From 67fa40bc2c484da0546333914ea07a89fe44eaaf Mon Sep 17 00:00:00 2001
From: Mridula <66699525+mpeddada1@users.noreply.github.com>
Date: Thu, 25 Aug 2022 16:23:29 -0400
Subject: [PATCH] Check if file exists when executable path is passed in
 through jib dockerClient.executable (#3744)

* Check if file exists when executable path is passed in through jib.dockerClient.executable
---
 .../tools/jib/docker/CliDockerClient.java     | 22 +++++++++----------
 .../tools/jib/docker/CliDockerClientTest.java |  9 ++++++++
 .../src/test/resources/core/docker/emptyFile  |  0
 jib-gradle-plugin/README.md                   |  2 +-
 jib-maven-plugin/README.md                    |  2 +-
 5 files changed, 21 insertions(+), 14 deletions(-)
 create mode 100644 jib-core/src/test/resources/core/docker/emptyFile

diff --git a/jib-core/src/main/java/com/google/cloud/tools/jib/docker/CliDockerClient.java b/jib-core/src/main/java/com/google/cloud/tools/jib/docker/CliDockerClient.java
index c62ff819a1..7c9c23cd9f 100644
--- a/jib-core/src/main/java/com/google/cloud/tools/jib/docker/CliDockerClient.java
+++ b/jib-core/src/main/java/com/google/cloud/tools/jib/docker/CliDockerClient.java
@@ -103,30 +103,28 @@ public List<DescriptorDigest> getDiffIds() throws DigestException {
   public static final Path DEFAULT_DOCKER_CLIENT = Paths.get("docker");
 
   /**
-   * Checks if Docker is installed on the user's system and accessible by running the default {@code
-   * docker} command.
+   * Checks if Docker is installed on the user's system by running the `docker` command.
    *
    * @return {@code true} if Docker is installed on the user's system and accessible
    */
   public static boolean isDefaultDockerInstalled() {
-    return isDockerInstalled(DEFAULT_DOCKER_CLIENT);
+    try {
+      new ProcessBuilder(DEFAULT_DOCKER_CLIENT.toString()).start();
+      return true;
+    } catch (IOException ex) {
+      return false;
+    }
   }
 
   /**
-   * Checks if Docker is installed on the user's system and accessible by running the given {@code
-   * docker} executable.
+   * Checks if Docker is installed on the user's system and by verifying if the executable path
+   * provided has the appropriate permissions.
    *
    * @param dockerExecutable path to the executable to test running
    * @return {@code true} if Docker is installed on the user's system and accessible
    */
   public static boolean isDockerInstalled(Path dockerExecutable) {
-    try {
-      new ProcessBuilder(dockerExecutable.toString()).start();
-      return true;
-
-    } catch (IOException ex) {
-      return false;
-    }
+    return Files.exists(dockerExecutable);
   }
 
   /**
diff --git a/jib-core/src/test/java/com/google/cloud/tools/jib/docker/CliDockerClientTest.java b/jib-core/src/test/java/com/google/cloud/tools/jib/docker/CliDockerClientTest.java
index 4d1f37f6ce..3e7cca5b4a 100644
--- a/jib-core/src/test/java/com/google/cloud/tools/jib/docker/CliDockerClientTest.java
+++ b/jib-core/src/test/java/com/google/cloud/tools/jib/docker/CliDockerClientTest.java
@@ -24,11 +24,13 @@
 import com.google.cloud.tools.jib.json.JsonTemplateMapper;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.io.ByteStreams;
+import com.google.common.io.Resources;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.net.URISyntaxException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Paths;
 import java.security.DigestException;
@@ -74,6 +76,13 @@ public void testIsDockerInstalled_fail() {
     Assert.assertFalse(CliDockerClient.isDockerInstalled(Paths.get("path/to/nonexistent/file")));
   }
 
+  @Test
+  public void testIsDockerInstalled_pass() throws URISyntaxException {
+    Assert.assertTrue(
+        CliDockerClient.isDockerInstalled(
+            Paths.get(Resources.getResource("core/docker/emptyFile").toURI())));
+  }
+
   @Test
   public void testLoad() throws IOException, InterruptedException {
     DockerClient testDockerClient =
diff --git a/jib-core/src/test/resources/core/docker/emptyFile b/jib-core/src/test/resources/core/docker/emptyFile
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/jib-gradle-plugin/README.md b/jib-gradle-plugin/README.md
index 452d5ea0d2..5a130b72d7 100644
--- a/jib-gradle-plugin/README.md
+++ b/jib-gradle-plugin/README.md
@@ -290,7 +290,7 @@ Property | Type | Default | Description
 
 Property | Type | Default | Description
 --- | --- | --- | ---
-`executable` | `File` | `docker` | Sets the path to the Docker executable that is called to load the image into the Docker daemon.
+`executable` | `File` | `docker` | Sets the path to the Docker executable that is called to load the image into the Docker daemon. **Please note**: Users are responsible for ensuring that the Docker path passed in is valid and has the right permissions to be executed.
 `environment` | `Map<String, String>` | *None* | Sets environment variables used by the Docker executable.
 
 #### System Properties
diff --git a/jib-maven-plugin/README.md b/jib-maven-plugin/README.md
index 37dc8acaee..b62c1b325d 100644
--- a/jib-maven-plugin/README.md
+++ b/jib-maven-plugin/README.md
@@ -341,7 +341,7 @@ Property | Type | Default | Description
 
 Property | Type | Default | Description
 --- | --- | --- | ---
-`executable` | string | `docker` | Sets the path to the Docker executable that is called to load the image into the Docker daemon.
+`executable` | string | `docker` | Sets the path to the Docker executable that is called to load the image into the Docker daemon. **Please note**: Users are responsible for ensuring that the Docker path passed in is valid and has the right permissions to be executed.
 `environment` | map | *None* | Sets environment variables used by the Docker executable.
 
 #### System Properties