Merge remote-tracking branch 'origin/master'

2019-11-26 11:46:25 +01:00
parent f7139cd489 f276417fd5
commit 93263a2541
4 changed files with 344 additions and 47 deletions
@@ -71,7 +71,9 @@ Table of content
   :maxdepth: 2
   :caption: Tutorial

-   tutorial/_brianstorm
+   tutorial/tutorial00
+   tutorial/tutorial01
+   tutorial/_brainstorm

 Indices and tables
 ==================
@@ -35,6 +35,12 @@ ACME's Infrastructure
  - Corporate Server
  - Backup Server

+Characters
+----------
+
+- Seasoned Ops
+- Junior Ops
+
 User Journey
 ------------

@@ -45,21 +51,26 @@ User Journey
  - Problem/Motivation: Each time an ACME project is finished it is
    desirable to make a backup of the entire database.  Given that the
    database server is a critical machine we don't want to grant SSH
-    access to lowly developers.  The script is very fast because the
+    access to lowly developers.  The script is fast because the
    database is small (for now).
  - pre-Kapow! solution: Launching the script via SSH shell.
-    ```
-    ssh user@server
-    $ ./backup_db.sh
-    ```
+
+    .. code-block:: console
+
+       $ ssh user@server
+       Password:
+       (server)$ ./backup_db.sh
+
  - Kapow!-enabled solution: Provide an HTTP endpoint that when accessed
    triggers the run of the backup script.
-    ```
-    curl -X PUT http://server:8080/db/backup
-    ```
-    ```
-    kapow route add -X PUT /db/backup -e ./backup_db.sh
-    ```
+
+    .. code-block:: console
+
+       $ kapow route add -X PUT /db/backup -e ./backup_db.sh
+
+    .. code-block:: console
+
+       $ curl -X PUT http://server:8080/db/backup

 #. Basic server monitoring

@@ -71,9 +82,10 @@ User Journey
  - pre-Kapow! solution: SSH into the host + cat /tmp/backup_db.log.
  - Kapow!-enabled solution: Provide an endpoint that returns the contents of
    /tmp/backup_db.log.
-    ```
-    cat /var/log/backup_db.log | kapow set /response/body
-    ```
+
+    .. code-block:: console
+
+       $ cat /tmp/backup_db.log | kapow set /response/body

 #. Filter over basic monitoring

@@ -89,51 +101,82 @@ User Journey
    this task.

  - Kapow!-enabled solution:
-    ```
-    LINES="$(kapow get /request/params/lines)"
-    FILTER="$(kapow get /request/params/filter)"
-    grep "$FILTER" /var/log/backup_db.log \
-      | tail -n"$LINES" \
-      | kapow set /response/body
-    ```
+
+    .. code-block:: sh
+
+       LINES="$(kapow get /request/params/lines)"
+       FILTER="$(kapow get /request/params/filter)"
+       grep "$FILTER" /var/log/backup_db.log \
+         | tail -n"$LINES" \
+         | kapow set /response/body

 #. Advanced database monitoring

  - User Learns: Compose complex HTTP responses with more than one local command.
  - Kapow! Concepts: HEREDOC and subshells
-  - Problem/Motivation:
-  - pre-Kapow! solution:
+  - Problem/Motivation: The OPs manager needs to have information about
+    the health status of our servers. And she is always asking to the
+    team to write a report that involves calling several commands.
+  - pre-Kapow! solution: SSH into the server and manually execute the
+    commands, collect the output and write the report.
  - Kapow!-enabled solution:
-    ```
-    {
-      echo Memory:
-      free -m
-      echo ================================================================================
-      echo Load:
-      uptime
-      echo ================================================================================
-      echo Disk:
-      df -h
-    } | kapow set /response/body
-    ```
+
+    From this:
+
+    .. code-block:: sh
+
+       echo Date: | kapow set /response/body
+       echo ======...==== | kapow set /response/body
+       echo Memory | kapow set /response/body
+       # ...
+
+
+    To this:
+
+    .. code-block:: sh
+
+       kapow set /response/headers/Content-Type text/plain
+       {
+         echo Date:
+         date
+         echo ================================================================================
+         echo Memory:
+         free -m
+         echo ================================================================================
+         echo Load:
+         uptime
+         echo ================================================================================
+         echo Disk:
+         df -h
+       } | kapow set /response/body

