger: %w", err)
+			}
+			logger := zapr.NewLogger(zl)
+
+			rntime, err := runtime.NewDocker()
+			if err != nil {
+				return fmt.Errorf("create runtime: %w", err)
+			}
+
+			conn, err := grpc.DialContext(cmd.Context(), opts.TinkServerAddr)
+			if err != nil {
+				return fmt.Errorf("dial tink server: %w", err)
+			}
+			defer conn.Close()
+			trnport := transport.NewGRPC(logger, workflow.NewWorkflowServiceClient(conn))
+
+			return (&agent.Agent{
+				Log:       logger,
+				ID:        opts.AgentID,
+				Transport: trnport,
+				Runtime:   rntime,
+			}).Start(cmd.Context())
+		},
+	}
+
+	flgs := cmd.Flags()
+	flgs.StringVar(&opts.AgentID, "agent-id", "", "An ID that uniquely identifies the agent instance")
+	flgs.StringVar(&opts.TinkServerAddr, "tink-server-addr", "127.0.0.1:42113", "Tink server address")
+
+	return &cmd
+}