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張 旭

Helm | - 0 views

helm.sh/architecture

helm kubernetes chart architecture system

shared by 張 旭 on 06 Aug 19 - No Cached
  • Helm is a tool for managing Kubernetes packages called charts
  • Install and uninstall charts into an existing Kubernetes cluster
  • The chart is a bundle of information necessary to create an instance of a Kubernetes application.
  • ...12 more annotations...
  • The config contains configuration information that can be merged into a packaged chart to create a releasable object.
  • A release is a running instance of a chart, combined with a specific config.
  • The Helm Client is a command-line client for end users.
  • Interacting with the Tiller server
  • The Tiller Server is an in-cluster server that interacts with the Helm client, and interfaces with the Kubernetes API server.
  • Combining a chart and configuration to build a release
  • Installing charts into Kubernetes, and then tracking the subsequent release
  • the client is responsible for managing charts, and the server is responsible for managing releases.
  • The Helm client is written in the Go programming language, and uses the gRPC protocol suite to interact with the Tiller server.
  • The Tiller server is also written in Go. It provides a gRPC server to connect with the client, and it uses the Kubernetes client library to communicate with Kubernetes.
  • The Tiller server stores information in ConfigMaps located inside of Kubernetes.
  • Configuration files are, when possible, written in YAML.
  • 張 旭 on 06 Aug 19
     
    "Helm is a tool for managing Kubernetes packages called charts"
張 旭

An App's Brief Journey from Source to Image · Cloud Native Buildpack Document... - 0 views

buildpacks.io/app-journey

devops buildpacks package docker

shared by 張 旭 on 02 Aug 19 - No Cached
  • A buildpack’s job is to gather everything your app needs to build and run, and it often does this job quickly and quietly.
  • a platform sequentially tests groups of buildpacks against your app’s source code.
  • transforming your source code into a runnable app image.
  • ...2 more annotations...
  • Detection criteria is specific to each buildpack – for instance, an NPM buildpack might look for a package.json, and a Go buildpack might look for Go source files.
  • A builder is essentially an image containing buildpacks.
張 旭

