Files
coder/agent/api.go
T
Kyle Carberry a621c3cb13 feat(agent): add process execution API and rewrite execute tool (#22416)
## Summary

Adds a new agent-side process management HTTP API and rewrites the chat
execute tool to use it instead of SSH sessions.

## What changed

### New agent/agentproc/ package

- **headtail.go** — Thread-safe io.Writer with bounded memory (16KB head
+ 16KB tail ring buffer). Provides LLM-ready output with truncation
metadata and long-line truncation at 2048 bytes.
- **headtail_test.go** — 16 tests including race detector coverage for
concurrent writes.
- **process.go** — Manager + Process types for lifecycle management
using agentexec.Execer for proper OOM/nice scores.
- **api.go** — HTTP API following the agentfiles chi router pattern. 4
endpoints: start, list, output, signal.

### Agent wiring (agent/agent.go, agent/api.go)

Mounts the process API at /api/v0/processes, mirroring how agentfiles is
mounted.

### SDK (codersdk/workspacesdk/agentconn.go)

4 new AgentConn interface methods + 7 request/response types:
- StartProcess, ListProcesses, ProcessOutput, SignalProcess

### Execute tool rewrite (coderd/chatd/chattool/execute.go)

- SSH to Agent API: conn.StartProcess() + conn.ProcessOutput() polling
- New parameters: workdir, run_in_background
- Structured response: success, exit_code, wall_duration_ms, error,
truncated, note, background_process_id
- Non-interactive env vars: GIT_EDITOR=true, TERM=dumb, NO_COLOR=1,
PAGER=cat, etc.
- Output truncation: HeadTailBuffer caps at 32KB for LLM consumption
- File-dump detection with advisory notes suggesting read_file
- Default timeout: 60s to 10s
- Foreground polling: 200ms intervals until exit or timeout

## Architecture

State lives on the agent, surviving coderd failover and instance
changes. Any coderd replica can query any agent via HTTP over tailnet.
2026-02-28 12:33:52 -05:00

104 lines
3.3 KiB
Go

package agent
import (
"net/http"
"github.com/go-chi/chi/v5"
"github.com/google/uuid"
"github.com/coder/coder/v2/coderd/httpapi"
"github.com/coder/coder/v2/coderd/httpmw/loggermw"
"github.com/coder/coder/v2/coderd/tracing"
"github.com/coder/coder/v2/codersdk"
"github.com/coder/coder/v2/codersdk/workspacesdk"
"github.com/coder/coder/v2/httpmw"
)
func (a *agent) apiHandler() http.Handler {
r := chi.NewRouter()
r.Use(
httpmw.Recover(a.logger),
tracing.StatusWriterMiddleware,
loggermw.Logger(a.logger),
)
r.Get("/", func(rw http.ResponseWriter, r *http.Request) {
httpapi.Write(r.Context(), rw, http.StatusOK, codersdk.Response{
Message: "Hello from the agent!",
})
})
r.Mount("/api/v0", a.filesAPI.Routes())
r.Mount("/api/v0/processes", a.processAPI.Routes())
if a.devcontainers {
r.Mount("/api/v0/containers", a.containerAPI.Routes())
} else if manifest := a.manifest.Load(); manifest != nil && manifest.ParentID != uuid.Nil {
r.HandleFunc("/api/v0/containers", func(w http.ResponseWriter, r *http.Request) {
httpapi.Write(r.Context(), w, http.StatusForbidden, codersdk.Response{
Message: "Dev Container feature not supported.",
Detail: "Dev Container integration inside other Dev Containers is explicitly not supported.",
})
})
} else {
r.HandleFunc("/api/v0/containers", func(w http.ResponseWriter, r *http.Request) {
httpapi.Write(r.Context(), w, http.StatusForbidden, codersdk.Response{
Message: "Dev Container feature not enabled.",
Detail: "To enable this feature, set CODER_AGENT_DEVCONTAINERS_ENABLE=true in your template.",
})
})
}
promHandler := PrometheusMetricsHandler(a.prometheusRegistry, a.logger)
r.Get("/api/v0/listening-ports", a.listeningPortsHandler.handler)
r.Get("/api/v0/netcheck", a.HandleNetcheck)
r.Get("/debug/logs", a.HandleHTTPDebugLogs)
r.Get("/debug/magicsock", a.HandleHTTPDebugMagicsock)
r.Get("/debug/magicsock/debug-logging/{state}", a.HandleHTTPMagicsockDebugLoggingState)
r.Get("/debug/manifest", a.HandleHTTPDebugManifest)
r.Get("/debug/prometheus", promHandler.ServeHTTP)
return r
}
type ListeningPortsGetter interface {
GetListeningPorts() ([]codersdk.WorkspaceAgentListeningPort, error)
}
type listeningPortsHandler struct {
// In production code, this is set to an osListeningPortsGetter, but it can be overridden for
// testing.
getter ListeningPortsGetter
ignorePorts map[int]string
}
// handler returns a list of listening ports. This is tested by coderd's
// TestWorkspaceAgentListeningPorts test.
func (lp *listeningPortsHandler) handler(rw http.ResponseWriter, r *http.Request) {
ports, err := lp.getter.GetListeningPorts()
if err != nil {
httpapi.Write(r.Context(), rw, http.StatusInternalServerError, codersdk.Response{
Message: "Could not scan for listening ports.",
Detail: err.Error(),
})
return
}
filteredPorts := make([]codersdk.WorkspaceAgentListeningPort, 0, len(ports))
for _, port := range ports {
if port.Port < workspacesdk.AgentMinimumListeningPort {
continue
}
// Ignore ports that we've been told to ignore.
if _, ok := lp.ignorePorts[int(port.Port)]; ok {
continue
}
filteredPorts = append(filteredPorts, port)
}
httpapi.Write(r.Context(), rw, http.StatusOK, codersdk.WorkspaceAgentListeningPortsResponse{
Ports: filteredPorts,
})
}