Add initial OAuth2 auth support

.gitignore

@@ -33,17 +33,17 @@
 # Generated binaries, checksums
 /release_assets
 
-# Ignore binaries generated by pre-v0.1.0 builds
-/check-mail
-
 # Ignore binaries at root of repo (often generated here when testing)
 /check_imap_mailbox
+/check_imap_mailbox_basic
+/check_imap_mailbox_oauth2
 /list-emails
 /lsimap
+/xoauth2
 
 # Help prevent accidentally including this credentials file in the repo
-/accounts.ini
+accounts.ini
 
 # Ignore log and report files generated by the list-emails application
-/output
-/log
+output/
+log/

Makefile

@@ -31,7 +31,11 @@
 SHELL = /bin/bash
 
 # Space-separated list of cmd/BINARY_NAME directories to build
-WHAT 					= check_imap_mailbox list-emails lsimap
+WHAT 					= check_imap_mailbox_basic \
+							check_imap_mailbox_oauth2 \
+							list-emails \
+							lsimap \
+							xoauth2 \
 
 # TODO: This will need to be standardized across all cmd files in order to
 # work as intended.
@@ -196,19 +200,19 @@ windows:
 
 	@for target in $(WHAT); do \
 		mkdir -p $(OUTPUTDIR)/$$target && \
-		echo "Running go generate for $$target 386 binary ..." && \
+		echo "  Running go generate for $$target 386 binary ..." && \
 		cd ./cmd/$$target && \
 		env GOOS=windows GOARCH=386 go generate && \
 		cd $$OLDPWD && \
-		echo "Building $$target 386 binary" && \
+		echo "  Building $$target 386 binary" && \
 		env GOOS=windows GOARCH=386 $(BUILDCMD) -o $(OUTPUTDIR)/$$target/$$target-$(VERSION)-windows-386.exe ./cmd/$$target && \
-		echo "Running go generate for $$target amd64 binary ..." && \
+		echo "  Running go generate for $$target amd64 binary ..." && \
 		cd ./cmd/$$target && \
 		env GOOS=windows GOARCH=amd64 go generate && \
 		cd $$OLDPWD && \
-		echo "Building $$target amd64 binary" && \
+		echo "  Building $$target amd64 binary" && \
 		env GOOS=windows GOARCH=amd64 $(BUILDCMD) -o $(OUTPUTDIR)/$$target/$$target-$(VERSION)-windows-amd64.exe ./cmd/$$target && \
-		echo "Generating $$target checksum files" && \
+		echo "  Generating $$target checksum files" && \
 		cd $(OUTPUTDIR)/$$target && \
 		$(CHECKSUMCMD) $$target-$(VERSION)-windows-386.exe > $$target-$(VERSION)-windows-386.exe.sha256 && \
 		$(CHECKSUMCMD) $$target-$(VERSION)-windows-amd64.exe > $$target-$(VERSION)-windows-amd64.exe.sha256 && \
@@ -225,11 +229,11 @@ linux:
 
 	@for target in $(WHAT); do \
 		mkdir -p $(OUTPUTDIR)/$$target && \
-		echo "Building $$target 386 binary" && \
+		echo "  Building $$target 386 binary" && \
 		env GOOS=linux GOARCH=386 $(BUILDCMD) -o $(OUTPUTDIR)/$$target/$$target-$(VERSION)-linux-386 ./cmd/$$target && \
-		echo "Building $$target amd64 binary" && \
+		echo "  Building $$target amd64 binary" && \
 		env GOOS=linux GOARCH=amd64 $(BUILDCMD) -o $(OUTPUTDIR)/$$target/$$target-$(VERSION)-linux-amd64 ./cmd/$$target && \
-		echo "Generating $$target checksum files" && \
+		echo "  Generating $$target checksum files" && \
 		cd $(OUTPUTDIR)/$$target && \
 		$(CHECKSUMCMD) $$target-$(VERSION)-linux-386 > $$target-$(VERSION)-linux-386.sha256 && \
 		$(CHECKSUMCMD) $$target-$(VERSION)-linux-amd64 > $$target-$(VERSION)-linux-amd64.sha256 && \

cmd/check_imap_mailbox/doc.go → cmd/check_imap_mailbox_basic/doc.go

@@ -5,7 +5,8 @@
 // Licensed under the MIT License. See LICENSE file in the project root for
 // full license information.
 
