first commit

.gitignore

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+pkg/*

Makefile

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+SHELL      := /bin/bash
+PROGRAM    := cwli
+VERSION    := v0.1.0
+GOOS       := $(shell go env GOOS)
+GOARCH     := $(shell go env GOARCH)
+ENTRYPOINT := cmd/cwli/main.go
+SRC        := $(wildcard *.go) $(wildcard */*.go)
+
+.PHONY: all
+	all: $(PROGRAM)
+
+$(PROGRAM): $(SRC) lint vet
+	go build \
+	-ldflags "-X github.com/winebarrel/cwli/cli.version=$(VERSION)" \
+	-o pkg/$(PROGRAM) $(ENTRYPOINT)
+
+.PHONY: package
+package: clean $(PROGRAM)
+	gzip -c pkg/$(PROGRAM) > pkg/$(PROGRAM)-$(VERSION)-$(GOOS)-$(GOARCH).gz
+	rm pkg/$(PROGRAM)
+
+.PHONY: lint
+lint:
+	golint -set_exit_status
+
+.PHONY: vet
+vet:
+	go vet
+
+.PHONY: clean
+clean:
+	rm -f pkg/*

README.md

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+# cwli
+
+## Usage
+
+```
+$ cwli -h
+Usage of cwli:
+  -query string
+      Query string
+  -showptr
+      Show @ptr in query result
+  -version
+      Print version and exit
+```
+
+```
+$ cwli
+ap-northeast-1> show groups;
+/aws/kinesisfirehose/my-kinesis
+/aws/lambda/my-lambda
+/aws/rds/cluster/my-rds/slow-query
+
+ap-northeast-1> head /aws/lambda/my-lambda limit 1;
+*************************** 1. row ***************************
+Timestamp: 1516438129835
+Message: START RequestId: bbd0dbdd-fdbe-11e7-a41f-398ced7d9303 Version: $LATEST
+
+ap-northeast-1> source /aws/lambda/my-lambda start=2018/11/19 end=2019/11/21 | field @timestamp, @message | limit 2;
+{"@timestamp":"2019-04-09 09:38:19.455","@message":"END RequestId: ab83228c-6af1-4c0b-a304-e043aecbe84a\n"}
+{"@timestamp":"2019-04-09 09:38:19.455","@message":"2019-04-09T09:38:19.455Z\tab83228c-6af1-4c0b-a304-e043aecbe84a\tLogEC2InstanceStateChange\n"}
+// Status: Complete
+// Statistics: BytesScanned=859801 RecordsMatched=2065 RecordsScanned=2065
+```
+
+### Passing to external command
+
+```
+ap-northeast-1> source /aws/lambda/my-lambda start=2018/11/19 end=2019/11/21 | field @timestamp, @message ! head -n 1 | tee output.jsonl;
+{"@timestamp":"2019-04-09 09:38:19.455","@message":"2019-04-09T09:38:19.455Z\tab83228c-6af1-4c0b-a304-e043aecbe84a\tLogEC2InstanceStateChange\n"}
+```
+
+```
+$ cat output.jsonl
+{"@timestamp":"2019-04-09 09:38:19.455","@message":"2019-04-09T09:38:19.455Z\tab83228c-6af1-4c0b-a304-e043aecbe84a\tLogEC2InstanceStateChange\n"}
+```

cli/flags.go

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+package cli
+
+import (
+	"flag"
+	"fmt"
+	"os"
+)
+
+var version string
+
+type Flags struct {
+	Query   string
+	Showptr bool
+}
+
+func ParseFlags() (flags *Flags) {
+	flags = &Flags{}
+	var printVersion bool
+
+	flag.StringVar(&flags.Query, "query", "", "Query string")
+	flag.BoolVar(&flags.Showptr, "showptr", false, "Show @ptr in query result")
+	flag.BoolVar(&printVersion, "version", false, "Print version and exit")
+	flag.Parse()
+
+	if printVersion {
+		fmt.Println(version)
+		os.Exit(0)
+	}
+
+	return
+}

cmd/cwli/main.go

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+package main
+
+import (
+	"log"
+
+	"github.com/winebarrel/cwli"
+	"github.com/winebarrel/cwli/cli"
+)
+
+func init() {
+	log.SetFlags(log.LstdFlags)
+}
+
+func main() {
+	flags := cli.ParseFlags()
+	runner := cwli.NewRunner(flags)
+	runner.Run()
+}

command_executor.go

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+package cwli
+
+import (
+	"io"
+	"log"
+	"os"
+	"os/exec"
+)
+
+func executeCommand(str string, input string) (err error) {
+	cmd := exec.Command("sh", "-c", str)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	stdin, err := cmd.StdinPipe()
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	go func() {
+		defer stdin.Close()
+		io.WriteString(stdin, input)
+	}()
+
+	err = cmd.Run()
+
+	return
+}

exec/executable.go

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+package exec
+
+import (
+	"io"
+
+	"github.com/aws/aws-sdk-go/service/cloudwatchlogs"
+	"github.com/winebarrel/cwli/cli"
+)
+
+type Executable interface {
+	Start(svc *cloudwatchlogs.CloudWatchLogs, flags *cli.Flags, out io.Writer) error
+}
+
+var Commands = []func(string) (Executable, error){
+	parseHelp,
+	parseShowGroups,
+	parseHead,
+	parseQuery,
+}

