Wandering Thoughts archives

2021-07-23: Why it matters that map values are unaddressable in Go
2021-07-22: Apache's mod_wsgi and the Python 2 issue it creates
Improving my web reading with Martin Tournoij's "readable" Firefox bookmarklet
2021-07-21: It's nice when programs switch to being launched from systemd user units
2021-07-19: Making a Go program build with Go modules can be not a small change
2021-07-18: On sending all syslog messages to one file
2021-07-17: The minimum for syslog configurations should be to log (nearly) everything
2021-07-16: The WireGuard VPN challenge of provisioning clients
Setting up a WireGuard client with NetworkManager (using nmcli)
2021-07-14: Making two Unix permissions mistakes in one
Some ways to get (or not get) information about system memory ranges on Linux
2021-07-12: Problems in the way of straightforward device naming in operating systems
Understanding something about udev's normal network device names on Linux
2021-07-10: Why Bash and GNU Readline's "bracketed paste" mode is not for us
University computer accounts are often surprisingly complicated
2021-07-08: Redirecting paths that start with two slashes in Apache
A semi-surprise with Python's urllib.parse and partial URLs
2021-07-07: The initramfs for old kernels can hide old versions of things
2021-07-06: Unused hardware in computers can now be distinctly inactive
2021-07-05: Losing track of part of our Amanda configuration and then recovering it
2021-07-04: Two ways to have Amanda always make full backups of a filesystem
2021-07-03: Some brief notes on turning Firefox bookmarklets into convenient buttons
2021-07-02: Dealing with CSS fixed position headers and footers in Firefox
2021-06-30: Giving your Linux network interfaces fixed names (under udevd and networkd)
2021-06-29: Monitoring the status of Linux network interfaces with Prometheus
2021-06-28: Be careful when matching on Ethernet addresses in systemd-networkd
I should keep track of what Python packages I install through pip
2021-06-27: Some notes on what's in Linux's /sys/class/net for network interface status
2021-06-26: Ethernet network cables can go bad over time, with odd symptoms
2021-06-25: A couple of Linux top-like programs for network traffic
2021-06-24: Go 1.17 is deprecating the traditional use of 'go get'
2021-06-22: I like WireGuard partly because it doesn't have 'sessions'
2021-06-21: A realization about our VPN and IPv6 traffic
Some notes on building Firefox from source on Ubuntu
2021-06-20: A bit on ZFS's coming raidz expansion and ZFS DVAs
2021-06-19: The Unix background of Linux's 'file-max' and nr_open kernel limits on file descriptors
2021-06-17: Apache directory indexes will notice and exclude blocked URLs in them
In Prometheus queries, on and ignoring don't drop labels from the result
2021-06-16: The challenge of what to set server BIOSes to do on power loss
2021-06-14: Some notes on Firefox's media autoplay settings as of Firefox 89
2021-06-13: A strong commitment to backwards compatibility means keeping your mistakes
Rust 1.x seems to not always be backward compatible in practice
2021-06-11: How we're dealing with our expiring OpenVPN TLS root certificate
TLS certificate durations turn out to be complicated and subtle
2021-06-10: Early notes on using the new python-lsp-server (pylsp) in GNU Emacs
2021-06-09: The modern web design aesthetic of hiding visited links
2021-06-07: My failure to arrange a graceful TLS root certificate rollover with OpenVPN
2021-06-06: TLS certificates have at least two internal representations of time
The case of the very old If-Modified-Since HTTP header
2021-06-04: HTTP/3 needs us (and other people) to make firewall changes
New versions of Bash (and readline) default to special handling of pasting into the shell (or other programs)
2021-06-02: Fedora co-mingles its source packages with Red Hat Enterprise Linux
Simple use of Let's Encrypt on OpenBSD is pleasantly straightforward (as of 6.8)
2021-05-31: It'd be useful if TLS libraries had better and more detailed error messages
I've come to like date-based names for log rotation
2021-05-30: Go 1.17 will still support the old GOPATH mode (as well as modules)
2021-05-28: Less can filter what it shows to you (a thing I recently learned)
2021-05-27: Some thoughts on having set up a personal Alertmanager instance
Being able to see links I've visited in Firefox is startlingly better
2021-05-26: Working around an AMDGPU automatic fan control problem on my Radeon RX 550
2021-05-24: Rust is a wave of the future
Why we don't have management connections to our switches (an old story)
2021-05-23: Our three generations of network implementations (over the time I've been here)
2021-05-22: I don't know how much memory our Prometheus setup needs
2021-05-20: The temptation to start using some Python type hints
2021-05-19: Fedora has significantly fumbled DKMS handling for Linux kernel modules
Speculating on why DKMS and other Linux things are large shell scripts
2021-05-17: Unix job control has some dark corners and challenging cases, illustrated
