fix: Inject coder ssh configuration between comments

package.json

@@ -140,7 +140,6 @@
     "ndjson": "^2.0.0",
     "pretty-bytes": "^6.0.0",
     "semver": "^7.3.8",
-    "ssh-config": "4.1.6",
     "tar-fs": "^2.1.1",
     "which": "^2.0.2",
     "ws": "^8.11.0",

src/SSHConfig.ts

@@ -0,0 +1,111 @@
+import { ensureDir } from "fs-extra"
+import * as fs from "fs/promises"
+import path from "path"
+
+class SSHConfigBadFormat extends Error {}
+
+interface Block {
+  raw: string
+}
+
+interface SSHValues {
+  Host: string
+  ProxyCommand: string
+  ConnectTimeout: string
+  StrictHostKeyChecking: string
+  UserKnownHostsFile: string
+  LogLevel: string
+}
+
+export class SSHConfig {
+  private filePath: string
+  private raw: string | undefined
+  private startBlockComment = "# --- START CODER VSCODE ---"
+  private endBlockComment = "# --- END CODER VSCODE ---"
+
+  constructor(filePath: string) {
+    this.filePath = filePath
+  }
+
+  async load() {
+    try {
+      this.raw = await fs.readFile(this.filePath, "utf-8")
+    } catch (ex) {
+      // Probably just doesn't exist!
+      this.raw = ""
+    }
+  }
+
+  async update(values: SSHValues) {
+    const block = this.getBlock()
+    if (block) {
+      this.eraseBlock(block)
+    }
+    this.appendBlock(values)
+    await this.save()
+  }
+
+  private getBlock(): Block | undefined {
+    const raw = this.getRaw()
+    const startBlockIndex = raw.indexOf(this.startBlockComment)
+    const endBlockIndex = raw.indexOf(this.endBlockComment)
+    const hasBlock = startBlockIndex > -1 && endBlockIndex > -1
+
+    if (!hasBlock) {
+      return
+    }
+
+    if (startBlockIndex === -1) {
+      throw new SSHConfigBadFormat("Start block not found")
+    }
+
+    if (startBlockIndex === -1) {
+      throw new SSHConfigBadFormat("End block not found")
+    }
+
+    if (endBlockIndex < startBlockIndex) {
+      throw new SSHConfigBadFormat("Malformed config, end block is before start block")
+    }
+
+    return {
+      raw: raw.substring(startBlockIndex, endBlockIndex + this.endBlockComment.length),
+    }
+  }
+
+  private eraseBlock(block: Block) {
+    this.raw = this.getRaw().replace(block.raw, "")
+  }
+
+  private appendBlock({ Host, ...otherValues }: SSHValues) {
+    const lines = [this.startBlockComment, `Host ${Host}`]
+    const keys = Object.keys(otherValues) as Array<keyof typeof otherValues>
+    keys.forEach((key) => {
+      lines.push(this.withIndentation(`${key} ${otherValues[key]}`))
+    })
+    lines.push(this.endBlockComment)
+    const raw = this.getRaw()
+    this.raw = `${raw.trimEnd()}\n${lines.join("\n")}`
+  }
+
+  private withIndentation(text: string) {
+    return `  ${text}`
+  }
+
+  private async save() {
+    await ensureDir(path.dirname(this.filePath), {
+      mode: 0o700, // only owner has rwx permission, not group or everyone.
+    })
+    return fs.writeFile(this.filePath, this.getRaw(), {
+      mode: 0o600, // owner rw
+      encoding: "utf-8",
+    })
+  }
+
+  private getRaw() {
+    if (this.raw === undefined) {
+      throw new Error("SSHConfig is not loaded. Try sshConfig.load()")
+    }
+
+    return this.raw
+  }
+}

