1VARNISH-CLI(7) VARNISH-CLI(7)
2
6 varnish-cli - Varnish Command Line Interface
7
9 Varnish has a command line interface (CLI) which can control and change
10 most of the operational parameters and the configuration of Varnish,
11 without interrupting the running service.
12 The CLI can be used for the following tasks:
14 configuration
16 You can upload, change and delete VCL files from the CLI.
17 parameters
19 You can inspect and change the various parameters Varnish has
20 available through the CLI. The individual parameters are docu‐
21 mented in the varnishd(1) man page.
22 bans Bans are filters that are applied to keep Varnish from serving
24 stale content. When you issue a ban Varnish will not serve any
25 banned object from cache, but rather re-fetch it from its back‐
26 end servers.
27 process management
29 You can stop and start the cache (child) process though the CLI.
30 You can also retrieve the latest stack trace if the child
31 process has crashed.
32 If you invoke varnishd(1) with -T, -M or -d the CLI will be available.
34 In debug mode (-d) the CLI will be in the foreground, with -T you can
35 connect to it with varnishadm or telnet and with -M varnishd will con‐
36 nect back to a listening service pushing the CLI to that service.
37 Please see varnishd(1) for details.
38 Syntax
40 The Varnish CLI is similar to another command line interface, the
41 Bourne Shell. Commands are usually terminated with a newline, and they
42 may take arguments. The command and its arguments are tokenized before
43 parsing, and as such arguments containing spaces must be enclosed in
44 double quotes.
45 It means that command parsing of
47 help banner
49 is equivalent to
51 "help" banner
53 because the double quotes only indicate the boundaries of the help
55 token.
56 Within double quotes you can escape characters with \ (backslash). The
58 \n, \r, and \t get translated to newlines, carriage returns, an tabs.
59 Double quotes and backslashes themselves can be escaped with \" and \\
60 respectively.
61 To enter characters in octals use the \nnn syntax. Hexadecimals can be
63 entered with the \xnn syntax.
64 Commands may not end with a newline when a shell-style here document
66 (here-document or heredoc) is used. The format of a here document is:
67 << word
69 here document
70 word
71 word can be any continuous string chosen to make sure it doesn't appear
73 naturally in the following here document. Traditionally EOF or END is
74 used.
75 Quoting pitfalls
77 Integrating with the Varnish CLI can be sometimes surprising when quot‐
78 ing is involved. For instance in Bourne Shell the delimiter used with
79 here documents may or may not be separated by spaces from the << token:
80 cat <<EOF
82 hello
83 world
84 EOF
85 hello
86 world
87 With the Varnish CLI, the << and EOF tokens must be separated by at
89 least one blank:
90 vcl.inline boot <<EOF
92 106 258
93 Message from VCC-compiler:
94 VCL version declaration missing
95 Update your VCL to Version 4 syntax, and add
96 vcl 4.0;
97 on the first line of the VCL files.
98 ('<vcl.inline>' Line 1 Pos 1)
99 <<EOF
100 ##---
101 Running VCC-compiler failed, exited with 2
103 VCL compilation failed
104 With the missing space, the here document can be added and the actual
106 VCL can be loaded:
107 vcl.inline test << EOF
109 vcl 4.0;
110 backend be {
112 .host = "localhost";
113 }
114 EOF
115 200 14
116 VCL compiled.
117 When using a front-end to the Varnish-CLI like varnishadm, one must
119 take into account the double expansion happening. First in the shell
120 launching the varnishadm command and then in the Varnish CLI itself.
121 When a command's parameter require spaces, you need to ensure that the
122 Varnish CLI will see the double quotes:
123 varnishadm param.set cc_command '"my alternate cc command"'
125 Change will take effect when VCL script is reloaded
127 Otherwise if you don't quote the quotes, you may get a seemingly unre‐
129 lated error message:
130 varnishadm param.set cc_command "my alternate cc command"
132 Unknown request.
133 Type 'help' for more info.
134 Too many parameters
135 Command failed with error code 105
137 If you are quoting with a here document, you must wrap it inside a
139 shell multi-line argument:
140 varnishadm vcl.inline test '<< EOF
142 vcl 4.0;
143 backend be {
145 .host = "localhost";
146 }
147 EOF'
148 VCL compiled.
149 Other pitfalls include variable expansion of the shell invoking var‐
151 nishadm but this is not directly related to the Varnish CLI. If you get
152 the quoting right you should be fine even with complex commands.
