service logs reference documentation

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

docs/reference/api/docker_remote_api.md

@@ -149,7 +149,7 @@ This section lists each version from latest to oldest.  Each listing includes a
 * `POST /containers/create` now takes `AutoRemove` in HostConfig, to enable auto-removal of the container on daemon side when the container's process exits.
 * `GET /containers/json` and `GET /containers/(id or name)/json` now return `"removing"` as a value for the `State.Status` field if the container is being removed. Previously, "exited" was returned as status.
 * `GET /containers/json` now accepts `removing` as a valid value for the `status` filter.
-* `GET /containers/json` now supports filtering containers by `health` status. 
+* `GET /containers/json` now supports filtering containers by `health` status.
 * `DELETE /volumes/(name)` now accepts a `force` query parameter to force removal of volumes that were already removed out of band by the volume driver plugin.
 * `POST /containers/create/` and `POST /containers/(name)/update` now validates restart policies.
 * `POST /containers/create` now validates IPAMConfig in NetworkingConfig, and returns error for invalid IPv4 and IPv6 addresses (`--ip` and `--ip6` in `docker create/run`).

docs/reference/api/docker_remote_api_v1.25.md

@@ -5629,6 +5629,49 @@ image](#create-an-image) section for more details.
 -   **404** – no such service
 -   **500** – server error
 
+### Get service logs
+
+`GET /services/(id or name)/logs`
+
+Get `stdout` and `stderr` logs from the service ``id``
+
+> **Note**:
+> This endpoint works only for services with the `json-file` or `journald` logging drivers.
+
+**Example request**:
+
+     GET /services/4fa6e0f0c678/logs?stderr=1&stdout=1&timestamps=1&follow=1&tail=10&since=1428990821 HTTP/1.1
+
+**Example response**:
+
+     HTTP/1.1 101 UPGRADED
+     Content-Type: application/vnd.docker.raw-stream
+     Connection: Upgrade
+     Upgrade: tcp
+
+     {% raw %}
+     {{ STREAM }}
+     {% endraw %}
+
+**Query parameters**:
+
+-   **details** - 1/True/true or 0/False/flase, Show extra details provided to logs. Default `false`.
+-   **follow** – 1/True/true or 0/False/false, return stream. Default `false`.
+-   **stdout** – 1/True/true or 0/False/false, show `stdout` log. Default `false`.
+-   **stderr** – 1/True/true or 0/False/false, show `stderr` log. Default `false`.
+-   **since** – UNIX timestamp (integer) to filter logs. Specifying a timestamp
+    will only output log-entries since that timestamp. Default: 0 (unfiltered)
+-   **timestamps** – 1/True/true or 0/False/false, print timestamps for
+        every log line. Default `false`.
+-   **tail** – Output specified number of lines at the end of logs: `all` or `<number>`. Default all.
+
+**Status codes**:
+
+-   **101** – no error, hints proxy about hijacking
+-   **200** – no error, no upgrade header found
+-   **404** – no such service
+-   **500** – server error
+
 ## 3.10 Tasks
 
 **Note**: Task operations require the engine to be part of a swarm.

docs/reference/commandline/service_logs.md

@@ -0,0 +1,67 @@
+---
+title: "service logs (experimental)"
+description: "The service logs command description and usage"
+keywords: "service, logs"
+advisory: "experimental"
+---
+
+<!-- This file is maintained within the docker/docker Github
+     repository at https://github.com/docker/docker/. Make all
+     pull requests against that repo. If you see this file in
+     another repository, consider it read-only there, as it will
+     periodically be overwritten by the definitive file. Pull
+     requests which include edits to this file in other repositories
+     will be rejected.
+-->
+
+# service logs
+
+```Markdown
+Usage:  docker service logs [OPTIONS] SERVICE
+
+Fetch the logs of a service
+
+Options:
+      --details        Show extra details provided to logs
+  -f, --follow         Follow log output
+      --help           Print usage
+      --since string   Show logs since timestamp
+      --tail string    Number of lines to show from the end of the logs (default "all")
+  -t, --timestamps     Show timestamps
+```
+
+The `docker service logs` command batch-retrieves logs present at the time of execution.
+
+> **Note**: this command is only functional for services that are started with
+> the `json-file` or `journald` logging driver.
+
+For more information about selecting and configuring login-drivers, refer to
+[Configure logging drivers](https://docs.docker.com/engine/admin/logging/overview/).
+
+The `docker service logs --follow` command will continue streaming the new output from
+the service's `STDOUT` and `STDERR`.
+
+Passing a negative number or a non-integer to `--tail` is invalid and the
+value is set to `all` in that case.
+
+The `docker service logs --timestamps` command will add an [RFC3339Nano timestamp](https://golang.org/pkg/time/#pkg-constants)
+, for example `2014-09-16T06:17:46.000000000Z`, to each
+log entry. To ensure that the timestamps are aligned the
+nano-second part of the timestamp will be padded with zero when necessary.
+
+The `docker service logs --details` command will add on extra attributes, such as
+environment variables and labels, provided to `--log-opt` when creating the
+service.
+
+The `--since` option shows only the service logs generated after
+a given date. You can specify the date as an RFC 3339 date, a UNIX
+timestamp, or a Go duration string (e.g. `1m30s`, `3h`). Besides RFC3339 date
+format you may also use RFC3339Nano, `2006-01-02T15:04:05`,
+`2006-01-02T15:04:05.999999999`, `2006-01-02Z07:00`, and `2006-01-02`. The local
+timezone on the client will be used if you do not provide either a `Z` or a
+`+-00:00` timezone offset at the end of the timestamp. When providing Unix
+timestamps enter seconds[.nanoseconds], where seconds is the number of seconds
+that have elapsed since January 1, 1970 (midnight UTC/GMT), not counting leap
+seconds (aka Unix epoch or Unix time), and the optional .nanoseconds field is a
+fraction of a second no more than nine digits long. You can combine the
+`--since` option with either or both of the `--follow` or `--tail` options.