40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212 | @agent_app.command()
async def start(
# deprecated main argument
work_queue: str = typer.Argument(
None,
show_default=False,
help="DEPRECATED: A work queue name or ID",
),
work_queues: List[str] = typer.Option(
None,
"-q",
"--work-queue",
help="One or more work queue names for the agent to pull from.",
),
work_queue_prefix: List[str] = typer.Option(
None,
"-m",
"--match",
help=(
"Dynamically matches work queue names with the specified prefix for the"
" agent to pull from,for example `dev-` will match all work queues with a"
" name that starts with `dev-`"
),
),
work_pool_name: str = typer.Option(
None,
"-p",
"--pool",
help="A work pool name for the agent to pull from.",
),
hide_welcome: bool = typer.Option(False, "--hide-welcome"),
api: str = SettingsOption(PREFECT_API_URL),
run_once: bool = typer.Option(
False, help="Run the agent loop once, instead of forever."
),
prefetch_seconds: int = SettingsOption(PREFECT_AGENT_PREFETCH_SECONDS),
# deprecated tags
tags: List[str] = typer.Option(
None,
"-t",
"--tag",
help=(
"DEPRECATED: One or more optional tags that will be used to create a work"
" queue. This option will be removed on 2023-02-23."
),
),
limit: int = typer.Option(
None,
"-l",
"--limit",
help="Maximum number of flow runs to start simultaneously.",
),
):
"""
Start an agent process to poll one or more work queues for flow runs.
"""
work_queues = work_queues or []
if work_queue is not None:
# try to treat the work_queue as a UUID
try:
async with get_client() as client:
q = await client.read_work_queue(UUID(work_queue))
work_queue = q.name
# otherwise treat it as a string name
except (TypeError, ValueError):
pass
work_queues.append(work_queue)
app.console.print(
(
"Agents now support multiple work queues. Instead of passing a single"
" argument, provide work queue names with the `-q` or `--work-queue`"
f" flag: `prefect agent start -q {work_queue}`\n"
),
style="blue",
)
if not work_queues and not tags and not work_queue_prefix and not work_pool_name:
exit_with_error("No work queues provided!", style="red")
elif bool(work_queues) + bool(tags) + bool(work_queue_prefix) > 1:
exit_with_error(
"Only one of `work_queues`, `match`, or `tags` can be provided.",
style="red",
)
if work_pool_name and tags:
exit_with_error(
"`tag` and `pool` options cannot be used together.", style="red"
)
if tags:
work_queue_name = f"Agent queue {'-'.join(sorted(tags))}"
app.console.print(
(
"`tags` are deprecated. For backwards-compatibility with old versions"
" of Prefect, this agent will create a work queue named"
f" `{work_queue_name}` that uses legacy tag-based matching. This option"
" will be removed on 2023-02-23."
),
style="red",
)
async with get_client() as client:
try:
work_queue = await client.read_work_queue_by_name(work_queue_name)
if work_queue.filter is None:
# ensure the work queue has legacy (deprecated) tag-based behavior
await client.update_work_queue(filter=dict(tags=tags))
except ObjectNotFound:
# if the work queue doesn't already exist, we create it with tags
# to enable legacy (deprecated) tag-matching behavior
await client.create_work_queue(name=work_queue_name, tags=tags)
work_queues = [work_queue_name]
if not hide_welcome:
if api:
app.console.print(
f"Starting v{prefect.__version__} agent connected to {api}..."
)
else:
app.console.print(
f"Starting v{prefect.__version__} agent with ephemeral API..."
)
async with PrefectAgent(
work_queues=work_queues,
work_queue_prefix=work_queue_prefix,
work_pool_name=work_pool_name,
prefetch_seconds=prefetch_seconds,
limit=limit,
) as agent:
if not hide_welcome:
app.console.print(ascii_name)
if work_pool_name:
app.console.print(
"Agent started! Looking for work from "
f"work pool '{work_pool_name}'..."
)
elif work_queue_prefix:
app.console.print(
"Agent started! Looking for work from "
f"queue(s) that start with the prefix: {work_queue_prefix}..."
)
else:
app.console.print(
"Agent started! Looking for work from "
f"queue(s): {', '.join(work_queues)}..."
)
async with anyio.create_task_group() as tg:
tg.start_soon(
partial(
critical_service_loop,
agent.get_and_submit_flow_runs,
PREFECT_AGENT_QUERY_INTERVAL.value(),
printer=app.console.print,
run_once=run_once,
jitter_range=0.3,
)
)
tg.start_soon(
partial(
critical_service_loop,
agent.check_for_cancelled_flow_runs,
PREFECT_AGENT_QUERY_INTERVAL.value(),
printer=app.console.print,
run_once=run_once,
jitter_range=0.3,
)
)
app.console.print("Agent stopped!")
|