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4th April 2024

Activism⚑

Feminism⚑

Privileges⚑

Life Management⚑

Time management⚑

Org Mode⚑

  • New: How to deal with recurring tasks that are not yet ready to be acted upon.

    By default when you mark a recurrent task as DONE it will transition the date (either appointment, SCHEDULED or DEADLINE) to the next date and change the state to TODO. I found it confusing because for me TODO actions are the ones that can be acted upon right now. That's why I'm using the next states instead:

    • INACTIVE: Recurrent task which date is not yet close so you should not take care of it.
    • READY: Recurrent task which date is overdue, we acknowledge the fact and mark the date as inactive (so that it doesn't clobber the agenda).

    The idea is that once an INACTIVE task reaches your agenda, either because the warning days of the DEADLINE make it show up, or because it's the SCHEDULED date you need to decide whether to change it to TODO if it's to be acted upon immediately or to READY and deactivate the date.

    INACTIVE then should be the default state transition for the recurring tasks once you mark it as DONE. To do this, set in your config:

    org_todo_repeat_to_state = "INACTIVE",

    If a project gathers a list of recurrent subprojects or subactions it can have the next states:

    • READY: If there is at least one subelement in state READY and the rest are INACTIVE
    • TODO: If there is at least one subelement in state TODO and the rest may have READY or INACTIVE
    • INACTIVE: The project is not planned to be acted upon soon.
    • WAITING: The project is planned to be acted upon but all its subelements are in INACTIVE state.

Roadmap Adjustment⚑

  • Correction: Change the concept of Task for Action.

    To remove the capitalist productive mindset from the concept

  • Correction: Action cleaning.

    Marking steps as done make help you get an idea of the evolution of the action. It can also be useful if you want to do some kind of reporting. On the other hand, having a long list of done steps (specially if you have many levels of step indentation may make the finding of the next actionable step difficult. It's a good idea then to often clean up all done items.

    • For non recurring actions use the LOGBOOK to move the done steps. for example: 
      ** DOING Do X
   :LOGBOOK:
   - [x] Done step 1
   - [-] Doing step 2
     - [x] Done substep 1
   :END:
   - [-] Doing step 2
     - [ ] substep 2

    This way the LOGBOOK will be automatically folded so you won't see the progress but it's at hand in case you need it.

    • For recurring actions:
    • Mark the steps as done
    • Archive the todo element.
    • Undo the archive.
    • Clean up the done items.

    This way you have a snapshot of the state of the action in your archive.

  • New: Project cleaning.

    Similar to action cleaning we want to keep the state clean. If there are not that many actions under the project we can leave the done elements as DONE, once they start to get clobbered up we can create a Closed section.

    For recurring projects:

    • Mark the actions as done
    • Archive the project element.
    • Undo the archive.
    • Clean up the done items.

Coding⚑

Languages⚑

Bash snippets⚑

  • New: Do relative import of a bash library.

    If you want to import a file lib.sh that lives in the same directory as the file that is importing it you can use the next snippet:

    source "$(dirname "$(realpath "$0")")/lib.sh"

    If you use source ./lib.sh you will get an import error if you run the script on any other place that is not the directory where lib.sh lives.

  • New: Check the battery status.

    This article gives many ways to check the status of a battery, for my purposes the next one is enough

    cat /sys/class/power_supply/BAT0/capacity
    feat(bash_snippets#Check if file is being sourced): Check if file is being sourced

    Assuming that you are running bash, put the following code near the start of the script that you want to be sourced but not executed:

    if [ "${BASH_SOURCE[0]}" -ef "$0" ]
then
    echo "Hey, you should source this script, not execute it!"
    exit 1
fi

    Under bash, ${BASH_SOURCE[0]} will contain the name of the current file that the shell is reading regardless of whether it is being sourced or executed.

    By contrast, $0 is the name of the current file being executed.

    -ef tests if these two files are the same file. If they are, we alert the user and exit.

    Neither -ef nor BASH_SOURCE are POSIX. While -ef is supported by ksh, yash, zsh and Dash, BASH_SOURCE requires bash. In zsh, however, ${BASH_SOURCE[0]} could be replaced by ${(%):-%N}.