-// Small CLI app used to generate listing of mailbox contents.
+// Nagios plugin used to monitor mailboxes for items. Uses Basic Auth to
+// authenticate.
 //
 // See our [GitHub repo]:
 //

cmd/check_imap_mailbox_basic/main.go

@@ -0,0 +1,122 @@
+// Copyright 2022 Adam Chalkley
+//
+// https://github.com/atc0005/check-mail
+//
+// Licensed under the MIT License. See LICENSE file in the project root for
+// full license information.
+
+//go:generate go-winres make --product-version=git-tag --file-version=git-tag
+
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"time"
+
+	zlog "github.com/rs/zerolog/log"
+
+	"github.com/atc0005/check-mail/internal/config"
+	"github.com/atc0005/go-nagios"
+)
+
+func main() {
+
+	ctx := context.Background()
+
+	// Start off assuming all is well, adjust as we go.
+	var nagiosExitState = nagios.ExitState{
+		LastError:      nil,
+		ExitStatusCode: nagios.StateOKExitCode,
+	}
+
+	// defer this from the start so it is the last deferred function to run
+	defer nagiosExitState.ReturnCheckResults()
+
+	// Setup configuration by parsing user-provided flags.
+	cfg, cfgErr := config.New(config.AppType{PluginIMAPMailboxBasicAuth: true})
+	switch {
+	case errors.Is(cfgErr, config.ErrVersionRequested):
+		fmt.Println(config.Version())
+
+		return
+
+	case cfgErr != nil:
+		// We're using the standalone Err function from rs/zerolog/log as we
+		// do not have a working configuration.
+		zlog.Err(cfgErr).Msg("Error initializing application")
+		nagiosExitState.ServiceOutput = fmt.Sprintf(
+			"%s: Error initializing application",
+			nagios.StateCRITICALLabel,
+		)
+		nagiosExitState.AddError(cfgErr)
+		nagiosExitState.ExitStatusCode = nagios.StateCRITICALExitCode
+
+		return
+	}
+
+	if cfg.EmitBranding {
+		// If enabled, show application details at end of notification
+		nagiosExitState.BrandingCallback = config.Branding("Notification generated by ")
+	}
+
+	// NOTE: This plugin is still intended for checking a single account, but
+	// sufficient work is in place to allow bulk processing if there is
+	// sufficient interest.
+	for i, account := range cfg.Accounts {
+
+		logger := cfg.Log.With().
+			Str("username", account.Username).
+			Str("server", account.Server).
+			Int("port", account.Port).
+			Str("folders_to_check", account.Folders.String()).
+			Logger()
+
+		// processAccount is responsible for setting the nagios.ExitState
+		// values, logging errors, etc.
+		results, err := processAccount(ctx, account, cfg, &nagiosExitState, logger)
+		if err != nil {
+			return
+		}
+
+		// Evaluate whether anything was found and sound an alert if so
+		if results.GotMail() {
+			logger.Debug().Msgf("%d messages found: %s",
+				results.TotalMessagesFound(),
+				results.MessagesFoundSummary(),
+			)
+			nagiosExitState.ServiceOutput = fmt.Sprintf(
+				"%s: %s: %d messages found: %s",
+				nagios.StateWARNINGLabel,
+				account.Username,
+				results.TotalMessagesFound(),
+				results.MessagesFoundSummary(),
+			)
+			nagiosExitState.ExitStatusCode = nagios.StateWARNINGExitCode
+			return
+		}
+
+		if i+1 < len(cfg.Accounts) {
+			// Delay processing the next account (unless we've processed them
+			// all) in an attempt to prevent encountering the "User is
+			// authenticated but not connected" error that is believed to
+			// occur when remote connections limit is exceeded.
+			time.Sleep(cfg.AccountProcessDelay())
+		}
+	}
+
+	// Give the all clear: no mail was found
+	cfg.Log.Debug().Msg("No messages found to report")
+
+	// these values are known, consistent regardless of checking one or many
+	// accounts
+	nagiosExitState.ExitStatusCode = nagios.StateOKExitCode
+
+	// customize ServiceOutput and LongServiceOutput based on number of
+	// specified accounts
+	setSummary(cfg.Accounts, &nagiosExitState)
+
+	// implied return here :)
+
+}