{"result":{"depiction_url":null,"edges":{"references":{"objects":[{"created":"2020-05-30T05:48:14Z","object_id":{"id":1454,"is_a":["text","documentation","reference"],"name":"doc_developerguide_configuration_zotonic_configuration","title":"Global configuration","uri":"https:\/\/zotonic.com\/id\/1454"},"seq":1000000}],"predicate":{"id":332,"is_a":["meta","predicate"],"name":"references","title":{"_type":"trans","tr":{"en":"References"}},"uri":"https:\/\/zotonic.com\/id\/references"}},"relation":{"objects":[{"created":"2020-05-30T05:48:14Z","object_id":{"id":1580,"is_a":["text","documentation","cookbook"],"name":"doc_cookbook_logstash","title":"Logging to Logstash","uri":"https:\/\/zotonic.com\/id\/1580"},"seq":1000000},{"created":"2020-05-30T05:48:14Z","object_id":{"id":1858,"is_a":["text","documentation","reference","module"],"name":"doc_module_mod_logging","title":"mod_logging","uri":"https:\/\/zotonic.com\/id\/1858"},"seq":1000000}],"predicate":{"id":303,"is_a":["meta","predicate"],"name":"relation","title":{"_type":"trans","tr":{"nl":"Relatie","en":"Relation"}},"uri":"http:\/\/purl.org\/dc\/terms\/relation"}}},"id":1640,"is_a":["text","documentation","developerguide"],"links":[{"rel":"self","target":"https:\/\/zotonic.com\/.zotonic\/websub\/topic\/1640"},{"rel":"hub","target":"https:\/\/zotonic.com\/.zotonic\/websub"}],"medium":null,"medium_url":null,"name":"doc_developerguide_logging","page_url":{"en":"https:\/\/zotonic.com\/docs\/1640\/logging","x-default":"https:\/\/zotonic.com\/docs\/1640\/logging"},"preview_url":null,"resource":{"body":"<div>\n            \n  <div class=\"section\">\n\n<aside class=\"admonition seealso\">\n<p class=\"first admonition-title\">See also<\/p>\n<p class=\"last\"><a class=\"reference internal\" href=\"\/id\/doc_cookbook_logstash#cookbook-logstash\"><span class=\"std std-ref\">Logging to Logstash<\/span><\/a> cookbook<\/p>\n<\/aside>\n<aside class=\"admonition seealso\">\n<p class=\"first admonition-title\">See also<\/p>\n<p class=\"last\">To log messages to the database, you can use <a class=\"reference internal\" href=\"\/id\/doc_module_mod_logging\"><span class=\"std std-ref\">mod_logging<\/span><\/a>.<\/p>\n<\/aside>\n<p>Zotonic uses <a class=\"reference external\" href=\"https:\/\/www.erlang.org\/doc\/man\/logger.html\">Logger<\/a> for logging. Logger metadata is automatically set by\nZotonic in the controller functions.<\/p>\n<p>To log a message from your code, simply call Logger directly:<\/p>\n<div class=\"highlight-erlang notranslate\"><div class=\"highlight\"><pre><span><\/span><span class=\"p\">-<\/span><span class=\"ni\">include_lib<\/span><span class=\"p\">(<\/span><span class=\"s\">&quot;kernel\/include\/logger.hrl&quot;<\/span><span class=\"p\">).<\/span>\n\n<span class=\"o\">?<\/span><span class=\"nv\">LOG_ERROR<\/span><span class=\"p\">(<\/span><span class=\"s\">&quot;Something went very wrong with <\/span><span class=\"si\">~p<\/span><span class=\"s\">&quot;<\/span><span class=\"p\">,<\/span> <span class=\"p\">[<\/span><span class=\"nv\">SomeParam<\/span><span class=\"p\">]).<\/span>\n<\/pre><\/div>\n<\/div>\n<p>which will write the following in the <code class=\"file docutils literal notranslate\"><span class=\"pre\">error.log<\/span><\/code> file:<\/p>\n<div class=\"highlight-none notranslate\"><div class=\"highlight\"><pre><span><\/span>2022-01-28 17:17:45 ERROR &lt;0.9.0&gt; [some_module:some_function\/0:42] ▸ text=&quot;Something went very wrong with whatever&quot;\n<\/pre><\/div>\n<\/div>\n<div class=\"section\">\n<h2>Configuration<\/h2>\n<p>In <a class=\"reference internal\" href=\"\/id\/doc_developerguide_configuration_zotonic_configuration#erlang-config\"><span class=\"std std-ref\">The erlang.config file<\/span><\/a> file, change the <code class=\"docutils literal notranslate\"><span class=\"pre\">kernel<\/span><\/code> section to configure log\nhandlers and formatters. See the <a class=\"reference external\" href=\"https:\/\/www.erlang.org\/doc\/apps\/kernel\/logger_chapter.html\">Logger documentation<\/a> for more information.<\/p>\n<p>For instance, to configure Logger for logging to Logstash, uncomment the <code class=\"docutils literal notranslate\"><span class=\"pre\">logstash<\/span><\/code>\nhandler in the logger configuration of your <code class=\"docutils literal notranslate\"><span class=\"pre\">erlang.config<\/span><\/code> file and check the\n<code class=\"docutils literal notranslate\"><span class=\"pre\">logstasher<\/span><\/code> configuration:<\/p>\n<div class=\"literal-block-wrapper docutils container\">\n<div class=\"code-block-caption\"><span class=\"caption-text\">erlang.config<\/span><\/div>\n<div class=\"highlight-erlang notranslate\"><div class=\"highlight\"><pre><span><\/span><span class=\"p\">{<\/span><span class=\"n\">kernel<\/span><span class=\"p\">,<\/span> <span class=\"p\">[<\/span>\n    <span class=\"c\">% Minimum log level for all loggers below.