Driver: Add page about Erlang

docs/connect/erlang/epgsql.md

@@ -0,0 +1,83 @@
+(erlang-epgsql)=
+
+# Erlang epgsql
+
+:::{div} sd-text-muted
+Connect to CrateDB from Erlang using epgsql.
+:::
+
+:::{rubric} About
+:::
+
+[epgsql] is the designated Erlang PostgreSQL client library. 
+
+:::{rubric} Synopsis
+:::
+
+`rebar.config`
+```erlang
+{deps,
+ [
+  {epgsql, ".*", {git, "https://github.com/epgsql/epgsql.git", {tag, "4.8.0"}}}
+ ]}.
+```
+`epgsql_example.erl`
+```erlang
+-module(epgsql_example).
+-export([start/0]).
+
+start() ->
+    {ok, C} = epgsql:connect(#{
+        host => "localhost",
+        username => "crate",
+        password => "crate",
+        database => "doc",
+        port => 5432,
+        timeout => 4000
+    }),
+    {ok, _, Result} = epgsql:squery(C, "SELECT mountain, height FROM sys.summits ORDER BY height DESC LIMIT 3"),
+    io:fwrite("~p~n", [Result]),
+    ok = epgsql:close(C),
+    init:stop().
+```
+
+:::{rubric} SSL connection
+:::
+
+Start the Erlang [SSL application] first,
+use the `ssl` and `ssl_opts` arguments on `epgsql:connect`, and
+replace username, password, and hostname with values matching
+your environment.
+
+Also use this variant to connect to CrateDB Cloud.
+```erlang
+start() ->
+    ssl:start(),
+    {ok, C} = epgsql:connect(#{
+        host => "testcluster.cratedb.net",
+        username => "admin",
+        password => "password",
+        database => "doc",
+        port => 5432,
+        ssl => true,
+        ssl_opts => [{verify, verify_none}],
+        timeout => 4000
+    }),
+```
+
+:::{rubric} Example
+:::
+
+Create the files `rebar.config` and `epgsql_example.erl` including the synopsis code shared above.
+
+:::{include} ../_cratedb.md
+:::
+```shell
+rebar3 compile
+erlc epgsql_example.erl
+rebar3 shell --eval 'epgsql_example:start().'
+```
+
+
+[epgsql]: https://github.com/epgsql/epgsql
+[SSL application]: https://www.erlang.org/docs/28/apps/ssl/ssl_app.html

docs/connect/erlang/index.md

@@ -0,0 +1,12 @@
+(connect-erlang)=
+
+# Erlang
+
+:::{div} sd-text-muted
+Connect to CrateDB from Erlang applications.
+:::
+
+:::{toctree}
+odbc
+epgsql
+:::

docs/connect/erlang/odbc.md

@@ -0,0 +1,72 @@
+(erlang-odbc)=
+
+# Erlang ODBC
+
+:::{div} sd-text-muted
+Connect to CrateDB from Erlang using ODBC.
+:::
+
+:::{rubric} About
+:::
+
+Erlang includes an [ODBC application] out of the box that provides an
+interface to communicate with relational SQL-databases, see also
+[Erlang ODBC examples].
+
+:::{rubric} Install
+:::
+
+:::{include} ../odbc/install.md
+:::
+
+:::{rubric} Synopsis
+:::
+
+Before running the example, ensure the PostgreSQL ODBC driver is
+installed on your system.
+
+`odbc_example.erl`
+```erlang
+-module(odbc_example).
+
+main(_) ->
+    odbc:start(),
+    {ok, Ref} = odbc:connect("Driver={PostgreSQL Unicode};Server=localhost;Port=5432;Uid=crate;Pwd=crate", []),
+    io:fwrite("~p~n", [odbc:sql_query(Ref, "SELECT mountain, height FROM sys.summits ORDER BY height DESC LIMIT 3")]),
+    init:stop().
+```
+
+:::{rubric} CrateDB Cloud
+:::
+
+For connecting to CrateDB Cloud, start the Erlang [SSL application],
+add `sslmode=require`, and replace `Server`, `Uid`, and `Pwd` with
+values matching your environment.
+
+`odbc_example.erl`
+```erlang
+-module(odbc_example).
+
+main(_) ->
+    ssl:start(),
+    odbc:start(),
+    {ok, Ref} = odbc:connect("Driver={PostgreSQL Unicode};Server=testcluster.cratedb.net;Port=5432;sslmode=require;Uid=admin;Pwd=password", []),
+    io:fwrite("~p~n", [odbc:sql_query(Ref, "SELECT mountain, height FROM sys.summits ORDER BY height DESC LIMIT 3")]),
+    init:stop().
+```
+
+:::{rubric} Example
+:::
+
+Create the file `odbc_example.erl` including the synopsis code shared above.
+
+:::{include} ../_cratedb.md
+:::
+```shell
+escript odbc_example.erl
+```
+
+
+[Erlang ODBC examples]: https://www.erlang.org/doc/apps/odbc/getting_started.html
+[ODBC application]: https://www.erlang.org/docs/28/apps/odbc/odbc.html
+[SSL application]: https://www.erlang.org/docs/28/apps/ssl/ssl_app.html

docs/connect/index.md

@@ -76,6 +76,16 @@ Any (ODBC)
 Elixir
 ::::
 
+::::{grid-item-card}
+:link: connect-erlang
+:link-type: ref
+:class-body: sd-fs-1 sd-text-center
+:class-footer: sd-fs-5 sd-font-weight-bold
+{fab}`erlang`
++++
+Erlang
+::::
+
 ::::{grid-item-card}
 :link: connect-go
 :link-type: ref
@@ -229,6 +239,7 @@ application
 :hidden:
 
 elixir/index
+erlang/index
 go/index
 java/index
 javascript