Skip to main content

Home/ Larvata/ Group items tagged ios

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
張 旭

What's the difference between Prometheus and Zabbix? - Stack Overflow - 0 views

stackoverflow.com/...-between-prometheus-and-zabbix

system monitor php go

shared by 張 旭 on 23 Apr 18 - No Cached
  • Zabbix has core written in C and webUI based on PHP
  • Zabbix stores data in RDBMS (MySQL, PostgreSQL, Oracle, sqlite) of user's choice.
  • Prometheus uses its own database embedded into backend process
  • ...8 more annotations...
  • Zabbix by default uses "pull" model when a server connects to agents on each monitoring machine, agents periodically gather the info and send it to a server.
  • Prometheus prefers "pull" model when a server gather info from client machines.
  • Prometheus requires an application to be instrumented with Prometheus client library (available in different programming languages) for preparing metrics.
  • expose metrics for Prometheus (similar to "agents" for Zabbix)
  • Zabbix uses its own tcp-based communication protocol between agents and a server.
  • Prometheus uses HTTP with protocol buffers (+ text format for ease of use with curl).
  • Prometheus offers basic tool for exploring gathered data and visualizing it in simple graphs on its native server and also offers a minimal dashboard builder PromDash. But Prometheus is and is designed to be supported by modern visualizing tools like Grafana.
  • Prometheus offers solution for alerting that is separated from its core into Alertmanager application.
張 旭

JSON Web Token Introduction - jwt.io - 0 views

jwt.io/introduction

javascript jwt authorization authentication oauth security

shared by 張 旭 on 24 Apr 18 - No Cached
  • a stateless authentication mechanism as the user state is never saved in server memory
  • In authentication, when the user successfully logs in using their credentials, a JSON Web Token will be returned and must be saved locally (typically in local storage, but cookies can be also used), instead of the traditional approach of creating a session in the server and returning a cookie.
  • ser agent should send the JWT, typically in the Authorization header using the Bearer schema.
  • ...2 more annotations...
  • It doesn't matter which domains are serving your APIs, so Cross-Origin Resource Sharing (CORS) won't be an issue as it doesn't use cookies.
  • WT and SAML tokens can use a public/private key pair in the form of a X.509 certificate for signing.
crazylion lee

grpc / grpc.io - 0 views

www.grpc.io

google grpc rpc

shared by crazylion lee on 27 Aug 16 - No Cached
  • crazylion lee on 27 Aug 16
     
    "A high performance, open-source universal RPC framework"
crazylion lee

flood-io/ruby-jmeter: A Ruby based DSL for building JMeter test plans - 0 views

github.com/ruby-jmeter

jmeter ruby

shared by crazylion lee on 12 Oct 16 - No Cached
  • crazylion lee on 12 Oct 16
     
    "A Ruby based DSL for building JMeter test plans"
crazylion lee

Instant.io - Streaming file transfer over WebTorrent - 0 views

instant.io

torrent web bt

shared by crazylion lee on 27 Sep 16 - No Cached
  • crazylion lee on 27 Sep 16
     
    "Streaming file transfer over WebTorrent (torrents on the web)"
張 旭

Upgrading kubeadm clusters | Kubernetes - 0 views

kubernetes.io/...kubeadm-upgrade

kubernetes system

shared by 張 旭 on 02 Jun 21 - No Cached
  • Swap must be disabled.
  • read the release notes carefully.
  • back up any important components, such as app-level state stored in a database.
  • ...16 more annotations...
  • All containers are restarted after upgrade, because the container spec hash value is changed.
  • The upgrade procedure on control plane nodes should be executed one node at a time.
  • /etc/kubernetes/admin.conf
  • kubeadm upgrade also automatically renews the certificates that it manages on this node. To opt-out of certificate renewal the flag --certificate-renewal=false can be used.
  • Manually upgrade your CNI provider plugin.
  • sudo systemctl daemon-reload sudo systemctl restart kubelet
  • If kubeadm upgrade fails and does not roll back, for example because of an unexpected shutdown during execution, you can run kubeadm upgrade again.
  • To recover from a bad state, you can also run kubeadm upgrade apply --force without changing the version that your cluster is running.
  • kubeadm-backup-etcd contains a backup of the local etcd member data for this control plane Node.
  • the contents of this folder can be manually restored in /var/lib/etcd
  • kubeadm-backup-manifests contains a backup of the static Pod manifest files for this control plane Node.
  • the contents of this folder can be manually restored in /etc/kubernetes/manifests
  • Enforces the version skew policies.
  • Upgrades the control plane components or rollbacks if any of them fails to come up.
  • Creates new certificate and key files of the API server and backs up old files if they're about to expire in 180 days.
  • backup folders under /etc/kubernetes/tmp
張 旭