153 JSON
155 A number of commands with informational responses support a -j parame‐
156 ter for JSON output, as specified below. The top-level structure of the
157 JSON response is an array with these first three elements:
158 · A version number for the JSON format (integer)
160 · An array of strings that comprise the CLI command just received
162 · The time at which the response was generated, as a Unix epoch time in
164 seconds with millisecond precision (floating point)
165 The remaining elements of the array form the data that are specific to
167 the CLI command, and their structure and content depend on the command.
168 For example, the response to status -j just contains a string in the
170 top-level array indicating the state of the child process ("running",
171 "stopped" and so forth):
172 [ 2, ["status", "-j"], 1538031732.632, "running"
174 ]
175 The JSON responses to other commands may have longer lists of elements,
177 which may have simple data types or form structured objects.
178 JSON output is only returned if command execution was successful. The
180 output for an error response is always the same as it would have been
181 for the command without the -j parameter.
182 Commands
184 auth <response>
185 Authenticate.
186 backend.list [-j] [-p] [<backend_pattern>]
188 List backends.
189 -p also shows probe status.
191 -j specifies JSON output.
193 Unless -j is specified for JSON output, the output format is five
195 columns of dynamic width, separated by white space with the fields:
196 · Backend name
198 · Admin: How health state is determined:
200 · healthy: Set healthy through backend.set_health.
202 · sick: Set sick through backend.set_health.
204 · probe: Health state determined by a probe or some other dynamic
206 mechanism.
207 · deleted: Backend has been deleted, but not yet cleaned up.
209 Admin has precedence over Health
211 · Probe X/Y: X out of Y checks have succeeded
213 X and Y are backend specific and may represent probe checks, other
215 backends or any other metric.
216 If there is no probe or the director does not provide details on
218 probe check results, 0/0 is output.
219 · Health: Probe health state
221 · healthy
223 · sick
225 If there is no probe, healthy is output.
227 · Last change: Timestamp when the health state last changed.
229 The health state reported here is generic. A backend's health may
231 also depend on the context it is being used in (e.g. the object's
232 hash), so the actual health state as visible from VCL (e.g. using
233 std.healthy()) may differ.
234 For -j, the object members should be self explanatory, matching the
236 fields described above. probe_message has the format [X, Y, "state"]
237 as described above for Probe. JSON Probe details (-j -p arguments)
238 are director specific.
239 backend.set_health <backend_pattern> [auto|healthy|sick]
241 Set health status on the backends.
242 ban <field> <operator> <arg> [&& <field> <oper> <arg> ...]
244 Mark obsolete all objects where all the conditions match.
245 See vcl(7)_ban for details
247 ban.list [-j]
249 List the active bans.
250 Unless -j is specified for JSON output, the output format is:
252 · Time the ban was issued.
254 · Objects referencing this ban.
256 · C if ban is completed = no further testing against it.
258 · if lurker debugging is enabled:
260 · R for req.* tests
262 · O for obj.* tests
264 · Pointer to ban object
266 · Ban specification
268 Durations of ban specifications get normalized, for example "7d"
270 gets changed into "1w".
271 banner
273 Print welcome banner.
274 help [-j] [<command>]
276 Show command/protocol help.
277 -j specifies JSON output.
279 panic.clear [-z]
281 Clear the last panic, if any, -z will clear related varnishstat
282 counter(s)
283 panic.show [-j]
285 Return the last panic, if any.
286 -j specifies JSON output -- the panic message is returned as an
288 unstructured JSON string.
289 param.reset <param>
291 Reset parameter to default value.
292 param.set <param> <value>
294 Set parameter value.
295 param.show [-l|-j] [<param>|changed]
297 Show parameters and their values.
298 The long form with -l shows additional information, including docu‐
300 mentation and minimum, maximum and default values, if defined for
301 the parameter. JSON output is specified with -j, in which the infor‐
302 mation for the long form is included; only one of -l or -j is per‐
303 mitted. If a parameter is specified with <param>, show only that
304 parameter. If changed is specified, show only those parameters whose
305 values differ from their defaults.
