|
| 1 | +package main |
| 2 | + |
| 3 | +import ( |
| 4 | + "bytes" |
| 5 | + "fmt" |
| 6 | + "io" |
| 7 | + "os" |
| 8 | + "os/exec" |
| 9 | + "runtime" |
| 10 | + |
| 11 | + "github.com/sirupsen/logrus" |
| 12 | + "github.com/urfave/cli/v2" |
| 13 | + |
| 14 | + "github.com/replicatedhq/helmvm/pkg/defaults" |
| 15 | + "github.com/replicatedhq/helmvm/pkg/goods" |
| 16 | +) |
| 17 | + |
| 18 | +var joinCommand = &cli.Command{ |
| 19 | + Name: "join", |
| 20 | + Usage: "Join the current node to an existing cluster", |
| 21 | + Flags: []cli.Flag{ |
| 22 | + &cli.StringFlag{ |
| 23 | + Name: "role", |
| 24 | + Usage: "The role of the node (can be controller or worker)", |
| 25 | + Value: "worker", |
| 26 | + }, |
| 27 | + }, |
| 28 | + Action: func(c *cli.Context) error { |
| 29 | + if err := canRunJoin(c); err != nil { |
| 30 | + return err |
| 31 | + } |
| 32 | + logrus.Infof("Materializing binaries") |
| 33 | + if err := goods.Materialize(); err != nil { |
| 34 | + return fmt.Errorf("unable to materialize binaries: %w", err) |
| 35 | + } |
| 36 | + logrus.Infof("Saving token to disk") |
| 37 | + if err := saveTokenToDisk(c.Args().First()); err != nil { |
| 38 | + return fmt.Errorf("unable to save token to disk: %w", err) |
| 39 | + } |
| 40 | + logrus.Infof("Installing binary") |
| 41 | + if err := installK0sBinary(); err != nil { |
| 42 | + return fmt.Errorf("unable to install k0s binary: %w", err) |
| 43 | + } |
| 44 | + logrus.Infof("Joining node to cluster") |
| 45 | + if err := runK0sInstallCommand(c.String("role")); err != nil { |
| 46 | + return fmt.Errorf("unable to join node to cluster: %w", err) |
| 47 | + } |
| 48 | + logrus.Infof("Creating systemd unit file") |
| 49 | + if err := createSystemdUnitFile(c.String("role")); err != nil { |
| 50 | + return fmt.Errorf("unable to create systemd unit file: %w", err) |
| 51 | + } |
| 52 | + logrus.Infof("Starting service") |
| 53 | + if err := startK0sService(); err != nil { |
| 54 | + return fmt.Errorf("unable to start service: %w", err) |
| 55 | + } |
| 56 | + return nil |
| 57 | + }, |
| 58 | +} |
| 59 | + |
| 60 | +// saveTokenToDisk saves the provided token in "/etc/k0s/join-token". |
| 61 | +func saveTokenToDisk(token string) error { |
| 62 | + if err := os.MkdirAll("/etc/k0s", 0755); err != nil { |
| 63 | + return err |
| 64 | + } |
| 65 | + data := []byte(token) |
| 66 | + if err := os.WriteFile("/etc/k0s/join-token", data, 0644); err != nil { |
| 67 | + return err |
| 68 | + } |
| 69 | + return nil |
| 70 | +} |
| 71 | + |
| 72 | +// installK0sBinary saves the embedded k0s binary to disk under /usr/local/bin. |
| 73 | +func installK0sBinary() error { |
| 74 | + in, err := os.Open(defaults.K0sBinaryPath()) |
| 75 | + if err != nil { |
| 76 | + return fmt.Errorf("unable to open embedded k0s binary: %w", err) |
| 77 | + } |
| 78 | + defer in.Close() |
| 79 | + out, err := os.OpenFile("/usr/local/bin/k0s", os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0755) |
| 80 | + if err != nil { |
| 81 | + return fmt.Errorf("unable to open k0s binary: %w", err) |
| 82 | + } |
| 83 | + defer out.Close() |
| 84 | + if _, err := io.Copy(out, in); err != nil { |
| 85 | + return fmt.Errorf("unable to copy k0s binary: %w", err) |
| 86 | + } |
| 87 | + return nil |
| 88 | +} |
| 89 | + |
| 90 | +// startK0sService starts the k0s service. |
| 91 | +func startK0sService() error { |