LXC vs Docker: Why Docker is Better | UpGuard - 0 views

www.upguard.com/...docker-vs-lxc

docker container devops

shared by 張 旭 on 28 Jun 21 - No Cached
  • LXC (LinuX Containers) is a OS-level virtualization technology that allows creation and running of multiple isolated Linux virtual environments (VE) on a single control host.
  • Docker, previously called dotCloud, was started as a side project and only open-sourced in 2013. It is really an extension of LXC’s capabilities.
  • run processes in isolation.
  • ...35 more annotations...
  • Docker is developed in the Go language and utilizes LXC, cgroups, and the Linux kernel itself. Since it’s based on LXC, a Docker container does not include a separate operating system; instead it relies on the operating system’s own functionality as provided by the underlying infrastructure.
  • Docker acts as a portable container engine, packaging the application and all its dependencies in a virtual container that can run on any Linux server.
  • a VE there is no preloaded emulation manager software as in a VM.
  • In a VE, the application (or OS) is spawned in a container and runs with no added overhead, except for a usually minuscule VE initialization process.
  • LXC will boast bare metal performance characteristics because it only packages the needed applications.
  • the OS is also just another application that can be packaged too.
  • a VM, which packages the entire OS and machine setup, including hard drive, virtual processors and network interfaces. The resulting bloated mass usually takes a long time to boot and consumes a lot of CPU and RAM.
  • don’t offer some other neat features of VM’s such as IaaS setups and live migration.
  • LXC as supercharged chroot on Linux. It allows you to not only isolate applications, but even the entire OS.
  • Libvirt, which allows the use of containers through the LXC driver by connecting to 'lxc:///'.
  • 'LXC', is not compatible with libvirt, but is more flexible with more userspace tools.
  • Portable deployment across machines
  • Versioning: Docker includes git-like capabilities for tracking successive versions of a container
  • Component reuse: Docker allows building or stacking of already created packages.
  • Shared libraries: There is already a public registry (http://index.docker.io/ ) where thousands have already uploaded the useful containers they have created.
  • Docker taking the devops world by storm since its launch back in 2013.
  • LXC, while older, has not been as popular with developers as Docker has proven to be
  • LXC having a focus on sys admins that’s similar to what solutions like the Solaris operating system, with its Solaris Zones, Linux OpenVZ, and FreeBSD, with its BSD Jails virtualization system
  • it started out being built on top of LXC, Docker later moved beyond LXC containers to its own execution environment called libcontainer.
  • Unlike LXC, which launches an operating system init for each container, Docker provides one OS environment, supplied by the Docker Engine
  • LXC tooling sticks close to what system administrators running bare metal servers are used to
  • The LXC command line provides essential commands that cover routine management tasks, including the creation, launch, and deletion of LXC containers.
  • Docker containers aim to be even lighter weight in order to support the fast, highly scalable, deployment of applications with microservice architecture.
  • With backing from Canonical, LXC and LXD have an ecosystem tightly bound to the rest of the open source Linux community.
  • Docker Swarm
  • Docker Trusted Registry
  • Docker Compose
  • Docker Machine
  • Kubernetes facilitates the deployment of containers in your data center by representing a cluster of servers as a single system.
  • Swarm is Docker’s clustering, scheduling and orchestration tool for managing a cluster of Docker hosts. 
  • rkt is a security minded container engine that uses KVM for VM-based isolation and packs other enhanced security features. 
  • Apache Mesos can run different kinds of distributed jobs, including containers. 
  • Elastic Container Service is Amazon’s service for running and orchestrating containerized applications on AWS
  • LXC offers the advantages of a VE on Linux, mainly the ability to isolate your own private workloads from one another. It is a cheaper and faster solution to implement than a VM, but doing so requires a bit of extra learning and expertise.
  • Docker is a significant improvement of LXC’s capabilities.
張 旭

