[k8s] Kubernetes support

Dockerfile_k8s

@@ -0,0 +1,50 @@
+FROM continuumio/miniconda3:22.11.1
+
+# TODO(romilb): Investigate if this image can be consolidated with the skypilot
+#  client image (`Dockerfile`)
+
+# Initialize conda for root user, install ssh and other local dependencies
+RUN apt update -y && \
+    apt install gcc rsync sudo patch openssh-server pciutils nano fuse -y && \
+    rm -rf /var/lib/apt/lists/* && \
+    apt remove -y python3 && \
+    conda init
+
+# Setup SSH and generate hostkeys
+RUN mkdir -p /var/run/sshd && \
+    sed -i 's/PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config && \
+    sed 's@session\s*required\s*pam_loginuid.so@session optional pam_loginuid.so@g' -i /etc/pam.d/sshd && \
+    cd /etc/ssh/ && \
+    ssh-keygen -A
+
+# Setup new user named sky and add to sudoers. Also add /opt/conda/bin to sudo path.
+RUN useradd -m -s /bin/bash sky && \
+    echo "sky ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers && \
+    echo 'Defaults        secure_path="/opt/conda/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"' > /etc/sudoers.d/sky
+
+# Switch to sky user
+USER sky
+
+# Install SkyPilot pip dependencies
+RUN pip install wheel Click colorama cryptography jinja2 jsonschema && \
+    pip install networkx oauth2client pandas pendulum PrettyTable && \
+    pip install ray==2.4.0 rich tabulate filelock && \
+    pip install packaging 'protobuf<4.0.0' pulp && \
+    pip install awscli boto3 pycryptodome==3.12.0 && \
+    pip install docker kubernetes
+
+# Add /home/sky/.local/bin/ to PATH
+RUN echo 'export PATH="$PATH:$HOME/.local/bin"' >> ~/.bashrc
+
+# Install SkyPilot. This is purposely separate from installing SkyPilot
+# dependencies to optimize rebuild time
+COPY --chown=sky . /skypilot/sky/
+
+# TODO(romilb): Installing SkyPilot may not be necessary since ray up will do it
+RUN cd /skypilot/ && \
+    sudo mv -v sky/setup_files/* . && \
+    pip install ".[aws]"
+
+# Set WORKDIR and initialize conda for sky user
+WORKDIR /home/sky
+RUN conda init

sky/__init__.py

@@ -32,19 +32,21 @@
 Lambda = clouds.Lambda
 SCP = clouds.SCP
 Local = clouds.Local
+Kubernetes = clouds.Kubernetes
 OCI = clouds.OCI
 optimize = Optimizer.optimize
 
 __all__ = [
     '__version__',
-    'IBM',
     'AWS',
     'Azure',
     'GCP',
+    'IBM',
+    'Kubernetes',
     'Lambda',
-    'SCP',
     'Local',
     'OCI',
+    'SCP',
     'Optimizer',
     'OptimizeTarget',
     'backends',