src/remote.ts

@@ -9,22 +9,20 @@ import {
 import { ProvisionerJobLog, Workspace, WorkspaceAgent } from "coder/site/src/api/typesGenerated"
 import EventSource from "eventsource"
 import find from "find-process"
-import { ensureDir } from "fs-extra"
 import * as fs from "fs/promises"
 import * as jsonc from "jsonc-parser"
 import * as os from "os"
 import * as path from "path"
 import prettyBytes from "pretty-bytes"
 import * as semver from "semver"
-import SSHConfig from "ssh-config"
 import * as vscode from "vscode"
 import * as ws from "ws"
+import { SSHConfig } from "./SSHConfig"
 import { Storage } from "./storage"
 
 export class Remote {
-  // Prefix is a magic string that is prepended to SSH
-  // hosts to indicate that they should be handled by
-  // this extension.
+  // Prefix is a magic string that is prepended to SSH hosts to indicate that
+  // they should be handled by this extension.
   public static readonly Prefix = "coder-vscode--"
 
   public constructor(
@@ -35,16 +33,17 @@ export class Remote {
 
   public async setup(remoteAuthority: string): Promise<vscode.Disposable | undefined> {
     const authorityParts = remoteAuthority.split("+")
-    // If the URI passed doesn't have the proper prefix
-    // ignore it. We don't need to do anything special,
-    // because this isn't trying to open a Coder workspace.
+    // If the URI passed doesn't have the proper prefix ignore it. We don't need
+    // to do anything special, because this isn't trying to open a Coder
+    // workspace.
     if (!authorityParts[1].startsWith(Remote.Prefix)) {
       return
     }
     const sshAuthority = authorityParts[1].substring(Remote.Prefix.length)
 
-    // Authorities are in the format: coder-vscode--<username>--<workspace>--<agent>
-    // Agent can be omitted then will be prompted for instead.
+    // Authorities are in the format:
+    // coder-vscode--<username>--<workspace>--<agent> Agent can be omitted then
+    // will be prompted for instead.
     const parts = sshAuthority.split("--")
     if (parts.length < 2 || parts.length > 3) {
       throw new Error(`Invalid Coder SSH authority. Must be: <username>--<workspace>--<agent?>`)
@@ -142,12 +141,12 @@ export class Remote {
       }
     }
 
-    // If a build is running we should stream the logs to the user so
-    // they can watch what's going on!
+    // If a build is running we should stream the logs to the user so they can
+    // watch what's going on!
     if (workspace.latest_build.status === "pending" || workspace.latest_build.status === "starting") {
       const writeEmitter = new vscode.EventEmitter<string>()
-      // We use a terminal instead of an output channel because it feels
-      // more familiar to a user!
+      // We use a terminal instead of an output channel because it feels more
+      // familiar to a user!
       const terminal = vscode.window.createTerminal({
         name: "Build Log",
         location: vscode.TerminalLocation.Panel,
@@ -218,8 +217,8 @@ export class Remote {
         agent = agents[0]
       }
 
-      // If there are multiple agents, we should select one here!
-      // TODO: Support multiple agents!
+      // If there are multiple agents, we should select one here! TODO: Support
+      // multiple agents!
     }
 
     if (!agent) {
@@ -337,12 +336,12 @@ export class Remote {
       return
     }
 
-    // This ensures the Remote SSH extension resolves
-    // the host to execute the Coder binary properly.
+    // This ensures the Remote SSH extension resolves the host to execute the
+    // Coder binary properly.
     //
-    // If we didn't write to the SSH config file,
-    // connecting would fail with "Host not found".
-    await this.updateSSHConfig(authorityParts[1])
+    // If we didn't write to the SSH config file, connecting would fail with
+    // "Host not found".
+    await this.updateSSHConfig()
 
     this.findSSHProcessID().then((pid) => {
       if (!pid) {
@@ -372,22 +371,15 @@ export class Remote {
     }
   }
 