Kubernetes Deployments: The Ultimate Guide - Semaphore - 1 views

semaphoreci.com/...kubernetes-deployment

docker kubernetes devops system

shared by 張 旭 on 21 Oct 19 - No Cached
  • Continuous integration gives you confidence in your code. To extend that confidence to the release process, your deployment operations need to come with a safety belt.
  • these Kubernetes objects ensure that you can progressively deploy, roll back and scale your applications without downtime.
  • A pod is just a group of containers (it can be a group of one container) that run on the same machine, and share a few things together.
  • ...34 more annotations...
  • the containers within a pod can communicate with each other over localhost
  • From a network perspective, all the processes in these containers are local.
  • we can never create a standalone container: the closest we can do is create a pod, with a single container in it.
  • Kubernetes is a declarative system (by opposition to imperative systems).
  • All we can do, is describe what we want to have, and wait for Kubernetes to take action to reconcile what we have, with what we want to have.
  • In other words, we can say, “I would like a 40-feet long blue container with yellow doors“, and Kubernetes will find such a container for us. If it doesn’t exist, it will build it; if there is already one but it’s green with red doors, it will paint it for us; if there is already a container of the right size and color, Kubernetes will do nothing, since what we have already matches what we want.
  • The specification of a replica set looks very much like the specification of a pod, except that it carries a number, indicating how many replicas
  • What happens if we change that definition? Suddenly, there are zero pods matching the new specification.
  • the creation of new pods could happen in a more gradual manner.
  • the specification for a deployment looks very much like the one for a replica set: it features a pod specification, and a number of replicas.
  • Deployments, however, don’t create or delete pods directly.
  • When we update a deployment and adjust the number of replicas, it passes that update down to the replica set.
  • When we update the pod specification, the deployment creates a new replica set with the updated pod specification. That replica set has an initial size of zero. Then, the size of that replica set is progressively increased, while decreasing the size of the other replica set.
  • we are going to fade in (turn up the volume) on the new replica set, while we fade out (turn down the volume) on the old one.
  • During the whole process, requests are sent to pods of both the old and new replica sets, without any downtime for our users.
  • A readiness probe is a test that we add to a container specification.
  • Kubernetes supports three ways of implementing readiness probes:Running a command inside a container;Making an HTTP(S) request against a container; orOpening a TCP socket against a container.
  • When we roll out a new version, Kubernetes will wait for the new pod to mark itself as “ready” before moving on to the next one.
  • If there is no readiness probe, then the container is considered as ready, as long as it could be started.
  • MaxSurge indicates how many extra pods we are willing to run during a rolling update, while MaxUnavailable indicates how many pods we can lose during the rolling update.
  • Setting MaxUnavailable to 0 means, “do not shutdown any old pod before a new one is up and ready to serve traffic“.
  • Setting MaxSurge to 100% means, “immediately start all the new pods“, implying that we have enough spare capacity on our cluster, and that we want to go as fast as possible.
  • kubectl rollout undo deployment web
  • the replica set doesn’t look at the pods’ specifications, but only at their labels.
  • A replica set contains a selector, which is a logical expression that “selects” (just like a SELECT query in SQL) a number of pods.
  • it is absolutely possible to manually create pods with these labels, but running a different image (or with different settings), and fool our replica set.
  • Selectors are also used by services, which act as the load balancers for Kubernetes traffic, internal and external.
  • internal IP address (denoted by the name ClusterIP)
  • during a rollout, the deployment doesn’t reconfigure or inform the load balancer that pods are started and stopped. It happens automatically through the selector of the service associated to the load balancer.
  • a pod is added as a valid endpoint for a service only if all its containers pass their readiness check. In other words, a pod starts receiving traffic only once it’s actually ready for it.
  • In blue/green deployment, we want to instantly switch over all the traffic from the old version to the new, instead of doing it progressively
  • We can achieve blue/green deployment by creating multiple deployments (in the Kubernetes sense), and then switching from one to another by changing the selector of our service
  • kubectl label pods -l app=blue,version=v1.5 status=enabled
  • kubectl label pods -l app=blue,version=v1.4 status-
  • 張 旭 on 21 Oct 19
     
    "Continuous integration gives you confidence in your code. To extend that confidence to the release process, your deployment operations need to come with a safety belt."
張 旭

Helm | Template Functions and Pipelines - 0 views

helm.sh/...functions_and_pipelines

helm

shared by 張 旭 on 02 Oct 21 - No Cached
  • When injecting strings from the .Values object into the template, we ought to quote these strings.
  • Helm has over 60 available functions. Some of them are defined by the Go template language itself. Most of the others are part of the Sprig template library
  • 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.
  • ...10 more annotations...
  • 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.
  • the default function: default DEFAULT_VALUE GIVEN_VALUE
  • all static default values should live in the values.yaml, and should not be repeated using the default command (otherwise they would be redundant).
  • the default command is perfect for computed values, which can not be declared inside values.yaml.
  • When lookup returns an object, it will return a dictionary.
  • The synopsis of the lookup function is lookup apiVersion, kind, namespace, name -> resource or resource list
  • When no object is found, an empty value is returned. This can be used to check for the existence of an object.
  • The lookup function uses Helm's existing Kubernetes connection configuration to query Kubernetes.
  • Helm is not supposed to contact the Kubernetes API Server during a helm template or a helm install|update|delete|rollback --dry-run, so the lookup function will return an empty list (i.e. dict) in such a case.
  • the operators (eq, ne, lt, gt, and, or and so on) are all implemented as functions. In pipelines, operations can be grouped with parentheses ((, and )).
  • 張 旭 on 02 Oct 21
     
