From b158f482eff27867cf0d694dd2a5f74bca265877 Mon Sep 17 00:00:00 2001 From: Jose Diaz-Gonzalez Date: Wed, 30 Sep 2026 17:47:27 -0400 Subject: [PATCH] fix: reset MAILTO after a cron entry that sets its own A task with its own `MAILTO` is now written in place, followed by a line resetting `MAILTO` to the global value, or to the `dokku` user when none is set, rather than grouped at the end of the crontab, so no other task is mailed to its recipient whatever order the tasks are written in. --- docs/development/plugin-triggers.md | 2 +- docs/processes/scheduled-cron-tasks.md | 2 +- plugins/cron/crontab.go | 56 ++++++----------- plugins/cron/crontab_test.go | 85 +++++++++++++++++--------- plugins/cron/templates/cron.tmpl | 10 +-- tests/unit/cron-3.bats | 7 +++ 6 files changed, 89 insertions(+), 73 deletions(-) diff --git a/docs/development/plugin-triggers.md b/docs/development/plugin-triggers.md index d18833250..d101177e5 100644 --- a/docs/development/plugin-triggers.md +++ b/docs/development/plugin-triggers.md @@ -689,7 +689,7 @@ APP="$1"; PROPERTY="$2" - Description: Allows injecting cron tasks into the written out scheduled cron task list. Each entry is newline delimited, and individual tasks come in the form `$SCHEDULE;$FULL_COMMAND;$ARBITRARY_DATA`. Individual implementations of cron writing can decide whether and how to include these cron tasks. The `ARBITRARY_DATA` includes the log file path for the basic `docker-local` cron implementation. - When `$CRON_ENTRY_FORMAT` is `json`, each entry may instead be printed as a json object on its own line, with the keys `schedule`, `command`, `log-file` and `mailto`. Only `schedule` and `command` are required. A task with a `mailto` value is written to the crontab under a `MAILTO` of its own rather than the global `MAILTO`, and its output is mailed to that address in addition to being appended to its `log-file`. Json entries and `;` delimited entries may be printed together. Older versions of Dokku do not pass `$CRON_ENTRY_FORMAT`, and fail to write the crontab if a json entry is printed, so a json entry should only be printed when the argument is `json`. + When `$CRON_ENTRY_FORMAT` is `json`, each entry may instead be printed as a json object on its own line, with the keys `schedule`, `command`, `log-file` and `mailto`. Only `schedule` and `command` are required. A task with a `mailto` value is written to the crontab after a `MAILTO` line of its own and followed by one resetting `MAILTO` to the global value, or to the `dokku` user when no global value is set, so the value only applies to that task. Its output is mailed to that address in addition to being appended to its `log-file`. Json entries and `;` delimited entries may be printed together. Older versions of Dokku do not pass `$CRON_ENTRY_FORMAT`, and fail to write the crontab if a json entry is printed, so a json entry should only be printed when the argument is `json`. - Invoked by: `dokku cron:list --global`, and when the `dokku` user crontab is written - Arguments: `$DOKKU_SCHEDULER $CRON_ENTRY_FORMAT` - Example: diff --git a/docs/processes/scheduled-cron-tasks.md b/docs/processes/scheduled-cron-tasks.md index 977d8dada..86ab44d2d 100644 --- a/docs/processes/scheduled-cron-tasks.md +++ b/docs/processes/scheduled-cron-tasks.md @@ -56,7 +56,7 @@ When running scheduled cron tasks, there are a few items to be aware of: - At this time, only the `PATH` and `SHELL` environment variables are specified in the cron template. - A `MAILTO` value can be set via the `cron:set` command. - A `MAILFROM` value can be set via the `cron:set` command. - - Tasks injected by plugins via the [`cron-entries` trigger](/docs/development/plugin-triggers.md#cron-entries) may set a `MAILTO` value of their own, which is used for that task instead of the