Hello Rust Belt Rust attendee, and thanks for your interest in my Rust Belt Rust workshop \u201cHEY! There\u2019s OCaml in My Rust!\u201d I appreciate the opportunity to introduce you to Rust, OCaml, or even possibly both! I hope you learn as much from the workshop as I did in preparation.<\/p>\n\n
The hands-on portion of the workshop will have attendees writing the same problem (binary search tree<\/a>) in OCaml and Rust and sharing observations and ideas with other attendees. We\u2019ll step through one or two of the tree operations and invite attendees to write operations of their own or to explore and improve the ones we\u2019ve already written. You have two options for environments if you\u2019d like to participate: using online playgrounds or locally on your development machine (highly recommended<\/em>).<\/p>\n\n All of the Rust examples are written to run using the Rust playground hosted by Integer32<\/a> or The Rust Language website<\/a>. The OCaml examples are written to run on OCamlPro\u2019s Try OCaml app<\/a>.<\/p>\n\n Here\u2019s a rundown of the software that should be installed and ready if you want to work locally:<\/p>\n\n You should have the following executables in your path when finished:<\/p>\n\n You\u2019re ready to go if you\u2019ve got those four programs installed.<\/p>\n\n I look forward to meeting you at Rust Belt Rust! Feel free to reach out to me on Twitter<\/a> if you have questions or just want to say hi!<\/p>\n","pubDate":"Wed, 12 Oct 2016 23:05:00 +0000","link":"http:\/\/kelcecil.com\/rust\/2016\/10\/12\/rust-belt-rust-workshop-info.html","guid":"http:\/\/kelcecil.com\/rust\/2016\/10\/12\/rust-belt-rust-workshop-info.html","category":["rust","instructions","rust"]},{"title":"Querying Unix Sockets with curl","description":" I recently found myself in a situation where I wanted to query the Docker socket to query their API for information, and I found myself wishing with every passing moment that I could just query a unix socket using a tool as simple and straight-forward as curl<\/em>. Imagine my joy when I discovered that curl<\/em> now has unix socket support in curl<\/em> 7.40 and later. Discovering this new feature made my day, and I\u2019m thrilled to share this with you.<\/p>\n\n Let\u2019s take a look at how this works by using curl<\/em>\u2019s unix socket support to find out what images our local Docker daemon has available.<\/p>\n\n That\u2019s pretty easy, huh? Simply use the \u2013unix-socket flag and make sure to throw http:<\/em> before your endpoint (omitting the protocol in 7.46 DEV will result in a malformed url error). You can skip specifying the HTTP method (-X) if you\u2019re okay with curl<\/em>\u2019s default of using the HTTP GET method.<\/p>\n\n How much effort does using curl<\/em> save? Here\u2019s an equivalent example using OpenBSD\u2019s netcat<\/em> (also available on Ubuntu Server 15.04):<\/p>\n\n How useful is using curl<\/em> over netcat<\/em>? Using curl<\/em> can potentially provide benefits in scripting and ease of use, but anyone who already has the muscle memory to hammer out something familiar to the netcat<\/em> line above might not be as easily persuaded by the convenience. curl<\/em> 7.40 may also not be available in some software repositories, so knowledge of using netcat<\/em> still may be useful if a newer version of curl<\/em> isn\u2019t available.<\/p>\n\n You\u2019ll be ready to work with a unix socket next time you find yourself in a similar position. Go forth and curl<\/em>!<\/p>\n","pubDate":"Mon, 07 Dec 2015 20:11:00 +0000","link":"http:\/\/kelcecil.com\/curl\/2015\/12\/07\/query-unix-socket-with-curl.html","guid":"http:\/\/kelcecil.com\/curl\/2015\/12\/07\/query-unix-socket-with-curl.html","category":["curl","unix-sockets","netcat","curl"]},{"title":"Keeping Your Github Fork Updated","description":" Tonight was a rainy, cold night in my town, so I spent the evening trying to get my four pull requests in for Digital Ocean\u2019s Hackoberfest<\/a>. I found myself updating an old fork on my Github page<\/a> and reflecting on the questions I had when starting with Git and Github. How to update my personal fork on Github from the original repository was one of my first tasks I learned, and I thought I\u2019d take the opportunity to pass the knowledge along in the spirit of Hackoberfest.