impl: support for downloading the cli signature

From the same source where the cli binary was downloaded.
Some of the previous classes like download result were updated to incorporate
details like where the file was saved or whether a file was found on the remote

Author: fioan89

src/main/kotlin/com/coder/toolbox/cli/CoderCLIManager.kt

@@ -3,7 +3,6 @@ package com.coder.toolbox.cli
 import com.coder.toolbox.CoderToolboxContext
 import com.coder.toolbox.cli.downloader.CoderDownloadApi
 import com.coder.toolbox.cli.downloader.CoderDownloadService
-import com.coder.toolbox.cli.downloader.DownloadResult
 import com.coder.toolbox.cli.ex.MissingVersionException
 import com.coder.toolbox.cli.ex.SSHConfigFormatException
 import com.coder.toolbox.sdk.v2.models.Workspace
@@ -160,7 +159,11 @@ class CoderCLIManager(
             downloader.downloadCli(buildVersion, showTextProgress)
         }
 
-        return cliDownloadResult == DownloadResult.Downloaded
+        var singatureDownloadResult = withContext(Dispatchers.IO) {
+            downloader.downloadSignature(showTextProgress)
+        }
+
+        return cliDownloadResult.isDownloaded()
     }
 
     /**

src/main/kotlin/com/coder/toolbox/cli/downloader/CoderDownloadApi.kt

@@ -20,4 +20,10 @@ interface CoderDownloadApi {
         @HeaderMap headers: Map<String, String> = emptyMap(),
         @Header("Accept-Encoding") acceptEncoding: String = "gzip",
     ): Response<ResponseBody>
+
+    @GET
+    suspend fun downloadSignature(
+        @Url url: String,
+        @HeaderMap headers: Map<String, String> = emptyMap()
+    ): Response<ResponseBody>
 }

src/main/kotlin/com/coder/toolbox/cli/downloader/CoderDownloadService.kt

@@ -6,16 +6,19 @@ import com.coder.toolbox.util.OS
 import com.coder.toolbox.util.getHeaders
 import com.coder.toolbox.util.getOS
 import com.coder.toolbox.util.sha1
+import com.coder.toolbox.util.withLastSegment
 import okhttp3.ResponseBody
 import retrofit2.Response
 import java.io.FileInputStream
+import java.net.HttpURLConnection.HTTP_NOT_FOUND
 import java.net.HttpURLConnection.HTTP_NOT_MODIFIED
 import java.net.HttpURLConnection.HTTP_OK
 import java.net.URL
 import java.nio.file.Files
 import java.nio.file.Path
 import java.nio.file.StandardOpenOption
 import java.util.zip.GZIPInputStream
+import kotlin.io.path.name
 import kotlin.io.path.notExists
 
 /**
@@ -32,21 +35,20 @@ class CoderDownloadService(
 
     suspend fun downloadCli(buildVersion: String, showTextProgress: (String) -> Unit): DownloadResult {
         val eTag = calculateLocalETag()
-        val headers = getRequestHeaders()
         if (eTag != null) {
             context.logger.info("Found existing binary at $localBinaryPath; calculated hash as $eTag")
         }
         val response = downloadApi.downloadCli(
             url = remoteBinaryURL.toString(),
             eTag = eTag?.let { "\"$it\"" },
-            headers = headers
+            headers = getRequestHeaders()
         )
 
         return when (response.code()) {
             HTTP_OK -> {
                 context.logger.info("Downloading binary to $localBinaryPath")
-                response.saveBinaryToDisk(buildVersion, showTextProgress)?.makeExecutable()
-                DownloadResult.Downloaded
+                response.saveToDisk(localBinaryPath, showTextProgress, buildVersion)?.makeExecutable()
+                DownloadResult.Downloaded(localBinaryPath)
             }
 
             HTTP_NOT_MODIFIED -> {
@@ -84,16 +86,17 @@ class CoderDownloadService(
         }
     }
 