    "When injecting strings from the .Values object into the template, we ought to quote these strings. "
crazylion lee

irfansharif/cfilter: Cuckoo Filter implementation in Go, better than Bloom Filters - 0 views

github.com/cfilter

filter bloom

shared by crazylion lee on 20 Aug 16 - No Cached
  • crazylion lee on 20 Aug 16
     
    "Cuckoo Filter "
crazylion lee

fogleman/primitive: Reproducing images with geometric primitives. - 0 views

github.com/primitive

go image processing

shared by crazylion lee on 07 Nov 16 - No Cached
  • crazylion lee on 07 Nov 16
     
    "Reproducing images with geometric primitives"
張 旭

Service objects in Rails will help you design clean and maintainable code. Here's how. - 0 views

www.netguru.co/...ice-objects-in-rails-will-help

service rails programming controller model pattern object

shared by 張 旭 on 30 Nov 16 - No Cached
  • Services has the benefit of concentrating the core logic of the application in a separate object, instead of scattering it around controllers and models.
  • Additional initialize arguments might include other context information if applicable.
  • And as programmers, we know that when something can go wrong, sooner or later it will!
  • ...7 more annotations...
  • we need a way to signal success or failure when using a service
  • what ActiveRecord save method uses
  • if the services role is to create or update rails models, it makes sense to return such an object as result.
  • utility objects to signal success or error
  • services will be used on the boundary between user interface and application
  • All the business logic is encapsulated in services and models
  • how we can use Service Objects, Status Objects and Rails’s Responders to produce a nice, consistent API
crazylion lee

tsenart/vegeta: HTTP load testing tool and library. It's over 9000! - 0 views

github.com/vegeta

http performance golang go load-testing loadtesting

shared by crazylion lee on 12 Dec 16 - No Cached
  • crazylion lee on 12 Dec 16
     
    "HTTP load testing tool and library"
crazylion lee

Build web application with Golang - GitBook - 0 views

www.gitbook.com/...details

go web

shared by crazylion lee on 17 Apr 16 - No Cached
  • crazylion lee on 17 Apr 16
     
    "Build web application with Golang"
張 旭

http - nginx upload client_max_body_size issue - Stack Overflow - 0 views

stackoverflow.com/...oad-client-max-body-size-issue

nginx upload file http server

shared by 張 旭 on 26 Sep 16 - No Cached
  • nginx "fails fast" when the client informs it that it's going to send a body larger than the client_max_body_size by sending a 413 response and closing the connection.
  • Because nginx closes the connection, the client sends data to the closed socket, causing a TCP RST.
  • Most clients don't read responses until the entire request body is sent.
  • ...2 more annotations...
  • Client body and buffers are key because nginx must buffer incoming data.
  • The clean setting frees up memory and consumption limits by instructing nginx to store incoming buffer in a file and then clean this file later from disk by deleting it.
crazylion lee

jdberry/tag · GitHub - 0 views

github.com/tag

go tag mac

shared by crazylion lee on 17 Jan 14 - No Cached
  • crazylion lee on 17 Jan 14
     
    "tag is a command line tool to manipulate tags on Mac OS X 10.9 Mavericks files, and to query for files with those tags. tag can use the file system's built-in metadata search functionality to rapidly find all files that have been tagged with a given set of tags."
張 旭

Best practices for writing Dockerfiles - Docker Documentation - 0 views

docs.docker.com/...dockerfile_best-practices

docker tutorial deploy

shared by 張 旭 on 29 May 15 - No Cached
  • Run only one process per container
  • use current Official Repositories as the basis for your image
  • put long or complex RUN statements on multiple lines separated with backslashes.
  • ...16 more annotations...
  • CMD instruction should be used to run the software contained by your image, along with any arguments
  • CMD should be given an interactive shell (bash, python, perl, etc)
  • COPY them individually, rather than all at once
  • COPY is preferred
  • using ADD to fetch packages from remote URLs is strongly discouraged
  • always use COPY
  • The best use for ENTRYPOINT is to set the image's main command, allowing that image to be run as though it was that command (and then use CMD as the default flags).
  • the image name can double as a reference to the binary as shown in the command above
  • ENTRYPOINT instruction can also be used in combination with a helper script
  • The VOLUME instruction should be used to expose any database storage area, configuration storage, or files/folders created by your docker container.
  • use USER to change to a non-root user
  • avoid installing or using sudo
  • avoid switching USER back and forth frequently.
  • always use absolute paths for your WORKDIR
  • ONBUILD is only useful for images that are going to be built FROM a given image
  • The “onbuild” image will fail catastrophically if the new build's context is missing the resource being added.
張 旭

