support for non-default docker host added

conan/internal/runner/docker.py

@@ -64,13 +64,26 @@ def __init__(self, conan_api, command, host_profile, build_profile, args, raw_ar
         import docker
         import docker.api.build
         try:
-            self.docker_client = docker.from_env()
-            self.docker_api = docker.APIClient()
+            docker_base_urls = [
+                None, # Default docker configuration, let the python library detect the socket
+                os.environ.get('DOCKER_HOST'), # Connect to socket defined in DOCKER_HOST
+                'unix:///var/run/docker.sock', # Default linux socket
+                f'unix://{os.path.expanduser("~")}/.rd/docker.sock' # Rancher linux socket
+            ]
+            for base_url in docker_base_urls:
+                try:
+                    ConanOutput().verbose(f'Trying to connect to docker "{base_url or "default"}" socket')
+                    self.docker_client = docker.DockerClient(base_url=base_url, version='auto')
+                    ConanOutput().verbose(f'Connected to docker "{base_url or "default"}" socket')
+                    break
+                except:
+                    continue
+            self.docker_api = self.docker_client.api
             docker.api.build.process_dockerfile = lambda dockerfile, path: ('Dockerfile', dockerfile)
         except:
             raise ConanException("Docker Client failed to initialize."
                                  "\n - Check if docker is installed and running"
-                                 "\n - Run 'pip install pip install conan[runners]'")
+                                 "\n - Run 'pip install conan[runners]'")
         self.conan_api = conan_api
         self.build_profile = build_profile
         self.args = args

test/integration/command/runner_test.py

@@ -9,7 +9,10 @@
 
 def docker_skip(test_image=None):
     try:
-        docker_client = docker.from_env()
+        try:
+            docker_client = docker.from_env()
+        except:
+            docker_client = docker.DockerClient(base_url=f'unix://{os.path.expanduser("~")}/.rd/docker.sock', version='auto') # Rancher
         if test_image:
             docker_client.images.pull(test_image)
     except docker.errors.DockerException: