Fixes #82 Add a client for the pod read-log endpoint

Author: dbolkensteyn

Diff for: src/index.ts

@@ -7,3 +7,4 @@ export * from './exec';
 export * from './portforward';
 export * from './types';
 export * from './yaml';
+export * from './log';

Diff for: src/log.ts

@@ -0,0 +1,98 @@
+import { Options } from 'request';
+import { Writable } from 'stream';
+
+import { KubeConfig } from './config';
+import { RequestInterface, DefaultRequest } from './watch';
+
+export interface LogOptions {
+    /**
+     * The container for which to stream logs. Defaults to only container if there is one container in the pod.
+     */
+    container?: string;
+
+    /**
+     * Follow the log stream of the pod. Defaults to false.
+     */
+    follow?: boolean;
+
+    /**
+     * If set, the number of bytes to read from the server before terminating the log output. This may not display a
+     * complete final line of logging, and may return slightly more or slightly less than the specified limit.
+     */
+    limitBytes?: number;
+
+    /**
+     * If true, then the output is pretty printed.
+     */
+    pretty?: boolean;
+
+    /**
+     * Return previous terminated container logs. Defaults to false.
+     */
+    previous?: boolean;
+
+    /**
+     * A relative time in seconds before the current time from which to show logs. If this value precedes the time a
+     * pod was started, only logs since the pod start will be returned. If this value is in the future, no logs will
+     * be returned. Only one of sinceSeconds or sinceTime may be specified.
+     */
+    sinceSeconds?: number;
+
+    /**
+     * If set, the number of lines from the end of the logs to show. If not specified, logs are shown from the creation
+     * of the container or sinceSeconds or sinceTime
+     */
+    tailLines?: number;
+
+    /**
+     * If true, add an RFC3339 or RFC3339Nano timestamp at the beginning of every line of log output. Defaults to false.
+     */
+    timestamps?: boolean;
+}
+
+export class Log {
+    public config: KubeConfig;
+    private readonly requestImpl: RequestInterface;
+
+    public constructor(config: KubeConfig, requestImpl?: RequestInterface) {
+        this.config = config;
+        if (requestImpl) {
+            this.requestImpl = requestImpl;
+        } else {
+            this.requestImpl = new DefaultRequest();
+        }
+    }
+
+    public log(
+        namespace: string,
+        podName: string,
+        stream: Writable,
+        done: (err: any) => void,
+        options: LogOptions = {},
+    ): any {
+        const path = `/api/v1/namespaces/${namespace}/pods/${podName}/log`;
+
+        const cluster = this.config.getCurrentCluster();
+        if (!cluster) {
+            throw new Error('No currently active cluster');
+        }
+        const url = cluster.server + path;
+
+        const requestOptions: Options = {
+            method: 'GET',
+            qs: options,
+            uri: url,
+        };
+        this.config.applyToRequest(requestOptions);
+
+        const req = this.requestImpl.webRequest(requestOptions, (error, response, body) => {
+            if (error) {
+                done(error);
+            } else {
+                done(null);
+            }
+        });
+        req.pipe(stream);
+        return req;
+    }
+}