grafana/pkg/plugins/datasource_plugin.go
2018-01-09 15:04:59 +01:00

139 lines
3.4 KiB
Go

package plugins
import (
"context"
"encoding/json"
"fmt"
"os"
"os/exec"
"path"
"path/filepath"
"runtime"
"strings"
"time"
"github.com/grafana/grafana/pkg/log"
"github.com/grafana/grafana/pkg/models"
"github.com/grafana/grafana/pkg/plugins/backend"
"github.com/grafana/grafana/pkg/tsdb"
shared "github.com/grafana/grafana/pkg/tsdb/models/proxy"
plugin "github.com/hashicorp/go-plugin"
)
type DataSourcePlugin struct {
FrontendPluginBase
Annotations bool `json:"annotations"`
Metrics bool `json:"metrics"`
Alerting bool `json:"alerting"`
QueryOptions map[string]bool `json:"queryOptions,omitempty"`
BuiltIn bool `json:"builtIn,omitempty"`
Mixed bool `json:"mixed,omitempty"`
HasQueryHelp bool `json:"hasQueryHelp,omitempty"`
Routes []*AppPluginRoute `json:"routes"`
Backend bool `json:"backend,omitempty"`
Executable string `json:"executable,omitempty"`
log log.Logger
client *plugin.Client
}
func (p *DataSourcePlugin) Load(decoder *json.Decoder, pluginDir string) error {
if err := decoder.Decode(&p); err != nil {
return err
}
if err := p.registerPlugin(pluginDir); err != nil {
return err
}
// look for help markdown
helpPath := filepath.Join(p.PluginDir, "QUERY_HELP.md")
if _, err := os.Stat(helpPath); os.IsNotExist(err) {
helpPath = filepath.Join(p.PluginDir, "query_help.md")
}
if _, err := os.Stat(helpPath); err == nil {
p.HasQueryHelp = true
}
DataSources[p.Id] = p
return nil
}
var handshakeConfig = plugin.HandshakeConfig{
ProtocolVersion: 1,
MagicCookieKey: "grafana_plugin_type",
MagicCookieValue: "datasource",
}
func buildExecutablePath(pluginDir, executable, os, arch string) string {
return path.Join(pluginDir, fmt.Sprintf("%s_%s_%s", executable, strings.ToLower(os), strings.ToLower(arch)))
}
func (p *DataSourcePlugin) initBackendPlugin(ctx context.Context, log log.Logger) error {
p.log = log.New("plugin-id", p.Id)
err := p.spawnSubProcess()
if err == nil {
go p.restartKilledProcess(ctx)
}
return err
}
func (p *DataSourcePlugin) spawnSubProcess() error {
cmd := buildExecutablePath(p.PluginDir, p.Executable, runtime.GOOS, runtime.GOARCH)
p.client = plugin.NewClient(&plugin.ClientConfig{
HandshakeConfig: handshakeConfig,
Plugins: map[string]plugin.Plugin{p.Id: &shared.TsdbPluginImpl{}},
Cmd: exec.Command(cmd),
AllowedProtocols: []plugin.Protocol{plugin.ProtocolGRPC},
Logger: backend.LogWrapper{Logger: p.log},
})
rpcClient, err := p.client.Client()
if err != nil {
return err
}
raw, err := rpcClient.Dispense(p.Id)
if err != nil {
return err
}
plugin := raw.(shared.TsdbPlugin)
tsdb.RegisterTsdbQueryEndpoint(p.Id, func(dsInfo *models.DataSource) (tsdb.TsdbQueryEndpoint, error) {
return &shared.DatasourcePluginWrapper{TsdbPlugin: plugin}, nil
})
return nil
}
func (p *DataSourcePlugin) restartKilledProcess(ctx context.Context) error {
ticker := time.NewTicker(time.Second * 1)
for {
select {
case <-ctx.Done():
return ctx.Err()
case <-ticker.C:
if p.client.Exited() {
err := p.spawnSubProcess()
p.log.Debug("Spawning new sub process", "name", p.Name, "id", p.Id)
if err != nil {
p.log.Error("Failed to spawn subprocess")
}
}
}
}
}
func (p *DataSourcePlugin) Kill() {
if p.client != nil {
p.log.Debug("Killing subprocess ", "name", p.Name)
p.client.Kill()
}
}