add k8sClient back

Author: jreadey

Dockerfile

@@ -23,7 +23,9 @@ RUN conda install --name hsds --yes \
         imagecodecs \
         hdf5plugin \
         numcodecs \
-        simplejson 
+        simplejson \
+        && \
+    conda run -n hsds --no-capture-output pip install --no-cache-dir kubernetes
 RUN conda-pack -n hsds -o /tmp/hsds-env.tar \
     && mkdir -p /opt/env/hsds \
     && cd /opt/env/hsds \

hsds/basenode.py

@@ -633,20 +633,10 @@ def baseInit(node_type):
         # will set node_ip at registration time
     else:
         # check to see if we are running in a k8s cluster
-        try:
-            k8s_app_label = config.get("k8s_app_label")
-            if "KUBERNETES_SERVICE_HOST" in os.environ:
-                log.info("running in kubernetes")
-                if k8s_app_label:
-                    log.info("setting is_k8s to True")
-                    app["is_k8s"] = True
-                else:
-                    msg = "k8s_app_label not set, running in k8s single pod"
-                    log.info(msg)
-        except KeyError:
-            # guard against KeyError since k8s_app_label is a recent key
-            log.warn("expected to find key k8s_app_label in config")
-        if "is_k8s" not in app:
+        if "KUBERNETES_SERVICE_HOST" in os.environ:
+            log.info("running in kubernetes")
+            app["is_k8s"] = True
+        else:
             # check to see if we are running in a docker container
             proc_file = "/proc/self/cgroup"
             if os.path.isfile(proc_file):
@@ -657,6 +647,7 @@ def baseInit(node_type):
                         if len(fields) >= 3:
                             field = fields[2]
                             if field.startswith("/docker/"):
+                                log.info("running in docker")
                                 app["is_docker"] = True
 
     if "is_dcos" in app:

hsds/util/k8sClient.py

@@ -0,0 +1,57 @@
+##############################################################################
+# Copyright by The HDF Group.                                                #
+# All rights reserved.                                                       #
+#                                                                            #
+# This file is part of HSDS (HDF5 Scalable Data Service), Libraries and      #
+# Utilities.  The full HSDS copyright notice, including                      #
+# terms governing use, modification, and redistribution, is contained in     #
+# the file COPYING, which can be found at the root of the source code        #
+# distribution tree.  If you do not have access to this file, you may        #
+# request a copy from help@hdfgroup.org.                                     #
+##############################################################################
+#
+# Kubernetes utility functions
+#
+
+from kubernetes import client as k8s_client
+from kubernetes import config as k8s_config
+import urllib3
+from .. import hsds_logger as log
+
+urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
+
+
+def getPodIps(k8s_app_label, k8s_namespace=None):
+    """ Return list of IPs of all pods in the cluster with given app label
+       (and namespace if set)
+    """
+
+    # get the config from within the cluster and set it as the default config
+    # for all new clients
+    k8s_config.load_incluster_config()
+    c = k8s_client.Configuration()  # go and get a copy of the default config
+    c.verify_ssl = False  # set verify_ssl to false in that config
+    # make that config the default for all new clients
+    k8s_client.Configuration.set_default(c)
+    v1 = k8s_client.CoreV1Api()
+    if k8s_namespace:
+        # get pods for given namespace
+        log.debug(f"getting pods for namespace: {k8s_namespace}")
+        ret = v1.list_namespaced_pod(namespace=k8s_namespace)
+    else:
+        log.info("getting pods for all namespaces")
+        ret = v1.list_pod_for_all_namespaces(watch=False)
+    pod_ips = []
+    for i in ret.items:
+        pod_ip = i.status.pod_ip
+        if not pod_ip:
+            continue
+        labels = i.metadata.labels
+        if labels and "app" in labels and labels["app"] == k8s_app_label:
+            msg = f"found hsds pod with app label: {k8s_app_label} "
+            msg += f"- ip: {pod_ip}"
+            log.debug(msg)
+            pod_ips.append(pod_ip)
+
+    pod_ips.sort()  # for assigning node numbers
+    return pod_ips