Developing with Docker - 1 views

engineering.ifttt.com/...developing-with-docker

shared by 張 旭 on 04 Dec 15 - No Cached
  • Before moving our production infrastructure over however, we decided that we wanted to start developing with them locally first. We could shake out any issues with our applications before risking the production environment.
  • using Chef and Vagrant to provision local VMs
  • Engineers at IFTTT currently all use Apple computers
  • ...7 more annotations...
  • /bin/true
    • 張 旭
      張 旭 on 04 Dec 15
       
      如果使用 docker create 就不用跑這個， 不過目前 docker-compose 沒有支援 volume-only 的 container
  • it will install gems onto the data volume from the bundler-cache container.
  • dev rm bundler-cache
    • 張 旭
      張 旭 on 04 Dec 15
       
      要完全刪除干淨，後面的指令可能是： docker rm -v bundler-cache
  • if you accidentally delete bundler-cache, you then have to install all your gems over again.
  • Containerization and Docker are powerful tools in your infrastructure toolbox.
  • highly recommend starting off in your developer environment first
  • the onboarding time for new developers go from a couple days or more to a matter of hours.
張 旭

What is DevOps? | Atlassian - 0 views

www.atlassian.com/devops

devops system

shared by 張 旭 on 13 Nov 18 - No Cached
  • DevOps is a set of practices that automates the processes between software development and IT teams, in order that they can build, test, and release software faster and more reliably.
  • increased trust, faster software releases, ability to solve critical issues quickly, and better manage unplanned work.
  • bringing together the best of software development and IT operations.
  • ...39 more annotations...
  • DevOps is a culture, a movement, a philosophy.
  • a firm handshake between development and operations
  • DevOps isn’t magic, and transformations don’t happen overnight.
  • Infrastructure as code
  • Culture is the #1 success factor in DevOps.
  • Building a culture of shared responsibility, transparency and faster feedback is the foundation of every high performing DevOps team.
  •  'not our problem' mentality
  • DevOps is that change in mindset of looking at the development process holistically and breaking down the barrier between Dev and Ops.
  • Speed is everything.
  • Lack of automated test and review cycles block the release to production and poor incident response time kills velocity and team confidence
  • Open communication helps Dev and Ops teams swarm on issues, fix incidents, and unblock the release pipeline faster.
  • Unplanned work is a reality that every team faces–a reality that most often impacts team productivity.
  • “cross-functional collaboration.”
  • All the tooling and automation in the world are useless if they aren’t accompanied by a genuine desire on the part of development and IT/Ops professionals to work together.
  • DevOps doesn’t solve tooling problems. It solves human problems.
  • Forming project- or product-oriented teams to replace function-based teams is a step in the right direction.
  • sharing a common goal and having a plan to reach it together
  • join sprint planning sessions, daily stand-ups, and sprint demos.
  • DevOps culture across every department
  • open channels of communication, and talk regularly
  • DevOps isn’t one team’s job. It’s everyone’s job.
  • automation eliminates repetitive manual work, yields repeatable processes, and creates reliable systems.
  • Build, test, deploy, and provisioning automation
  • continuous delivery: the practice of running each code change through a gauntlet of automated tests, often facilitated by cloud-based infrastructure, then packaging up successful builds and promoting them up toward production using automated deploys.
  • automated deploys alert IT/Ops to server “drift” between environments, which reduces or eliminates surprises when it’s time to release.
  • “configuration as code.”
  • when DevOps uses automated deploys to send thoroughly tested code to identically provisioned environments, “Works on my machine!” becomes irrelevant.
  • A DevOps mindset sees opportunities for continuous improvement everywhere.
  • regular retrospectives
  • A/B testing
  • failure is inevitable. So you might as well set up your team to absorb it, recover, and learn from it (some call this “being anti-fragile”).
  • Postmortems focus on where processes fell down and how to strengthen them – not on which team member f'ed up the code.
  • Our engineers are responsible for QA, writing, and running their own tests to get the software out to customers.
  • How long did it take to go from development to deployment? 
  • How long does it take to recover after a system failure?
  • service level agreements (SLAs)
  • Devops isn't any single person's job. It's everyone's job.
  • DevOps is big on the idea that the same people who build an application should be involved in shipping and running it.
  • developers and operators pair with each other in each phase of the application’s lifecycle.
crazylion lee

