api: add follow param to file stream endpoint (#6049 )

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.

2019-08-01 08:32:43 -04:00

17 KiB

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layout	page_title	sidebar_current	description
api	Client - HTTP API	api-client	The /client endpoints are used to access client statistics and inspect allocations running on a particular client.

Client HTTP API

The /client endpoints are used to interact with the Nomad clients.

Since Nomad 0.8.0, both a client and server can handle client endpoints. This is particularly useful for when a direct connection to a client is not possible due to the network configuration. For high volume access to the client endpoints, particularly endpoints streaming file contents, direct access to the node should be preferred as it avoids adding additional load to the servers.

When accessing the endpoints via the server, if the desired node is ambiguous based on the URL, an additional ?node_id query parameter must be provided to disambiguate.

Read Stats

This endpoint queries the actual resources consumed on a node. The API endpoint is hosted by the Nomad client and requests have to be made to the nomad client whose resource usage metrics are of interest.

Method	Path	Produces
`GET`	`/client/stats`	`application/json`

The table below shows this endpoint's support for blocking queries and required ACLs.

Blocking Queries	ACL Required
`NO`	`node:read`

Parameters

node_id (string: <optional>) - Specifies the node to query. This is required when the endpoint is being accessed via a server. This is specified as part of the URL. Note, this must be the full node ID, not the short 8-character one. This is specified as part of the path.

Sample Request

$ curl \
    https://localhost:4646/v1/client/stats

Sample Response

{
  "AllocDirStats": {
    "Available": 142943150080,
    "Device": "",
    "InodesUsedPercent": 0.05312946180421879,
    "Mountpoint": "",
    "Size": 249783500800,
    "Used": 106578206720,
    "UsedPercent": 42.668233241448746
  },
  "CPU": [
    {
      "CPU": "cpu0",
      "Idle": 80,
      "System": 11,
      "Total": 20,
      "User": 9
    },
    {
      "CPU": "cpu1",
      "Idle": 99,
      "System": 0,
      "Total": 1,
      "User": 1
    },
    {
      "CPU": "cpu2",
      "Idle": 89,
      "System": 7.000000000000001,
      "Total": 11,
      "User": 4
    },
    {
      "CPU": "cpu3",
      "Idle": 100,
      "System": 0,
      "Total": 0,
      "User": 0
    },
    {
      "CPU": "cpu4",
      "Idle": 92.92929292929293,
      "System": 4.040404040404041,
      "Total": 7.07070707070707,
      "User": 3.0303030303030303
    },
    {
      "CPU": "cpu5",
      "Idle": 99,
      "System": 1,
      "Total": 1,
      "User": 0
    },
    {
      "CPU": "cpu6",
      "Idle": 92.07920792079209,
      "System": 4.9504950495049505,
      "Total": 7.920792079207921,
      "User": 2.9702970297029703
    },
    {
      "CPU": "cpu7",
      "Idle": 99,
      "System": 0,
      "Total": 1,
      "User": 1
    }
  ],
  "CPUTicksConsumed": 1126.8044804480448,
  "DiskStats": [
    {
      "Available": 142943150080,
      "Device": "/dev/disk1",
      "InodesUsedPercent": 0.05312946180421879,
      "Mountpoint": "/",
      "Size": 249783500800,
      "Used": 106578206720,
      "UsedPercent": 42.668233241448746
    }
  ],
  "Memory": {
    "Available": 6232244224,
    "Free": 470618112,
    "Total": 17179869184,
    "Used": 10947624960
  },
  "Timestamp": 1495743032992498200,
  "Uptime": 193520
}

Read Allocation Statistics

The client allocation endpoint is used to query the actual resources consumed by an allocation.

Method	Path	Produces
`GET`	`/client/allocation/:alloc_id/stats`	`application/json`

The table below shows this endpoint's support for blocking queries and required ACLs.

Blocking Queries	ACL Required
`NO`	`namespace:read-job`

Parameters

:alloc_id (string: <required>) - Specifies the allocation ID to query. This is specified as part of the URL. Note, this must be the full allocation ID, not the short 8-character one. This is specified as part of the path.

Sample Request

$ curl \
    https://localhost:4646/v1/client/allocation/5fc98185-17ff-26bc-a802-0c74fa471c99/stats

Sample Response

{
  "ResourceUsage": {
    "CpuStats": {
      "Measured": [
        "Throttled Periods",
        "Throttled Time",
        "Percent"
      ],
      "Percent": 0.14159538847117795,
      "SystemMode": 0,
      "ThrottledPeriods": 0,
      "ThrottledTime": 0,
      "TotalTicks": 3.256693934837093,
      "UserMode": 0
    },
    "MemoryStats": {
      "Cache": 1744896,
      "KernelMaxUsage": 0,
      "KernelUsage": 0,
      "MaxUsage": 4710400,
      "Measured": [
        "RSS",
        "Cache",
        "Swap",
        "Max Usage"
      ],
      "RSS": 1486848,
      "Swap": 0
    }
  },
  "Tasks": {
    "redis": {
      "Pids": null,
      "ResourceUsage": {
        "CpuStats": {
          "Measured": [
            "Throttled Periods",
            "Throttled Time",
            "Percent"
          ],
          "Percent": 0.14159538847117795,
          "SystemMode": 0,
          "ThrottledPeriods": 0,
          "ThrottledTime": 0,
          "TotalTicks": 3.256693934837093,
          "UserMode": 0
        },
        "MemoryStats": {
          "Cache": 1744896,
          "KernelMaxUsage": 0,
          "KernelUsage": 0,
          "MaxUsage": 4710400,
          "Measured": [
            "RSS",
            "Cache",
            "Swap",
            "Max Usage"
          ],
          "RSS": 1486848,
          "Swap": 0
        }
      },
      "Timestamp": 1495743243970720000
    }
  },
  "Timestamp": 1495743243970720000
}