 #. Share your achievements

  - User Learns: Format a complex HTTP response with JSON format to feed the corporate dashboard.
  - Kapow! Concepts: backtick interpolation and `kapow set /response/headers`
-  - Problem/Motivation:
-  - pre-Kapow! solution:
+  - Problem/Motivation: The OPs manager wants to create a dashboard to
+    see the server health information in real time. She hired a fronted
+    developer to make a nice dashboard application and we need to
+    provide him with the information in a format suitable for display.
+  - pre-Kapow! solution: Write a php/perl/python script to serve this
  - Kapow!-enabled solution:
-    ``` DON'T HANDWRITE JSON
-    echo "{memory: `free -m`, ...uups..}'  | kapow set /response/body
-    ```

-    ``` USE JQ
-    MEMORY=$(free -m)
-    LOAD=$(uptime)
-    DISK=$(df -h)
-    jq -nc --arg memory "$MEMORY" '{"memory": $memory}'
-    ```
+    Don't handwrite `JSON`
+
+    .. code-block:: sh
+
+       kapow set /response/body application/json
+       echo "{memory: `free -m`, ...uups...}"  | kapow set /response/body
+
+    Use ``jq``
+
+    .. code-block:: sh
+
+       MEMORY=$(free -m)
+       LOAD=$(uptime)
+       DISK=$(df -h)
+       kapow set /response/body application/json
+       jq -nc --arg memory "$MEMORY" '{"memory": $memory}' | kapow set /response/body

