ansible.tex

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\documentclass{beamer}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
%\usepackage{verbatim}
\usepackage{graphicx}
\usepackage{amsmath}
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\usepackage{minted}
\usepackage{ulem}
\usepackage{hyperref}
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\AtBeginSection[]
{
  \begin{frame}<beamer>
      \frametitle{Syllabus}
      {\scriptsize\tableofcontents[currentsection,hideothersubsections]
      }
    \end{frame}
}

\fvset{commandchars=\\\{\}}

\title{Ansible \textit{set\_fact} \& \textit{add\_host}}
\author{Julien Girardin}
\date{\today}

\titlegraphic{
    \includegraphics[width=0.06\textwidth]{images/ansible_badge.png}
    \hspace{0.1cm}
    \includegraphics[width=0.3\textwidth]{images/ansible.png}
}

\begin{document}

\maketitle{}

\begin{frame}
    \begin{exampleblock}{Versions disclaimer}
        Should work on ansible >= 1.9

        (Special mentions for ansible 2.0 only)
    \end{exampleblock}
\end{frame}

\section{Server scope variable}

\begin{frame}[fragile]
\frametitle{Example}
    \begin{exampleblock}{Example featuring \textit{set\_fact}}
        \begin{minted}{yaml}
- name: "A task with set_fact"
  set_fact: ga=foo
  args:
    bu: bar
    zo: baz|bool
    meu: >- # add "-" to strip the \n at the end
      {{ complex_computation_in_jinja|list }}
        \end{minted}
    \end{exampleblock}
\end{frame}


\begin{frame}[fragile]
    \begin{columns}
    \column{0.4\textwidth}
        \begin{block}{site\_1.yml}
        \footnotesize{
            \inputminted[firstline=1, lastline=2]
                        {yaml}{sources/site_1.yml}
            \inputminted[firstline=3, lastline=3,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/site_1.yml}
            \inputminted[firstline=4, lastline=10]
                        {yaml}{sources/site_1.yml}
            \inputminted[firstline=11, lastline=11,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/site_1.yml}
        }
        \end{block}

    \column{0.55\textwidth}
        \vbox to .7\textheight{
        \footnotesize{
            \inputminted[firstline=58, lastline=60,
                        breaklines,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/roles/graphite/tasks/main.yml}
            \vfill
            \inputminted[firstline=1, lastline=5,
                        breaklines,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/roles/ferm_basic/tasks/main.yml}
        }
        }
    \end{columns}
\end{frame}

\begin{frame}[fragile]
\begin{columns}
    \column{0.4\textwidth}
    \begin{alertblock}{site\_2.yml}
        \footnotesize{
            \inputminted{yaml}{sources/site_2.yml}
        }
    \end{alertblock}
    \column{0.55\textwidth}
        \scriptsize{
        \begin{Verbatim}[label={Ansible output 1}]
TASK [graphite | Expose graphite ports] *******
\textcolor{Green}{ok: [graphite]}
\textcolor{Green}{ok: [shinken]}

TASK [ferm_basic | Open tcp port in firewall] *
\textcolor{Orange}{changed: [graphite]}
\textcolor{Orange}{changed: [shinken]}

TASK [shinken | Export Shinken web UI ports] **
\textcolor{Green}{ok: [graphite]}
\textcolor{Green}{ok: [shinken]}

TASK [ferm_basic | Open tcp port in firewall] *
\textcolor{Orange}{changed: [graphite]}
\textcolor{Orange}{changed: [shinken]}
        \end{Verbatim}
        }
\end{columns}
\vfill
\begin{center}
    \visible<2->{
        $\Rightarrow$ First: remove the shinken ports. Then: add it again.
    }
\end{center}
\end{frame}

\begin{frame}[fragile]
\begin{columns}
    \column{0.4\textwidth}
        \begin{block}{site\_3.yml}
        \footnotesize{
            \inputminted[firstline=1, lastline=2]
                        {yaml}{sources/site_3.yml}
            \inputminted[firstline=3, lastline=3,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/site_3.yml}
            \inputminted[firstline=4, lastline=6]
                        {yaml}{sources/site_3.yml}
            \inputminted[firstline=7, lastline=7,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/site_3.yml}
            \inputminted[firstline=8]
                        {yaml}{sources/site_3.yml}
        }
        \end{block}
    \column{0.55\textwidth}
        \vbox to .7\textheight{
        \scriptsize{
            \inputminted[firstline=64, lastline=70,
                        breaklines,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/roles/graphite/tasks/main.yml}
            \vfill
            \inputminted[firstline=1, lastline=9,
                        breaklines,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/roles/ferm_full/tasks/ports_dict.yml}
        }
        }
\end{columns}
\end{frame}

\begin{frame}[fragile]
\begin{columns}
    \column{0.4\textwidth}
        \begin{block}{site\_4.yml}
        \footnotesize{
            \inputminted[firstline=1, lastline=6]
                        {yaml}{sources/site_4.yml}
            \inputminted[firstline=7, lastline=8,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/site_4.yml}
            \inputminted[firstline=9]
                        {yaml}{sources/site_4.yml}
        }
        \end{block}
    \column{0.55\textwidth}
        \vbox to .9\textheight{
        \scriptsize{
            \inputminted[firstline=13,
                        breaklines,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/roles/ferm_full/tasks/ports_dict.yml}
            \vfill
            \textit{cleanup\_input.yml:}
            \inputminted[breaklines,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/roles/ferm_full/tasks/cleanup_input.yml}
        }
        }
\end{columns}
\end{frame}

\begin{frame}[fragile]
    \begin{alertblock}{Warning}
        A missing tag \textit{ferm} or \textit{firewall}
        may un-expose a port and remove it from firewall
    \end{alertblock}

