.. role:: ref(emphasis)
.. _varnish-cli(7):
===========
varnish-cli
===========
------------------------------
Varnish Command Line Interface
------------------------------
:Manual section: 7
DESCRIPTION
===========
Varnish has a command line interface (CLI) which can control and change
most of the operational parameters and the configuration of Varnish,
without interrupting the running service.
The CLI can be used for the following tasks:
configuration
You can upload, change and delete VCL files from the CLI.
parameters
You can inspect and change the various parameters Varnish has
available through the CLI. The individual parameters are
documented in the varnishd(1) man page.
bans
Bans are filters that are applied to keep Varnish from serving
stale content. When you issue a ban Varnish will not serve any
*banned* object from cache, but rather re-fetch it from its
backend servers.
process management
You can stop and start the cache (child) process though the
CLI. You can also retrieve the latest stack trace if the child
process has crashed.
If you invoke varnishd(1) with -T, -M or -d the CLI will be
available. In debug mode (-d) the CLI will be in the foreground, with
-T you can connect to it with varnishadm or telnet and with -M
varnishd will connect back to a listening service *pushing* the CLI to
that service. Please see :ref:`varnishd(1)` for details.
.. _ref_syntax:
Syntax
------
Commands are usually terminated with a newline. Long command can be
entered using shell-style *here document* (here-document or heredoc).
The format of here document is::
<< word
here document
word
*word* can be any continuous string chosen to make sure it doesn't appear
naturally in the following *here document*. Often EOF or END is used.
When using the here document style of input there are no restrictions
on length. When using newline-terminated commands maximum length is
limited by the varnishd parameter *cli_buffer*.
When commands are newline terminated they get *tokenized* before
parsing so if you have significant spaces enclose your strings in
double quotes. Within the quotes you can escape characters with
\\. The \n, \r and \t get translated to newlines, carriage returns and
tabs. Double quotes themselves can be escaped with a backslash.
To enter characters in octals use the \\nnn syntax. Hexadecimals can
be entered with the \\xnn syntax.
Commands
--------
.. include:: ../include/cli.rst
Backend Pattern
---------------
A backend pattern can be a backend name or a combination of a VCL name
and backend name in "VCL.backend" format. If the VCL name is omitted,
the active VCL is assumed. Partial matching on the backend and VCL
names is supported using shell-style wilcards, e.g. asterisk (*).
Examples::
backend.list def*
backend.list b*.def*
backend.set_health default sick
backend.set_health def* healthy
backend.set_health * auto
Ban Expressions
---------------
A ban expression consists of one or more conditions. A condition
consists of a field, an operator, and an argument. Conditions can be
ANDed together with "&&".
A field can be any of the variables from VCL, for instance req.url,
req.http.host or obj.http.set-cookie.
Operators are "==" for direct comparison, "~" for a regular
expression match, and ">" or "<" for size comparisons. Prepending
an operator with "!" negates the expression.
The argument could be a quoted string, a regexp, or an integer.
Integers can have "KB", "MB", "GB" or "TB" appended for size related
fields.
.. _ref_vcl_temperature:
VCL Temperature
---------------
A VCL program goes through several states related to the different
commands: it can be loaded, used, and later discarded. You can load
several VCL programs and switch at any time from one to another. There
is only one active VCL, but the previous active VCL will be maintained
active until all its transactions are over.
Over time, if you often refresh your VCL and keep the previous
versions around, resource consumption will increase, you can't escape
that. However, most of the time you want only one to pay the price only
for the active VCL and keep older VCLs in case you'd need to rollback
to a previous version.
The VCL temperature allows you to minimize the footprint of inactive
VCLs. Once a VCL becomes cold, Varnish will release all the resources
that can be be later reacquired. You can manually set the temperature
of a VCL or let varnish
automatically handle it.
Scripting
---------
If you are going to write a script that talks CLI to varnishd, the
include/cli.h contains the relevant magic numbers.
One particular magic number to know, is that the line with the status
code and length field always is exactly 13 characters long, including
the NL character.