-    private fun Response<ResponseBody>.saveBinaryToDisk(
-        buildVersion: String,
-        showTextProgress: (String) -> Unit
+    private fun Response<ResponseBody>.saveToDisk(
+        localPath: Path,
+        showTextProgress: (String) -> Unit,
+        buildVersion: String? = null
     ): Path? {
         val responseBody = this.body() ?: return null
-        Files.deleteIfExists(localBinaryPath)
-        Files.createDirectories(localBinaryPath.parent)
+        Files.deleteIfExists(localPath)
+        Files.createDirectories(localPath.parent)
 
         val outputStream = Files.newOutputStream(
-            localBinaryPath,
+            localPath,
             StandardOpenOption.CREATE,
             StandardOpenOption.TRUNCATE_EXISTING
         )
@@ -108,7 +111,7 @@ class CoderDownloadService(
         var bytesRead: Int
         var totalRead = 0L
         // caching this because the settings store recomputes it every time
-        val binaryName = context.settingsStore.defaultCliBinaryNameByOsAndArch
+        val binaryName = localPath.name
         sourceStream.use { source ->
             outputStream.use { sink ->
                 while (source.read(buffer).also { bytesRead = it } != -1) {
@@ -143,4 +146,39 @@ class CoderDownloadService(
         val gb = mb / 1024.0
         return String.format("%.1f GB", gb)
     }
+
+    suspend fun downloadSignature(showTextProgress: (String) -> Unit): DownloadResult {
+        val defaultCliNameWithoutExt = context.settingsStore.defaultCliBinaryNameByOsAndArch.split('.').first()
+        val signatureName = "$defaultCliNameWithoutExt.asc"
+
+        val signatureURL = remoteBinaryURL.withLastSegment(signatureName)
+        val localSignaturePath = localBinaryPath.parent.resolve(signatureName)
+        context.logger.info("Downloading signature from $signatureURL")
+
+        val response = downloadApi.downloadSignature(
+            url = signatureURL.toString(),
+            headers = getRequestHeaders()
+        )
+
+        return when (response.code()) {
+            HTTP_OK -> {
+                response.saveToDisk(localSignaturePath, showTextProgress)
+                DownloadResult.Downloaded(localSignaturePath)
+            }
+
+            HTTP_NOT_FOUND -> {
+                context.logger.warn("Signature file not found at $signatureURL")
+                DownloadResult.NotFound
+            }
+
+            else -> {
+                DownloadResult.Failed(
+                    ResponseException(
+                        "Failed to download signature from $signatureURL",
+                        response.code()
+                    )
+                )
+            }
+        }
+    }
 }

src/main/kotlin/com/coder/toolbox/cli/downloader/DownloadResult.kt

@@ -1,10 +1,16 @@
 package com.coder.toolbox.cli.downloader
 
+import java.nio.file.Path
+
+
 /**
  * Result of a download operation
  */
 sealed class DownloadResult {
     object Skipped : DownloadResult()
-    object Downloaded : DownloadResult()
+    object NotFound : DownloadResult()
+    data class Downloaded(val savePath: Path) : DownloadResult()
     data class Failed(val error: Exception) : DownloadResult()
+
+    fun isDownloaded(): Boolean = this is Downloaded
 }

src/main/kotlin/com/coder/toolbox/util/URLExtensions.kt

@@ -13,6 +13,20 @@ fun URL.withPath(path: String): URL = URL(
     if (path.startsWith("/")) path else "/$path",
 )
 
+fun URL.withLastSegment(segment: String): URL {
+    val uri = this.toURI()
+    val basePath = uri.path.substringBeforeLast('/')
+    val newPath = "$basePath/$segment"
+    val newUri = URI(
+        uri.scheme,
+        uri.authority,
+        newPath,
+        uri.query,
+        uri.fragment
+    )
+    return newUri.toURL()
+}
+
 /**
  * Return the host, converting IDN to ASCII in case the file system cannot
  * support the necessary character set.