sky/adaptors/kubernetes.py

@@ -0,0 +1,140 @@
+"""Kubernetes adaptors"""
+
+# pylint: disable=import-outside-toplevel
+
+import functools
+import os
+
+from sky.utils import ux_utils, env_options
+
+kubernetes = None
+urllib3 = None
+
+_configured = False
+_core_api = None
+_auth_api = None
+_networking_api = None
+_custom_objects_api = None
+
+# Timeout to use for API calls
+API_TIMEOUT = 5
+
+
+def import_package(func):
+
+    @functools.wraps(func)
+    def wrapper(*args, **kwargs):
+        global kubernetes
+        global urllib3
+        if kubernetes is None:
+            try:
+                import kubernetes as _kubernetes
+                import urllib3 as _urllib3
+            except ImportError:
+                # TODO(romilb): Update this message to point to installation
+                #  docs when they are ready.
+                raise ImportError('Fail to import dependencies for Kubernetes. '
+                                  'Run `pip install kubernetes` to '
+                                  'install them.') from None
+            kubernetes = _kubernetes
+            urllib3 = _urllib3
+        return func(*args, **kwargs)
+
+    return wrapper
+
+
+@import_package
+def get_kubernetes():
+    return kubernetes
+
+
+@import_package
+def _load_config():
+    global _configured
+    if _configured:
+        return
+    try:
+        # Load in-cluster config if running in a pod
+        # Kubernetes set environment variables for service discovery do not
+        # show up in SkyPilot tasks. For now, we work around by using
+        # DNS name instead of environment variables.
+        # See issue: https://github.com/skypilot-org/skypilot/issues/2287
+        os.environ['KUBERNETES_SERVICE_HOST'] = 'kubernetes.default.svc'
+        os.environ['KUBERNETES_SERVICE_PORT'] = '443'
+        kubernetes.config.load_incluster_config()
+    except kubernetes.config.config_exception.ConfigException:
+        try:
+            kubernetes.config.load_kube_config()
+        except kubernetes.config.config_exception.ConfigException as e:
+            suffix = ''
+            if env_options.Options.SHOW_DEBUG_INFO.get():
+                suffix += f' Error: {str(e)}'
+            # Check if exception was due to no current-context
+            if 'Expected key current-context' in str(e):
+                err_str = ('Failed to load Kubernetes configuration. '
+                           'Kubeconfig does not contain any valid context(s).'
+                           f'{suffix}\n'
+                           '    If you were running a local Kubernetes '
+                           'cluster, run `sky local up` to start the cluster.')
+            else:
+                err_str = (
+                    'Failed to load Kubernetes configuration. '
+                    f'Please check if your kubeconfig file is valid.{suffix}')
+            with ux_utils.print_exception_no_traceback():
+                raise ValueError(err_str) from None
+    _configured = True
+
+
+@import_package
+def core_api():
+    global _core_api
+    if _core_api is None:
+        _load_config()
+        _core_api = kubernetes.client.CoreV1Api()
+
+    return _core_api
+
+
+@import_package
+def auth_api():
+    global _auth_api
+    if _auth_api is None:
+        _load_config()
+        _auth_api = kubernetes.client.RbacAuthorizationV1Api()
+
+    return _auth_api
+
+
+@import_package
+def networking_api():
+    global _networking_api
+    if _networking_api is None:
+        _load_config()
+        _networking_api = kubernetes.client.NetworkingV1Api()
+
+    return _networking_api
+
+
+@import_package
+def custom_objects_api():
+    global _custom_objects_api
+    if _custom_objects_api is None:
+        _load_config()
+        _custom_objects_api = kubernetes.client.CustomObjectsApi()
+
+    return _custom_objects_api
+
+
+@import_package
+def api_exception():
+    return kubernetes.client.rest.ApiException
+
+
+@import_package
+def config_exception():
+    return kubernetes.config.config_exception.ConfigException
+
+
+@import_package
+def max_retry_error():
+    return urllib3.exceptions.MaxRetryError

sky/authentication.py

@@ -372,3 +372,33 @@ def setup_scp_authentication(config: Dict[str, Any]) -> Dict[str, Any]:
     with open(public_key_path, 'r') as f:
         public_key = f.read()
     return _replace_ssh_info_in_config(config, public_key)
+
+
+def setup_kubernetes_authentication(config: Dict[str, Any]) -> Dict[str, Any]:
+    get_or_generate_keys()
+
+    # Run kubectl command to add the public key to the cluster.
+    public_key_path = os.path.expanduser(PUBLIC_SSH_KEY_PATH)
+    key_label = clouds.Kubernetes.SKY_SSH_KEY_SECRET_NAME
+    cmd = f'kubectl create secret generic {key_label} ' \
+          f'--from-file=ssh-publickey={public_key_path}'
+    try:
+        subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=True)
+    except subprocess.CalledProcessError as e:
+        output = e.output.decode('utf-8')
+        suffix = f'\nError message: {output}'
+        if 'already exists' in output:
+            logger.debug(
+                f'Key {key_label} already exists in the cluster, using it...')
+        elif any(err in output for err in ['connection refused', 'timeout']):
+            with ux_utils.print_exception_no_traceback():
+                raise ConnectionError(
+                    'Failed to connect to the cluster. Check if your '
+                    'cluster is running, your kubeconfig is correct '
+                    'and you can connect to it using: '
+                    f'kubectl get namespaces.{suffix}') from e
+        else:
+            logger.error(suffix)
+            raise
+
+    return config