On SSH Certificates

Not to be confused with TLS (was: SSL) certificates. why? Problem 1: Does anyone check SSH server keys before accepting them? The authenticity of host ‘server (’ can’t be established. ECDSA key fingerprint is SHA256:P45XQklRehB7js1bfqpbRX+dq0vTEQoJbcwACNrSGow. ECDSA key fingerprint is MD5:d2:4a:3d:a1:59:ec:30:fe:36:11:1a:61:7c:f1:3f:eb. Are you sure you want to continue connecting (yes/no) A mechanism to distribute the known […]

Open source smarter heating?

I live in a Victorian house, so it loses heat like crazy. There are some rooms which stay nice and cool in the summer, but they’re also cold in the winter. And I have the data which tells me that we average 32kWh of gas a day, over the whole year. Over the summer it’s […]

Building Ubuntu via PXE

I already have a Raspberry Pi serving up Centos over the network, and I wanted to add Ubuntu. I’d previously had this working over NFS; I stumbled over a backup of my configuration for 14.04, 12.04, and 11.10 using NFS. However, my Centos setup uses http (plus TFTP for the PXE bit) as I’d found […]

Ruby gem version dependency hell (gettext 3.3.0)

$ /bin/bundle install –gemfile=ci/Gemfile Gem::InstallError: gettext requires Ruby version >= 2.5.0. An error occurred while installing gettext (3.3.0), and Bundler cannot continue. Make sure that `gem install gettext -v ‘3.3.0’` succeeds before bundling. TL;DR, this works – there’s another option which might work, see below, but I can’t be bothered to try. This is two […]

stash of /etc/os-release files

Which I use for bootstrapping puppet apply. Ubuntu 18.04 (symlink to /usr/lib/os-release) NAME=”Ubuntu” VERSION=”18.04.3 LTS (Bionic Beaver)” ID=ubuntu ID_LIKE=debian PRETTY_NAME=”Ubuntu 18.04.3 LTS” VERSION_ID=”18.04″ HOME_URL=”https://www.ubuntu.com/” SUPPORT_URL=”https://help.ubuntu.com/” BUG_REPORT_URL=”https://bugs.launchpad.net/ubuntu/” PRIVACY_POLICY_URL=”https://www.ubuntu.com/legal/terms-and-policies/privacy-policy” VERSION_CODENAME=bionic UBUNTU_CODENAME=bionic Fedora 31 NAME=Fedora VERSION=”31 (Workstation Edition)” ID=fedora VERSION_ID=31 VERSION_CODENAME=”” PLATFORM_ID=”platform:f31″ PRETTY_NAME=”Fedora 31 (Workstation Edition)” ANSI_COLOR=”0;34″ LOGO=fedora-logo-icon CPE_NAME=”cpe:/o:fedoraproject:fedora:31″ HOME_URL=”https://fedoraproject.org/” DOCUMENTATION_URL=”https://docs.fedoraproject.org/en-US/fedora/f31/system-administrators-guide/” SUPPORT_URL=”https://fedoraproject.org/wiki/Communicating_and_getting_help” BUG_REPORT_URL=”https://bugzilla.redhat.com/” REDHAT_BUGZILLA_PRODUCT=”Fedora” REDHAT_BUGZILLA_PRODUCT_VERSION=31 REDHAT_SUPPORT_PRODUCT=”Fedora” REDHAT_SUPPORT_PRODUCT_VERSION=31 PRIVACY_POLICY_URL=”https://fedoraproject.org/wiki/Legal:PrivacyPolicy” […]

systemctl mask failure

You cannot mask services defined in /etc/systemd/system. It relies on creating a symlink there with the same name as the file which defines the service. hat tip stack exchange From the big book of unhelpful error messages # /bin/systemctl mask gitlab-runner.service Failed to execute operation: Invalid argument # systemctl status gitlab-runner.service ● gitlab-runner.service – GitLab […]

Mount dependencies with systemd

Introduction: services that depend on NFS If a linux server boots and a block device isn’t available, it’ll drop into some sort of single-user mode. This was the way with init, and is the way with systemd. NFS, not so much. In my experience, systemd will start services implicitly dependent on an NFS mount the […]

heimdall on Centos7

You want to flash a Samsung Galaxy Android device. You’ll need heimdall. It’s not available as a package for Centos7, so you’ll need to compile it. Expanded instructions It uses cmake, which I’d not tripped over before, and the build process is a good deal messier than I expected. As in literally, it leaves stuff […]