| 92 | + cmd := exec.Command("/usr/local/bin/k0s", "start") |
| 93 | + stdout := bytes.NewBuffer(nil) |
| 94 | + stderr := bytes.NewBuffer(nil) |
| 95 | + cmd.Stdout = stdout |
| 96 | + cmd.Stderr = stderr |
| 97 | + if err := cmd.Run(); err != nil { |
| 98 | + logrus.Errorf("service start failed:") |
| 99 | + fmt.Fprintf(os.Stderr, "%s\n", stderr.String()) |
| 100 | + fmt.Fprintf(os.Stdout, "%s\n", stdout.String()) |
| 101 | + return err |
| 102 | + } |
| 103 | + return nil |
| 104 | +} |
| 105 | + |
| 106 | +// canRunJoin checks if we can run the join command. Checks if we are running on linux, |
| 107 | +// if we are root, and if a token has been provided through the command line. |
| 108 | +func canRunJoin(c *cli.Context) error { |
| 109 | + if runtime.GOOS != "linux" { |
| 110 | + return fmt.Errorf("join command is only supported on linux") |
| 111 | + } |
| 112 | + if os.Getuid() != 0 { |
| 113 | + return fmt.Errorf("join command must be run as root") |
| 114 | + } |
| 115 | + if c.Args().Len() != 1 { |
| 116 | + return fmt.Errorf("usage: %s node join <token>", defaults.BinaryName()) |
| 117 | + } |
| 118 | + if role := c.String("role"); role != "controller" && role != "worker" { |
| 119 | + return fmt.Errorf("role must be either controller or worker") |
| 120 | + } |
| 121 | + return nil |
| 122 | +} |
| 123 | + |
| 124 | +// createSystemdUnitFile links the k0s systemd unit file. |
| 125 | +func createSystemdUnitFile(role string) error { |
| 126 | + dst := fmt.Sprintf("/etc/systemd/system/%s.service", defaults.BinaryName()) |
| 127 | + if _, err := os.Stat(dst); err == nil { |
| 128 | + if err := os.Remove(dst); err != nil { |
| 129 | + return err |
| 130 | + } |
| 131 | + } |
| 132 | + src := "/etc/systemd/system/k0scontroller.service" |
| 133 | + if role == "worker" { |
| 134 | + src = "/etc/systemd/system/k0sworker.service" |
| 135 | + } |
| 136 | + if err := os.Symlink(src, dst); err != nil { |
| 137 | + return err |
| 138 | + } |
| 139 | + cmd := exec.Command("systemctl", "daemon-reload") |
| 140 | + stdout := bytes.NewBuffer(nil) |
| 141 | + stderr := bytes.NewBuffer(nil) |
| 142 | + cmd.Stdout = stdout |
| 143 | + cmd.Stderr = stderr |
| 144 | + if err := cmd.Run(); err != nil { |
| 145 | + logrus.Errorf("systemctl reload failed:") |
| 146 | + fmt.Fprintf(os.Stderr, "%s\n", stderr.String()) |
| 147 | + fmt.Fprintf(os.Stdout, "%s\n", stdout.String()) |
| 148 | + return err |
| 149 | + } |
| 150 | + return nil |
| 151 | +} |
| 152 | + |
| 153 | +// runK0sInstallCommand runs the 'k0s install' command using the provided role. |
| 154 | +func runK0sInstallCommand(role string) error { |
| 155 | + a := []string{"install", role, "--token-file", "/etc/k0s/join-token", "--force"} |
| 156 | + if role == "controller" { |
| 157 | + a = append(a, "--enable-worker") |
| 158 | + } |
| 159 | + cmd := exec.Command("/usr/local/bin/k0s", a...) |
| 160 | + stdout := bytes.NewBuffer(nil) |
| 161 | + stderr := bytes.NewBuffer(nil) |
| 162 | + cmd.Stdout = stdout |
| 163 | + cmd.Stderr = stderr |
| 164 | + if err := cmd.Run(); err != nil { |
| 165 | + logrus.Errorf("install failed:") |
| 166 | + fmt.Fprintf(os.Stderr, "%s\n", stderr.String()) |
| 167 | + fmt.Fprintf(os.Stdout, "%s\n", stdout.String()) |
| 168 | + return err |
| 169 | + } |
| 170 | + return nil |
| 171 | +} |
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