Doc: Continue with tutorial brainstorming session.

Co-authored-by: Hector Hurtado <hector.hurtado@bbva.com> Co-authored-by: pancho horrillo <pedrofelipe.horrillo@bbva.com>
2019-11-25 17:36:35 +01:00
parent 3d27490f3c
commit 8939f59403
1 changed files with 79 additions and 16 deletions
@@ -38,31 +38,94 @@ ACME's Infrastructure
 User Journey
 ------------

-#. Actions over the database. Launch database backup script with an HTTP call.
+#. Actions over the server. Launch database backup script with an HTTP call.

-   - User Learns: Add a route that executes a command locally.
-   - Kapow! Concepts: `kapow route add`
+  - User Learns: Add a route that executes a command locally.
+  - Kapow! Concepts: `kapow route add` 
+  - 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
+    database is small (for now).
+  - Solution: Instead of launching the script via SSH shell we can
+    provide an HTTP endpoint to perform the task.
+    ```
+    ssh user@server
+    $ ./backup_db.sh
+    ```
+  - Final Kapow!:
+    ```
+    curl -X PUT http://server:8080/db/backup
+    ```
+    ```
+    kapow route add -X PUT /db/backup -e ./backup_db.sh
+    ```

-#. Basic database monitorization
+#. Basic server monitoring

-   - User Learns: Execute local commands and output it results to the HTTP body.
-   - Kapow! Concepts: `kapow set /response/body`
+  - User Learns: Execute local commands and output it results to the HTTP body.
+  - Kapow! Concepts: `kapow set /response/body`
+  - Problem/Motivation: 
+  - Solution:
+  - Final Kapow!:
+    ```
+    cat /var/log/backup_db.log | kapow set /response/body
+    ```

-#. Advanced database monitorization
-   - User Learns: Compose complex HTTP responses with more than one local command.
-   - Kapow! Concepts: HEREDOC and subshells
+#. Filter over basic monitoring
+
+  - User Learns: Get a parameter from the user and use it to select the
+    script.
+  - Kapow! Concepts: `kapow get /request/params` 
+  - Problem/Motivation:
+  - Solution:
+  - Final Kapow!:
+    ```
+    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:
+  - Solution:
+  - Final Kapow!:
+    ```
+    {
+      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`
+  - 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:
+  - Solution:
+  - Final Kapow!:
+    ``` DON'T HANDWRITE JSON
+    echo "{memory: `free -m`, ...uups..}'  | kapow set /response/body
+    ```

-#. Unifing the interface (???)
+    ``` USE JQ
+    MEMORY=$(free -m)
+    LOAD=$(uptime)
+    DISK=$(df -h)
+    jq -nc --arg memory "$MEMORY" '{"memory": $memory}'
+    ```

-   - User Learns: Add logic to the handler. React to a specific request. 
-   - Kapow! Concepts: `kapow get /request/headers` and IF (bash)
-
-  
 Ideas
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