 Ideas
 -----
@@ -147,3 +190,32 @@ Ideas

   Add this to serve the webpage that uses the implemented HTTP API
   kapow route add / -c 'kapow set /resonse/headers/Content-Type text/html ; curl --output - http:// | kapow set /response/body'
+
+
+Test
+----
+
+**User**
+
+  Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod
+  tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At
+  vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren,
+  no sea takimata sanctus est Lorem ipsum dolor sit amet.
+
+**Admin**
+
+  Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod
+  tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At
+  vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren,
+  no sea takimata sanctus est Lorem ipsum dolor sit amet.
+
+**User**
+
+  Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod
+  tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. 
+
+  .. code-block:: console
+
+     $ cat something.txt
+
+  Right?
@@ -0,0 +1,37 @@
+Your First Day at Work
+======================
+
+**Senior**
+
+  Welcome to ACME Inc.  This is your first day here, right?
+
+**Junior**
+
+  Hi! I am excited to start working.  What will be my first task?
+
+**Senior**
+
+  First let me explain to you what is our infrastructure.
+
+**Junior**
+
+  Ok.
+
+**Senior**
+
+  We have two Linux machines that provide services to our employees.
+
+  1. The Corporate Server:  Provides email, database and web services.
+
+  2. The Backup Server:  It is used to store backup of the important
+     company data. 
+
+**Junior**
+
+  That's it? Ok, just like Google.
+
+**Senior**
+
+  Well, I think is time for you to start with your first task.  It just
+  so happens that we received another request to backup the database
+  from the projects team.
@@ -0,0 +1,186 @@
+Backup that Database!
+=====================
+
+**Junior**
+
+  A Backup? Don't you have this kind of things already automated?
+
+**Senior**
+
+  Well, is not that simple. We of course have periodic backups. But, our
+  project team ask us for a backup every time a project is finished.
+
+  I've already prepared a script to do the task. Before executing it in
+  production download it and test it in your own machine.
+
+  .. todo::
+
+     - Link backup script from Github.
+
+**Junior**
+
+  Ok, done! When I executed it the output says:
+
+  .. code-block:: console
+
+     $ ./backup_db.sh
+     Backup done!
+     Your log file is at /tmp/backup_db.log
+
+**Senior**
+
+  That's right. That script performed the backup and stored it into the
+  **Backup Server** and appended some information into the backup log
+  file at ``/tmp/backup_db.log``.
+
+  Now you can SSH into the **Corporate Server** and make the real
+  backup.
+
+
+**Junior**
+
+  Wait, wait... how long have you been doing this?
+
+
+**Senior**
+
+  This procedure was already here when I arrived.
+
+**Junior**
+
+  And why don't they do it themselves?  I mean, what do you contribute
+  to the process?
+
+**Senior**
+
+  I am the only allowed to SSH into the **Corporate Server** for obvious
+  reasons.
+
+**Junior**
+
+  Why do you need to SSH in the first place? Couldn't it be done
+  without SSH?
+
+**Senior**
+
+  Actually it could be done with a promising new tool I've just found...
+  Kapow!
+
+  Is a tool that allows you to publish scripts as HTTP services.  If we
+  use it here we can give them the ability to do the backup whenever
+  they want.
+
+**Junior**
+
+  Sounds like less work for me.  I like it. 
+
+**Senior**
+
+  Ok then, let's try on your laptop first.
+
+  First of all you have to follow the installation instructions XXX. 
+
+**Junior**
+
+  I've just installed it in my laptop, but I don't understand how all of
+  this is going to work.
+
+**Senior**
+
+  Don't worry it is pretty easy.  Basically we will provide an HTTP
+  endpoint managed by Kapow! at the **Corporate Server**; when the
+  project team wants to perform a backup they only need to call the
+  endpoint and Kapow! will call the backup script.
+
+**Junior**
+
+  It seems pretty easy.  How can I create the endpoint?
+
+**Senior**
+
+  First you have to start a fresh server. Please run this in your laptop:
+
+  .. code-block:: console
+
+     $ kapow server
+
+  .. warning::
+
+     It is important that you run this command in the same directory
+     in which you downloaded ``backup_db.sh``.
+
+**Junior**
+
+  Done! But it doesn't do anything.
+
+**Senior**
+
+  Now you have the port 8080 open but don't have any endpoints defined.
+  To define our endpoint you have to run this in another terminal:
+
+  .. code-block:: console
+
+     $ kapow route add -X PUT /db/backup -e ./backup_db.sh
+
+  This will create an endpoint accessible via
+  ``http://localhost:8080/db/backup``. This endpoint have to be invoked
+  with the ``PUT`` method to prevent accidental calls.
+
+**Junior**
+
+  Cool! Do we need to do all this stuff every time we start the
+  **Corporate Server**?
+
+**Senior**
+
+  Not at all. The have thought of everything. You can put all your route
+  definitions in a special script file and pass it to the server on
+  startup. They call those files `POW` files and have ``.pow``
+  extension.
+
+  It should look something like:
+
+  .. code-block:: console
+
+     $ cat backup.pow
+     kapow route add -X PUT /db/backup -e ./backup_db.sh
+
+  And then you can start Kapow! with it:
+
+  .. code-block:: console
+
+     $ kapow server backup.pow
+
+**Junior**
+
+  Great! Now it says:
+
+  .. code-block:: console
+
+     $ kapow server backup.pow
+     2019/11/26 11:40:01 Running powfile: "backup.pow"
+     {"id":"19bb4ac7-1039-11ea-aa00-106530610c4d","method":"PUT","url_pattern":"/db/backup","entrypoint":"./backup_db.sh","command":"","index":0}
+     2019/11/26 11:40:01 Done running powfile: "backup.pow"
+
+  I understand that this is proof that we have the endpoint available.
+
+**Senior**
+
+  That appears to be the case, but better we check it.
+
+  Call it with ``curl``:
+
+  .. code-block:: console
+
+     $ curl -X PUT http://localhost:8080/db/backup
+
+**Junior**
+
+  Yay! I can see the log file at ``/tmp/backup_db.log``
+
+**Senior**
+
+  That's great. I am going to install all this in the *Corporate Server*
+  and forget about the old procedure.
+
+  That enough for your first day! You can go home.