/
manifold.go
315 lines (273 loc) · 8.03 KB
/
manifold.go
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// Copyright 2015 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.
package collect
import (
"path"
"sync"
"time"
corecharm "github.com/juju/charm/v12"
"github.com/juju/charm/v12/hooks"
"github.com/juju/errors"
"github.com/juju/loggo"
"github.com/juju/names/v5"
"github.com/juju/worker/v3"
"github.com/juju/worker/v3/dependency"
"github.com/juju/juju/agent"
jworker "github.com/juju/juju/worker"
"github.com/juju/juju/worker/common/charmrunner"
"github.com/juju/juju/worker/fortress"
"github.com/juju/juju/worker/metrics/spool"
"github.com/juju/juju/worker/uniter"
"github.com/juju/juju/worker/uniter/charm"
"github.com/juju/juju/worker/uniter/runner"
"github.com/juju/juju/worker/uniter/runner/context"
"github.com/juju/juju/wrench"
)
const (
defaultSocketName = "metrics-collect.socket"
)
// Logger is here to stop the desire of creating a package level Logger.
// Don't do this, instead use the logger passed into the manifold.
type logger interface{}
var (
_ logger = struct{}{}
defaultPeriod = 5 * time.Minute
// errMetricsNotDefined is returned when the charm the uniter is running does
// not declare any metrics.
errMetricsNotDefined = errors.New("no metrics defined")
// readCharm function reads the charm directory and extracts declared metrics and the charm url.
readCharm = func(unitTag names.UnitTag, paths context.Paths) (string, map[string]corecharm.Metric, error) {
ch, err := corecharm.ReadCharm(paths.GetCharmDir())
if err != nil {
return "", nil, errors.Annotatef(err, "failed to read charm from: %v", paths.GetCharmDir())
}
chURL, err := charm.ReadCharmURL(path.Join(paths.GetCharmDir(), charm.CharmURLPath))
if err != nil {
return "", nil, errors.Trace(err)
}
charmMetrics := map[string]corecharm.Metric{}
if ch.Metrics() != nil {
charmMetrics = ch.Metrics().Metrics
}
return chURL, charmMetrics, nil
}
// newRecorder returns a struct that implements the spool.MetricRecorder
// interface.
newRecorder = func(unitTag names.UnitTag, paths context.Paths, metricFactory spool.MetricFactory) (spool.MetricRecorder, error) {
chURL, charmMetrics, err := readCharm(unitTag, paths)
if err != nil {
return nil, errors.Trace(err)
}
if len(charmMetrics) == 0 {
return nil, errMetricsNotDefined
}
return metricFactory.Recorder(charmMetrics, chURL, unitTag.String())
}
newSocketListener = func(path string, handler spool.ConnectionHandler) (stopper, error) {
return spool.NewSocketListener(path, handler)
}
)
type stopper interface {
Stop() error
}
// Clock represents time methods used by this package.
type Clock interface {
Now() time.Time
}
// Logger represents the logging methods used in this package.
type Logger interface {
Debugf(string, ...interface{})
Tracef(string, ...interface{})
Root() loggo.Logger
}
// ManifoldConfig identifies the resource names upon which the collect manifold
// depends.
type ManifoldConfig struct {
Period *time.Duration
AgentName string
MetricSpoolName string
CharmDirName string
Clock Clock
Logger Logger
}
// Manifold returns a collect-metrics manifold.
