Merge pull request #2 from seeker89/kille-whiles

Add source code for chapter 2: Killer whiles

Author: seeker89

Makefile

@@ -0,0 +1,6 @@
+all: killer-whiles
+
+killer-whiles:
+	(cd examples/killer-whiles && make)
+
+.PHONY: killer-whiles

examples/killer-whiles/Makefile

@@ -0,0 +1,17 @@
+CFLAGS=-O0
+
+all: mystery000 mystery001 faas
+
+%.o: %.c
+	cc -o $@ $< $(CFLAGS)
+
+faas:
+	# link our fake faas services
+	sudo ln -f -s /home/chaos/src/examples/killer-whiles/faas001_a.service /lib/systemd/system/faas001_a.service
+	sudo ln -f -s /home/chaos/src/examples/killer-whiles/faas001_b.service /lib/systemd/system/faas001_b.service
+	sudo systemctl daemon-reload
+	# link our fake load-balancer
+	sudo ln -f -s /home/chaos/src/examples/killer-whiles/nginx.loadbalancer.conf /etc/nginx/conf.d/nginx.loadbalancer.conf
+	sudo systemctl restart nginx
+
+.PHONY: fass

examples/killer-whiles/cereal_killer.sh

@@ -0,0 +1,23 @@
+echo "Listing backend services"
+ps auxf | grep killer-whiles | grep python
+echo
+
+echo "Killing instance A (port 8001)"
+ps auxf | grep 8001 | awk '{system("sudo kill " $2)}'
+sleep 0.5
+systemctl status faas001_a
+echo
+
+echo "Wait some time in-between killings"
+sleep 2
+echo
+
+echo "Killing instance A (port 8002)"
+ps auxf | grep 8002 | awk '{system("sudo kill " $2)}'
+sleep 0.5
+systemctl status faas001_b
+echo
+
+echo "Listing backend services"
+ps auxf | grep killer-whiles | grep python
+echo "Done here!"

examples/killer-whiles/faas001_a.service

@@ -0,0 +1,6 @@
+[Unit]
+Description=FizzBuzz as a Service API prototype - instance A
+
+[Service]
+ExecStart=python3 -m http.server 8001 --directory /home/chaos/src/examples/killer-whiles/static
+Restart=always

examples/killer-whiles/faas001_b.service

@@ -0,0 +1,6 @@
+[Unit]
+Description=FizzBuzz as a Service API prototype - instance B
+
+[Service]
+ExecStart=python3 -m http.server 8002 --directory /home/chaos/src/examples/killer-whiles/static
+Restart=always

examples/killer-whiles/killer_while.sh

@@ -0,0 +1,25 @@
+# restart instance A a few times, spaced out by 1.5 second delays
+i="0"
+while [ $i -le 5 ]
+do
+    echo "Killing faas001_a ${i}th time"
+    ps auxf | grep killer-whiles | grep python | grep 8001 | awk '{system("sudo kill " $2)}'
+    sleep 0.5
+    i=$[$i+1]
+done
+
+systemctl status faas001_a --no-pager
+
+sleep 2
+
+# restart instance B a few times, spaced out by 1.5 second delays
+i="0"
+while [ $i -le 5 ]
+do
+    echo "Killing faas001_b ${i}th time"
+    ps auxf | grep killer-whiles | grep python | grep 8002 | awk '{system("sudo kill " $2)}'
+    sleep 0.5
+    i=$[$i+1]
+done
+
+systemctl status faas001_b --no-pager

examples/killer-whiles/mystery000.c

@@ -0,0 +1,4 @@
+int main()
+{
+    return 1/0;
+}

examples/killer-whiles/mystery001.c

@@ -0,0 +1,29 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int main()
+{
+    int wait = 1;
+    int block_size = 64*1024*1024;
+    int step = 1024*1024;
+    char * allocated_block;
+    
+    while (1) {
+
+        if ((allocated_block = (char*)malloc(block_size)) == NULL) {
+            //printf("Couldn't malloc %d!\n", block_size);
+            if (block_size > 2*step){
+                block_size -= step;
+            }
+        } else {
+            // slowly write data to our newly allocated memory to actually claim it and use some CPU
+            for (int i=0; i < block_size; i++){
+                *(allocated_block + i) = 'Y';
+            }
+        }
+        sleep(wait); 
+    }
+
+    return 0;
+}

examples/killer-whiles/nginx.loadbalancer.conf

@@ -0,0 +1,15 @@
+# http {
+    # http block already in /etc/nginx/nginx.conf
+    upstream backend {
+        server 127.0.0.1:8001 max_fails=1 fail_timeout=1s;
+        server 127.0.0.1:8002 max_fails=1 fail_timeout=1s;
+    }
+    server {
+        listen 8003;
+
+        location / {
+            proxy_pass http://backend;
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        }
+    }
+# }

examples/killer-whiles/run_ab.sh

@@ -0,0 +1,5 @@
+# print the command
+set -o xtrace
+
+# run the benchmark
+ab -t 30 -c 10 -l http://127.0.0.1:8003/api/v1/

examples/killer-whiles/static/api/v1/index.html

@@ -0,0 +1,3 @@
+{
+    "FizzBuzz": true
+}

vm/ansible/prerequisites/defaults/main.yml

@@ -0,0 +1,7 @@
+---
+packages_to_install:
+  - git
+  - vim
+  - curl
+  - nginx
+  - apache2-utils

vm/ansible/prerequisites/tasks/main.yml

@@ -1,12 +1,18 @@
 ---
-- name: Install git
+- name: Preinstall packages
   become: true
   apt:
-    name: git
+    name: "{{ item }}"
     state: present
     update_cache: yes
+  loop: "{{ packages_to_install }}"
 
 - name: Check out the book source code to home
   git:
     repo: 'https://github.com/seeker89/chaos-engineering-in-action.git'
     dest: /home/chaos/src
+
+- name: Make all the examples
+  shell: make
+  args:
+    chdir: /home/chaos/src

vm/http/preseed.cfg

@@ -239,13 +239,13 @@ d-i partman-auto/choose_recipe select atomic
 
 # Partitioning
 d-i partman-basicfilesystems/no_swap boolean false
-
-d-i partman-auto/expert_recipe string boot-root : \
+d-i partman-auto/expert_recipe string boot-root :: \
         5120 1 -1 ext4 \
             $primary{ } $bootable{ } \
             method{ format } format{ } \
             use_filesystem{ } filesystem{ ext4 } \
             label { root } mountpoint{ / } .
+d-i partman-auto/choose_recipe select boot-root
 
 # If you just want to change the default filesystem from ext3 to something
 # else, you can do that without providing a full recipe.