\n<\/p>\n\n I have a fork of Kubernetes<\/a> in my Github account for preparing pull requests. I can clone my repository to my development workstation using git clone<\/em>:<\/p>\n\n The URI used in the git clone<\/em> command is stored as a remote named origin<\/em>. We can verify this very easily using git remote<\/em>:<\/p>\n\n This remote named origin is the repository location we are referring to when we perform git push origin master<\/em> or git pull origin master<\/em>. origin<\/em> is only one possible location, and we can add other remote repositories such as the upstream repository that we\u2019d like to pull data from. Let\u2019s add the main Kubernetes repository as a remote named upstream<\/em> using git remote add<\/em>.<\/p>\n\n We can now easily update our code from the upstream Kubernetes repository with a simple git pull<\/em>. You can then push your repository to origin to update your forked repository.<\/p>\n\n Excellent work! Our forked repository is now up to date with the upstream repository, and we\u2019re ready to hack on our favorite project!<\/p>\n","pubDate":"Wed, 28 Oct 2015 02:36:00 +0000","link":"http:\/\/kelcecil.com\/git\/2015\/10\/28\/updating-repo-from-upstream.html","guid":"http:\/\/kelcecil.com\/git\/2015\/10\/28\/updating-repo-from-upstream.html","category":["git","github","open source","git"]},{"title":"Cross Compiling in Go 1.5","description":" Are you a developer that develops on one operating system and deploys to another? You might be an open source developer that wants to generate binaries for combinations of operating systems and platforms? One of the coolest features of Go 1.5 is how easy cross-compiling your applications for other architectures and operating systems can be, and I\u2019m going to show you how in this post.\n<\/p>\n\n Why might we need to cross-compile our code? One of my favorite aspects of Golang are the binaries that are produced during a build. Gone are the days of having to install a runtime and dependencies on production boxes to execute that incredibly helpful script. Go\u2019s static binaries include everything you\u2019ll need to run your app in a single easy-to-transfer executable. This is a fantastic asset for system administrators,<\/a> but this convenience comes with a minor concern. Using low-level binaries means that we\u2019ll need binaries prepared for specific processor architecture and platform combinations. This may sound like a hassle, but read on to see how Go 1.5 makes this task trivial!<\/p>\n\n Let\u2019s take this incredibly simple Go application and pretend this is a slick tool for system administrators:<\/p>\n\n What an awesome, feature-rich tool! Let\u2019s build our tool using go build<\/em>:<\/p>\n\n go build<\/em> uses the host operating system and processor architecture by default. We can verify the format of the produced binary using the file<\/em> utility and see this binary was prepared for a x86-64 (64-bit, Intel-based) processor running on Mac OS (which uses the Mach-O file format<\/a>):<\/p>\n\n We now have this excellent utility that works on a x86-64, Mac OS machine, but we need to compile our application for x86-64, Linux-based machines. You can easily set the target operating system and processor architecture using the environment variables GOOS and GOARCH respectively. Building for a Linux system using an x86-64 processor (commonly also referred to as an amd64 processor) is as simple as running this one-liner:<\/p>\n\n The file<\/em> utility tells us that our binary has been prepared using the ELF executable format and ready for action on a x86-64 Linux system.<\/p>\n\n Easy, huh? Cross-compiling in Go 1.5 is that simple!<\/p>\n\n I can hear your next question from the other side of the internet. What architectures and operating systems does Go 1.5 support? Go currently enjoys operating system support for Windows, OS X, Linux, plenty of BSD variants, and Plan 9<\/a> among others. Supported architectures includes x86, x86-64 (amd64), 32 and 64-bit arm processors, PowerPC, and others! A list of valid operating system and processor architecture combinations are available in the Go documentation<\/a>.<\/p>\n\n We can also take a peak inside the source for go build<\/em><\/a> and see what go build<\/em> will accept.<\/p>\n\n\n
