| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | package dockersd |
| 4 | |
| 5 | import ( |
| 6 | "context" |
| 7 | "fmt" |
| 8 | "log/slog" |
| 9 | "net" |
| 10 | "strconv" |
| 11 | "strings" |
| 12 | "time" |
| 13 | |
| 14 | "github.com/netdata/netdata/go/plugins/logger" |
| 15 | "github.com/netdata/netdata/go/plugins/pkg/confopt" |
| 16 | "github.com/netdata/netdata/go/plugins/plugin/agent/discovery/sd/model" |
| 17 | "github.com/netdata/netdata/go/plugins/plugin/go.d/pkg/dockerhost" |
| 18 | |
| 19 | typesContainer "github.com/docker/docker/api/types/container" |
| 20 | docker "github.com/docker/docker/client" |
| 21 | ) |
| 22 | |
| 23 | func NewDiscoverer(cfg Config) (*Discoverer, error) { |
| 24 | d := &Discoverer{ |
| 25 | Logger: logger.New().With( |
| 26 | slog.String("component", "service discovery"), |
| 27 | slog.String("discoverer", "docker"), |
| 28 | ), |
| 29 | cfgSource: cfg.Source, |
| 30 | newDockerClient: func(addr string) (dockerClient, error) { |
| 31 | return docker.NewClientWithOpts(docker.WithHost(addr)) |
| 32 | }, |
| 33 | addr: docker.DefaultDockerHost, |
| 34 | listInterval: time.Second * 60, |
| 35 | timeout: time.Second * 2, |
| 36 | seenTggSources: make(map[string]bool), |
| 37 | started: make(chan struct{}), |
| 38 | } |
| 39 | |
| 40 | if addr := dockerhost.FromEnv(); addr != "" && d.addr == docker.DefaultDockerHost { |
| 41 | d.Infof("using docker host from environment: %s ", addr) |
| 42 | d.addr = addr |
| 43 | } |
| 44 | |
| 45 | if cfg.Timeout.Duration() > 0 { |
| 46 | d.timeout = cfg.Timeout.Duration() |
| 47 | } |
| 48 | if cfg.Address != "" { |
| 49 | d.addr = cfg.Address |
| 50 | } |
| 51 | |
| 52 | return d, nil |
| 53 | } |
| 54 | |
| 55 | type Config struct { |
| 56 | Source string `yaml:"-" json:"-"` |
| 57 | |
| 58 | Address string `yaml:"address,omitempty" json:"address,omitempty"` |
| 59 | Timeout confopt.Duration `yaml:"timeout,omitempty" json:"timeout,omitempty"` |
| 60 | } |
| 61 | |
| 62 | type ( |
| 63 | Discoverer struct { |
| 64 | *logger.Logger |
| 65 | model.Base |
| 66 | |
| 67 | dockerClient dockerClient |
| 68 | newDockerClient func(addr string) (dockerClient, error) |
| 69 | addr string |
| 70 | |
| 71 | cfgSource string |
| 72 | |
| 73 | listInterval time.Duration |
| 74 | timeout time.Duration |
| 75 | seenTggSources map[string]bool // [targetGroup.Source] |
| 76 | |
| 77 | started chan struct{} |
| 78 | } |
| 79 | dockerClient interface { |
| 80 | NegotiateAPIVersion(context.Context) |
| 81 | ContainerList(context.Context, typesContainer.ListOptions) ([]typesContainer.Summary, error) |
| 82 | Close() error |
| 83 | } |
| 84 | ) |
| 85 | |
| 86 | func (d *Discoverer) String() string { |
| 87 | return "sd:docker" |
| 88 | } |
| 89 | |
| 90 | func (d *Discoverer) Discover(ctx context.Context, in chan<- []model.TargetGroup) { |
| 91 | d.Info("instance is started") |
| 92 | defer func() { d.cleanup(); d.Info("instance is stopped") }() |
| 93 | |
| 94 | close(d.started) |
| 95 | |
| 96 | if d.dockerClient == nil { |
| 97 | client, err := d.newDockerClient(d.addr) |
| 98 | if err != nil { |
| 99 | d.Errorf("error on creating docker client: %v", err) |
| 100 | return |
| 101 | } |
| 102 | d.dockerClient = client |
| 103 | } |
| 104 | |
| 105 | d.dockerClient.NegotiateAPIVersion(ctx) |
| 106 | |
