keepalived issue with iptables

When talking about High Availability services, we can use keepalived to do a automatic failover between 2 host.

Keepalived is working like a charm by using a virtual ip. 1 Master elected for normal operation, and others as backup.
When master have issue, backup will take over the services.

Issue arise with configuration, where there is iptables entry to drop any vrrp traffic type. This was issue with the configuration.

To mitigate this, look for the config of keepalived.conf . change entry from :

vrrp_strict 

to become :

vrrp_accept

This entry will make keepalived will not use iptables.

Keepalived version we use was V1.3.5

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Environment variable with ChicagoBoss

On Chicagoboss I need to have some configuration variable set in the main configuration. Just like my experience with Django framework on settings.py

In Chicagoboss, we can do it also and add our on config variable in the configuration file, which are boss.config.

These below are the part of the config we can custom :

%% APPLICATION CONFIGURATIONS

%% domains - A list of domains to serve the application on
%% static_prefix - The URL prefix of static assets
%% doc_prefix - The URL prefix for developer documentation
{ myapp, [
    {path, "../myapp"},
    {base_url, "/"},

    {dummy, true}
]}

So we can add the variable for our application with below settings :

%% APPLICATION CONFIGURATIONS

%% domains - A list of domains to serve the application on
%% static_prefix - The URL prefix of static assets
%% doc_prefix - The URL prefix for developer documentation
{ myapp, [
    {path, "../myapp"},
    {base_url, "/"},

    {dummy, true}.
    {mail_from, "justme@mydomain.com"},
    {api_key, "324298nvUYSCN298snk92442ps"}

]}

Now how we can use it on the application. We can use :

application:get_env(myapp, api_key).

If we want to print out on console :

io:fwrite("~p", [application:get_env(myapp, api_key)]).

And if we want to assign the variable to our local variable in the app we can use :

{ok, apikey} = application:get_env(myapp, api_key).

With this we can add as many as variable we need on the config.

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