306 ping [-j] [<timestamp>]
308 Keep connection alive.
309 The response is formatted as JSON if -j is specified.
311 quit
313 Close connection.
314 start
316 Start the Varnish cache process.
317 status [-j]
319 Check status of Varnish cache process.
320 -j specifies JSON output.
322 stop
324 Stop the Varnish cache process.
325 storage.list [-j]
327 List storage devices.
328 -j specifies JSON output.
330 vcl.discard <configname|label>
332 Unload the named configuration (when possible).
333 vcl.inline <configname> <quoted_VCLstring> [auto|cold|warm]
335 Compile and load the VCL data under the name provided.
336 Multi-line VCL can be input using the here document ref_syntax.
338 vcl.label <label> <configname>
340 Apply label to configuration.
341 A VCL label is like a UNIX symbolic link, a name without substance,
343 which points to another VCL.
344 Labels are mandatory whenever one VCL references another.
346 vcl.list [-j]
348 List all loaded configuration.
349 Unless -j is specified for JSON output, the output format is five
351 or seven columns of dynamic width, separated by white space with
352 the fields:
353 · status: active, available or discarded
355 · state: label, cold, warm, or auto
357 · temperature: init, cold, warm, busy or cooling
359 · busy: number of references to this vcl (integer)
361 · name: the name given to this vcl or label
363 · [ <- | -> ] and label info last two fields)
365 · -> <vcl> : label "points to" the named <vcl>
367 · <- (<n> label[s]): the vcl has <n> label(s)
369 vcl.load <configname> <filename> [auto|cold|warm]
371 Compile and load the VCL file under the name provided.
372 vcl.show [-v] <configname>
374 Display the source code for the specified configuration.
375 vcl.state <configname> [auto|cold|warm]
377 Force the state of the named configuration.
378 vcl.symtab
380 Dump the VCL symbol-tables.
381 vcl.use <configname|label>
383 Switch to the named configuration immediately.
384 Backend Pattern
386 A backend pattern can be a backend name or a combination of a VCL name
387 and backend name in "VCL.backend" format. If the VCL name is omitted,
388 the active VCL is assumed. Partial matching on the backend and VCL
389 names is supported using shell-style wilcards, e.g. asterisk (*).
390 Examples:
392 backend.list def*
394 backend.list b*.def*
395 backend.set_health default sick
396 backend.set_health def* healthy
397 backend.set_health * auto
398 Ban Expressions
400 A ban expression consists of one or more conditions. A condition con‐
401 sists of a field, an operator, and an argument. Conditions can be
402 ANDed together with "&&".
403 A field can be any of the variables from VCL, for instance req.url,
405 req.http.host or obj.http.set-cookie.
406 Operators are "==" for direct comparison, "~" for a regular expression
408 match, and ">" or "<" for size comparisons. Prepending an operator
409 with "!" negates the expression.
410 The argument could be a quoted string, a regexp, or an integer. Inte‐
412 gers can have "KB", "MB", "GB" or "TB" appended for size related
413 fields.
414 VCL Temperature
416 A VCL program goes through several states related to the different com‐
417 mands: it can be loaded, used, and later discarded. You can load sev‐
418 eral VCL programs and switch at any time from one to another. There is
419 only one active VCL, but the previous active VCL will be maintained
420 active until all its transactions are over.
421 Over time, if you often refresh your VCL and keep the previous versions
423 around, resource consumption will increase, you can't escape that. How‐
424 ever, most of the time you want only one to pay the price only for the
425 active VCL and keep older VCLs in case you'd need to rollback to a pre‐
426 vious version.
427 The VCL temperature allows you to minimize the footprint of inactive
429 VCLs. Once a VCL becomes cold, Varnish will release all the resources
430 that can be be later reacquired. You can manually set the temperature
431 of a VCL or let varnish automatically handle it.
432 Scripting
434 If you are going to write a script that talks CLI to varnishd, the
435 include/cli.h contains the relevant magic numbers.
436 One particular magic number to know, is that the line with the status
438 code and length field always is exactly 13 characters long, including
439 the NL character.
440 The varnishapi library contains functions to implement the basics of
442 the CLI protocol, see the vcli.h include file.