global value. The output of such a task is mailed to that address as well as appended to the task's log file. + - Tasks injected by plugins via the [`cron-entries` trigger](/docs/development/plugin-triggers.md#cron-entries) may set a `MAILTO` value of their own, which is used for that task instead of the global value. `MAILTO` is reset after the task to the global value, or to the `dokku` user when no global value is set, so no other task is mailed to that address. The output of such a task is mailed to that address as well as appended to the task's log file. - Each scheduled task is executed within a one-off `run` container, and thus inherit any docker-options specified for `run` containers. Resources are never shared between scheduled tasks. - Scheduled cron tasks are supported on a per-scheduler basis. Schedulers that use the host crontab - such as `docker-local` - have their `app.json` cron tasks written to the `dokku` user crontab, while schedulers that manage their own cron backend - such as `k3s` - schedule them natively. - Tasks for _all_ apps managed by a host-crontab scheduler such as `docker-local` are written to a single crontab file owned by the `dokku` user. The `dokku` user's crontab should be considered reserved for this purpose. diff --git a/plugins/cron/crontab.go b/plugins/cron/crontab.go index 42cd1c0b2..6d03e4b14 100644 --- a/plugins/cron/crontab.go +++ b/plugins/cron/crontab.go @@ -4,9 +4,7 @@ import ( _ "embed" "encoding/json" "fmt" - "maps" "os" - "slices" "strings" "text/template" @@ -19,6 +17,9 @@ import ( //go:embed templates/cron.tmpl var cronTemplate string +// crontabUser is the user whose crontab the host-cron tasks are written to +const crontabUser = "dokku" + // usesHostCron reports whether the given scheduler writes its cron tasks to the // host crontab (as opposed to managing its own cron backend). An empty scheduler // or an unimplemented scheduler-uses-host-cron trigger is treated as false. @@ -281,7 +282,7 @@ func writeCronTab() error { result, err := common.CallExecCommand(common.ExecCommandInput{ Command: "crontab", - Args: []string{"-u", "dokku", tmpFile.Name()}, + Args: []string{"-u", crontabUser, tmpFile.Name()}, }) if err != nil { return fmt.Errorf("Unable to update schedule file: %w", err) @@ -295,43 +296,22 @@ func writeCronTab() error { return nil } -// cronMailtoGroup is the set of tasks written to the crontab under a MAILTO of -// their own -type cronMailtoGroup struct { - // Mailto is the MAILTO value the tasks are written under - Mailto string - - // Tasks are the tasks written under the MAILTO value - Tasks []CronTask -} - -// cronTemplateData builds the data the cron template is executed with. Tasks -// that set their own MAILTO are grouped by it and written after every other -// task, so the global MAILTO applies to all of the tasks before them. +// cronTemplateData builds the data the cron template is executed with. A task +// that sets its own MAILTO is written between a MAILTO line of its own and one +// resetting it, so every task after it goes back to the global MAILTO. Without +// a global MAILTO it is reset to the crontab's owner, which is who cron mails +// when MAILTO is unset - an empty MAILTO would stop cron mailing anyone. func cronTemplateData(tasks []CronTask, mailfrom string, mailto string) map[string]interface{} { - globalTasks := []CronTask{} - groups := map[string][]CronTask{} - for _, task := range tasks { - if task.Mailto == "" { - globalTasks = append(globalTasks, task) - continue - } - groups[task.Mailto] = append(groups[task.Mailto], task) - } - - mailtoGroups := []cronMailtoGroup{} - for _, groupMailto := range slices.Sorted(maps.Keys(groups)) { - mailtoGroups = append(mailtoGroups, cronMailtoGroup{ - Mailto: groupMailto, - Tasks: