types/logger, logtail: add mechanism to do structured JSON logs

e.g. the change to ipnlocal in this commit ultimately logs out:

{"logtail":{"client_time":"2022-02-17T20:40:30.511381153-08:00","server_time":"2022-02-18T04:40:31.057771504Z"},"type":"Hostinfo","val":{"GoArch":"amd64","Hostname":"tsdev","IPNVersion":"1.21.0-date.20220107","OS":"linux","OSVersion":"Debian 11.2 (bullseye); kernel=5.10.0-10-amd64"},"v":1}

Change-Id: I668646b19aeae4a2fed05170d7b279456829c844
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick
2022-02-17 20:41:49 -08:00
committed by Brad Fitzpatrick
parent 8c3c5e80b7
commit 84138450a4
5 changed files with 83 additions and 1 deletions

View File

@@ -530,6 +530,9 @@ func (l *Logger) encode(buf []byte, level int) []byte {
"client_time": now.Format(time.RFC3339Nano),
}
}
if level > 0 {
obj["v"] = level
}
b, err := json.Marshal(obj)
if err != nil {
@@ -577,6 +580,7 @@ var (
openBracketV = []byte("[v")
v1 = []byte("[v1] ")
v2 = []byte("[v2] ")
vJSON = []byte("[v\x00JSON]") // precedes log level '0'-'9' byte, then JSON value
)
// level 0 is normal (or unknown) level; 1+ are increasingly verbose
@@ -590,5 +594,14 @@ func parseAndRemoveLogLevel(buf []byte) (level int, cleanBuf []byte) {
if bytes.Contains(buf, v2) {
return 2, bytes.ReplaceAll(buf, v2, nil)
}
if i := bytes.Index(buf, vJSON); i != -1 {
rest := buf[i+len(vJSON):]
if len(rest) >= 2 {
v := rest[0]
if v >= '0' && v <= '9' {
return int(v - '0'), rest[1:]
}
}
}
return 0, buf
}

View File

@@ -275,6 +275,11 @@ func TestParseAndRemoveLogLevel(t *testing.T) {
0,
"[v3] no level 3",
},
{
"some ignored text then [v\x00JSON]5{\"foo\":1234}",
5,
`{"foo":1234}`,
},
}
for _, tt := range tests {
@@ -368,6 +373,14 @@ func TestEncode(t *testing.T) {
`{"foo":"bar"}`,
`{"foo":"bar","logtail":{"client_time":"1970-01-01T00:02:03.000000456Z"}}` + "\n",
},
{
"foo: [v\x00JSON]0{\"foo\":1}",
"{\"foo\":1,\"logtail\":{\"client_time\":\"1970-01-01T00:02:03.000000456Z\"}}\n",
},
{
"foo: [v\x00JSON]2{\"foo\":1}",
"{\"foo\":1,\"logtail\":{\"client_time\":\"1970-01-01T00:02:03.000000456Z\"},\"v\":2}\n",
},
}
for _, tt := range tests {
buf := new(simpleMemBuf)