func Manifold(config ManifoldConfig) dependency.Manifold {
return dependency.Manifold{
Inputs: []string{
config.AgentName,
config.MetricSpoolName,
config.CharmDirName,
},
Start: func(context dependency.Context) (worker.Worker, error) {
collector, err := newCollect(config, context)
if err != nil {
return nil, err
}
return spool.NewPeriodicWorker(collector.Do, collector.period, jworker.NewTimer, collector.stop), nil
},
}
}
func socketName(baseDir, unitTag string) string {
return path.Join(baseDir, defaultSocketName)
}
func newCollect(config ManifoldConfig, context dependency.Context) (*collect, error) {
if wrench.IsActive("metricscollector", "short-interval") {
defaultPeriod = 10 * time.Second
}
period := defaultPeriod
if config.Period != nil {
period = *config.Period
}
var agent agent.Agent
if err := context.Get(config.AgentName, &agent); err != nil {
return nil, errors.Trace(err)
}
var metricFactory spool.MetricFactory
err := context.Get(config.MetricSpoolName, &metricFactory)
if err != nil {
return nil, errors.Trace(err)
}
var charmdir fortress.Guest
err = context.Get(config.CharmDirName, &charmdir)
if err != nil {
return nil, errors.Trace(err)
}
err = charmdir.Visit(func() error {
return nil
}, context.Abort())
if err != nil {
return nil, errors.Trace(err)
}
agentConfig := agent.CurrentConfig()
tag := agentConfig.Tag()
unitTag, ok := tag.(names.UnitTag)
if !ok {
return nil, errors.Errorf("expected a unit tag, got %v", tag)
}
paths := uniter.NewWorkerPaths(agentConfig.DataDir(), unitTag, "metrics-collect", nil)
runner := &hookRunner{
unitTag: unitTag.String(),
paths: paths,
clock: config.Clock,
logger: config.Logger,
}
var listener stopper
charmURL, validMetrics, err := readCharm(unitTag, paths)
if err != nil {
return nil, errors.Trace(err)
}
curl, err := corecharm.ParseURL(charmURL)
if err != nil {
return nil, errors.Trace(err)
}
if len(validMetrics) > 0 && curl.Schema == "local" {
h := newHandler(handlerConfig{
charmdir: charmdir,
agent: agent,
unitTag: unitTag,
metricsFactory: metricFactory,
runner: runner,
})
listener, err = newSocketListener(socketName(paths.State.BaseDir, unitTag.String()), h)
if err != nil {
return nil, err
}
}
collector := &collect{
period: period,
agent: agent,
metricFactory: metricFactory,
charmdir: charmdir,
listener: listener,
runner: runner,
logger: config.Logger,
}
return collector, nil
}
type collect struct {
period time.Duration
agent agent.Agent
metricFactory spool.MetricFactory
charmdir fortress.Guest
listener stopper
runner *hookRunner
logger Logger
}
func (w *collect) stop() {
if w.listener != nil {
_ = w.listener.Stop()
}
}
// Do satisfies the worker.PeriodWorkerCall function type.
func (w *collect) Do(stop <-chan struct{}) (err error) {
defer func() {
// See bug https://pad/lv/1733469
// If this function which is run by a PeriodicWorker
// exits with an error, we need to call stop() to
// ensure the listener socket is closed.
if err != nil {
w.stop()
}
}()
config := w.agent.CurrentConfig()
tag := config.Tag()
unitTag, ok := tag.(names.UnitTag)
if !ok {
return errors.Errorf("expected a unit tag, got %v", tag)
}
paths := uniter.NewWorkerPaths(config.DataDir(), unitTag, "metrics-collect", nil)
recorder, err := newRecorder(unitTag, paths, w.metricFactory)
if errors.Cause(err) == errMetricsNotDefined {
w.logger.Tracef("%v", err)
return nil
} else if err != nil {
return errors.Annotate(err, "failed to instantiate metric recorder")
}
err = w.charmdir.Visit(func() error {
return w.runner.do(recorder)
}, stop)
if err == fortress.ErrAborted {
w.logger.Tracef("cannot execute collect-metrics: %v", err)
return nil
}
if spool.IsMetricsDataError(err) {
w.logger.Debugf("cannot record metrics: %v", err)
return nil
}
return err
}
type hookRunner struct {
m sync.Mutex
unitTag string
paths uniter.Paths
clock Clock
logger Logger
}
func (h *hookRunner) do(recorder spool.MetricRecorder) error {
h.m.Lock()
defer h.m.Unlock()
h.logger.Debugf("recording metrics")
ctx := newHookContext(hookConfig{
unitName: h.unitTag,
recorder: recorder,
clock: h.clock,
logger: h.logger,
})
err := ctx.addJujuUnitsMetric()
if err != nil {
return errors.Annotatef(err, "error adding 'juju-units' metric")
}
r := runner.NewRunner(ctx, h.paths, nil)
handlerType, err := r.RunHook(string(hooks.CollectMetrics))
switch {
case charmrunner.IsMissingHookError(errors.Cause(err)):
fallthrough
case err == nil && handlerType == runner.InvalidHookHandler:
h.logger.Debugf("skipped %q hook (missing)", hooks.CollectMetrics)
case err != nil:
return errors.Annotatef(err, "error running %q hook", hooks.CollectMetrics)
default:
h.logger.Debugf("ran %q hook (via %s)", hooks.CollectMetrics, handlerType)
}
return nil
}