  • New: Parsing bash arguments.

    Long story short, it's nasty, think of using a python script with typer instead.

    There are some possibilities to do this:

IDES⚑

Vim autosave⚑

  • New: Manually toggle the autosave function.

    Besides running auto-save at startup (if you have enabled = true in your config), you may as well:

    • ASToggle: toggle auto-save

Generic Coding Practices⚑

Writing good documentation⚑

DevOps⚑

Monitoring⚑

Loki⚑

  • New: Alert when query returns no data.

    Sometimes the queries you want to alert happen when the return value is NaN or No Data. For example if you want to monitory the happy path by setting an alert if a string is not found in some logs in a period of time.

    count_over_time({filename="/var/log/mail.log"} |= `Mail is sent` [24h]) < 1

    This won't trigger the alert because the count_over_time doesn't return a 0 but a NaN. One way to solve it is to use the vector(0) operator with the operation or on() vector(0) 

    (count_over_time({filename="/var/log/mail.log"} |= `Mail is sent` [24h]) or on() vector(0)) < 1

  • New: Monitor loki metrics.

    Since Loki reuses the Prometheus code for recording rules and WALs, it also gains all of Prometheus’ observability.

    To scrape loki metrics with prometheus add the next snippet to the prometheus configuration:

      - job_name: loki
    metrics_path: /metrics
    static_configs:
    - targets:
      - loki:3100

    This assumes that loki is a docker in the same network as prometheus.

    There are some rules in the awesome prometheus alerts repo

    ---
groups:
- name: Awesome Prometheus loki alert rules
  # https://samber.github.io/awesome-prometheus-alerts/rules#loki
  rules:
  - alert: LokiProcessTooManyRestarts
    expr: changes(process_start_time_seconds{job=~".*loki.*"}[15m]) > 2
    for: 0m
    labels:
      severity: warning
    annotations:
      summary: Loki process too many restarts (instance {{ $labels.instance }})
      description: "A loki process had too many restarts (target {{ $labels.instance }})\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"
  - alert: LokiRequestErrors
    expr: 100 * sum(rate(loki_request_duration_seconds_count{status_code=~"5.."}[1m])) by (namespace, job, route) / sum(rate(loki_request_duration_seconds_count[1m])) by (namespace, job, route) > 10
    for: 15m
    labels:
      severity: critical
    annotations:
      summary: Loki request errors (instance {{ $labels.instance }})
      description: "The {{ $labels.job }} and {{ $labels.route }} are experiencing errors\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"
  - alert: LokiRequestPanic
    expr: sum(increase(loki_panic_total[10m])) by (namespace, job) > 0
    for: 5m
    labels:
      severity: critical
    annotations:
      summary: Loki request panic (instance {{ $labels.instance }})
      description: "The {{ $labels.job }} is experiencing {{ printf \"%.2f\" $value }}% increase of panics\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"
  - alert: LokiRequestLatency
    expr: (histogram_quantile(0.99, sum(rate(loki_request_duration_seconds_bucket{route!~"(?i).*tail.*"}[5m])) by (le)))  > 1
    for: 5m
    labels:
      severity: critical
    annotations:
      summary: Loki request latency (instance {{ $labels.instance }})
      description: "The {{ $labels.job }} {{ $labels.route }} is experiencing {{ printf \"%.2f\" $value }}s 99th percentile latency\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

    And there are some guidelines on the rest of the metrics in the grafana documentation

    Monitor the ruler

    Prometheus exposes a number of metrics for its WAL implementation, and these have all been prefixed with loki_ruler_wal_.

    For example: prometheus_remote_storage_bytes_total → loki_ruler_wal_prometheus_remote_storage_bytes_total

    Additional metrics are exposed, also with the prefix loki_ruler_wal_. All per-tenant metrics contain a tenant label, so be aware that cardinality could begin to be a concern if the number of tenants grows sufficiently large.

