feat: add public plan library for system-agent

pkg/plan/go.mod

@@ -0,0 +1,5 @@
+module github.com/rancher/rancher/pkg/plan
+
+go 1.25.0
+
+toolchain go1.25.8

pkg/plan/plan.go

@@ -0,0 +1,27 @@
+package plan
+
+import (
+	"crypto/sha256"
+	"encoding/json"
+	"fmt"
+)
+
+// Parse decodes a JSON-encoded plan into a Plan struct and returns an error if the JSON is invalid.
+// This is used to extract Plan Secret data into a structured format.
+func Parse(raw []byte) (Plan, error) {
+	var plan Plan
+	if err := json.Unmarshal(raw, &plan); err != nil {
+		return Plan{}, fmt.Errorf("failed to parse plan: %w", err)
+	}
+
+	return plan, nil
+}
+
+// Checksum computes the sha-256 checksum of the plan bytes.
+// Used for backward compatibility with orchestrators that compare applied-checksum.
+func Checksum(raw []byte) string {
+	h := sha256.New()
+	h.Write(raw)
+
+	return fmt.Sprintf("%x", h.Sum(nil))
+}

pkg/plan/plan_test.go

@@ -0,0 +1,164 @@
+package plan
+
+import (
+	"encoding/json"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func TestParse(t *testing.T) {
+	t.Run("valid plan json", func(t *testing.T) {
+		raw := `{"files":[{"path":"/tmp/test","content":"aGVsbG8gd29ybGQ="}],"instructions":[{"name":"setup","command":"/bin/sh"}]}`
+
+		p, err := Parse([]byte(raw))
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		if len(p.Files) != 1 || p.Files[0].Path != "/tmp/test" {
+			t.Errorf("unexpected files: %+v", p.Files)
+		}
+
+		if len(p.OneTimeInstructions) != 1 || p.OneTimeInstructions[0].Name != "setup" {
+			t.Errorf("unexpected instructions: %+v", p.OneTimeInstructions)
+		}
+	})
+
+	t.Run("invalid plan json", func(t *testing.T) {
+		_, err := Parse([]byte(`{not valid json`))
+		if err == nil {
+			t.Fatal("expected an error")
+		}
+
+		if !strings.Contains(err.Error(), "failed to parse plan") {
+			t.Errorf("unexpected error message: %v", err)
+		}
+	})
+}
+
+func TestMarshalParse(t *testing.T) {
+	original := Plan{
+		Files: []File{
+			{
+				Content:     "aGVsbG8gd29ybGQ=",
+				UID:         -1,
+				GID:         -1,
+				Path:        "/etc/myapp/config.yaml",
+				Permissions: "0644",
+			},
+			{
+				Path:      "/etc/myapp/",
+				Directory: true,
+			},
+		},
+		OneTimeInstructions: []OneTimeInstruction{
+			{
+				CommonInstruction: CommonInstruction{
+					Name:    "install",
+					Command: "/bin/sh",
+					Args:    []string{"-c", "echo hello"},
+				},
+				SaveOutput: true,
+			},
+		},
+		PeriodicInstructions: []PeriodicInstruction{
+			{
+				CommonInstruction: CommonInstruction{
+					Name:    "healthcheck",
+					Command: "/bin/sh",
+					Args:    []string{"-c", "echo ok"},
+				},
+				PeriodSeconds:    60,
+				SaveStderrOutput: true,
+			},
+		},
+	}
+
+	data, err := json.Marshal(original)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+
+	var restored Plan
+	restored, err = Parse([]byte(data))
+	if err != nil {
+		t.Fatalf("parse: %v", err)
+	}
+
+	if !reflect.DeepEqual(original, restored) {
+		t.Errorf("plan changed after encode/parse\nwant: %+v\n got: %+v", original, restored)
+	}
+}
+
+func TestParseJSONKeys(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		validate func(t *testing.T, p Plan)
+	}{
+		{
+			name:  "files",
+			input: `{"files":[{"path":"/tmp/test","content":"aGVsbG8gd29ybGQ="}]}`,
+			validate: func(t *testing.T, p Plan) {
+				if len(p.Files) != 1 || p.Files[0].Path != "/tmp/test" {
+					t.Errorf("got %+v", p.Files)
+				}
+			},
+		},
+		{
+			name:  "instructions",
+			input: `{"instructions":[{"name":"test","command":"/bin/sh"}]}`,
+			validate: func(t *testing.T, p Plan) {
+				if len(p.OneTimeInstructions) != 1 || p.OneTimeInstructions[0].Name != "test" {
+					t.Errorf("got %+v", p.OneTimeInstructions)
+				}
+			},
+		},
+		{
+			name:  "periodicInstructions",
+			input: `{"periodicInstructions":[{"name":"cron","periodSeconds":300}]}`,
+			validate: func(t *testing.T, p Plan) {
+				if len(p.PeriodicInstructions) != 1 || p.PeriodicInstructions[0].PeriodSeconds != 300 {
+					t.Errorf("got %+v", p.PeriodicInstructions)
+				}
+			},
+		},
+		{
+			name:  "probes / httpGet",
+			input: `{"probes":{"web":{"httpGet":{"url":"http://localhost/health","insecure":true}}}}`,
+			validate: func(t *testing.T, p Plan) {
+				probe, ok := p.Probes["web"]
+				if !ok {
+					t.Fatal("probes.web missing")
+				}
+				if probe.HTTPGetAction.URL != "http://localhost/health" || !probe.HTTPGetAction.Insecure {
+					t.Errorf("got %+v", probe.HTTPGetAction)
+				}
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var p Plan
+
+			p, err := Parse([]byte(tt.input))
+			if err != nil {
+				t.Fatalf("parse: %v", err)
+			}
+
+			tt.validate(t, p)
+		})
+	}
+}
+
+func TestChecksum(t *testing.T) {
+	input := []byte(`{"files":[]}`)
+
+	// verify idempotency by calling Checksum() twice with the same input
+	output1, output2 := Checksum(input), Checksum(input)
+	if output1 != output2 {
+		t.Error("checksum result is not idempotent")
+	}
+}