<\/span>\n    <span class=\"p\">{<\/span><span class=\"n\">logger_level<\/span><span class=\"p\">,<\/span> <span class=\"n\">info<\/span><span class=\"p\">},<\/span>\n\n    <span class=\"p\">{<\/span><span class=\"n\">logger<\/span><span class=\"p\">,<\/span> <span class=\"p\">[<\/span>\n\n        <span class=\"c\">%% To use logstash:<\/span>\n        <span class=\"c\">%% - Enable the logstasher_h handler<\/span>\n        <span class=\"c\">%% - Configure logstasher (see below the kernel config)<\/span>\n        <span class=\"c\">%%<\/span>\n        <span class=\"c\">% {handler, logstash, logstasher_h,<\/span>\n        <span class=\"c\">%     #{<\/span>\n        <span class=\"c\">%         level =&gt; info<\/span>\n        <span class=\"c\">%     }<\/span>\n        <span class=\"c\">% },<\/span>\n\n        <span class=\"c\">% Log of all information to the terminal\/console.<\/span>\n        <span class=\"c\">% The &#39;logger_level&#39; above defines what is shown on the console.<\/span>\n        <span class=\"p\">{<\/span><span class=\"n\">handler<\/span><span class=\"p\">,<\/span> <span class=\"n\">default<\/span><span class=\"p\">,<\/span> <span class=\"n\">z_logger_h<\/span><span class=\"p\">,<\/span>\n            <span class=\"p\">#{<\/span>\n                <span class=\"n\">level<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">debug<\/span><span class=\"p\">,<\/span>\n                <span class=\"n\">formatter<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"p\">{<\/span><span class=\"n\">z_logger_formatter<\/span><span class=\"p\">,<\/span>\n                    <span class=\"p\">#{<\/span>\n                        <span class=\"n\">prettify<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">true<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">colored<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">true<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">time_designator<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"sc\">$\\s<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">time_offset<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"s\">&quot;&quot;<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">time_unit<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">second<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">strip_tz<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">true<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">level_capitalize<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">true<\/span>\n                    <span class=\"p\">}<\/span>\n                <span class=\"p\">}<\/span>\n            <span class=\"p\">}<\/span>\n        <span class=\"p\">},<\/span>\n\n        <span class=\"c\">% Error log on disk.<\/span>\n        <span class=\"c\">% LOG_DIR is replaced with the default Zotonic ZOTONIC_LOG_DIR directory.<\/span>\n        <span class=\"p\">{<\/span><span class=\"n\">handler<\/span><span class=\"p\">,<\/span> <span class=\"n\">error_log<\/span><span class=\"p\">,<\/span> <span class=\"n\">z_logger_h<\/span><span class=\"p\">,<\/span>\n            <span class=\"p\">#{<\/span>\n                <span class=\"n\">level<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">error<\/span><span class=\"p\">,<\/span>\n                <span class=\"n\">config<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"p\">#{<\/span>\n                    <span class=\"n\">type<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">file<\/span><span class=\"p\">,<\/span>\n                    <span class=\"n\">file<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"s\">&quot;LOG_DIR\/error.log&quot;<\/span><span class=\"p\">,<\/span>\n                    <span class=\"n\">max_no_files<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"mi\">10<\/span><span class=\"p\">,<\/span>\n                    <span class=\"n\">max_no_bytes<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"mi\">52428800<\/span> <span class=\"c\">% 10 x 5mb<\/span>\n                <span class=\"p\">},<\/span>\n                <span class=\"n\">formatter<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"p\">{<\/span><span class=\"n\">z_logger_formatter<\/span><span class=\"p\">,<\/span>\n                    <span class=\"p\">#{<\/span>\n                        <span class=\"n\">prettify<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">true<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">colored<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">false<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">time_designator<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"sc\">$\\s<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">time_offset<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"s\">&quot;&quot;<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">time_unit<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">second<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">strip_tz<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">true<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">level_capitalize<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">true<\/span>\n                    <span class=\"p\">}<\/span>\n                <span class=\"p\">}<\/span>\n            <span class=\"p\">}<\/span>\n        <span class=\"p\">},<\/span>\n\n        <span class=\"c\">% Console log on disk.