Merge pull request #6062 from jwhonce/wip/docs

[CI:DOC] Bring README.md up to date
This commit is contained in:
OpenShift Merge Robot
2020-05-01 20:59:05 +02:00
committed by GitHub
3 changed files with 39 additions and 34 deletions

View File

@ -1,23 +1,16 @@
# Adding a podman V2 commands
# Podman CLI
## Build podman V2
The following is an example of how to add a new primary command (`manifest`) and a sub-command (`inspect`) to the Podman CLI.
This is example code, the production code has additional error checking and the business logic provided.
```shell script
$ cd $GOPATH/src/github.com/containers/libpod/cmd/podmanV2
```
If you wish to include the libpod library in your program,
```shell script
$ go build -tags 'ABISupport' .
```
The `--remote` flag may be used to connect to the Podman service using the API.
Otherwise, direct calls will be made to the Libpod library.
```shell script
$ go build -tags '!ABISupport' .
```
The Libpod library is not linked into the executable.
All calls are made via the API and `--remote=False` is an error condition.
See items below for details on building, installing, contributing to Podman:
- [Readme](README.md)
- [Contributing](CONTRIBUTING.md)
- [Podman Usage](transfer.md)
- [Trouble Shooting](troubleshooting.md)
- [Code Of Conduct](CODE-OF-CONDUCT.md)
## Adding a new command `podman manifests`
## Adding a new command `podman manifest`
```shell script
$ mkdir -p $GOPATH/src/github.com/containers/libpod/cmd/podmanV2/manifests
```
@ -27,6 +20,7 @@ package manifests
import (
"github.com/containers/libpod/cmd/podman/registry"
"github.com/containers/libpod/cmd/podman/validate"
"github.com/containers/libpod/pkg/domain/entities"
"github.com/spf13/cobra"
)
@ -36,11 +30,11 @@ var (
manifestCmd = &cobra.Command{
Use: "manifest",
Short: "Manage manifests",
Args: cobra.ExactArgs(1),
Long: "Manage manifests",
Example: "podman manifests IMAGE",
Example: "podman manifest IMAGE",
TraverseChildren: true,
PersistentPreRunE: preRunE,
RunE: registry.SubCommandExists, // Report error if there is no sub command given
RunE: validate.SubCommandExists, // Report error if there is no sub command given
}
)
func init() {
@ -51,15 +45,6 @@ func init() {
// The definition for this command
Command: manifestCmd,
})
// Setup cobra templates, sub commands will inherit
manifestCmd.SetHelpTemplate(registry.HelpTemplate())
manifestCmd.SetUsageTemplate(registry.UsageTemplate())
}
// preRunE populates the image engine for sub commands
func preRunE(cmd *cobra.Command, args []string) error {
_, err := registry.NewImageEngine(cmd, args)
return err
}
```
To "wire" in the `manifest` command, edit the file ```$GOPATH/src/github.com/containers/libpod/cmd/podmanV2/main.go``` to add:
@ -87,7 +72,11 @@ var (
Short: "Display manifest from image",
Long: "Displays the low-level information on a manifest identified by image name or ID",
RunE: inspect,
Example: "podman manifest DEADBEEF",
Annotations: map[string]string{
// Add this annotation if this command cannot be run rootless
// registry.ParentNSRequired: "",
},
Example: "podman manifest inspect DEADBEEF",
}
)
@ -98,6 +87,7 @@ func init() {
Mode: []entities.EngineMode{entities.ABIMode, entities.TunnelMode},
// The definition for this command
Command: inspectCmd,
// The parent command to proceed this command on the CLI
Parent: manifestCmd,
})
@ -106,8 +96,22 @@ func init() {
// Business logic: cmd is inspectCmd, args is the positional arguments from os.Args
func inspect(cmd *cobra.Command, args []string) error {
// Business logic using registry.ImageEngine
// Business logic using registry.ImageEngine()
// Do not pull from libpod directly use the domain objects and types
return nil
}
```
## Helper functions
The complete set can be found in the `validate` package, here are some examples:
- `cobra.Command{ Args: validate.NoArgs }` used when the command does not accept errors
- `cobra.Command{ Args: validate.IdOrLatestArgs }` used to ensure either a list of ids given or the --latest flag
- `cobra.Command{ RunE: validate.SubCommandExists }` used to validate a subcommand given to a command
- `validate.ChoiceValue` used to create a `pflag.Value` that validate user input against a provided slice of values. For example:
```go
flags := cobraCommand.Flags()
created := validate.ChoiceValue(&opts.Sort, "command", "created", "id", "image", "names", "runningfor", "size", "status")
flags.Var(created, "sort", "Sort output by: "+created.Choices())
```

View File

@ -67,8 +67,8 @@ func listFlagSet(flags *pflag.FlagSet) {
flags.BoolVar(&listOpts.Sync, "sync", false, "Sync container state with OCI runtime")
flags.UintVarP(&listOpts.Watch, "watch", "w", 0, "Watch the ps output on an interval in seconds")
created := validate.ChoiceValue(&listOpts.Sort, "command", "created", "id", "image", "names", "runningfor", "size", "status")
flags.Var(created, "sort", "Sort output by: "+created.Choices())
sort := validate.ChoiceValue(&listOpts.Sort, "command", "created", "id", "image", "names", "runningfor", "size", "status")
flags.Var(sort, "sort", "Sort output by: "+sort.Choices())
if registry.IsRemote() {
_ = flags.MarkHidden("latest")

View File

@ -523,7 +523,8 @@ func (ic *ContainerEngine) ContainerAttach(ctx context.Context, nameOrId string,
}
// If the container is in a pod, also set to recursively start dependencies
if err := terminal.StartAttachCtr(ctx, ctr, options.Stdout, options.Stderr, options.Stdin, options.DetachKeys, options.SigProxy, false, ctr.PodID() != ""); err != nil && errors.Cause(err) != define.ErrDetach {
err = terminal.StartAttachCtr(ctx, ctr, options.Stdout, options.Stderr, options.Stdin, options.DetachKeys, options.SigProxy, false, ctr.PodID() != "")
if err != nil && errors.Cause(err) != define.ErrDetach {
return errors.Wrapf(err, "error attaching to container %s", ctr.ID())
}
return nil