The differences between Docker, containerd, CRI-O and runc - Tutorial Works - 0 views

www.tutorialworks.com/ocker-containerd-runc-crio-oci

docker container devops

shared by 張 旭 on 28 Jun 21 - No Cached
  • Docker isn’t the only container contender on the block.
  • Container Runtime Interface (CRI), which defines an API between Kubernetes and the container runtime
  • Open Container Initiative (OCI) which publishes specifications for images and containers.
  • ...20 more annotations...
  • for a lot of people, the name “Docker” itself is synonymous with the word “container”.
  • Docker created a very ergonomic (nice-to-use) tool for working with containers – also called docker.
  • docker is designed to be installed on a workstation or server and comes with a bunch of tools to make it easy to build and run containers as a developer, or DevOps person.
  • containerd: This is a daemon process that manages and runs containers.
  • runc: This is the low-level container runtime (the thing that actually creates and runs containers).
  • libcontainer, a native Go-based implementation for creating containers.
  • Kubernetes includes a component called dockershim, which allows it to support Docker.
  • Kubernetes prefers to run containers through any container runtime which supports its Container Runtime Interface (CRI).
  • Kubernetes will remove support for Docker directly, and prefer to use only container runtimes that implement its Container Runtime Interface.
  • Both containerd and CRI-O can run Docker-formatted (actually OCI-formatted) images, they just do it without having to use the docker command or the Docker daemon.
  • Docker images, are actually images packaged in the Open Container Initiative (OCI) format.
  • CRI is the API that Kubernetes uses to control the different runtimes that create and manage containers.
  • CRI makes it easier for Kubernetes to use different container runtimes
  • containerd is a high-level container runtime that came from Docker, and implements the CRI spec
  • containerd was separated out of the Docker project, to make Docker more modular.
  • CRI-O is another high-level container runtime which implements the Container Runtime Interface (CRI).
  • The idea behind the OCI is that you can choose between different runtimes which conform to the spec.
  • runc is an OCI-compatible container runtime.
  • A reference implementation is a piece of software that has implemented all the requirements of a specification or standard.
  • runc provides all of the low-level functionality for containers, interacting with existing low-level Linux features, like namespaces and control groups.
張 旭

