feature: add command for exporting service to peer or partition #15654
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,3 @@ | ||
| ```release-note:feature | ||
| cli: Adds new command - `consul services export` - for exporting a service to a peer or partition | ||
| ``` |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,260 @@ | ||
| package export | ||
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| import ( | ||
| "errors" | ||
| "flag" | ||
| "fmt" | ||
| "strings" | ||
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| "github.com/mitchellh/cli" | ||
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| "github.com/hashicorp/consul/agent" | ||
| "github.com/hashicorp/consul/api" | ||
| "github.com/hashicorp/consul/command/flags" | ||
| ) | ||
|
|
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| func New(ui cli.Ui) *cmd { | ||
| c := &cmd{UI: ui} | ||
| c.init() | ||
| return c | ||
| } | ||
|
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| type cmd struct { | ||
| UI cli.Ui | ||
| flags *flag.FlagSet | ||
| http *flags.HTTPFlags | ||
| help string | ||
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| serviceName string | ||
| peerNames string | ||
| partitionNames string | ||
| } | ||
|
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| func (c *cmd) init() { | ||
| c.flags = flag.NewFlagSet("", flag.ContinueOnError) | ||
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| c.flags.StringVar(&c.serviceName, "name", "", "(Required) Specify the name of the service you want to export.") | ||
| c.flags.StringVar(&c.peerNames, "consumer-peers", "", "(Required) A comma-separated list of cluster peers to export the service to. In Consul Enterprise, this flag is optional if -consumer-partitions is specified.") | ||
| c.flags.StringVar(&c.partitionNames, "consumer-partitions", "", "(Enterprise only) A comma-separated list of admin partitions within the same datacenter to export the service to. This flag is optional if -consumer-peers is specified.") | ||
|
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| c.http = &flags.HTTPFlags{} | ||
| flags.Merge(c.flags, c.http.ClientFlags()) | ||
| flags.Merge(c.flags, c.http.MultiTenancyFlags()) | ||
| c.help = flags.Usage(help, c.flags) | ||
| } | ||
|
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| func (c *cmd) Run(args []string) int { | ||
| if err := c.flags.Parse(args); err != nil { | ||
| return 1 | ||
| } | ||
|
|
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| if err := c.validateFlags(); err != nil { | ||
| c.UI.Error(err.Error()) | ||
| return 1 | ||
| } | ||
|
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| peerNames, err := c.getPeerNames() | ||
| if err != nil { | ||
| c.UI.Error(err.Error()) | ||
| return 1 | ||
| } | ||
|
|
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| partitionNames, err := c.getPartitionNames() | ||
| if err != nil { | ||
| c.UI.Error(err.Error()) | ||
| return 1 | ||
| } | ||
|
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| client, err := c.http.APIClient() | ||
| if err != nil { | ||
| c.UI.Error(fmt.Sprintf("Error connect to Consul agent: %s", err)) | ||
| return 1 | ||
| } | ||
|
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| // Name matches partition, so "default" if none specified | ||
| cfgName := "default" | ||
| if c.http.Partition() != "" { | ||
| cfgName = c.http.Partition() | ||
| } | ||
|
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| entry, _, err := client.ConfigEntries().Get(api.ExportedServices, cfgName, &api.QueryOptions{Namespace: ""}) | ||
| if err != nil && !strings.Contains(err.Error(), agent.ConfigEntryNotFoundErr) { | ||
| c.UI.Error(fmt.Sprintf("Error reading config entry %s/%s: %v", "exported-services", "default", err)) | ||
| return 1 | ||
| } | ||
|
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| var cfg *api.ExportedServicesConfigEntry | ||
| if entry == nil { | ||
| cfg = c.initializeConfigEntry(cfgName, peerNames, partitionNames) | ||
| } else { | ||
| existingCfg, ok := entry.(*api.ExportedServicesConfigEntry) | ||
| if !ok { | ||
| c.UI.Error(fmt.Sprintf("Existing config entry has incorrect type: %t", entry)) | ||
| return 1 | ||
| } | ||
|
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| cfg = c.updateConfigEntry(existingCfg, peerNames, partitionNames) | ||
| } | ||
|
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| ok, _, err := client.ConfigEntries().CAS(cfg, cfg.GetModifyIndex(), nil) | ||
| if err != nil { | ||
| c.UI.Error(fmt.Sprintf("Error writing config entry: %s", err)) | ||
| return 1 | ||
| } else if !ok { | ||
| c.UI.Error(fmt.Sprintf("Config entry was changed during update. Please try again")) | ||
| return 1 | ||
| } | ||
|
Comment on lines
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+106
There was a problem hiding this comment. Nice due diligence in handling this case :) |
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| switch { | ||
| case len(c.peerNames) > 0 && len(c.partitionNames) > 0: | ||
| c.UI.Info(fmt.Sprintf("Successfully exported service %q to cluster peers %q and to partitions %q", c.serviceName, c.peerNames, c.partitionNames)) | ||
| case len(c.peerNames) > 0: | ||
| c.UI.Info(fmt.Sprintf("Successfully exported service %q to cluster peers %q", c.serviceName, c.peerNames)) | ||
| case len(c.partitionNames) > 0: | ||
| c.UI.Info(fmt.Sprintf("Successfully exported service %q to partitions %q", c.serviceName, c.partitionNames)) | ||
| } | ||
|
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| return 0 | ||
| } | ||
|
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| func (c *cmd) validateFlags() error { | ||
| if c.serviceName == "" { | ||
| return errors.New("Missing the required -name flag") | ||
| } | ||
|
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| if c.peerNames == "" && c.partitionNames == "" { | ||
| return errors.New("Missing the required -consumer-peers or -consumer-partitions flag") | ||
| } | ||
|
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| return nil | ||
| } | ||
|
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| func (c *cmd) getPeerNames() ([]string, error) { | ||
| var peerNames []string | ||
