<div dir="ltr"><div><div><br></div><blockquote class="gmail_quote" style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline"> - under_build/<profile>/rel/<rel</span><wbr style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">ease>/bin/<release> console it fails (returns undefined), so the app crashes on start, regardless of whether <profile> is prod or default</span></blockquote><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial;background-color:rgb(255,255,255);float:none;display:inline">it may or may not be crashing due the mnesia configuration .</span><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">you may have to check the the erl_crash.dump to see the cause of the crash . </div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">How do I set mnesia application environment variables in the release project? (Or, maybe, how do I get the OTP application to be able to access the release project's application environment variables?)</span></blockquote><div> </div><div>in the relx section of your rebar.config you can set a sys_config to be used</div><div><div>{relx, </div><div><span style="white-space:pre"> </span>[</div><div><span style="white-space:pre"> </span>{sys_config,"config/sys.config"}</div></div><div> ]</div><div> </div>in that sys.config you can setup environmental variables to be used by your applications including an entry for mnesia.</div><div style="text-align:start;text-indent:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><div>[</div><div><span style="white-space:pre"> </span>{mnesia, </div><div><span style="white-space:pre"> </span>[{dir,"/tmp/my_db_dir"}]</div><div><span style="white-space:pre"> </span>},</div><div><span style="white-space:pre"> </span>{app1,[{a,1},{b,2}],</div><div><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;white-space:pre"> </span><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">{app2,[{a,3},{b,4}]</span><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;white-space:pre"> </span><br></div><div><span style="white-space:pre"> </span>}</div><div>]</div></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">this will be used by your release system when the release is created .</div><div style="text-align:start;text-indent:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">check out <a href="http://www.rebar3.org/docs/releases">http://www.rebar3.org/docs/releases</a> .<br></div><div style="text-align:start;text-indent:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="text-align:start;text-indent:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br></div></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br></div><div> </div><div class="gmail_extra"><div class="gmail_quote">On Sat, Apr 14, 2018 at 3:17 PM, Igor Clark <span dir="ltr"><<a href="mailto:igor.clark@gmail.com" target="_blank">igor.clark@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi list,<br>
<br>
I have an OTP application which uses mnesia. It checks/ensures the schema and table files exist and then calls application:ensure_started( mnesia ) in its application:start/2 callback. It works fine when I run the application on its own under rebar3 shell, but it doesn't work when I try to run it from an OTP release:<br>
<br>
- When I run the OTP app under rebar3 shell in its own separate directory, with { mnesia, [ { dir, "/tmp/my_db_dir" } ] } in priv/sys.config, it works fine and application:get_env( mnesia, dir ) returns /tmp/my_db_dir as normal/expected<br>
<br>
- If I set { mnesia, [ { dir, "/tmp/my_db_dir" } ] } in <release>/config/sys.config, then:<br>
<br>
- under rebar3 shell --name=myapp@mynode, calling application:get_env( mnesia, dir ) succeeds (returns /tmp/my_db_dir) , and the app uses reads/writes mnesia tables successfully<br>
<br>
- under_build/<profile>/rel/<rel<wbr>ease>/bin/<release> console it fails (returns undefined), so the app crashes on start, regardless of whether <profile> is prod or default<br>
<br>
How do I set mnesia application environment variables in the release project? (Or, maybe, how do I get the OTP application to be able to access the release project's application environment variables?)<br>
<br>
Also, I realise I could be going about this the wrong way - maybe mnesia should be configured inside the specific OTP app, even under a release? Apart from the fact that that doesn't seem to work (as I have it set up, anyway), I'm aware I should steer clear of "included applications" - not least because I want to be able to use the OTP app in other projects - so I guess there's a broader question of how to configure mnesia in general, in how & when to create schema and tables, if it could be used by multiple OTP apps in a release?<br>
<br>
Bit puzzled, appreciate any advice!<br>
<br>
Cheers,<br>
Igor<br>
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