2021-05-16: Unix job control and its interactions with TTYs (and shells)
2021-05-15: Downsampling your metrics data is a compromise (what we could call a 'hack')
The size of our Prometheus setup as of May 2021
2021-05-14: The Bourne shell and Bash aren't the right languages for larger programs
2021-05-12: The Bourne shell lets you set variables in if expressions
Firefox and the challenge of trying to make visited links clearly visible
2021-05-10: Errors during SMTP conversations aren't trustworthy, illustrated
2021-05-09: DKMS built one of my kernel modules for the wrong kernel
Storing ZFS send streams is not a good backup method
2021-05-08: It's pleasantly easy to install PyPy yourself (from their binaries)
2021-05-07: Understanding OpenSSH's various options around keys and key algorithms
2021-05-06: The different types of modern (2021) SSH keys (and some opinions)
2021-05-05: It's possible for Firefox to forget about:config preferences you've set
2021-05-03: Our future upgrade wave of Ubuntu 18.04 machines
Understanding OpenSSH's future deprecation of the 'ssh-rsa' signature scheme
2021-05-02: Realizing one general way to construct symmetric ciphers
2021-04-30: Discovering outside people attempting to do dynamic DNS updates to us
There's plenty of our work that's not being done from home
2021-04-29: The shift from "two factor" to "multi-factor" authentication
2021-04-28: Firefox's slow takeover of the address bar's space
2021-04-26: The question of how to do non-annoying multi-factor authentication for SSH
Maybe a local, on-machine caching DNS resolver should be standard (for us)
2021-04-25: The question of having SATA drives behind modern SAS expanders
2021-04-24: Why people care about SAS despite not being 'enterprise'
2021-04-23: How I want to use pip with PyPy to install third party programs
2021-04-21: Go 1.17 will allow converting a slice to an array pointer (some of the time)
2021-04-20: PyPy starts fast enough for our Python 2 commands
2021-04-19: Trying out learning more Vim on demand
2021-04-18: Using NVMe SSDs over SATA SSDs in basic servers is an awkward sales pitch
My view of Wayland here in 2021
2021-04-16: A Firefox surprise from disabling dom.event.clipboardevents.enabled
2021-04-15: Learning about the idea of the HTTP self-post
Link: "a2d<C-V>3gE: Vim normal mode grammar
2021-04-14: Some things on ZFS (on Linux) per-dataset basic IO statistics
2021-04-13: Getting NVMe and related terminology straight (for once)
2021-04-12: SSD versus NVMe for basic servers today (in early 2021)
Counting how many times something started or stopped failing in Prometheus
2021-04-11: Vendors put varied and peculiar things in system DMI information
2021-04-09: Why NFS servers generally have a 'reply cache'
What NFSv3 operations can be in the Linux nfsd reply cache
2021-04-07: Rust's rustup tool is surprisingly nice and well behaved
2021-04-06: Modern Linux can require a link signal before it configures IP addresses
2021-04-05: A stable Unix updating its version of Go isn't straightforward
2021-04-04: Some uses for Prometheus's resets() function
You need a version of Go with module support (ideally good support)
2021-04-02: ZFS on Linux is improving the handling of disk names on import
Programs that read IPMI sensors tell you subtly different things
2021-03-31: Understanding Prometheus' changes() function and what it can do for me
Systemd's NSS myhostname module surprised me recently
2021-03-29: Nil in Go is typed in theory and sort of untyped in practice
2021-03-28: What tool you use to read IPMI sensor information can matter
2021-03-27: Internet routing can now vary based on things you wouldn't expect
The attractions of reading sensor information from IPMIs
2021-03-26: Linux's hardware monitoring can lie to you
2021-03-24: HTTPS is really multiple protocols these days
2021-03-23: Discovering Vim's Visual (selection) mode
2021-03-22: Portability has ongoing costs for code that's changing
2021-03-21: My uncertainty about swapping and swap sizing for SSDs and NVMe drives
My experience with x2go is that it's okay but not compelling
2021-03-20: Paging out memory can be 'global' or 'local' these days
2021-03-19: Remote X versus 'seamless windows' in remote desktop software
2021-03-18: Safari is now probably the influential wild card browser for user privacy
2021-03-17: Remote X has been a life saver over this past year
2021-03-16: The fading HTTP Referer header and (Google) Search paywall bypasses
2021-03-15: Different views of what are basic and advanced Vim features
2021-03-14: I wish Prometheus had some features to deal with 'missing' metrics
2021-03-13: Prometheus and the case of the stuck metrics
2021-03-11: Wrangling HTTP and HTTPS versions of the same Apache virtual host
What OpenSSH sshd logs when a session disconnects (on Linux)
2021-03-10: The tradeoffs of Go version behavior in go.mod module files
2021-03-09: Go version directives in go.mod files: some notes and crude usage numbers
2021-03-08: Packaging Python 2 doesn't mean that Linux distributions support it