pkg/plan/probe.go

@@ -0,0 +1,27 @@
+package plan
+
+// Probe describes a health check to be performed against the node.
+type Probe struct {
+	Name                string        `json:"name,omitempty"`
+	InitialDelaySeconds int           `json:"initialDelaySeconds,omitempty"` // default 0
+	TimeoutSeconds      int           `json:"timeoutSeconds,omitempty"`      // default 1
+	SuccessThreshold    int           `json:"successThreshold,omitempty"`    // default 1
+	FailureThreshold    int           `json:"failureThreshold,omitempty"`    // default 3
+	HTTPGetAction       HTTPGetAction `json:"httpGet,omitempty"`
+}
+
+// HTTPGetAction describes an HTTP GET request used by a Probe.
+type HTTPGetAction struct {
+	URL        string `json:"url,omitempty"`
+	Insecure   bool   `json:"insecure,omitempty"`
+	ClientCert string `json:"clientCert,omitempty"`
+	ClientKey  string `json:"clientKey,omitempty"`
+	CACert     string `json:"caCert,omitempty"`
+}
+
+// ProbeStatus represents the current health status of a probe as reported by the agent.
+type ProbeStatus struct {
+	Healthy      bool `json:"healthy,omitempty"`
+	SuccessCount int  `json:"successCount,omitempty"`
+	FailureCount int  `json:"failureCount,omitempty"`
+}

pkg/plan/types.go

@@ -0,0 +1,59 @@
+package plan
+
+// Plan represents the basic unit of work performed by the system-agent.
+type Plan struct {
+	Files                []File                `json:"files,omitempty"`
+	OneTimeInstructions  []OneTimeInstruction  `json:"instructions,omitempty"`
+	Probes               map[string]Probe      `json:"probes,omitempty"`
+	PeriodicInstructions []PeriodicInstruction `json:"periodicInstructions,omitempty"`
+}
+
+// File represents a file to be written on the node by the system-agent.
+// Path is the absolute path on the node (e.g. /etc/kubernetes/ssl/ca.pem).
+// Content is base64-encoded. If Directory is true, a directory is created, not a file.
+type File struct {
+	Content     string `json:"content,omitempty"`
+	Directory   bool   `json:"directory,omitempty"`
+	UID         int    `json:"uid,omitempty"`
+	GID         int    `json:"gid,omitempty"`
+	Path        string `json:"path,omitempty"`
+	Permissions string `json:"permissions,omitempty"` // internally, the string will be converted to a uint32 to satisfy os.FileMode
+	Action      string `json:"action,omitempty"`
+}
+
+// CommonInstruction holds fields shared by all instruction types.
+type CommonInstruction struct {
+	Name    string   `json:"name,omitempty"`
+	Image   string   `json:"image,omitempty"`
+	Env     []string `json:"env,omitempty"`
+	Args    []string `json:"args,omitempty"`
+	Command string   `json:"command,omitempty"`
+}
+
+// OneTimeInstruction is an instruction that is executed exactly once.
+type OneTimeInstruction struct {
+	CommonInstruction
+	SaveOutput bool `json:"saveOutput,omitempty"`
+}
+
+// PeriodicInstruction is an instruction that is executed on a recurring schedule.
+type PeriodicInstruction struct {
+	CommonInstruction
+	PeriodSeconds    int  `json:"periodSeconds,omitempty"` // default 600, i.e. 10 minutes
+	SaveStderrOutput bool `json:"saveStderrOutput,omitempty"`
+}
+
+// PeriodicInstructionOutput holds the result of a periodic instruction execution.
+// The Stdout and Stderr fields are gzip+base64 encoded byte slices.
+type PeriodicInstructionOutput struct {
+	Name     string `json:"name"`
+	Stdout   []byte `json:"stdout"`
+	Stderr   []byte `json:"stderr"`
+	ExitCode int    `json:"exitCode"`
+	// LastSuccessfulRunTime is a time.UnixDate formatted string of the last successful run.
+	LastSuccessfulRunTime string `json:"lastSuccessfulRunTime"`
+	// Failures is the number of consecutive times this instruction has failed.
+	Failures int `json:"failures"`
+	// LastFailedRunTime is a time.UnixDate formatted string of when the instruction started failing.
+	LastFailedRunTime string `json:"lastFailedRunTime"`
+}