<\/span>\n        <span class=\"c\">% LOG_DIR is replaced with the default Zotonic ZOTONIC_LOG_DIR directory.<\/span>\n        <span class=\"p\">{<\/span><span class=\"n\">handler<\/span><span class=\"p\">,<\/span> <span class=\"n\">console_log<\/span><span class=\"p\">,<\/span> <span class=\"n\">z_logger_h<\/span><span class=\"p\">,<\/span>\n            <span class=\"p\">#{<\/span>\n                <span class=\"n\">level<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">debug<\/span><span class=\"p\">,<\/span>\n                <span class=\"n\">config<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"p\">#{<\/span>\n                    <span class=\"n\">type<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">file<\/span><span class=\"p\">,<\/span>\n                    <span class=\"n\">file<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"s\">&quot;LOG_DIR\/console.log&quot;<\/span><span class=\"p\">,<\/span>\n                    <span class=\"n\">max_no_files<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"mi\">10<\/span><span class=\"p\">,<\/span>\n                    <span class=\"n\">max_no_bytes<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"mi\">52428800<\/span> <span class=\"c\">% 10 x 5mb<\/span>\n                <span class=\"p\">},<\/span>\n                <span class=\"n\">formatter<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"p\">{<\/span><span class=\"n\">z_logger_formatter<\/span><span class=\"p\">,<\/span>\n                    <span class=\"p\">#{<\/span>\n                        <span class=\"n\">prettify<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">true<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">colored<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">false<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">time_designator<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"sc\">$\\s<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">time_offset<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"s\">&quot;&quot;<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">time_unit<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">second<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">strip_tz<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">true<\/span><span class=\"p\">,<\/span>\n                        <span class=\"n\">level_capitalize<\/span> <span class=\"o\">=&gt;<\/span> <span class=\"n\">true<\/span>\n                    <span class=\"p\">}<\/span>\n                <span class=\"p\">}<\/span>\n            <span class=\"p\">}<\/span>\n        <span class=\"p\">}<\/span>\n    <span class=\"p\">]}<\/span>\n<span class=\"p\">]},<\/span>\n\n<span class=\"c\">%% Logstash configuration.<\/span>\n<span class=\"c\">%% If a logger handler with &#39;logstasher_h&#39; is defined then zotonic_core will start the<\/span>\n<span class=\"c\">%% logstasher application.<\/span>\n<span class=\"p\">{<\/span><span class=\"n\">logstasher<\/span><span class=\"p\">,<\/span> <span class=\"p\">[<\/span>\n    <span class=\"p\">{<\/span><span class=\"n\">transport<\/span><span class=\"p\">,<\/span> <span class=\"n\">console<\/span><span class=\"p\">},<\/span> <span class=\"c\">% tcp | udp | console<\/span>\n    <span class=\"p\">{<\/span><span class=\"n\">host<\/span><span class=\"p\">,<\/span> <span class=\"s\">&quot;localhost&quot;<\/span><span class=\"p\">},<\/span>  <span class=\"c\">% inet:hostname()<\/span>\n    <span class=\"p\">{<\/span><span class=\"n\">port<\/span><span class=\"p\">,<\/span> <span class=\"mi\">5000<\/span><span class=\"p\">}<\/span>          <span class=\"c\">% inet:port_number()<\/span>\n<span class=\"p\">]},<\/span>\n<\/pre><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n           <\/div>","category_id":{"id":317,"is_a":["meta","category"],"name":"developerguide","title":"Developer guide","uri":"https:\/\/zotonic.com\/id\/developerguide"},"content_group_id":{"id":339,"is_a":["meta","content_group"],"name":"default_content_group","title":{"_type":"trans","tr":{"en":"Default Content Group"}},"uri":"https:\/\/zotonic.com\/id\/default_content_group"},"created":"2020-05-30T05:47:29Z","creator_id":{"id":336,"is_a":["person","robot"],"name":"gitbot","title":"Git","uri":"https:\/\/zotonic.com\/id\/336"},"github_url":"https:\/\/github.com\/zotonic\/zotonic\/tree\/master\/doc\/developer-guide\/logging.rst","is_authoritative":true,"is_dependent":false,"is_featured":false,"is_protected":false,"is_published":true,"is_unfindable":false,"language":["en"],"modified":"2022-02-15T10:01:21Z","modifier_id":{"id":336,"is_a":["person","robot"],"name":"gitbot","title":"Git","uri":"https:\/\/zotonic.com\/id\/336"},"name":"doc_developerguide_logging","pivot_geocode":null,"pivot_location_lat":null,"pivot_location_lng":null,"privacy":0,"publication_end":"9999-06-01T00:00:00Z","publication_start":"2022-02-15T10:01:21Z","slug":"logging","title":"Logging","title_slug":"logging","tz":"UTC","uri":null,"version":18,"visible_for":0},"uri":"https:\/\/zotonic.com\/id\/1640","uri_template":"https:\/\/zotonic.com\/id\/:id","websub":{"hub":"https:\/\/zotonic.com\/.zotonic\/websub","topic":"https:\/\/zotonic.com\/.zotonic\/websub\/topic\/1640"}},"status":"ok"}