-  // updateSSHConfig updates the SSH configuration with a wildcard
-  // that handles all Coder entries.
-  private async updateSSHConfig(sshHost: string) {
+  // updateSSHConfig updates the SSH configuration with a wildcard that handles
+  // all Coder entries.
+  private async updateSSHConfig() {
     let sshConfigFile = vscode.workspace.getConfiguration().get<string>("remote.SSH.configFile")
     if (!sshConfigFile) {
       sshConfigFile = path.join(os.homedir(), ".ssh", "config")
     }
-    let sshConfigRaw: string
-    try {
-      sshConfigRaw = await fs.readFile(sshConfigFile, "utf8")
-    } catch (ex) {
-      // Probably just doesn't exist!
-      sshConfigRaw = ""
-    }
-    const parsedConfig = SSHConfig.parse(sshConfigRaw)
-    const computedHost = parsedConfig.compute(sshHost)
+    const sshConfig = new SSHConfig(sshConfigFile)
+    await sshConfig.load()
 
     let binaryPath: string | undefined
     if (this.mode === vscode.ExtensionMode.Production) {
@@ -399,9 +391,8 @@ export class Remote {
       throw new Error("Failed to fetch the Coder binary!")
     }
 
-    parsedConfig.remove({ Host: computedHost.Host })
     const escape = (str: string): string => `"${str.replace(/"/g, '\\"')}"`
-    parsedConfig.append({
+    const sshValues = {
       Host: `${Remote.Prefix}*`,
       ProxyCommand: `${escape(binaryPath)} vscodessh --network-info-dir ${escape(
         this.storage.getNetworkInfoPath(),
@@ -412,14 +403,13 @@ export class Remote {
       StrictHostKeyChecking: "no",
       UserKnownHostsFile: "/dev/null",
       LogLevel: "ERROR",
-    })
+    }
 
-    await ensureDir(path.dirname(sshConfigFile))
-    await fs.writeFile(sshConfigFile, parsedConfig.toString())
+    await sshConfig.update(sshValues)
   }
 
-  // showNetworkUpdates finds the SSH process ID that is being used by
-  // this workspace and reads the file being created by the Coder CLI.
+  // showNetworkUpdates finds the SSH process ID that is being used by this
+  // workspace and reads the file being created by the Coder CLI.
   private showNetworkUpdates(sshPid: number): vscode.Disposable {
     const networkStatus = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Left, 1000)
     const networkInfoFile = path.join(this.storage.getNetworkInfoPath(), `${sshPid}.json`)
@@ -510,14 +500,13 @@ export class Remote {
     }
   }
 
-  // findSSHProcessID returns the currently active SSH process ID
-  // that is powering the remote SSH connection.
+  // findSSHProcessID returns the currently active SSH process ID that is
+  // powering the remote SSH connection.
   private async findSSHProcessID(timeout = 15000): Promise<number | undefined> {
     const search = async (logPath: string): Promise<number | undefined> => {
-      // This searches for the socksPort that Remote SSH is connecting to.
-      // We do this to find the SSH process that is powering this connection.
-      // That SSH process will be logging network information periodically to
-      // a file.
+      // This searches for the socksPort that Remote SSH is connecting to. We do
+      // this to find the SSH process that is powering this connection. That SSH
+      // process will be logging network information periodically to a file.
       const text = await fs.readFile(logPath, "utf8")
       const matches = text.match(/-> socksPort (\d+) ->/)
       if (!matches) {

yarn.lock

@@ -4557,11 +4557,6 @@ sprintf-js@~1.0.2:
   resolved "https://registry.yarnpkg.com/sprintf-js/-/sprintf-js-1.0.3.tgz#04e6926f662895354f3dd015203633b857297e2c"
   integrity sha512-D9cPgkvLlV3t3IzL0D0YLvGA9Ahk4PcvVwUbN0dSGr1aP0Nrt4AEnTUbuGvquEC0mA64Gqt1fzirlRs5ibXx8g==
 
-ssh-config@4.1.6:
-  version "4.1.6"
-  resolved "https://registry.yarnpkg.com/ssh-config/-/ssh-config-4.1.6.tgz#008eee24f5e5029dc64d50de4a5a7a12342db8b1"
-  integrity sha512-YdPYn/2afoBonSFoMSvC1FraA/LKKrvy8UvbvAFGJ8gdlKuANvufLLkf8ynF2uq7Tl5+DQBIFyN37//09nAgNQ==
-
 state-toggle@^1.0.0:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/state-toggle/-/state-toggle-1.0.3.tgz#e123b16a88e143139b09c6852221bc9815917dfe"