Read File

This endpoint reads the contents of a file in an allocation directory.

Method	Path	Produces
`GET`	`/client/fs/cat/:alloc_id`	`text/plain`

The table below shows this endpoint's support for blocking queries and required ACLs.

Blocking Queries	ACL Required
`NO`	`namespace:read-fs`

Parameters

:alloc_id (string: <required>) - Specifies the allocation ID to query. This is specified as part of the URL. Note, this must be the full allocation ID, not the short 8-character one. This is specified as part of the path.
path (string: "/") - Specifies the path of the file to read, relative to the root of the allocation directory.

Sample Request

$ curl \
    https://localhost:4646/v1/client/fs/cat/5fc98185-17ff-26bc-a802-0c74fa471c99

$ curl \
    https://localhost:4646/v1/client/fs/cat/5fc98185-17ff-26bc-a802-0c74fa471c99?path=alloc/file.json

Sample Response

(whatever was in the file...)

Read File at Offset

This endpoint reads the contents of a file in an allocation directory at a particular offset and limit.

Method	Path	Produces
`GET`	`/client/fs/readat/:alloc_id`	`text/plain`

The table below shows this endpoint's support for blocking queries and required ACLs.

Blocking Queries	ACL Required
`NO`	`namespace:read-fs`

Parameters

:alloc_id (string: <required>) - Specifies the allocation ID to query. This is specified as part of the URL. Note, this must be the full allocation ID, not the short 8-character one. This is specified as part of the path.
path (string: "/") - Specifies the path of the file to read, relative to the root of the allocation directory.
offset (int: <required>) - Specifies the byte offset from where content will be read.
limit (int: <required>) - Specifies the number of bytes to read from the offset.

Sample Request

$ curl \
    https://localhost:4646/v1/client/fs/readat/5fc98185-17ff-26bc-a802-0c74fa471c99?path=/alloc/foo&offset=1323&limit=19303

Sample Response

(whatever was in the file, starting from offset, up to limit bytes...)

Stream File

This endpoint streams the contents of a file in an allocation directory.

Method	Path	Produces
`GET`	`/client/fs/stream/:alloc_id`	`text/plain`

The table below shows this endpoint's support for blocking queries and required ACLs.

Blocking Queries	ACL Required
`NO`	`namespace:read-fs`

Parameters

:alloc_id (string: <required>) - Specifies the allocation ID to query. This is specified as part of the URL. Note, this must be the full allocation ID, not the short 8-character one. This is specified as part of the path.
path (string: "/") - Specifies the path of the file to read, relative to the root of the allocation directory.
follow (bool: true)- Specifies whether to tail the file.
offset (int: <required>) - Specifies the byte offset from where content will be read.
origin (string: "start|end") - Applies the relative offset to either the start or end of the file.

Sample Request

$ curl \
    https://localhost:4646/v1/client/fs/stream/5fc98185-17ff-26bc-a802-0c74fa471c99?path=/alloc/logs/redis.log

Sample Response

{
  "File": "alloc/logs/redis.log",
  "Offset": 3604480,
  "Data": "NTMxOTMyCjUzMTkzMwo1MzE5MzQKNTMx..."
},
{
  "File": "alloc/logs/redis.log",
  "FileEvent": "file deleted"
}

Field Reference

The return value is a stream of frames. These frames contain the following fields:

Data - A base64 encoding of the bytes being streamed.
FileEvent - An event that could cause a change in the streams position. The possible values are "file deleted" and "file truncated".
Offset - Offset is the offset into the stream.
File - The name of the file being streamed.

Stream Logs

This endpoint streams a task's stderr/stdout logs.

Method	Path	Produces
`GET`	`/client/fs/logs/:alloc_id`	`text/plain`

The table below shows this endpoint's support for blocking queries and required ACLs.

Blocking Queries	ACL Required
`NO`	`namespace:read-logs` or `namespace:read-fs`

Parameters

:alloc_id (string: <required>) - Specifies the allocation ID to query. This is specified as part of the URL. Note, this must be the full allocation ID, not the short 8-character one. This is specified as part of the path.
task (string: <required>) - Specifies the name of the task inside the allocation to stream logs from.
follow (bool: false)- Specifies whether to tail the logs.
type (string: "stderr|stdout") - Specifies the stream to stream.
offset (int: 0) - Specifies the offset to start streaming from.
origin (string: "start|end") - Specifies either "start" or "end" and applies the offset relative to either the start or end of the logs respectively. Defaults to "start".
plain (bool: false) - Return just the plain text without framing. This can be useful when viewing logs in a browser.

