DockerCLI/cli/command/system/inspect.go

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add //go:build directives to prevent downgrading to go1.16 language This is a follow-up to 0e73168b7e6d1d029d76d05b843b1aaec46739a8 This repository is not yet a module (i.e., does not have a `go.mod`). This is not problematic when building the code in GOPATH or "vendor" mode, but when using the code as a module-dependency (in module-mode), different semantics are applied since Go1.21, which switches Go _language versions_ on a per-module, per-package, or even per-file base. A condensed summary of that logic [is as follows][1]: - For modules that have a go.mod containing a go version directive; that version is considered a minimum _required_ version (starting with the go1.19.13 and go1.20.8 patch releases: before those, it was only a recommendation). - For dependencies that don't have a go.mod (not a module), go language version go1.16 is assumed. - Likewise, for modules that have a go.mod, but the file does not have a go version directive, go language version go1.16 is assumed. - If a go.work file is present, but does not have a go version directive, language version go1.17 is assumed. When switching language versions, Go _downgrades_ the language version, which means that language features (such as generics, and `any`) are not available, and compilation fails. For example: # github.com/docker/cli/cli/context/store /go/pkg/mod/github.com/docker/cli@v25.0.0-beta.2+incompatible/cli/context/store/storeconfig.go:6:24: predeclared any requires go1.18 or later (-lang was set to go1.16; check go.mod) /go/pkg/mod/github.com/docker/cli@v25.0.0-beta.2+incompatible/cli/context/store/store.go:74:12: predeclared any requires go1.18 or later (-lang was set to go1.16; check go.mod) Note that these fallbacks are per-module, per-package, and can even be per-file, so _(indirect) dependencies_ can still use modern language features, as long as their respective go.mod has a version specified. Unfortunately, these failures do not occur when building locally (using vendor / GOPATH mode), but will affect consumers of the module. Obviously, this situation is not ideal, and the ultimate solution is to move to go modules (add a go.mod), but this comes with a non-insignificant risk in other areas (due to our complex dependency tree). We can revert to using go1.16 language features only, but this may be limiting, and may still be problematic when (e.g.) matching signatures of dependencies. There is an escape hatch: adding a `//go:build` directive to files that make use of go language features. From the [go toolchain docs][2]: > The go line for each module sets the language version the compiler enforces > when compiling packages in that module. The language version can be changed > on a per-file basis by using a build constraint. > > For example, a module containing code that uses the Go 1.21 language version > should have a `go.mod` file with a go line such as `go 1.21` or `go 1.21.3`. > If a specific source file should be compiled only when using a newer Go > toolchain, adding `//go:build go1.22` to that source file both ensures that > only Go 1.22 and newer toolchains will compile the file and also changes > the language version in that file to Go 1.22. This patch adds `//go:build` directives to those files using recent additions to the language. It's currently using go1.19 as version to match the version in our "vendor.mod", but we can consider being more permissive ("any" requires go1.18 or up), or more "optimistic" (force go1.21, which is the version we currently use to build). For completeness sake, note that any file _without_ a `//go:build` directive will continue to use go1.16 language version when used as a module. [1]: https://github.com/golang/go/blob/58c28ba286dd0e98fe4cca80f5d64bbcb824a685/src/cmd/go/internal/gover/version.go#L9-L56 [2]; https://go.dev/doc/toolchain#:~:text=The%20go%20line%20for,file%20to%20Go%201.22 Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2023-12-14 07:51:57 -05:00
// FIXME(thaJeztah): remove once we are a module; the go:build directive prevents go from downgrading language version to go1.16:
//go:build go1.19
package system
import (
"context"
"fmt"
"strings"
"github.com/docker/cli/cli"
"github.com/docker/cli/cli/command"
"github.com/docker/cli/cli/command/inspect"
flagsHelper "github.com/docker/cli/cli/flags"
"github.com/docker/docker/api/types"
"github.com/docker/docker/api/types/network"
"github.com/docker/docker/errdefs"
"github.com/pkg/errors"
"github.com/spf13/cobra"
)
type inspectOptions struct {
format string
inspectType string
size bool
ids []string
}
// NewInspectCommand creates a new cobra.Command for `docker inspect`
func NewInspectCommand(dockerCli command.Cli) *cobra.Command {
var opts inspectOptions
cmd := &cobra.Command{
Use: "inspect [OPTIONS] NAME|ID [NAME|ID...]",
Short: "Return low-level information on Docker objects",
Args: cli.RequiresMinArgs(1),
RunE: func(cmd *cobra.Command, args []string) error {
opts.ids = args
return runInspect(cmd.Context(), dockerCli, opts)
},
}
flags := cmd.Flags()
flags.StringVarP(&opts.format, "format", "f", "", flagsHelper.InspectFormatHelp)
flags.StringVar(&opts.inspectType, "type", "", "Return JSON for specified type")
flags.BoolVarP(&opts.size, "size", "s", false, "Display total file sizes if the type is container")
return cmd
}
func runInspect(ctx context.Context, dockerCli command.Cli, opts inspectOptions) error {
var elementSearcher inspect.GetRefFunc
switch opts.inspectType {
case "", "container", "image", "node", "network", "service", "volume", "task", "plugin", "secret":
elementSearcher = inspectAll(ctx, dockerCli, opts.size, opts.inspectType)
default:
return errors.Errorf("%q is not a valid value for --type", opts.inspectType)
}
return inspect.Inspect(dockerCli.Out(), opts.ids, opts.format, elementSearcher)
}
func inspectContainers(ctx context.Context, dockerCli command.Cli, getSize bool) inspect.GetRefFunc {
return func(ref string) (any, []byte, error) {
return dockerCli.Client().ContainerInspectWithRaw(ctx, ref, getSize)
}
}
func inspectImages(ctx context.Context, dockerCli command.Cli) inspect.GetRefFunc {
return func(ref string) (any, []byte, error) {
return dockerCli.Client().ImageInspectWithRaw(ctx, ref)
}
}
func inspectNetwork(ctx context.Context, dockerCli command.Cli) inspect.GetRefFunc {
return func(ref string) (any, []byte, error) {
return dockerCli.Client().NetworkInspectWithRaw(ctx, ref, network.InspectOptions{})
}
}
func inspectNode(ctx context.Context, dockerCli command.Cli) inspect.GetRefFunc {
return func(ref string) (any, []byte, error) {
return dockerCli.Client().NodeInspectWithRaw(ctx, ref)
}
}
func inspectService(ctx context.Context, dockerCli command.Cli) inspect.GetRefFunc {
return func(ref string) (any, []byte, error) {
// Service inspect shows defaults values in empty fields.