| if c.peerNames != "" { | ||
| peerNames = strings.Split(c.peerNames, ",") | ||
| for _, peerName := range peerNames { | ||
| if peerName == "" { | ||
| return nil, fmt.Errorf("Invalid peer %q", peerName) | ||
| } | ||
| } | ||
| } | ||
| return peerNames, nil | ||
| } | ||
|
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| func (c *cmd) getPartitionNames() ([]string, error) { | ||
| var partitionNames []string | ||
| if c.partitionNames != "" { | ||
| partitionNames = strings.Split(c.partitionNames, ",") | ||
| for _, partitionName := range partitionNames { | ||
| if partitionName == "" { | ||
|
There was a problem hiding this comment. Is there any other validation of peer or partition names beyond "is it empty" that the backend does? I guess the possible harm is that someone could write a config entry for a non-existent partition, or one with a mistyped/garbled name? That said, we output a string like So maybe additional validation isn't important (unless it was really easy to do). There was a problem hiding this comment. @DanStough and I talked at one point about adding validation in the backend for this as a separate PR. Today, you can write a config entry that exports to a non-existent peer or partition using |
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| return nil, fmt.Errorf("Invalid partition %q", partitionName) | ||
| } | ||
| } | ||
| } | ||
| return partitionNames, nil | ||
| } | ||
|
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| func (c *cmd) initializeConfigEntry(cfgName string, peerNames, partitionNames []string) *api.ExportedServicesConfigEntry { | ||
| return &api.ExportedServicesConfigEntry{ | ||
| Name: cfgName, | ||
| Services: []api.ExportedService{ | ||
| { | ||
| Name: c.serviceName, | ||
| Namespace: c.http.Namespace(), | ||
| Consumers: buildConsumers(peerNames, partitionNames), | ||
| }, | ||
| }, | ||
| } | ||
| } | ||
|
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| func (c *cmd) updateConfigEntry(cfg *api.ExportedServicesConfigEntry, peerNames, partitionNames []string) *api.ExportedServicesConfigEntry { | ||
| serviceExists := false | ||
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| for i, service := range cfg.Services { | ||
| if service.Name == c.serviceName && service.Namespace == c.http.Namespace() { | ||
| serviceExists = true | ||
|
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| // Add a consumer for each peer where one doesn't already exist | ||
| for _, peerName := range peerNames { | ||
| peerExists := false | ||
| for _, consumer := range service.Consumers { | ||
| if consumer.Peer == peerName { | ||
| peerExists = true | ||
| break | ||
| } | ||
| } | ||
| if !peerExists { | ||
| cfg.Services[i].Consumers = append(cfg.Services[i].Consumers, api.ServiceConsumer{Peer: peerName}) | ||
| } | ||
| } | ||
|
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| // Add a consumer for each partition where one doesn't already exist | ||
| for _, partitionName := range partitionNames { | ||
| partitionExists := false | ||
|
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| for _, consumer := range service.Consumers { | ||
| if consumer.Partition == partitionName { | ||
| partitionExists = true | ||
| break | ||
| } | ||
| } | ||
| if !partitionExists { | ||
| cfg.Services[i].Consumers = append(cfg.Services[i].Consumers, api.ServiceConsumer{Partition: partitionName}) | ||
| } | ||
| } | ||
| } | ||
| } | ||
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| if !serviceExists { | ||
| cfg.Services = append(cfg.Services, api.ExportedService{ | ||
| Name: c.serviceName, | ||
| Namespace: c.http.Namespace(), | ||
| Consumers: buildConsumers(peerNames, partitionNames), | ||
| }) | ||
| } | ||
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| return cfg | ||
| } | ||
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| func buildConsumers(peerNames []string, partitionNames []string) []api.ServiceConsumer { | ||
| var consumers []api.ServiceConsumer | ||
| for _, peer := range peerNames { | ||
| consumers = append(consumers, api.ServiceConsumer{ | ||
| Peer: peer, | ||
| }) | ||
| } | ||
| for _, partition := range partitionNames { | ||
| consumers = append(consumers, api.ServiceConsumer{ | ||
| Partition: partition, | ||
| }) | ||
| } | ||
| return consumers | ||
| } | ||
|
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| //======== | ||
|
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| func (c *cmd) Synopsis() string { | ||
| return synopsis | ||
| } | ||
|
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| func (c *cmd) Help() string { | ||
| return flags.Usage(c.help, nil) | ||
| } | ||
|
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| const ( | ||
| synopsis = "Export a service from one peer or admin partition to another" | ||
| help = ` | ||
| Usage: consul services export [options] -name <service name> -consumer-peers <other cluster name> | ||
|
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| Export a service to a peered cluster. | ||
|
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| $ consul services export -name=web -consumer-peers=other-cluster | ||
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| Use the -consumer-partitions flag instead of -consumer-peers to export to a different partition in the same cluster. | ||
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| $ consul services export -name=web -consumer-partitions=other-partition | ||
|
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| Additional flags and more advanced use cases are detailed below. | ||
| ` | ||
| ) | ||
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What happens if partitions are specified in OSS?
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This follows the same theme as other enterprise features in this PR. The command with partitions specified will go through even for OSS users, same as if you use
$ consul config writetoday (since this is really all that's happening behind the scenes).Since the established pattern is to allow Enterprise features in the OSS CLI, the correct thing to do in the longer term IMO is to add server validation for this config entry that returns an error in this case.