Sample Request

$ curl \
    https://localhost:4646/v1/client/fs/logs/5fc98185-17ff-26bc-a802-0c74fa471c99

Sample Response

{
  "File": "alloc/logs/redis.stdout.0",
  "Offset": 3604480,
  "Data": "NTMxOTMyCjUzMTkzMwo1MzE5MzQKNTMx..."
},
{
  "File": "alloc/logs/redis.stdout.0",
  "FileEvent": "file deleted"
}

Field Reference

The return value is a stream of frames. These frames contain the following fields:

Data - A base64 encoding of the bytes being streamed.
FileEvent - An event that could cause a change in the streams position. The possible values are "file deleted" and "file truncated".
Offset - Offset is the offset into the stream.
File - The name of the file being streamed.

List Files

This endpoint lists files in an allocation directory.

Method	Path	Produces
`GET`	`/client/fs/ls/:alloc_id`	`text/plain`

The table below shows this endpoint's support for blocking queries and required ACLs.

Blocking Queries	ACL Required
`NO`	`namespace:read-fs`

Parameters

:alloc_id (string: <required>) - Specifies the allocation ID to query. This is specified as part of the URL. Note, this must be the full allocation ID, not the short 8-character one. This is specified as part of the path.
path (string: "/") - Specifies the path of the file to read, relative to the root of the allocation directory.

Sample Request

$ curl \
    https://localhost:4646/v1/client/fs/ls/5fc98185-17ff-26bc-a802-0c74fa471c99

Sample Response

[
  {
    "Name": "alloc",
    "IsDir": true,
    "Size": 4096,
    "FileMode": "drwxrwxr-x",
    "ModTime": "2016-03-15T15:40:00.414236712-07:00"
  },
  {
    "Name": "redis",
    "IsDir": true,
    "Size": 4096,
    "FileMode": "drwxrwxr-x",
    "ModTime": "2016-03-15T15:40:56.810238153-07:00"
  }
]

Stat File

This endpoint stats a file in an allocation.

Method	Path	Produces
`GET`	`/client/fs/stat/:alloc_id`	`text/plain`

The table below shows this endpoint's support for blocking queries and required ACLs.

Blocking Queries	ACL Required
`NO`	`namespace:read-fs`

Parameters

:alloc_id (string: <required>) - Specifies the allocation ID to query. This is specified as part of the URL. Note, this must be the full allocation ID, not the short 8-character one. This is specified as part of the path.
path (string: "/") - Specifies the path of the file to read, relative to the root of the allocation directory.

Sample Request

$ curl \
    https://localhost:4646/v1/client/fs/stat/5fc98185-17ff-26bc-a802-0c74fa471c99

Sample Response

{
  "Name": "redis-syslog-collector.out",
  "IsDir": false,
  "Size": 96,
  "FileMode": "-rw-rw-r--",
  "ModTime": "2016-03-15T15:40:56.822238153-07:00"
}

GC Allocation

This endpoint forces a garbage collection of a particular, stopped allocation on a node.

Method	Path	Produces
`GET`	`/client/allocation/:alloc_id/gc`	`application/json`

The table below shows this endpoint's support for blocking queries and required ACLs.

Blocking Queries	ACL Required
`NO`	`namespace:submit-job`

Parameters

:alloc_id (string: <required>) - Specifies the allocation ID to query. This is specified as part of the URL. Note, this must be the full allocation ID, not the short 8-character one. This is specified as part of the path.

Sample Request

$ curl \
    https://nomad.rocks/v1/client/allocation/5fc98185-17ff-26bc-a802-0c74fa471c99/gc

GC All Allocation

This endpoint forces a garbage collection of all stopped allocations on a node.

Method	Path	Produces
`GET`	`/client/gc`	`text/plain`

The table below shows this endpoint's support for blocking queries and required ACLs.

Blocking Queries	ACL Required
`NO`	`node:write`

Parameters

node_id (string: <optional>) - Specifies the node to target. This is required when the endpoint is being accessed via a server. This is specified as part of the URL. Note, this must be the full node ID, not the short 8-character one. This is specified as part of the path.

Sample Request

$ curl \
    https://localhost:4646/v1/client/gc

17 KiB Raw Blame History

Client HTTP API

Read Stats

Parameters

Sample Request

Sample Response

Read Allocation Statistics

Parameters

Sample Request

Sample Response

Read File

Parameters

Sample Request

Sample Response

Read File at Offset

Parameters

Sample Request

Sample Response

Stream File

Parameters

Sample Request

Sample Response

Field Reference

Stream Logs

Parameters

Sample Request

Sample Response

Field Reference

List Files

Parameters

Sample Request

Sample Response

Stat File

Parameters

Sample Request

Sample Response

GC Allocation

Parameters

Sample Request

GC All Allocation

Parameters

Sample Request

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