Træfik - 0 views

docs.traefik.io

go proxy

shared by crazylion lee on 31 Aug 18 - No Cached
張 旭

Swarm task states | Docker Documentation - 0 views

docs.docker.com/...swarm-task-states

docker swarm system

shared by 張 旭 on 07 Sep 18 - No Cached
  • Each service can start multiple tasks.
  • Tasks are execution units that run once to completion.
  • The task progresses forward through a number of states, and its state doesn’t go backward.
張 旭

Let's Encrypt & Docker - Træfik - 0 views

docs.traefik.io/...docker-and-lets-encrypt

traefik docker networking proxy

shared by 張 旭 on 19 Sep 18 - No Cached
  • automatically discover any services on the Docker host and let Træfik reconfigure itself automatically when containers get created (or shut down) so HTTP traffic can be routed accordingly.
  • use Træfik as a layer-7 load balancer with SSL termination for a set of micro-services used to run a web application.
  • Docker containers can only communicate with each other over TCP when they share at least one network.
  • ...15 more annotations...
  • Docker under the hood creates IPTable rules so containers can't reach other containers unless you'd want to
  • Træfik can listen to Docker events and reconfigure its own internal configuration when containers are created (or shut down).
  • Enable the Docker provider and listen for container events on the Docker unix socket we've mounted earlier.
  • Enable automatic request and configuration of SSL certificates using Let's Encrypt. These certificates will be stored in the acme.json file, which you can back-up yourself and store off-premises.
  • there isn't a single container that has any published ports to the host -- everything is routed through Docker networks.
  • Thanks to Docker labels, we can tell Træfik how to create its internal routing configuration.
  • container labels and service labels
  • With the traefik.enable label, we tell Træfik to include this container in its internal configuration.
  • tell Træfik to use the web network to route HTTP traffic to this container.
  • Service labels allow managing many routes for the same container.
  • When both container labels and service labels are defined, container labels are just used as default values for missing service labels but no frontend/backend are going to be defined only with these labels.
  • In the example, two service names are defined : basic and admin. They allow creating two frontends and two backends.
  • Always specify the correct port where the container expects HTTP traffic using traefik.port label.
  • all containers that are placed in the same network as Træfik will automatically be reachable from the outside world
  • With the traefik.frontend.auth.basic label, it's possible for Træfik to provide a HTTP basic-auth challenge for the endpoints you provide the label for.
張 旭

Handling Arguments in Bash Scripts - DEV Community - 0 views

dev.to/...arguments-in-bash-scripts-3o5m

bash shell programming

shared by 張 旭 on 21 Mar 19 - No Cached
  • positional arguments. They hold the arguments given after your script as it was run on the command line
  • $0: The Script Name
  • $#: Argument Count
  • ...2 more annotations...
  • $?: Most Recent Exit Code
  • When you quote $*, it will output all of the arguments received as one single string, separated by a space1 regardless of how they were quoted going in, but it will quote that string so that it doesn't get split up later.
  • 張 旭 on 21 Mar 19
     
    "positional arguments. They hold the arguments given after your script as it was run on the command line"
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