    Some key metrics to note are:

    • loki_ruler_wal_appender_ready: whether a WAL appender is ready to accept samples (1) or not (0)
    • loki_ruler_wal_prometheus_remote_storage_samples_total: number of samples sent per tenant to remote storage
    • loki_ruler_wal_prometheus_remote_storage_samples_pending_total: samples buffered in memory, waiting to be sent to remote storage
    • loki_ruler_wal_prometheus_remote_storage_samples_failed_total: samples that failed when sent to remote storage
    • loki_ruler_wal_prometheus_remote_storage_samples_dropped_total: samples dropped by relabel configurations
    • loki_ruler_wal_prometheus_remote_storage_samples_retried_total: samples re-resent to remote storage
    • loki_ruler_wal_prometheus_remote_storage_highest_timestamp_in_seconds: highest timestamp of sample appended to WAL
    • loki_ruler_wal_prometheus_remote_storage_queue_highest_sent_timestamp_seconds: highest timestamp of sample sent to remote storage.

  • New: Get a useful Source link in the alertmanager.

    This still doesn't work. Currently for the ruler external_url if you use the URL of your Grafana installation: e.g. external_url: "https://grafana.example.com" it creates a Source link in alertmanager similar to https://grafana.example.com/graph?g0.expr=%28sum+by%28thing%29%28count_over_time%28%7Bnamespace%3D%22foo%22%7D+%7C+json+%7C+bar%3D%22maxRetries%22%5B5m%5D%29%29+%3E+0%29&g0.tab=1, which isn't valid.

    This url templating (via /graph?g0.expr=%s&g0.tab=1) appears to be coming from prometheus. There is not a workaround yet

Promtail⚑

  • New: Set the hostname label on all logs.

    There are many ways to do it:

    This won't work if you're using promtail within a docker-compose because you can't use bash expansion in the docker-compose.yaml file - Allowing env expansion and setting it in the promtail conf. You can launch the promtail command with -config.expand-env and then set in each scrape jobs: 

    labels:
    host: ${HOSTNAME}
    This won't work either if you're using promtail within a docker as it will give you the ID of the docker - Set it in the promtail_config_clients field as external_labels of each promtail config: 
    promtail_config_clients:
  - url: "http://{{ loki_url }}:3100/loki/api/v1/push"
    external_labels:
      hostname: "{{ ansible_hostname }}"
    - Hardcode it for each promtail config scraping config as static labels. If you're using ansible or any deployment method that supports jinja expansion set it that way 
    labels:
    host: {{ ansible_hostname }}

AlertManager⚑

  • Correction: Add another source on how to silence alerts.

    If previous guidelines don't work for you, you can use the sleep peacefully guidelines to tackle it at query level.

Hardware⚑

ECC RAM⚑

  • New: Check if system is actually using ECC.

    Another way is to run dmidecode. For ECC support you'll see: 

    $: dmidecode -t memory | grep ECC
  Error Correction Type: Single-bit ECC
  # or
  Error Correction Type: Multi-bit ECC

    No ECC:

    $: dmidecode -t memory | grep ECC
  Error Correction Type: None

    You can also test it with rasdaemon

Operating Systems⚑

Linux⚑

Linux Snippets⚑

aleph⚑

HAProxy⚑

ffmpeg⚑

  • New: Reduce the video size.

    If you don't mind using H.265 replace the libx264 codec with libx265, and push the compression lever further by increasing the CRF value — add, say, 4 or 6, since a reasonable range for H.265 may be 24 to 30. Note that lower CRF values correspond to higher bitrates, and hence produce higher quality videos.

    ffmpeg -i input.mp4 -vcodec libx265 -crf 28 output.mp4

    If you want to stick to H.264 reduce the bitrate. You can check the current one with ffprobe input.mkv. Once you've chosen the new rate change it with:

    ffmpeg -i input.mp4 -b 3000k output.mp4

    Additional options that might be worth considering is setting the Constant Rate Factor, which lowers the average bit rate, but retains better quality. Vary the CRF between around 18 and 24 — the lower, the higher the bitrate.

    ffmpeg -i input.mp4 -vcodec libx264 -crf 20 output.mp4

Android⚑

ICSx5⚑

  • New: Introduce ICSx5.

    ICSx5 is an android app to sync calendars.

    References

Other⚑