four43's questions

It seems like MongoDB 3.6 isn't automatically configured to restart if it crashes. Looking at the systemd service that is bundled with the latest .deb package for Ubuntu 16.04LTS it doesn't seem to have restarts configured:

$ sudo systemctl cat mongod
# /lib/systemd/system/mongod.service
[Unit]
Description=High-performance, schema-free document-oriented database
After=network.target
Documentation=https://docs.mongodb.org/manual

[Service]
User=mongodb
Group=mongodb
ExecStart=/usr/bin/mongod --config /etc/mongod.conf
PIDFile=/var/run/mongodb/mongod.pid
# file size
LimitFSIZE=infinity
# cpu time
LimitCPU=infinity
# virtual memory size
LimitAS=infinity
# open files
LimitNOFILE=64000
# processes/threads
LimitNPROC=64000
# locked memory
LimitMEMLOCK=infinity
# total threads (user+kernel)
TasksMax=infinity
TasksAccounting=false

# Recommended limits for for mongod as specified in
# http://docs.mongodb.org/manual/reference/ulimit/#recommended-settings

[Install]
WantedBy=multi-user.target

Sending SIGKILL and SIGSEGV both kill the process and it isn't restarted. I'm not sure if those are "caught" by systemd and not just restarted however.

So a few questions: Is this crucial for a high availability service like a database? It sure seems like it. Is there any reason MongoDB wouldn't have this configured out of the box?

We are running containers on Kubernetes on Amazon AWS. This cluster was created via the kube-up set of scripts. Everything was provisioned correctly and working fine. We ran into a snag however - our fairly large servers, c4.xlarges, are only allowed to run 40 pods. This is a small number for us, as we are running many small pods, some rarely used. Is there a way to up this limit from the salt master or the launch configuration? What is the best route to go about doing this?

Thanks.

We have a deployed API in Kubernetes. The API is deployed via replication controller to pods and a managing rc. I would like to update the configuration to the API pods using rolling-update. I can do that, however the only way I can get the rolling-update command to not error is by changing the name of the RC. But doing this breaks the link from my Service (exposed as a load balancer) to the RC and it cannot find my pods anymore. Does someone have an example config for updating a replication controller without changing the name?

apiVersion: v1
kind: ReplicationController
metadata:
    name: my-api
    labels:
        name: my-api
spec:
    replicas: 4
    selector:
        name: my-api
    template:
        metadata:
            labels:
                name: my-api
        spec:
            containers:
              - name: my-api
                image: docker-registry.example.com/mynamespace/my-api
                command: [ "sh", "-c", "/do/the/thing/run"]
                resources:
                    limits:
                        cpu: 0
                ports:
                  - name: web
                    containerPort: 80
                env:
                  - name: "HELLO"
                    value: "WORLD"

And I would like, for example to change the env var "HELLO" to "Bob" or something.

We are using Kubernetes and successfully running our apps. However with our pods running and no traffic our minions are running with high CPU. Looking into the issue further:

• influxdb and heapster are running with high CPU, all of our containers are using 0% CPU, the box is at rest with a load of 8 on a dual core server...

• Looking at the individual containers doesn't seem to yield any answers, the logs are quiet

Grafana lets me view charts but the charts are broken and not really making a lot of sense. Is there any way to just remove this functionality all together from Kuberentes?

Kubernetes v1.0.6 deployed on Ubuntu Vivid on AWS

We are using Kubernetes v1.1.0-beta and I am curious if Kubernetes supports env_file, like Docker Compose? On Pod/ReplicationController creation it would read in the file specified by env_file and set the variables on that pod. Is this a thing or just env map?

I need to use port 2049/tcp for another purpose. Is there a way to change which port NFSD binds to? I don't need NFSv3 or NFSv2 so I am not using rpcbind service. I cannot find that config option...

A pod in my Kubernetes cluster is stuck on "ContainerCreating" after running a create. How do I see logs for this operation in order to diagnose why it is stuck? kubectl logs doesn't seem to work since the container needs to be in a non-pending state.

Following this guestbook tutorial.

Near the end they sort of gloss over how to create a LoadBalancer or assign NodePorts to the service. They reference this doc that describes the different types and what they do, but don't really go into detail about how to apply them to a service. Is there a way to update the running service, creating and attaching a load balancer to the specified ports?

Using Amazon Web Services to host our cluster, it supports load balancer great at creation of a service, but I'm not sure how to modify the service.

EDIT:

Trying this resulted in an error:

$ kubectl expose service frontend --port=80 --type=LoadBalancer
Error from server: service "frontend" already exists