Helm | - 0 views

helm.sh/...chart_template_guide

helm kubernetes chart devops development

shared by 張 旭 on 06 Aug 19 - No Cached
  • Templates generate manifest files, which are YAML-formatted resource descriptions that Kubernetes can understand.
  • service.yaml: A basic manifest for creating a service endpoint for your deployment
  • In Kubernetes, a ConfigMap is simply a container for storing configuration data.
  • ...88 more annotations...
  • deployment.yaml: A basic manifest for creating a Kubernetes deployment
  • using the suffix .yaml for YAML files and .tpl for helpers.
  • It is just fine to put a plain YAML file like this in the templates/ directory.
  • helm get manifest
  • The helm get manifest command takes a release name (full-coral) and prints out all of the Kubernetes resources that were uploaded to the server. Each file begins with --- to indicate the start of a YAML document
  • Names should be unique to a release
  • The name: field is limited to 63 characters because of limitations to the DNS system.
  • release names are limited to 53 characters
  • {{ .Release.Name }}
  • A template directive is enclosed in {{ and }} blocks.
  • The values that are passed into a template can be thought of as namespaced objects, where a dot (.) separates each namespaced element.
  • The leading dot before Release indicates that we start with the top-most namespace for this scope
  • The Release object is one of the built-in objects for Helm
  • When you want to test the template rendering, but not actually install anything, you can use helm install ./mychart --debug --dry-run
  • Using --dry-run will make it easier to test your code, but it won’t ensure that Kubernetes itself will accept the templates you generate.
  • Objects are passed into a template from the template engine.
  • create new objects within your templates
  • Objects can be simple, and have just one value. Or they can contain other objects or functions.
  • Release is one of the top-level objects that you can access in your templates.
  • Release.Namespace: The namespace to be released into (if the manifest doesn’t override)
  • Values: Values passed into the template from the values.yaml file and from user-supplied files. By default, Values is empty.
  • Chart: The contents of the Chart.yaml file.
  • Files: This provides access to all non-special files in a chart.
  • Files.Get is a function for getting a file by name
  • Files.GetBytes is a function for getting the contents of a file as an array of bytes instead of as a string. This is useful for things like images.
  • Template: Contains information about the current template that is being executed
  • BasePath: The namespaced path to the templates directory of the current chart
  • The built-in values always begin with a capital letter.
  • Go’s naming convention
  • use only initial lower case letters in order to distinguish local names from those built-in.
  • If this is a subchart, the values.yaml file of a parent chart
  • Individual parameters passed with --set
  • values.yaml is the default, which can be overridden by a parent chart’s values.yaml, which can in turn be overridden by a user-supplied values file, which can in turn be overridden by --set parameters.
  • While structuring data this way is possible, the recommendation is that you keep your values trees shallow, favoring flatness.
  • If you need to delete a key from the default values, you may override the value of the key to be null, in which case Helm will remove the key from the overridden values merge.
  • Kubernetes would then fail because you can not declare more than one livenessProbe handler.
  • When injecting strings from the .Values object into the template, we ought to quote these strings.
  • quote
  • Template functions follow the syntax functionName arg1 arg2...
  • While we talk about the “Helm template language” as if it is Helm-specific, it is actually a combination of the Go template language, some extra functions, and a variety of wrappers to expose certain objects to the templates.
  • Drawing on a concept from UNIX, pipelines are a tool for chaining together a series of template commands to compactly express a series of transformations.
  • pipelines are an efficient way of getting several things done in sequence
  • The repeat function will echo the given string the given number of times
  • default DEFAULT_VALUE GIVEN_VALUE. This function allows you to specify a default value inside of the template, in case the value is omitted.
  • all static default values should live in the values.yaml, and should not be repeated using the default command
  • Operators are implemented as functions that return a boolean value.
  • To use eq, ne, lt, gt, and, or, not etcetera place the operator at the front of the statement followed by its parameters just as you would a function.
  • if and
  • if or
  • with to specify a scope
  • range, which provides a “for each”-style loop
  • block declares a special kind of fillable template area
  • A pipeline is evaluated as false if the value is: a boolean false a numeric zero an empty string a nil (empty or null) an empty collection (map, slice, tuple, dict, array)
  • incorrect YAML because of the whitespacing
  • When the template engine runs, it removes the contents inside of {{ and }}, but it leaves the remaining whitespace exactly as is.
  • {{- (with the dash and space added) indicates that whitespace should be chomped left, while -}} means whitespace to the right should be consumed.
  • Newlines are whitespace!
  • an * at the end of the line indicates a newline character that would be removed
  • Be careful with the chomping modifiers.
  • the indent function
  • Scopes can be changed. with can allow you to set the current scope (.) to a particular object.
  • Inside of the restricted scope, you will not be able to access the other objects from the parent scope.
  • range
  • The range function will “range over” (iterate through) the pizzaToppings list.
  • Just like with sets the scope of ., so does a range operator.
  • The toppings: |- line is declaring a multi-line string.
  • not a YAML list. It’s a big string.
  • the data in ConfigMaps data is composed of key/value pairs, where both the key and the value are simple strings.
  • The |- marker in YAML takes a multi-line string.
  • range can be used to iterate over collections that have a key and a value (like a map or dict).
  • In Helm templates, a variable is a named reference to another object. It follows the form $name
  • Variables are assigned with a special assignment operator: :=
  • {{- $relname := .Release.Name -}}
  • capture both the index and the value
  • the integer index (starting from zero) to $index and the value to $topping
  • For data structures that have both a key and a value, we can use range to get both
  • Variables are normally not “global”. They are scoped to the block in which they are declared.
  • one variable that is always global - $ - this variable will always point to the root context.
  • $.
  • $.
  • Helm template language is its ability to declare multiple templates and use them together.
  • A named template (sometimes called a partial or a subtemplate) is simply a template defined inside of a file, and given a name.
  • when naming templates: template names are global.
  • If you declare two templates with the same name, whichever one is loaded last will be the one used.
  • you should be careful to name your templates with chart-specific names.
  • templates in subcharts are compiled together with top-level templates
  • naming convention is to prefix each defined template with the name of the chart: {{ define "mychart.labels" }}
  • Helm has over 60 available functions.
crazylion lee

GitHub - pyroscope-io/pyroscope: - 0 views

github.com/...pyroscope

apm ruby golang python node

shared by crazylion lee on 23 Feb 21 - No Cached
  • crazylion lee on 23 Feb 21
     
    "Pyroscope is an open source continuous profiling platform. It will help you: "
張 旭

