I enjoy using Prometheus and have toyed around with it for some time particularly in combination with Kubernetes. I signed up with Linode [referral] compelled by the addition of a managed Kubernetes service called Linode Kubernetes Engine (LKE). I have an anxiety that I’ll inadvertently leave resources running (unused) on a cloud platform. Instead of refreshing the relevant billing page, it struck me that Prometheus may (not yet proven) help.

I’ve written a couple of deployment options (Google Compute Engine; Kubernetes) for an open-source project. The Kubernetes deployment provides NodePort and (TCP) LoadBalancer options and I’ve been trying (unsuccessfully) to add HTTPS Load-balancing. I should (!) try to deploy to Google Kubernetes Engine (GKE) but I’ve been using microk8s, Digital Ocean Managed Kubernetes and the Linode LKE Beta. Each of these requires an implementation of Ingress controller. For GKE, GCP’s HTTP/S Load-balancer (GCLB) is used.

I’ve finally being able to hack my way through to a working Rust gRPC client (for PyPi Transparency). It’s not very good: poorly structured, hacky etc. but it serves the purpose of giving me a foothold into Rust development so that I can evolve it as I learn the language and its practices. There are several Rust crates (SDK) for gRPC. There’s no sanctioned SDK for Rust on grpc.io. I chose stepancheg’s grpc-rust because it’s a pure Rust implementation (not built atop the C implementation).

I’ve been noodling around with another Trillian personality. Another in a theme that interests me in providing tamperproof logs for the packages in the popular package management registries. The Golang team recently announced Go Module Mirror which is built atop Trillian. It seems to me that all the package registries (Go Modules, npm, Maven, NuGet etc.) would benefit from tamperproof logs hosted by a trusted 3rd-party. As you may have guessed, PyPi Transparency is a log for PyPi packages.

cAdvisor has long been a favorite monitoring tool of mine. I’m using Docker Compose for local testing and have begun including a cAdvisor in my docker-compose.yaml files. cadvisor: restart: always image: google/cadvisor:${CADVISOR_VERSION} container_name: cadvisor # command: # - --prometheus_endpoint="/metrics" # Default volumes: - "/:/rootfs:ro" - "/var/run:/var/run:rw" - "/sys:/sys:ro" - "/var/snap/docker/current:/var/lib/docker:ro" #- "/var/lib/docker/:/var/lib/docker:ro" expose: - "8080" ports: - 8080:8080 I’d not realized until recently, that cAdvisor also surfaces a Prometheus metrics endpoint and so, if you do follow this path and you’re also using Prometheus, don’t forget to add cAdvisor to your Prometheus targets.

Google Cloud Platform Free Tier appears (please verify this for yourself) to provide the ability to run a(n admittedly miniscule) Kubernetes cluster for free. So, why do this? It provides a definitive Kubernetes (Engine) experience on Google Cloud Platform that you may use for learning and testing. Kubernetes Engine the master node(s) and the control plane are free. Kubernetes (i.e. Compute Engine) nodes potentially incur charges including for the VM runtime and any attached storage, snapshots etc.

Tweaked yesterday’s solution so that it will randomly select one from several hosts with which it’s configured. package proxy import ( "log" "math/rand" "net/http" "net/url" "os" "strings" "time" ) func robin() { hostsList := os.Getenv("PROXY_HOST") if hostsList == "" { log.Fatal("'PROXY_HOST' environment variable should contain comma-separated list of hosts") } // Comma-separated lists of hosts hosts := strings.Split(hostsList, ",") urls := make([]*url.URL, len(hosts)) for i, host := range hosts { var origin = Endpoint{ Host: host, Port: os.

I’m investigating the use of LetsEncrypt for gRPC services. I found this straightforward post by Scott Devoid and am going to try this approach. Before I can do that, I need to be able to publish services (make them Internet-accessible) and would like to try to continue to use GCP for free. Some time ago, I wrote about using the excellent Microk8s on GCP. Using an f1-micro, I’m hoping (!) to stay within the Compute Engine free tier.

The Go team is developing a Language Server Protocol [LSP] implementation) called gopls. Visual Studio Code (and others) support LSP. Other languages (e.g. Python have LSP implementations too). I’ve been using gopls for some time. It works (mostly) very well and replaces multiple, indepedent tools with two (gopls and delve). My Visual Studio Code settings that include gopls is: "go.autocompleteUnimportedPackages": true, "go.useLanguageServer": true, "[go]": { "editor.snippetSuggestions": "none", "editor.formatOnSave": true, "editor.codeActionsOnSave": { "source.

The goal of pypi-transparency is very similar to the underlying motivation for the Golang team’s Checksum Database (also built with Trillian). Even though, PyPi provides hashes of the content of packages it hosts, the developer must trust that PyPi’s data is consistent. One ambition with pypi-transparency is to provide a companion, tamperproof log of PyPi package files in order to provide a double-check of these hashes. It is important to understand what this does (and does not) provide.