zrepl/client/zfsabstractions_create_step_hold.go
Christian Schwarz 10a14a8c50 [#307] add package trace, integrate it with logging, and adopt it throughout zrepl
package trace:

- introduce the concept of tasks and spans, tracked as linked list within ctx
    - see package-level docs for an overview of the concepts
    - **main feature 1**: unique stack of task and span IDs
        - makes it easy to follow a series of log entries in concurrent code
    - **main feature 2**: ability to produce a chrome://tracing-compatible trace file
        - either via an env variable or a `zrepl pprof` subcommand
        - this is not a CPU profile, we already have go pprof for that
        - but it is very useful to visually inspect where the
          replication / snapshotter / pruner spends its time
          ( fixes #307 )

usage in package daemon/logging:

- goal: every log entry should have a trace field with the ID stack from package trace

- make `logging.GetLogger(ctx, Subsys)` the authoritative `logger.Logger` factory function
    - the context carries a linked list of injected fields which
      `logging.GetLogger` adds to the logger it returns
    - `logging.GetLogger` also uses package `trace` to get the
      task-and-span-stack and injects it into the returned logger's fields
2020-05-19 11:30:02 +02:00

59 lines
1.4 KiB
Go

package client
import (
"context"
"fmt"
"github.com/pkg/errors"
"github.com/spf13/pflag"
"github.com/zrepl/zrepl/cli"
"github.com/zrepl/zrepl/endpoint"
"github.com/zrepl/zrepl/zfs"
)
var zabsCreateStepHoldFlags struct {
target string
jobid JobIDFlag
}
var zabsCmdCreateStepHold = &cli.Subcommand{
Use: "step",
Run: doZabsCreateStep,
NoRequireConfig: true,
Short: `create a step hold or bookmark`,
SetupFlags: func(f *pflag.FlagSet) {
f.StringVarP(&zabsCreateStepHoldFlags.target, "target", "t", "", "snapshot to be held / bookmark to be held")
f.VarP(&zabsCreateStepHoldFlags.jobid, "jobid", "j", "jobid for which the hold is installed")
},
}
func doZabsCreateStep(ctx context.Context, sc *cli.Subcommand, args []string) error {
if len(args) > 0 {
return errors.New("subcommand takes no arguments")
}
f := &zabsCreateStepHoldFlags
fs, _, _, err := zfs.DecomposeVersionString(f.target)
if err != nil {
return errors.Wrapf(err, "%q invalid target", f.target)
}
if f.jobid.FlagValue() == nil {
return errors.Errorf("jobid must be set")
}
v, err := zfs.ZFSGetFilesystemVersion(ctx, f.target)
if err != nil {
return errors.Wrapf(err, "get info about target %q", f.target)
}
step, err := endpoint.HoldStep(ctx, fs, v, *f.jobid.FlagValue())
if err != nil {
return errors.Wrap(err, "create step hold")
}
fmt.Println(step.String())
return nil
}