return dockerCli.Client().ServiceInspectWithRaw(ctx, ref, types.ServiceInspectOptions{InsertDefaults: true})
}
}
func inspectTasks(ctx context.Context, dockerCli command.Cli) inspect.GetRefFunc {
return func(ref string) (any, []byte, error) {
return dockerCli.Client().TaskInspectWithRaw(ctx, ref)
}
}
func inspectVolume(ctx context.Context, dockerCli command.Cli) inspect.GetRefFunc {
return func(ref string) (any, []byte, error) {
return dockerCli.Client().VolumeInspectWithRaw(ctx, ref)
}
}
func inspectPlugin(ctx context.Context, dockerCli command.Cli) inspect.GetRefFunc {
return func(ref string) (any, []byte, error) {
return dockerCli.Client().PluginInspectWithRaw(ctx, ref)
}
}
func inspectSecret(ctx context.Context, dockerCli command.Cli) inspect.GetRefFunc {
return func(ref string) (any, []byte, error) {
return dockerCli.Client().SecretInspectWithRaw(ctx, ref)
}
}
func inspectAll(ctx context.Context, dockerCli command.Cli, getSize bool, typeConstraint string) inspect.GetRefFunc {
inspectAutodetect := []struct {
objectType string
isSizeSupported bool
isSwarmObject bool
objectInspector func(string) (any, []byte, error)
}{
{
objectType: "container",
isSizeSupported: true,
objectInspector: inspectContainers(ctx, dockerCli, getSize),
},
{
objectType: "image",
objectInspector: inspectImages(ctx, dockerCli),
},
{
objectType: "network",
objectInspector: inspectNetwork(ctx, dockerCli),
},
{
objectType: "volume",
objectInspector: inspectVolume(ctx, dockerCli),
},
{
objectType: "service",
isSwarmObject: true,
objectInspector: inspectService(ctx, dockerCli),
},
{
objectType: "task",
isSwarmObject: true,
objectInspector: inspectTasks(ctx, dockerCli),
},
{
objectType: "node",
isSwarmObject: true,
objectInspector: inspectNode(ctx, dockerCli),
},
{
objectType: "plugin",
objectInspector: inspectPlugin(ctx, dockerCli),
},
{
objectType: "secret",
isSwarmObject: true,
objectInspector: inspectSecret(ctx, dockerCli),
},
}
// isSwarmManager does an Info API call to verify that the daemon is
// a swarm manager.
isSwarmManager := func() bool {
info, err := dockerCli.Client().Info(ctx)
if err != nil {
fmt.Fprintln(dockerCli.Err(), err)
return false
}
return info.Swarm.ControlAvailable
}
return func(ref string) (any, []byte, error) {
const (
swarmSupportUnknown = iota
swarmSupported
swarmUnsupported
)
isSwarmSupported := swarmSupportUnknown
for _, inspectData := range inspectAutodetect {
if typeConstraint != "" && inspectData.objectType != typeConstraint {
continue
}
if typeConstraint == "" && inspectData.isSwarmObject {
if isSwarmSupported == swarmSupportUnknown {
if isSwarmManager() {
isSwarmSupported = swarmSupported
} else {
isSwarmSupported = swarmUnsupported
}
}
if isSwarmSupported == swarmUnsupported {
continue
}
}
v, raw, err := inspectData.objectInspector(ref)
if err != nil {
if typeConstraint == "" && isErrSkippable(err) {
continue
}
return v, raw, err
}
if getSize && !inspectData.isSizeSupported {
fmt.Fprintf(dockerCli.Err(), "WARNING: --size ignored for %s\n", inspectData.objectType)
}
return v, raw, err
}
return nil, nil, errors.Errorf("Error: No such object: %s", ref)
}
}
func isErrSkippable(err error) bool {
return errdefs.IsNotFound(err) ||
strings.Contains(err.Error(), "not supported") ||
strings.Contains(err.Error(), "invalid reference format")
}