443 Authentication with -S
445 If the -S secret-file is given as argument to varnishd, all network CLI
446 connections must authenticate, by proving they know the contents of
447 that file.
448 The file is read at the time the auth command is issued and the con‐
450 tents is not cached in varnishd, so it is possible to update the file
451 on the fly.
452 Use the unix file permissions to control access to the file.
454 An authenticated session looks like this:
456 critter phk> telnet localhost 1234
458 Trying ::1...
459 Trying 127.0.0.1...
460 Connected to localhost.
461 Escape character is '^]'.
462 107 59
463 ixslvvxrgkjptxmcgnnsdxsvdmvfympg
464 Authentication required.
466 auth 455ce847f0073c7ab3b1465f74507b75d3dc064c1e7de3b71e00de9092fdc89a
468 200 279
469 -----------------------------
470 Varnish Cache CLI 1.0
471 -----------------------------
472 Linux,4.4.0-1-amd64,x86_64,-jnone,-smalloc,-smalloc,-hcritbit
473 varnish-trunk revision dc360a4
474 Type 'help' for command list.
476 Type 'quit' to close CLI session.
477 Type 'start' to launch worker process.
478 The CLI status of 107 indicates that authentication is necessary. The
480 first 32 characters of the response text is the challenge "ixsl...mpg".
481 The challenge is randomly generated for each CLI connection, and
482 changes each time a 107 is emitted.
483 The most recently emitted challenge must be used for calculating the
485 authenticator "455c...c89a".
486 The authenticator is calculated by applying the SHA256 function to the
488 following byte sequence:
489 · Challenge string
491 · Newline (0x0a) character.
493 · Contents of the secret file
495 · Challenge string
497 · Newline (0x0a) character.
499 and dumping the resulting digest in lower-case hex.
501 In the above example, the secret file contained foon and thus:
503 critter phk> cat > _
505 ixslvvxrgkjptxmcgnnsdxsvdmvfympg
506 foo
507 ixslvvxrgkjptxmcgnnsdxsvdmvfympg
508 ^D
509 critter phk> hexdump -C _
510 00000000 69 78 73 6c 76 76 78 72 67 6b 6a 70 74 78 6d 63 |ixslvvxrgkjptxmc|
511 00000010 67 6e 6e 73 64 78 73 76 64 6d 76 66 79 6d 70 67 |gnnsdxsvdmvfympg|
512 00000020 0a 66 6f 6f 0a 69 78 73 6c 76 76 78 72 67 6b 6a |.foo.ixslvvxrgkj|
513 00000030 70 74 78 6d 63 67 6e 6e 73 64 78 73 76 64 6d 76 |ptxmcgnnsdxsvdmv|
514 00000040 66 79 6d 70 67 0a |fympg.|
515 00000046
516 critter phk> sha256 _
517 SHA256 (_) = 455ce847f0073c7ab3b1465f74507b75d3dc064c1e7de3b71e00de9092fdc89a
518 critter phk> openssl dgst -sha256 < _
519 455ce847f0073c7ab3b1465f74507b75d3dc064c1e7de3b71e00de9092fdc89a
520 The sourcefile lib/libvarnish/cli_auth.c contains a useful function
522 which calculates the response, given an open filedescriptor to the
523 secret file, and the challenge string.
524
526 Load a multi-line VCL using shell-style here document:
527 vcl.inline example << EOF
529 vcl 4.0;
530 backend www {
532 .host = "127.0.0.1";
533 .port = "8080";
534 }
535 EOF
536 Ban all requests where req.url exactly matches the string /news:
538 ban req.url == "/news"
540 Ban all documents where the serving host is "example.com" or "www.exam‐
542 ple.com", and where the Set-Cookie header received from the backend
543 contains "USERID=1663":
544 ban req.http.host ~ "^(?i)(www\\.)?example\\.com$" && obj.http.set-cookie ~ "USERID=1663"
546
548 This manual page was originally written by Per Buer and later modified
549 by Federico G. Schwindt, Dridi Boukelmoune, Lasse Karstensen and
550 Poul-Henning Kamp.
551
553 · varnishadm(1)
554 · varnishd(1)
556 · vcl(7)
558 VARNISH-CLI(7)