2021-03-06: Some views and notes on ZFS deduplication today
2021-03-05: How not to use Apache's RewriteRule directive in a reverse proxy
2021-03-04: Systemd needs (or could use) a linter for unit files
2021-03-03: What signal a RJ-45 serial connection is (probably) missing
2021-03-02: The Python ctypes security issue and Python 2
2021-03-01: Link: Taking This Serially
The balance of power between distributions and software authors
2021-02-28: Dot-separated DNS name components aren't even necessarily subdomains, illustrated
2021-02-27: My Firefox addons as of Firefox 86 (and the current development version)
My pragmatic sysadmin view on subdomains and DNS zones
2021-02-25: The HTTP Referer header is fading away (at least as a useful thing)
2021-02-24: How convenience in Prometheus labels for alerts led me into a quiet mistake
How (and where) Prometheus alerts get their labels
2021-02-22: The mhbuild directives I want for sending MIME attachments with MH
How I set up testing alerts in our Prometheus environment
2021-02-20: Modern software controls dependencies because it helps software authors
2021-02-19: ZFS pool partial (selective) feature upgrades are coming in OpenZFS
2021-02-18: Understanding what 'systemctl restart' means and when I want to use it
2021-02-17: TLS certificates specifying hosts via their CommonName field is more or less gone
When browsers (or at least Firefox) send HTTP Basic Authentication headers
2021-02-15: How ZFS on Linux brings up pools and filesystems at boot under systemd
2021-02-14: Some observed read latencies for SSDs and NVMe drives under Fedora 32
Link: What was the original reason for the design of AT&T assembly syntax?
2021-02-13: Where the default values for Python function arguments are stored
2021-02-12: An interesting issue around using is with a literal in Python
2021-02-11: Getting high IOPS requires concurrency on modern SSDs and NVMe drives
2021-02-10: Let's Encrypt is preparing for an emergency and that's good for TLS in general
The issue of IOPS versus latency on SSDs and NVMe drives
2021-02-09: Normal situations should not be warnings (especially not repeated ones)
2021-02-07: Strict SameSite web cookie policies probably don't do much for us
2021-02-06: Talkd and 'mesg n': a story from the old Unix days
2021-02-05: Limiting what branches I track from an upstream Git repository
2021-02-04: There are limitations to what expendable addresses can help with
2021-02-03: Junk email as a cover for more nefarious things
2021-02-02: The small oddity in the Unix exec*() family
2021-02-01: Go 1.16 will make system calls through libc on OpenBSD
2021-01-31: The limitations on find's -exec option and implementation convenience
2021-01-30: I wish every program that wanted 'a SQL database' would let me use SQLite
2021-01-29: Illustrating the importance of fully multi-core program building today
Forecasting drive failures is not always as useful as it sounds
2021-01-27: Making tracking upstream Git repositories a bit quieter
find mostly doesn't need xargs today on modern Unixes
2021-01-25: Time for Python 2 users to make sure we have a copy of Pip and other pieces
2021-01-24: Your monitoring and alerts remember things for you
Thinking through what can go badly with databases on ZFS
2021-01-22: SMART Threshold numbers turn out to not be useful for us in practice
2021-01-21: A lingering sign of old hopes for ZFS deduplication
Real email has MIME attachments that are HTML
2021-01-20: A realization about the Linux CPU pressure stall information
2021-01-18: Where Firefox's text encoding menus are
2021-01-17: Password managers automate checking the website address for you
One reason to not trust SMART attribute data for consumer drives
2021-01-15: SMART attributes can predict SSD failures under the right circumstances
2021-01-14: Understanding WireGuard's AllowedIPs setting (and a bit of tcpdump)
2021-01-13: Installing Pip in Python 2 environments that don't provide it already
What you can and can't build in Go's module mode
2021-01-11: How to make Bash fail badly on Ubuntu 16.04 by typo'ing a command name
2021-01-10: Thinking through why you shouldn't use plaintext passwords in authentication, even inside TLS
What timestamps you get back along with Prometheus query results
2021-01-08: How to extract raw time series data from Prometheus
2021-01-07: I got to experience the march of storage technology today
2021-01-06: In modern email, it's easy for plaintext and HTML parts to drift apart
Link: ARM support in Linux distributions demystified
Unix shell pipelines have two usage patterns
2021-01-05: TLS Certificate Authority root certificate expiry dates are not how trust in them is managed
2021-01-03: TLS Certificate Authority root certificates and their dates
The modern web and (alleged) software stagnation in the past few decades
2021-01-01: An interesting and puzzling bit of Linux server utilization
By month for 2021: Jan Feb Mar Apr May Jun Jul; before 2021.

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