From 0ae2a02ce6e4d3f2e8d3ecf54358414bec7ff62d Mon Sep 17 00:00:00 2001 From: Akihiro Suda Date: Fri, 2 Sep 2016 07:40:06 +0000 Subject: [PATCH] add `docker events --format` Signed-off-by: Akihiro Suda --- command/system/events.go | 54 ++++++++++++++++++++++++++++++++-------- 1 file changed, 43 insertions(+), 11 deletions(-) diff --git a/command/system/events.go b/command/system/events.go index b9d740f356..f2946b8763 100644 --- a/command/system/events.go +++ b/command/system/events.go @@ -3,8 +3,10 @@ package system import ( "fmt" "io" + "io/ioutil" "sort" "strings" + "text/template" "time" "golang.org/x/net/context" @@ -15,6 +17,7 @@ import ( "github.com/docker/docker/cli/command" "github.com/docker/docker/opts" "github.com/docker/docker/pkg/jsonlog" + "github.com/docker/docker/utils/templates" "github.com/spf13/cobra" ) @@ -22,6 +25,7 @@ type eventsOptions struct { since string until string filter opts.FilterOpt + format string } // NewEventsCommand creates a new cobra.Command for `docker events` @@ -41,11 +45,18 @@ func NewEventsCommand(dockerCli *command.DockerCli) *cobra.Command { flags.StringVar(&opts.since, "since", "", "Show all events created since timestamp") flags.StringVar(&opts.until, "until", "", "Stream events until this timestamp") flags.VarP(&opts.filter, "filter", "f", "Filter output based on conditions provided") + flags.StringVar(&opts.format, "format", "", "Format the output using the given go template") return cmd } func runEvents(dockerCli *command.DockerCli, opts *eventsOptions) error { + tmpl, err := makeTemplate(opts.format) + if err != nil { + return cli.StatusError{ + StatusCode: 64, + Status: "Error parsing format: " + err.Error()} + } options := types.EventsOptions{ Since: opts.since, Until: opts.until, @@ -58,33 +69,48 @@ func runEvents(dockerCli *command.DockerCli, opts *eventsOptions) error { } defer responseBody.Close() - return streamEvents(responseBody, dockerCli.Out()) + return streamEvents(dockerCli.Out(), responseBody, tmpl) +} + +func makeTemplate(format string) (*template.Template, error) { + if format == "" { + return nil, nil + } + tmpl, err := templates.Parse(format) + if err != nil { + return tmpl, err + } + // we execute the template for an empty message, so as to validate + // a bad template like "{{.badFieldString}}" + return tmpl, tmpl.Execute(ioutil.Discard, &eventtypes.Message{}) } // streamEvents decodes prints the incoming events in the provided output. -func streamEvents(input io.Reader, output io.Writer) error { +func streamEvents(out io.Writer, input io.Reader, tmpl *template.Template) error { return DecodeEvents(input, func(event eventtypes.Message, err error) error { if err != nil { return err } - printOutput(event, output) - return nil + if tmpl == nil { + return prettyPrintEvent(out, event) + } + return formatEvent(out, event, tmpl) }) } type eventProcessor func(event eventtypes.Message, err error) error -// printOutput prints all types of event information. +// prettyPrintEvent prints all types of event information. // Each output includes the event type, actor id, name and action. // Actor attributes are printed at the end if the actor has any. -func printOutput(event eventtypes.Message, output io.Writer) { +func prettyPrintEvent(out io.Writer, event eventtypes.Message) error { if event.TimeNano != 0 { - fmt.Fprintf(output, "%s ", time.Unix(0, event.TimeNano).Format(jsonlog.RFC3339NanoFixed)) + fmt.Fprintf(out, "%s ", time.Unix(0, event.TimeNano).Format(jsonlog.RFC3339NanoFixed)) } else if event.Time != 0 { - fmt.Fprintf(output, "%s ", time.Unix(event.Time, 0).Format(jsonlog.RFC3339NanoFixed)) + fmt.Fprintf(out, "%s ", time.Unix(event.Time, 0).Format(jsonlog.RFC3339NanoFixed)) } - fmt.Fprintf(output, "%s %s %s", event.Type, event.Action, event.Actor.ID) + fmt.Fprintf(out, "%s %s %s", event.Type, event.Action, event.Actor.ID) if len(event.Actor.Attributes) > 0 { var attrs []string @@ -97,7 +123,13 @@ func printOutput(event eventtypes.Message, output io.Writer) { v := event.Actor.Attributes[k] attrs = append(attrs, fmt.Sprintf("%s=%s", k, v)) } - fmt.Fprintf(output, " (%s)", strings.Join(attrs, ", ")) + fmt.Fprintf(out, " (%s)", strings.Join(attrs, ", ")) } - fmt.Fprint(output, "\n") + fmt.Fprint(out, "\n") + return nil +} + +func formatEvent(out io.Writer, event eventtypes.Message, tmpl *template.Template) error { + defer out.Write([]byte{'\n'}) + return tmpl.Execute(out, event) }