Files
kata-containers/cli/run.go
James O. D. Hunt 3a1bbd0271 tracing: Add initial opentracing support
Add initial support for opentracing by using the `jaeger` package.
Since opentracing uses the `context` package, add a `context.Context`
as the first parameter to all the functions that we might want to
trace. Trace "spans" (trace points) are then added by extracting the
trace details from the specified context parameter.

Notes:

- Although the tracer is created in `main()`, the "root span"
  (aka the first trace point) is not added until `beforeSubcommands()`.

  This is by design and is a compromise: by delaying the creation of the
  root span, the spans become much more readable since using the web-based
  JaegerUI, you will see traces like this:

  ```
  kata-runtime: kata-runtime create
  ------------  -------------------
       ^                ^
       |                |
  Trace name        First span name
                    (which clearly shows the CLI command that was run)
  ```

  Creating the span earlier means it is necessary to expand 'n' spans in
  the UI before you get to see the name of the CLI command that was run.
  In adding support, this became very tedious, hence my design decision to
  defer the creation of the root span until after signal handling has been
  setup and after CLI options have been parsed, but still very early in
  the code path.

  - At this stage, the tracing stops at the `virtcontainers` call
  boundary.

- Tracing is "always on" as there doesn't appear to be a way to toggle
  it. However, its resolves to a "nop" unless the tracer can talk to a
  jaeger agent.

Note that this commit required a bit of rework to `beforeSubcommands()`
to reduce the cyclomatic complexity.

Fixes #557.

Signed-off-by: James O. D. Hunt <james.o.hunt@intel.com>
2018-08-10 16:13:48 +01:00

129 lines
3.2 KiB
Go

// Copyright (c) 2014,2015,2016 Docker, Inc.
// Copyright (c) 2017 Intel Corporation
//
// SPDX-License-Identifier: Apache-2.0
//
package main
import (
"context"
"errors"
"fmt"
"os"
"syscall"
"github.com/kata-containers/runtime/virtcontainers/pkg/oci"
opentracing "github.com/opentracing/opentracing-go"
"github.com/urfave/cli"
)
var runCLICommand = cli.Command{
Name: "run",
Usage: "create and run a container",
ArgsUsage: `<container-id>
<container-id> is your name for the instance of the container that you
are starting. The name you provide for the container instance must be unique
on your host.`,
Description: `The run command creates an instance of a container for a bundle. The bundle
is a directory with a specification file named "config.json" and a root
filesystem.`,
Flags: []cli.Flag{
cli.StringFlag{
Name: "bundle, b",
Value: "",
Usage: `path to the root of the bundle directory, defaults to the current directory`,
},
cli.StringFlag{
Name: "console",
Value: "",
Usage: "path to a pseudo terminal",
},
cli.StringFlag{
Name: "console-socket",
Value: "",
Usage: "path to an AF_UNIX socket which will receive a file descriptor referencing the master end of the console's pseudoterminal",
},
cli.StringFlag{
Name: "pid-file",
Value: "",
Usage: "specify the file to write the process id to",
},
cli.BoolFlag{
Name: "detach, d",
Usage: "detach from the container's process",
},
cli.BoolFlag{
Name: "no-pivot",
Usage: "warning: this flag is meaningless to kata-runtime, just defined in order to be compatible with docker in ramdisk",
},
},
Action: func(context *cli.Context) error {
ctx, err := cliContextToContext(context)
if err != nil {
return err
}
runtimeConfig, ok := context.App.Metadata["runtimeConfig"].(oci.RuntimeConfig)
if !ok {
return errors.New("invalid runtime config")
}
return run(ctx, context.Args().First(),
context.String("bundle"),
context.String("console"),
context.String("console-socket"),
context.String("pid-file"),
context.Bool("detach"),
runtimeConfig)
},
}
func run(ctx context.Context, containerID, bundle, console, consoleSocket, pidFile string, detach bool,
runtimeConfig oci.RuntimeConfig) error {
span, ctx := opentracing.StartSpanFromContext(ctx, "run")
defer span.Finish()
consolePath, err := setupConsole(console, consoleSocket)
if err != nil {
return err
}
if err := create(ctx, containerID, bundle, consolePath, pidFile, detach, runtimeConfig); err != nil {
return err
}
sandbox, err := start(ctx, containerID)
if err != nil {
return err
}
if detach {
return nil
}
containers := sandbox.GetAllContainers()
if len(containers) == 0 {
return fmt.Errorf("There are no containers running in the sandbox: %s", sandbox.ID())
}
p, err := os.FindProcess(containers[0].GetPid())
if err != nil {
return err
}
ps, err := p.Wait()
if err != nil {
return fmt.Errorf("Process state %s: %s", ps.String(), err)
}
// delete container's resources
if err := delete(ctx, sandbox.ID(), true); err != nil {
return err
}
//runtime should forward container exit code to the system
return cli.NewExitError("", ps.Sys().(syscall.WaitStatus).ExitStatus())
}