| 107 | if err := d.listContainers(ctx, in); err != nil { |
| 108 | d.Error(err) |
| 109 | return |
| 110 | } |
| 111 | |
| 112 | tk := time.NewTicker(d.listInterval) |
| 113 | defer tk.Stop() |
| 114 | |
| 115 | for { |
| 116 | select { |
| 117 | case <-ctx.Done(): |
| 118 | return |
| 119 | case <-tk.C: |
| 120 | if err := d.listContainers(ctx, in); err != nil { |
| 121 | d.Warning(err) |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | func (d *Discoverer) listContainers(ctx context.Context, in chan<- []model.TargetGroup) error { |
| 128 | listCtx, cancel := context.WithTimeout(ctx, d.timeout) |
| 129 | defer cancel() |
| 130 | |
| 131 | containers, err := d.dockerClient.ContainerList(listCtx, typesContainer.ListOptions{}) |
| 132 | if err != nil { |
| 133 | return err |
| 134 | } |
| 135 | |
| 136 | var tggs []model.TargetGroup |
| 137 | seen := make(map[string]bool) |
| 138 | |
| 139 | for _, cntr := range containers { |
| 140 | if tgg := d.buildTargetGroup(cntr); tgg != nil { |
| 141 | tggs = append(tggs, tgg) |
| 142 | seen[tgg.Source()] = true |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | for src := range d.seenTggSources { |
| 147 | if !seen[src] { |
| 148 | tggs = append(tggs, &targetGroup{source: src}) |
| 149 | } |
| 150 | } |
| 151 | d.seenTggSources = seen |
| 152 | |
| 153 | select { |
| 154 | case <-ctx.Done(): |
| 155 | case in <- tggs: |
| 156 | } |
| 157 | |
| 158 | return nil |
| 159 | } |
| 160 | |
| 161 | func (d *Discoverer) buildTargetGroup(cntr typesContainer.Summary) model.TargetGroup { |
| 162 | if len(cntr.Names) == 0 || cntr.NetworkSettings == nil || len(cntr.NetworkSettings.Networks) == 0 { |
| 163 | return nil |
| 164 | } |
| 165 | |
| 166 | tgg := &targetGroup{ |
| 167 | source: cntrSource(cntr), |
| 168 | } |
| 169 | if d.cfgSource != "" { |
| 170 | tgg.source += fmt.Sprintf(",%s", d.cfgSource) |
| 171 | } |
| 172 | |
| 173 | for netDriver, network := range cntr.NetworkSettings.Networks { |
| 174 | // container with network mode host will be discovered by local-listeners |
| 175 | for _, port := range cntr.Ports { |
| 176 | tgt := &target{ |
| 177 | ID: cntr.ID, |
| 178 | Name: strings.TrimPrefix(cntr.Names[0], "/"), |
| 179 | Image: cntr.Image, |
| 180 | Command: cntr.Command, |
| 181 | Labels: model.MapAny(cntr.Labels), |
| 182 | PrivatePort: strconv.Itoa(int(port.PrivatePort)), |
| 183 | PublicPort: strconv.Itoa(int(port.PublicPort)), |
| 184 | PublicPortIP: port.IP, |
| 185 | PortProtocol: port.Type, |
| 186 | NetworkMode: cntr.HostConfig.NetworkMode, |
| 187 | NetworkDriver: netDriver, |
| 188 | IPAddress: network.IPAddress, |
| 189 | } |
| 190 | tgt.Address = net.JoinHostPort(tgt.IPAddress, tgt.PrivatePort) |
| 191 | |
| 192 | hash, err := model.CalcHash(tgt) |
| 193 | if err != nil { |
| 194 | continue |
| 195 | } |
| 196 | |
| 197 | tgt.hash = hash |
| 198 | |
| 199 | tgg.targets = append(tgg.targets, tgt) |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | return tgg |
| 204 | } |
| 205 | |
| 206 | func (d *Discoverer) cleanup() { |
| 207 | if d.dockerClient != nil { |
| 208 | _ = d.dockerClient.Close() |
| 209 | } |
| 210 | } |
| 211 | |
| 212 | func cntrSource(cntr typesContainer.Summary) string { |
| 213 | name := strings.TrimPrefix(cntr.Names[0], "/") |
| 214 | return fmt.Sprintf("discoverer=docker,container=%s,image=%s", name, cntr.Image) |
| 215 | } |