This fixes two bugs:
First, FS Logs API endpoint only propagated error back to user if it was
encoded with code, which isn't common. Other errors get suppressed and
callers get an empty response with 200 error code. Now, these endpoints
return a 500 status code along with the error message.
Before
```
$ curl -v "http://127.0.0.1:4646/v1/client/fs/logs/qwerqwera?follow=false&offset=0&origin=start®ion=global&task=redis&type=stdout"; echo
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to 127.0.0.1 (127.0.0.1) port 4646 (#0)
> GET /v1/client/fs/logs/qwerqwera?follow=false&offset=0&origin=start®ion=global&task=redis&type=stdout HTTP/1.1
> Host: 127.0.0.1:4646
> User-Agent: curl/7.54.0
> Accept: */*
>
< HTTP/1.1 200 OK
< Vary: Accept-Encoding
< Vary: Origin
< Date: Fri, 04 Oct 2019 19:47:21 GMT
< Content-Length: 0
<
* Connection #0 to host 127.0.0.1 left intact
```
After
```
$ curl -v "http://127.0.0.1:4646/v1/client/fs/logs/qwerqwera?follow=false&offset=0&origin=start®ion=global&task=redis&type=stdout"; echo
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to 127.0.0.1 (127.0.0.1) port 4646 (#0)
> GET /v1/client/fs/logs/qwerqwera?follow=false&offset=0&origin=start®ion=global&task=redis&type=stdout HTTP/1.1
> Host: 127.0.0.1:4646
> User-Agent: curl/7.54.0
> Accept: */*
>
< HTTP/1.1 500 Internal Server Error
< Vary: Accept-Encoding
< Vary: Origin
< Date: Fri, 04 Oct 2019 19:48:12 GMT
< Content-Length: 60
< Content-Type: text/plain; charset=utf-8
<
* Connection #0 to host 127.0.0.1 left intact
alloc lookup failed: index error: UUID must be 36 characters
```
Second, we return 400 status code for request validation errors.
Before
```
$ curl -v "http://127.0.0.1:4646/v1/client/fs/logs/qwerqwera"; echo
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to 127.0.0.1 (127.0.0.1) port 4646 (#0)
> GET /v1/client/fs/logs/qwerqwera HTTP/1.1
> Host: 127.0.0.1:4646
> User-Agent: curl/7.54.0
> Accept: */*
>
< HTTP/1.1 500 Internal Server Error
< Vary: Accept-Encoding
< Vary: Origin
< Date: Fri, 04 Oct 2019 19:47:29 GMT
< Content-Length: 22
< Content-Type: text/plain; charset=utf-8
<
* Connection #0 to host 127.0.0.1 left intact
must provide task name
```
After
```
$ curl -v "http://127.0.0.1:4646/v1/client/fs/logs/qwerqwera"; echo
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to 127.0.0.1 (127.0.0.1) port 4646 (#0)
> GET /v1/client/fs/logs/qwerqwera HTTP/1.1
> Host: 127.0.0.1:4646
> User-Agent: curl/7.54.0
> Accept: */*
>
< HTTP/1.1 400 Bad Request
< Vary: Accept-Encoding
< Vary: Origin
< Date: Fri, 04 Oct 2019 19:49:18 GMT
< Content-Length: 22
< Content-Type: text/plain; charset=utf-8
<
* Connection #0 to host 127.0.0.1 left intact
must provide task name
```
The `/v1/client/fs/stream endpoint` supports tailing a file by writing
chunks out as they come in. But not all browsers support streams
(ex IE11) so we need to be able to tail a file without streaming.
The fs stream and logs endpoint use the same implementation for
filesystem streaming under the hood, but the fs stream always passes
the `follow` parameter set to true. This adds the same toggle to the
fs stream endpoint that we have for logs. It defaults to true for
backwards compatibility.
httptest.ResponseRecorder exposes a bytes.Buffer which we were reading
and writing concurrently to test streaming log APIs. This is a race, so
I wrapped the struct in a lock with some helpers.
This PR enhances the API package by having client only RPCs route
through the server when they are low cost and for filesystem access to
first attempt a direct connection to the node and then falling back to
a server routed request.
Many thanks to @iverberk for the original PR (#1609), but we ended up
not wanting to ship this implementation with 0.5.
We'll come back to it after 0.5 and hopefully find a way to leverage
filesystem accounting and quotas, so we can skip the expensive polling.
Mahmood Ali