groups[groupMailto], - }) + resetMailto := mailto + if resetMailto == "" { + resetMailto = crontabUser } return map[string]interface{}{ - "Tasks": globalTasks, - "MailtoGroups": mailtoGroups, - "Mailfrom": mailfrom, - "Mailto": mailto, + "Tasks": tasks, + "Mailfrom": mailfrom, + "Mailto": mailto, + "ResetMailto": resetMailto, } } @@ -339,7 +319,7 @@ func cronTemplateData(tasks []CronTask, mailfrom string, mailto string) map[stri func deleteCrontab() error { result, err := common.CallExecCommand(common.ExecCommandInput{ Command: "crontab", - Args: []string{"-l", "-u", "dokku"}, + Args: []string{"-l", "-u", crontabUser}, }) if err != nil || result.ExitCode != 0 { return nil @@ -347,7 +327,7 @@ func deleteCrontab() error { result, err = common.CallExecCommand(common.ExecCommandInput{ Command: "crontab", - Args: []string{"-r", "-u", "dokku"}, + Args: []string{"-r", "-u", crontabUser}, }) if err != nil { return fmt.Errorf("Unable to remove schedule file: %w", err) diff --git a/plugins/cron/crontab_test.go b/plugins/cron/crontab_test.go index ec02286a2..8949ec39c 100644 --- a/plugins/cron/crontab_test.go +++ b/plugins/cron/crontab_test.go @@ -153,16 +153,10 @@ func TestParseInjectedCronEntriesKeepsTextIDs(t *testing.T) { } } -// TestCronTemplateGroupsTasksByMailto pins that tasks with their own MAILTO are -// written after every task that uses the global MAILTO, grouped under a MAILTO -// line per recipient. -func TestCronTemplateGroupsTasksByMailto(t *testing.T) { - tasks := []CronTask{ - {Schedule: "@daily", AltCommand: "/bin/zeta", LogFile: "/var/log/dokku/zeta.log", Mailto: "zeta@example.com"}, - {Schedule: "@daily", AltCommand: "/bin/true", LogFile: "/var/log/dokku/log.log"}, - {Schedule: "@hourly", AltCommand: "/bin/alpha", LogFile: "/var/log/dokku/alpha.log", Mailto: "alpha@example.com"}, - {Schedule: "@weekly", AltCommand: "/bin/zeta-weekly", Mailto: "zeta@example.com"}, - } +// renderCronTemplate renders the cron template for the given tasks and global +// MAILTO +func renderCronTemplate(t *testing.T, tasks []CronTask, mailto string) string { + t.Helper() tmpl, err := getCronTemplate() if err != nil { @@ -170,46 +164,81 @@ func TestCronTemplateGroupsTasksByMailto(t *testing.T) { } var got bytes.Buffer - if err := tmpl.Execute(&got, cronTemplateData(tasks, "", "global@example.com")); err != nil { + if err := tmpl.Execute(&got, cronTemplateData(tasks, "", mailto)); err != nil { t.Fatalf("Execute() returned an error: %v", err) } + return got.String() +} + +// TestCronTemplateResetsMailtoAfterATaskWithItsOwn pins that a task with its own +// MAILTO is written in place between a MAILTO line of its own and one resetting +// it to the global MAILTO, so no task after it is mailed to its recipient. +func TestCronTemplateResetsMailtoAfterATaskWithItsOwn(t *testing.T) { + tasks := []CronTask{ + {Schedule: "@daily", AltCommand: "/bin/true", LogFile: "/var/log/dokku/log.log"}, + {Schedule: "@hourly", AltCommand: "/bin/alpha", LogFile: "/var/log/dokku/alpha.log", Mailto: "alpha@example.com"}, + {Schedule: "@daily", AltCommand: "/bin/false"}, + {Schedule: "@daily", AltCommand: "/bin/zeta", LogFile: "/var/log/dokku/zeta.log", Mailto: "zeta@example.com"}, + {Schedule: "@weekly", AltCommand: "/bin/zeta-weekly", Mailto: "zeta@example.com"}, + } + want := strings.Join([]string{ "MAILTO=global@example.com", "PATH=/usr/local/bin:/usr/bin:/bin", "SHELL=/bin/bash", "", "@daily /bin/true &>> /var/log/dokku/log.log", - "", "MAILTO=alpha@example.com", "@hourly /bin/alpha 2>&1 | tee -a /var/log/dokku/alpha.log", - "", + "MAILTO=global@example.com", + "@daily /bin/false", "MAILTO=zeta@example.com", "@daily /bin/zeta 2>&1 | tee -a /var/log/dokku/zeta.log", + "MAILTO=global@example.com", + "MAILTO=zeta@example.com", "@weekly /bin/zeta-weekly", + "MAILTO=global@example.com", "", }, "\n") - if