exec/head.go

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+package exec
+
+import (
+	"fmt"
+	"io"
+	"regexp"
+	"strconv"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/service/cloudwatchlogs"
+	"github.com/winebarrel/cwli/cli"
+)
+
+var regexpHead = regexp.MustCompile(`(?i)^head\s+(\S+)(?:\s+limit\s+([0-9]+))?\s*$`)
+
+type headCommand struct {
+	group string
+	limit int64
+}
+
+func parseHead(str string) (cmd Executable, err error) {
+	submatch := regexpHead.FindStringSubmatch(str)
+
+	if len(submatch) == 0 {
+		return
+	}
+
+	group := submatch[1]
+	limit := int64(3)
+
+	if submatch[2] != "" {
+		limit, err = strconv.ParseInt(submatch[2], 10, 64)
+
+		if err != nil {
+			return
+		}
+	}
+
+	if limit <= 0 {
+		err = fmt.Errorf("Invalid limit: %d", limit)
+		return
+	}
+
+	cmd = &headCommand{
+		group: group,
+		limit: limit,
+	}
+
+	return
+}
+
+func describeLogGroup(svc *cloudwatchlogs.CloudWatchLogs, group string) (logGroup *cloudwatchlogs.LogGroup, err error) {
+	params := &cloudwatchlogs.DescribeLogGroupsInput{
+		LogGroupNamePrefix: aws.String(group),
+		Limit:              aws.Int64(1),
+	}
+
+	resp, err := svc.DescribeLogGroups(params)
+
+	if err != nil {
+		return
+	}
+
+	if len(resp.LogGroups) == 0 || *resp.LogGroups[0].LogGroupName != group {
+		err = fmt.Errorf("LogGroup was not found: %s", group)
+		return
+	}
+
+	logGroup = resp.LogGroups[0]
+
+	return
+}
+
+func describeLogStream(svc *cloudwatchlogs.CloudWatchLogs, logGroup *cloudwatchlogs.LogGroup) (logStream *cloudwatchlogs.LogStream, err error) {
+	params := &cloudwatchlogs.DescribeLogStreamsInput{
+		LogGroupName: logGroup.LogGroupName,
+		Descending:   aws.Bool(true),
+		OrderBy:      aws.String("LastEventTime"),
+		Limit:        aws.Int64(1),
+	}
+
+	resp, err := svc.DescribeLogStreams(params)
+
+	if err != nil {
+		return
+	}
+
+	if len(resp.LogStreams) == 0 {
+		err = fmt.Errorf("LogStream was not found in %s", *logGroup.LogGroupName)
+		return
+	}
+
+	logStream = resp.LogStreams[0]
+
+	return
+}
+
+func getLogEvent(svc *cloudwatchlogs.CloudWatchLogs, logGroup *cloudwatchlogs.LogGroup, logStream *cloudwatchlogs.LogStream, limit int64) (events []*cloudwatchlogs.OutputLogEvent, err error) {
+	params := &cloudwatchlogs.GetLogEventsInput{
+		LogGroupName:  logGroup.LogGroupName,
+		LogStreamName: logStream.LogStreamName,
+		StartTime:     logStream.LastEventTimestamp,
+		Limit:         aws.Int64(limit),
+	}
+
+	resp, err := svc.GetLogEvents(params)
+
+	if err != nil {
+		return
+	}
+
+	if len(resp.Events) == 0 {
+		err = fmt.Errorf("Events was not found in %s", *logGroup.LogGroupName)
+		return
+	}
+
+	events = resp.Events
+
+	return
+}
+
+func (cmd *headCommand) Start(svc *cloudwatchlogs.CloudWatchLogs, flags *cli.Flags, out io.Writer) (err error) {
+	logGroup, err := describeLogGroup(svc, cmd.group)
+
+	if err != nil {
+		return
+	}
+
+	logStream, err := describeLogStream(svc, logGroup)
+
+	if err != nil {
+		return
+	}
+
+	events, err := getLogEvent(svc, logGroup, logStream, cmd.limit)
+
+	if err != nil {
+		return
+	}
+
+	for i, event := range events {
+		fmt.Fprintf(out, "*************************** %d. row ***************************\n", i+1)
+		fmt.Fprintf(out, "Timestamp: %d\n", *event.Timestamp)
+		fmt.Fprintf(out, "Message: %s\n", *event.Message)
+	}
+
+	return
+}
+
+func usageHead() string {
+	return "head LOG-GROUP [limit N]\n\tPrint first lines of a Log Group"
+}

exec/help.go

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+package exec
+
+import (
+	"fmt"
+	"io"
+	"regexp"
+
+	"github.com/aws/aws-sdk-go/service/cloudwatchlogs"
+	"github.com/winebarrel/cwli/cli"
+)
+
+var usages = []func() string{
+	usageHelp,
+	usageShowGroups,
+	usageHead,
+	usageQuery,
+}
+
+var regexpHelp = regexp.MustCompile(`(?i)^help\s*$`)
+
+type helpCommand struct {
+}
+
+func parseHelp(str string) (cmd Executable, err error) {
+	if !regexpHelp.MatchString(str) {
+		return
+	}
+
+	cmd = &helpCommand{}
+
+	return
+}
+
+func (cmd *helpCommand) Start(svc *cloudwatchlogs.CloudWatchLogs, flags *cli.Flags, out io.Writer) (err error) {
+
+	for _, usage := range usages {
+		fmt.Fprintln(out, usage())
+	}
+
+	return
+}
+
+func usageHelp() string {
+	return "help\n\tPrint a help message"
+}