Merge pull request #95 from thin-edge/feat-container-logs-command

feat: add internal command to get container logs

Author: reubenmiller

cli/tools/cmd.go

@@ -14,6 +14,7 @@ func NewToolsCommand(cmdCli cli.Cli) *cobra.Command {
 	}
 	cmd.AddCommand(
 		NewContainerCloneCommand(cmdCli),
+		NewContainerLogsCommand(cmdCli),
 	)
 	return cmd
 }

cli/tools/container_logs.go

@@ -0,0 +1,94 @@
+/*
+Copyright © 2024 thin-edge.io <[email protected]>
+*/
+package tools
+
+import (
+	"context"
+	"errors"
+	"log/slog"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/thin-edge/tedge-container-plugin/pkg/cli"
+	"github.com/thin-edge/tedge-container-plugin/pkg/container"
+)
+
+type ContainerLogsCommand struct {
+	*cobra.Command
+
+	CommandContext cli.Cli
+
+	// Options
+	Tail       string
+	Since      string
+	Until      string
+	Timestamps bool
+	Follow     bool
+	Details    bool
+}
+
+// NewContainerLogsCommand creates a new container logs command
+func NewContainerLogsCommand(ctx cli.Cli) *cobra.Command {
+	command := &ContainerLogsCommand{
+		CommandContext: ctx,
+	}
+	cmd := &cobra.Command{
+		Use:          "container-logs [OPTIONS] CONTAINER",
+		Short:        "Fetch the logs of a container",
+		RunE:         command.RunE,
+		Args:         cobra.ArbitraryArgs,
+		SilenceUsage: true,
+	}
+
+	cmd.Flags().StringVar(&command.Since, "since", "", "Show logs since timestamp (e.g. 2013-01-02T13:23:37Z) or relative (e.g. 42m for 42 minutes)")
+	cmd.Flags().StringVar(&command.Until, "until", "", "Show logs before a timestamp (e.g. 2013-01-02T13:23:37Z) or relative (e.g. 42m for 42 minutes)")
+	cmd.Flags().StringVarP(&command.Tail, "tail", "n", "all", "Number of lines to show from the end of the logs")
+	cmd.Flags().BoolVarP(&command.Follow, "follow", "f", false, "Follow log output")
+	cmd.Flags().BoolVarP(&command.Timestamps, "timestamps", "t", false, "Show timestamps")
+	cmd.Flags().BoolVar(&command.Details, "details", false, "Show extra details provided to logs")
+	command.Command = cmd
+	return cmd
+}
+
+func (c *ContainerLogsCommand) RunE(cmd *cobra.Command, args []string) error {
+	slog.Debug("Executing", "cmd", cmd.CalledAs(), "args", args)
+
+	containerCli, err := container.NewContainerClient()
+	if err != nil {
+		return err
+	}
+
+	ctx := context.Background()
+
+	if len(args) == 0 {
+		slog.Info("Fetching logs for current container (if running inside a container)")
+		con, err := containerCli.Self(ctx)
+		if err != nil {
+			return err
+		}
+		args = append(args, con.ID)
+	}
+
+	// Write container logs (stdout and stderr) to stdout
+	out := cmd.OutOrStdout()
+	errs := make([]error, 0)
+	for _, con := range args {
+		idOrName := strings.TrimPrefix(con, "/")
+		slog.Info("Fetching logs.", "id", idOrName)
+		if err := containerCli.ContainerLogs(ctx, out, idOrName, container.LogsOptions{
+			ShowStdout: true,
+			ShowStderr: true,
+			Since:      c.Since,
+			Until:      c.Until,
+			Timestamps: c.Timestamps,
+			Follow:     c.Follow,
+			Tail:       c.Tail,
+			Details:    c.Details,
+		}); err != nil {
+			errs = append(errs, err)
+		}
+	}
+
+	return errors.Join(errs...)
+}

pkg/container/container.go

@@ -924,6 +924,22 @@ func (c *ContainerClient) UpdateRequired(ctx context.Context, containerID string
 	return true, prevContainer, nil
 }
 
+// Log options type alias
+type LogsOptions container.LogsOptions
+
+func (c *ContainerClient) ContainerLogs(ctx context.Context, w io.Writer, containerID string, opts LogsOptions) error {
+	reader, logErr := c.Client.ContainerLogs(ctx, containerID, container.LogsOptions(opts))
+	if logErr != nil {
+		return logErr
+	}
+	defer reader.Close()
+	_, err := StdCopy(w, w, reader)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 type CloneOptions struct {
 	Image        string
 	HealthyAfter time.Duration

tests/container-logs.robot

@@ -0,0 +1,47 @@
+*** Settings ***
+Resource    ./resources/common.robot
+Library    String
+Library    Cumulocity
+Library    DeviceLibrary    bootstrap_script=bootstrap.sh
+
+Suite Setup    Suite Setup
+
+Test Tags    docker    podman
+
+*** Test Cases ***
+
+Get Container Logs
+    # Run dummy container then exit
+    DeviceLibrary.Execute Command    cmd=tedge-container engine docker run --name app10 httpd:2.4.61-alpine sh -c 'echo hello inside container stdout; echo hello inside container stderr >&2;'
+
+    # Fetch logs
+    ${output}=    DeviceLibrary.Execute Command    sudo tedge-container tools container-logs app10
+    Should Contain    ${output}    hello inside container stdout
+    Should Contain    ${output}    hello inside container stderr
+
+Get Container Logs with only last N lines
+    # Run dummy container then exit
+    DeviceLibrary.Execute Command    cmd=tedge-container engine docker run --name app11 httpd:2.4.61-alpine sh -c 'echo hello inside container stdout; echo hello inside container stderr >&2;'
+
+    # Fetch logs
+    ${output}=    DeviceLibrary.Execute Command    sudo tedge-container tools container-logs app11 -n 1
+
+    ${total_lines}=    String.Get Line Count    ${output}
+    Should Be Equal As Integers    ${total_lines}    1
+
+    Should Not Contain    ${output}    hello inside container stdout
+    Should Contain    ${output}    hello inside container stderr
+
+*** Keywords ***
+
+Suite Setup
+    ${DEVICE_SN}=    Setup
+    Set Suite Variable    $DEVICE_SN
+    Cumulocity.External Identity Should Exist    ${DEVICE_SN}
+    Cumulocity.Should Have Services    name=tedge-container-plugin    service_type=service    min_count=1    max_count=1    timeout=30
+
+    ${operation}=    Cumulocity.Execute Shell Command    sudo tedge-container engine docker network create tedge ||:
+    Operation Should Be SUCCESSFUL    ${operation}    timeout=60
+
+    # Create data directory
+    DeviceLibrary.Execute Command    mkdir /data