Production environment | Kubernetes - 0 views

kubernetes.io/...production-environment

devops kubernetes

shared by 張 旭 on 25 Jan 23 - No Cached
  • to promote an existing cluster for production use
  • Separating the control plane from the worker nodes.
  • Having enough worker nodes available
  • ...22 more annotations...
  • You can use role-based access control (RBAC) and other security mechanisms to make sure that users and workloads can get access to the resources they need, while keeping workloads, and the cluster itself, secure. You can set limits on the resources that users and workloads can access by managing policies and container resources.
  • you need to plan how to scale to relieve increased pressure from more requests to the control plane and worker nodes or scale down to reduce unused resources.
  • Managed control plane: Let the provider manage the scale and availability of the cluster's control plane, as well as handle patches and upgrades.
  • The simplest Kubernetes cluster has the entire control plane and worker node services running on the same machine.
  • You can deploy a control plane using tools such as kubeadm, kops, and kubespray.
  • Secure communications between control plane services are implemented using certificates.
  • Certificates are automatically generated during deployment or you can generate them using your own certificate authority.
  • Separate and backup etcd service: The etcd services can either run on the same machines as other control plane services or run on separate machines
  • Create multiple control plane systems: For high availability, the control plane should not be limited to a single machine
  • Some deployment tools set up Raft consensus algorithm to do leader election of Kubernetes services. If the primary goes away, another service elects itself and take over.
  • Groups of zones are referred to as regions.
  • if you installed with kubeadm, there are instructions to help you with Certificate Management and Upgrading kubeadm clusters.
  • Production-quality workloads need to be resilient and anything they rely on needs to be resilient (such as CoreDNS).
  • Add nodes to the cluster: If you are managing your own cluster you can add nodes by setting up your own machines and either adding them manually or having them register themselves to the cluster’s apiserver.
  • Set up node health checks: For important workloads, you want to make sure that the nodes and pods running on those nodes are healthy.
  • Authentication: The apiserver can authenticate users using client certificates, bearer tokens, an authenticating proxy, or HTTP basic auth.
  • Authorization: When you set out to authorize your regular users, you will probably choose between RBAC and ABAC authorization.
  • Role-based access control (RBAC): Lets you assign access to your cluster by allowing specific sets of permissions to authenticated users. Permissions can be assigned for a specific namespace (Role) or across the entire cluster (ClusterRole).
  • Attribute-based access control (ABAC): Lets you create policies based on resource attributes in the cluster and will allow or deny access based on those attributes.
  • Set limits on workload resources
  • Set namespace limits: Set per-namespace quotas on things like memory and CPU
  • Prepare for DNS demand: If you expect workloads to massively scale up, your DNS service must be ready to scale up as well.
張 旭

Installing Addons | Kubernetes - 0 views

kubernetes.io/...addons

kubernetes network networking

shared by 張 旭 on 25 Jan 23 - No Cached
  • Calico is a networking and network policy provider. Calico supports a flexible set of networking options so you can choose the most efficient option for your situation, including non-overlay and overlay networks, with or without BGP. Calico uses the same engine to enforce network policy for hosts, pods, and (if using Istio & Envoy) applications at the service mesh layer.
  • Cilium is a networking, observability, and security solution with an eBPF-based data plane. Cilium provides a simple flat Layer 3 network with the ability to span multiple clusters in either a native routing or overlay/encapsulation mode, and can enforce network policies on L3-L7 using an identity-based security model that is decoupled from network addressing. Cilium can act as a replacement for kube-proxy; it also offers additional, opt-in observability and security features.
  • CoreDNS is a flexible, extensible DNS server which can be installed as the in-cluster DNS for pods.
  • ...1 more annotation...
  • The node problem detector runs on Linux nodes and reports system issues as either Events or Node conditions.
crazylion lee

CodeFlask.js -- Simple code editor for awesome web pages. - 0 views

kazzkiq.github.io/CodeFlask.js

wysiwyg code editor

shared by crazylion lee on 16 Oct 15 - No Cached
  • crazylion lee on 16 Oct 15
     
    "A micro code-editor for awesome web pages."
crazylion lee

A Good Vimrc - 0 views

dougblack.io/...a-good-vimrc.html

vim vimrc

shared by crazylion lee on 15 Oct 15 - No Cached
  • crazylion lee on 15 Oct 15
     
    "There is just one rule you must follow when crafting your own .vimrc."
crazylion lee

slick - the last carousel you'll ever need - 1 views

kenwheeler.github.io/slick

slider carousel jquery plugin javascript

shared by crazylion lee on 21 Oct 16 - No Cached
  • crazylion lee on 21 Oct 16
     
    "the last carousel you'll ever need"
« First ‹ Previous 41 - 60 of 270 Next › Last »
Showing 20▼ items per page