implement 'ganache instances logs <name>' with support for --since, --until, and --follow

Author: jeffsmale90

src/packages/cli/package-lock.json

@@ -72,6 +72,7 @@
     "@types/node": "17.0.0",
     "chalk": "4.1.0",
     "cli-table": "0.3.11",
-    "marked-terminal": "4.1.0"
+    "marked-terminal": "4.1.0",
+    "parse-duration": "1.0.2"
   }
 }

src/packages/cli/package.json

@@ -17,6 +17,7 @@ import { EOL } from "os";
 import marked from "marked";
 import TerminalRenderer from "marked-terminal";
 import { _DefaultServerOptions } from "@ganache/core";
+import parseDuration from "parse-duration";
 
 marked.setOptions({
   renderer: new TerminalRenderer({
@@ -272,6 +273,30 @@ export default function (
               stopArgs.action = "stop";
             }
           )
+          .command(
+            "logs <name>",
+            "fetch logs for the instance specified by <name>",
+            logsArgs => {
+              logsArgs.positional("name", { type: "string" });
+              logsArgs
+                .options("follow", {
+                  type: "boolean",
+                  alias: ["f"],
+                  description: "continue streaming the instances logs"
+                })
+                .options("since", {
+                  type: "string",
+                  alias: ["s"]
+                })
+                .options("until", {
+                  type: "string",
+                  alias: ["u"]
+                });
+            },
+            logsArgs => {
+              logsArgs.action = "logs";
+            }
+          )
           .version(false);
       }
     )
@@ -307,13 +332,39 @@ export default function (
         "flavor" | "action"
       >)
     };
+  } else if (parsedArgs.action === "logs") {
+    finalArgs = {
+      action: "logs",
+      name: parsedArgs.name as string,
+      follow: parsedArgs.follow as boolean,
+      since: getTimestampFromInput(parsedArgs.since as string),
+      until: getTimestampFromInput(parsedArgs.until as string)
+    };
   } else {
     throw new Error(`Unknown action: ${parsedArgs.action}`);
   }
 
   return finalArgs;
 }
 
+function getTimestampFromInput(input: string): number | null {
+  if (input == null) {
+    return null;
+  }
+
+  const parsedDate = Date.parse(input);
+  if (!Number.isNaN(parsedDate)) {
+    return parsedDate;
+  }
+
+  const duration = parseDuration(input, "ms");
+  if (duration == null) {
+    throw new Error(`Invalid duration ${input}`);
+  }
+
+  return Date.now() - duration;
+}
+
 /**
  * Expands the arguments into an object including only namespaced keys from the
  * `args` argument.

src/packages/cli/src/args.ts

@@ -13,12 +13,14 @@ import {
   stopDetachedInstance,
   startDetachedInstance,
   getDetachedInstances,
-  formatUptime
+  formatUptime,
+  getInstanceLogsPath,
+  getDetachedInstanceByName
 } from "./detach";
 import { TruffleColors } from "@ganache/colors";
 import Table from "cli-table";
 import chalk from "chalk";
-
+import { getLogsStream } from "./logs-stream";
 const porscheColor = chalk.hex(TruffleColors.porsche);
 
 const logAndForceExit = (messages: any[], exitCode = 0) => {
@@ -171,6 +173,36 @@ if (argv.action === "start") {
       console.error("Instance not found");
     }
   });
+} else if (argv.action === "logs") {
+  const instanceName = argv.name;
+
+  getDetachedInstanceByName(instanceName)
+    .then(_ => {
+      const path = getInstanceLogsPath(instanceName);
+
+      const stream = getLogsStream(path, {
+        follow: argv.follow,
+        since: argv.since,
+        until: argv.until
+      });
+
+      stream.on("error", err => {
+        if ((err as NodeJS.ErrnoException).code === "ENOENT") {
+          console.log(
+            `No logs are available for ${instanceName}.\nTry calling some RPC methods.`
+          );
+        }
+      });
+      stream.pipe(process.stdout);
+      //todo: we need to be able to quit from this if `--follow` is provided
+    })
+    .catch(err => {
+      if ((err as NodeJS.ErrnoException).code === "ENOENT") {
+        console.error("Instance not found");
+      } else {
+        console.error(err);
+      }
+    });
 } else if (argv.action === "start-detached") {
   startDetachedInstance(process.argv, argv, version)
     .then(instance => {