Logs

Cloud shows two kinds of log. A build log belongs to one deployment and records how it was built and released. A runtime log belongs to one running container and records what your application writes to its output. Both are read live from the platform when you open them: Cloud keeps no copy of its own.

Every deployment has its own page with a Build log. Pressing Deploy opens that page at once; later, open it from the Deployments page or from a service's Deployments section.

The log streams line by line while the deployment runs. Until the platform has started the build there is nothing to read, and the log says "The engine has not started this build yet."; while the deployment is still in progress the page asks again every second, so the first lines arrive without a reload.

A database has no build: the platform pulls its image and starts it. Its deployment's page shows the Database log instead, the database's own output, which starts once the database runs. Deployments explains the statuses and what a failed deployment's sentence means.

A build log has no line limit, time range or log type: it is the whole build. Search, copy, download and hold work on it as they do on a runtime log.

There are two places to read what a service writes:

• A service's Logs section streams the service's first running container. It is there while the service is Running or in Error; otherwise it reads "Nothing is running. Deploy the service and its log appears here."

• The Logs page in the rail reads any service of the organization the console is in. Pick one under Service. When the service has more than one container (replicas, or the containers of a compose stack), a row of container links appears, each with its state, and the log is titled "Log of" and the container's name.

Each line shows the time the platform recorded it, in your browser's time zone, with the date added for lines from an earlier day.

Two menus decide what the log opens on:

The log shows the latest lines inside the time range, up to the line limit, then follows new lines as they arrive. Changing either menu opens the log again from the platform, so the view empties and refills.

Thirty days is as far back as a runtime log reaches, and a log starts where its container started. A deploy starts new containers, so after a deploy the log you open is the new container's.

The search field (Search the log) and the Log type menu narrow the lines already in the view. Neither is sent to the platform, so a search never reaches further back than the line limit and time range. The count beside the status reads, for example, "40 of 300 lines", and a search that matches nothing reads "No line matches."

Log type offers All types, Error, Warning, Success, Info and Debug. Cloud reads a line's type in this order:

1. A level the line declares: a level, severity or log.level field in a JSON line (including the numeric levels of loggers such as pino), or level= in a logfmt line.

2. An HTTP status in the line: 5xx is an error, 4xx a warning, 2xx a success.

3. Its words: error, fatal, failed or an exception mark an error; warn, deprecated or retrying a warning; done, ready or listening a success; debug:, trace or verbose a debug line.

Anything else is Info. A line that says a fault is absent, such as errors=0 or error: none, is not read as an error. If your application writes structured logs with a level field, the type is always the one it declared.

• Hold the log still (the pause button) stops the view from moving so you can read a line. Lines that arrive meanwhile are kept, the status reads "Held" with how many are waiting, and Let the log move adds them in order.

• The view follows the newest line until you scroll up, and follows again once you scroll back to the end.

• Copy and Download take the lines the view shows, after any search or log type, each with its timestamp. Download saves them as a .log text file.

• The view keeps the latest 5000 lines. Past that, the status reads "last 5000" and the oldest lines drop off the top.

There is no log forwarding to another service. Download is how a log leaves Cloud.

A log is a live connection. Its status chip reads Connecting, Live or Closed, and a closed log shows why beside the chip, with Reconnect to open it again:

Logs and terminal closed goes through each of these in more depth, and Limits lists every ceiling in one place.