\end{frame}

\section{Global scope variable}
%\subsection{Read vars from other servers}


\begin{frame}[fragile]
\frametitle{Example}
    \begin{exampleblock}{The classical but usefull \textit{hostvars}}
        \footnotesize{
        \begin{minted}[breaklines]{yaml}
- hosts: master
  tasks:
    - name: "Get content from master"
      slurp:
        path: /root/.ssh/id_rsa.pub
      register: sshkey
      delegate_to: "{{ groups.master[0] }}"
      run_once: True

- hosts: slaves
  tasks:
    - name: "Add sshpub key from the master"
      authorized_keys:
        key: "{{ hostvars[groups.master[0]].sshkey.content|b64decode }}"
        user: root
        \end{minted}
        }
    \end{exampleblock}
\end{frame}

%\subsection{add\_host}

\begin{frame}[fragile]
\begin{block}{Global vars}
How to pass a variable globally ?

(ie: whatever the server who set the var and whatever the server who read the var)
\end{block}

\visible<2->{
    \begin{center}
    $\Rightarrow$ \textbf{\textit{Groups}}
    \end{center}
    }
\end{frame}

\begin{frame}[fragile]
\frametitle{Example}
    \begin{exampleblock}{Example featuring \textit{add\_host}}
        \begin{minted}{yaml}
- name: "Example with add_hosts"
  add_host:
    name: "{{ groups.slaves[0] }}"
    groups: leader
    foo: bar
        \end{minted}
    \end{exampleblock}
\end{frame}

\begin{frame}[fragile]
\frametitle{Common pitfall}
    \textit{add\_host} litteraly breaks the parallelism of ansible.

    It seems to have: \fbox{\lstinline{run_once: True}} always enabled.
    \begin{columns}
    \column{0.5\textwidth}
        \begin{alertblock}{Doesn't work as expected}
            \footnotesize{
            \begin{minted}{yaml}
- name: "Add hosts to shinken"
  add_host:
    name: "{{ inventory_hostname }}"
    groups: shinken
            \end{minted}
            }
        \end{alertblock}
    \column{0.45\textwidth}
%        \visible<2->{
        \begin{minipage}{\textwidth}
        \begin{exampleblock}{Thing you might want}
            \footnotesize{
            \begin{minted}{yaml}
- name: "Add hosts to shinken"
  add_host:
    name: "{{ item }}"
    groups: shinken
  with_items: "{{ play_hosts }}"
            \end{minted}
            }
        \end{exampleblock}
        \end{minipage}
%        }
    \end{columns}
\end{frame}

\begin{frame}
\begin{columns}
    \column{0.45\textwidth}
        \begin{block}{site\_5.yml}
        \footnotesize{
            \inputminted[firstline=1, lastline=2]
                        {yaml}{sources/site_5.yml}
            \inputminted[firstline=3, lastline=3,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/site_5.yml}
            \inputminted[firstline=4, lastline=7]
                        {yaml}{sources/site_5.yml}
            \inputminted[firstline=8, lastline=8,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/site_5.yml}
            \inputminted[firstline=9]
                        {yaml}{sources/site_5.yml}
        }
        \end{block}
    \column{0.5\textwidth}
        \vbox to .7\textheight{
        \scriptsize{
            \inputminted[firstline=74, lastline=79,
                        breaklines,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/roles/graphite/tasks/main.yml}
            \vfill
            \textit{\tiny{
                shinken\_graphite/templates/graphite\_module.cfg.j2}}
            \inputminted[breaklines,
                        frame=single,
                        framesep=0pt]
                        {yaml}{sources/roles/shinken_graphite/templates/graphite_module.cfg.j2}
        }
        }
\end{columns}
\end{frame}

\section{Fun facts (short)}

\begin{frame}[fragile]
    \frametitle{Set var on another host}
    \begin{block}{Since ansible $\sim$ 1.9}
    \begin{minted}{yaml}
- name:
  add_host:
    name: "another.server"
    group: all
    foo: bar
    \end{minted}
    \end{block}
\end{frame}


\begin{frame}[fragile]
    \frametitle{Variable pointer}
    \begin{block}{Since ansible 2.0}
        \inputminted[firstline=1]{yaml}{sources/variable_name.yml}
    \end{block}
\end{frame}



\end{document}