\n
# curl -X METHOD --unix-socket \/path\/to\/socket.sock <endpoint><\/span>\nkcecil@ubuntu:~$ <\/span>curl -X GET --unix-socket \/var\/run\/docker.sock http:\/images\/json\n[{<\/span>\"Id\"<\/span>:\"3a10494514dcef7fb1b48fb4ce3c25a941bfdb5b8dfd3a0275267fc1094e9782\"<\/span>,\"ParentId\"<\/span>:\"e34cf9c36b25be359613467859eb53af43787adeb35e902d68dc2a26d4b15538\"<\/span>,\"RepoTags\"<\/span>:[\"kelcecil\/chucksay:latest\"<\/span>]<\/span>,\"RepoDigests\"<\/span>:[],\"Created\"<\/span>:1433631743,\"Size\"<\/span>:0,\"VirtualSize\"<\/span>:486914149,\"Labels\"<\/span>:{}}]<\/span><\/code><\/pre><\/figure>\n\nkcecil@ubuntu:~$ <\/span>echo<\/span> -e \"GET \/images\/json HTTP\/1.0<\/span>\\r\\n<\/span>\"<\/span> | netcat -U \/var\/run\/docker.sock\nHTTP\/1.0 200 OK\nContent-Type: application\/json\nServer: Docker\/1.9.1 (<\/span>linux)<\/span>\nDate: Mon, 07 Dec 2015 21:44:20 GMT\nContent-Length: 277\n\n[{<\/span>\"Id\"<\/span>:\"3a10494514dcef7fb1b48fb4ce3c25a941bfdb5b8dfd3a0275267fc1094e9782\"<\/span>,\"ParentId\"<\/span>:\"e34cf9c36b25be359613467859eb53af43787adeb35e902d68dc2a26d4b15538\"<\/span>,\"RepoTags\"<\/span>:[\"kelcecil\/chucksay:latest\"<\/span>]<\/span>,\"RepoDigests\"<\/span>:[],\"Created\"<\/span>:1433631743,\"Size\"<\/span>:0,\"VirtualSize\"<\/span>:486914149,\"Labels\"<\/span>:{}}]<\/span><\/code><\/pre><\/figure>\n\n> <\/span>git clone git@github.com:kelcecil\/kubernetes.git\nCloning into 'kubernetes'<\/span>...\nremote: Counting objects: 162966, done<\/span>.\nremote: Compressing objects: 100% (<\/span>6\/6)<\/span>, done<\/span>.\nremote: Total 162966 (<\/span>delta 0)<\/span>, reused 0 (<\/span>delta 0)<\/span>, pack-reused 162960\nReceiving objects: 100% (<\/span>162966\/162966)<\/span>, 124.80 MiB | 8.79 MiB\/s, done<\/span>.\nResolving deltas: 100% (<\/span>106653\/106653)<\/span>, done<\/span>.\nChecking connectivity... done<\/span>.<\/code><\/pre><\/figure>\n\n> <\/span>git remote -v \norigin git@github.com:kelcecil\/kubernetes.git (<\/span>fetch)<\/span>\norigin git@github.com:kelcecil\/kubernetes.git (<\/span>push)<\/span><\/code><\/pre><\/figure>\n\n> <\/span>git remote add upstream git@github.com:kubernetes\/kubernetes.git\n> <\/span>git remote -v\norigin git@github.com:kelcecil\/kubernetes.git (<\/span>fetch)<\/span>\norigin git@github.com:kelcecil\/kubernetes.git (<\/span>push)<\/span>\nupstream git@github.com:kubernetes\/kubernetes.git (<\/span>fetch)<\/span>\nupstream git@github.com:kubernetes\/kubernetes.git (<\/span>push)<\/span><\/code><\/pre><\/figure>\n\n> <\/span>git pull upstream master\n...\n> <\/span>git push origin master\n...<\/code><\/pre><\/figure>\n\npackage<\/span> <\/span>main<\/span>\n\n<\/span>import<\/span> <\/span>(<\/span>\n <\/span>\"fmt\"<\/span>\n <\/span>\"time\"<\/span>\n<\/span>)<\/span>\n\n<\/span>func<\/span> <\/span>main<\/span>()<\/span> <\/span>{<\/span>\n <\/span>for<\/span> <\/span>{<\/span>\n <\/span>fmt<\/span>.<\/span>Println<\/span>(<\/span>\"Hello!\"<\/span>)<\/span>\n <\/span>time<\/span>.<\/span>Sleep<\/span>(<\/span>time<\/span>.<\/span>Second<\/span>)<\/span>\n <\/span>}<\/span>\n<\/span>}<\/span><\/code><\/pre><\/figure>\n\ngo build -o hello main.go<\/code><\/pre><\/figure>\n\n> <\/span>file hello\nhello: Mach-O 64-bit executable x86_64<\/code><\/pre><\/figure>\n\nGOOS<\/span>=<\/span>linux GOARCH<\/span>=<\/span>amd64 go build -o hello main.go<\/code><\/pre><\/figure>\n\n> <\/span>file hello\nhello: ELF 64-bit LSB executable, x86-64, version 1 (<\/span>SYSV)<\/span>, statically linked, not stripped<\/code><\/pre><\/figure>\n\n\/\/ The known architectures.<\/span>\n<\/span>var<\/span> <\/span>okgoarch<\/span> <\/span>=<\/span> <\/span>[]<\/span>string<\/span>{<\/span>\n\t<\/span>\"386\"<\/span>,<\/span>\n\t<\/span>\"amd64\"<\/span>,<\/span>\n\t<\/span>\"amd64p32\"<\/span>,<\/span>\n\t<\/span>\"arm\"<\/span>,<\/span>