got.String() != want { - t.Errorf("rendered crontab =\n%s\nwant\n%s", got.String(), want) + if got := renderCronTemplate(t, tasks, "global@example.com"); got != want { + t.Errorf("rendered crontab =\n%s\nwant\n%s", got, want) } } -// TestCronTemplateWithoutMailtoGroups pins that a crontab without tasks that set +// TestCronTemplateResetsMailtoToTheCrontabOwner pins that without a global +// MAILTO, a task with its own is followed by a MAILTO naming the crontab's +// owner, who cron mails when MAILTO is unset. An empty MAILTO would stop cron +// mailing anyone about the tasks after it. +func TestCronTemplateResetsMailtoToTheCrontabOwner(t *testing.T) { + tasks := []CronTask{ + {Schedule: "@hourly", AltCommand: "/bin/alpha", LogFile: "/var/log/dokku/alpha.log", Mailto: "alpha@example.com"}, + {Schedule: "@daily", AltCommand: "/bin/true", LogFile: "/var/log/dokku/log.log"}, + } + + want := strings.Join([]string{ + "PATH=/usr/local/bin:/usr/bin:/bin", + "SHELL=/bin/bash", + "", + "MAILTO=alpha@example.com", + "@hourly /bin/alpha 2>&1 | tee -a /var/log/dokku/alpha.log", + "MAILTO=dokku", + "@daily /bin/true &>> /var/log/dokku/log.log", + "", + }, "\n") + if got := renderCronTemplate(t, tasks, ""); got != want { + t.Errorf("rendered crontab =\n%s\nwant\n%s", got, want) + } +} + +// TestCronTemplateWithoutTaskMailto pins that a crontab without tasks that set // their own MAILTO renders as it did before per-task MAILTO values existed. -func TestCronTemplateWithoutMailtoGroups(t *testing.T) { +func TestCronTemplateWithoutTaskMailto(t *testing.T) { tasks := []CronTask{ {Schedule: "@daily", AltCommand: "/bin/true", LogFile: "/var/log/dokku/log.log"}, } - tmpl, err := getCronTemplate() - if err != nil { - t.Fatalf("getCronTemplate() returned an error: %v", err) - } - - var got bytes.Buffer - if err := tmpl.Execute(&got, cronTemplateData(tasks, "", "")); err != nil { - t.Fatalf("Execute() returned an error: %v", err) - } + got := renderCronTemplate(t, tasks, "") want := strings.Join([]string{ "PATH=/usr/local/bin:/usr/bin:/bin", @@ -218,7 +247,7 @@ func TestCronTemplateWithoutMailtoGroups(t *testing.T) { "@daily /bin/true &>> /var/log/dokku/log.log", "", }, "\n") - if got.String() != want { - t.Errorf("rendered crontab =\n%s\nwant\n%s", got.String(), want) + if got != want { + t.Errorf("rendered crontab =\n%s\nwant\n%s", got, want) } } diff --git a/plugins/cron/templates/cron.tmpl b/plugins/cron/templates/cron.tmpl index 8e6114fc3..34648f3e6 100644 --- a/plugins/cron/templates/cron.tmpl +++ b/plugins/cron/templates/cron.tmpl @@ -8,11 +8,11 @@ PATH=/usr/local/bin:/usr/bin:/bin SHELL=/bin/bash {{ range $task := .Tasks -}} +{{ if $task.Mailto -}} +MAILTO={{ $task.Mailto }} +{{ end -}} {{ $task.Schedule }} {{ $task.DokkuRunCommand }} -{{ end -}} -{{ range $group := .MailtoGroups }} -MAILTO={{ $group.Mailto }} -{{ range $task := $group.Tasks -}} -{{ $task.Schedule }} {{ $task.DokkuRunCommand }} +{{ if $task.Mailto -}} +MAILTO={{ $.ResetMailto }} {{ end -}} {{ end -}} diff --git a/tests/unit/cron-3.bats b/tests/unit/cron-3.bats index e1c843940..843f71af9 100644 --- a/tests/unit/cron-3.bats +++ b/tests/unit/cron-3.bats @@ -132,6 +132,13 @@ EOF assert_output_contains "MAILTO=ops@example.com" assert_output_contains "@hourly /bin/false 2>&1 | tee -a /var/log/dokku/log.log" + # the global MAILTO is restored for every task after the one with its own + run /bin/bash -c "grep -A1 -F 'tee -a /var/log/dokku/log.log' /var/spool/cron/crontabs/dokku | tail -n 1" + echo "output: $output" + echo "status: $status" + assert_success + assert_output "MAILTO=global@example.com" + run /bin/bash -c "dokku cron:list --global --format json | jq -r '.[] | select(.schedule == \"@hourly\") | .mailto'" echo "output: $output" echo "status: $status"