The varnishapi library contains functions to implement the basics of
the CLI protocol, see the `vcli.h` include file.
.. _ref_psk_auth:
Authentication with -S
----------------------
If the -S secret-file is given as argument to varnishd, all network
CLI connections must authenticate, by proving they know the contents
of that file.
The file is read at the time the auth command is issued and the
contents is not cached in varnishd, so it is possible to update the
file on the fly.
Use the unix file permissions to control access to the file.
An authenticated session looks like this::
critter phk> telnet localhost 1234
Trying ::1...
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
107 59
ixslvvxrgkjptxmcgnnsdxsvdmvfympg
Authentication required.
auth 455ce847f0073c7ab3b1465f74507b75d3dc064c1e7de3b71e00de9092fdc89a
200 279
-----------------------------
Varnish Cache CLI 1.0
-----------------------------
Linux,4.4.0-1-amd64,x86_64,-jnone,-smalloc,-smalloc,-hcritbit
varnish-trunk revision dc360a4
Type 'help' for command list.
Type 'quit' to close CLI session.
Type 'start' to launch worker process.
The CLI status of 107 indicates that authentication is necessary. The
first 32 characters of the response text is the challenge
"ixsl...mpg". The challenge is randomly generated for each CLI
connection, and changes each time a 107 is emitted.
The most recently emitted challenge must be used for calculating the
authenticator "455c...c89a".
The authenticator is calculated by applying the SHA256 function to the
following byte sequence:
* Challenge string
* Newline (0x0a) character.
* Contents of the secret file
* Challenge string
* Newline (0x0a) character.
and dumping the resulting digest in lower-case hex.
In the above example, the secret file contained foo\n and thus::
critter phk> cat > _
ixslvvxrgkjptxmcgnnsdxsvdmvfympg
foo
ixslvvxrgkjptxmcgnnsdxsvdmvfympg
^D
critter phk> hexdump -C _
00000000 69 78 73 6c 76 76 78 72 67 6b 6a 70 74 78 6d 63 |ixslvvxrgkjptxmc|
00000010 67 6e 6e 73 64 78 73 76 64 6d 76 66 79 6d 70 67 |gnnsdxsvdmvfympg|
00000020 0a 66 6f 6f 0a 69 78 73 6c 76 76 78 72 67 6b 6a |.foo.ixslvvxrgkj|
00000030 70 74 78 6d 63 67 6e 6e 73 64 78 73 76 64 6d 76 |ptxmcgnnsdxsvdmv|
00000040 66 79 6d 70 67 0a |fympg.|
00000046
critter phk> sha256 _
SHA256 (_) = 455ce847f0073c7ab3b1465f74507b75d3dc064c1e7de3b71e00de9092fdc89a
critter phk> openssl dgst -sha256 < _
455ce847f0073c7ab3b1465f74507b75d3dc064c1e7de3b71e00de9092fdc89a
The sourcefile lib/libvarnish/cli_auth.c contains a useful function
which calculates the response, given an open filedescriptor to the
secret file, and the challenge string.
EXAMPLES
========
Load a multi-line VCL using shell-style *here document*::
vcl.inline example << EOF
vcl 4.0;
backend www {
.host = "127.0.0.1";
.port = "8080";
}
EOF
Ban all requests where req.url exactly matches the string /news::
ban req.url == "/news"
Ban all documents where the serving host is "example.com" or
"www.example.com", and where the Set-Cookie header received from the
backend contains "USERID=1663"::
ban req.http.host ~ "^(?i)(www\\.)example.com$" && obj.http.set-cookie ~ "USERID=1663"
AUTHORS
=======
This manual page was originally written by Per Buer and later modified
by Federico G. Schwindt, Dridi Boukelmoune, Lasse Karstensen and
Poul-Henning Kamp.
SEE ALSO
========
* :ref:`varnishadm(1)`
* :ref:`varnishd(1)`
* :ref:`vcl(7)`
Henceforth, whatever our philosopher says about Matter will apply to extension and to extension alone. It cannot be apprehended by sight, nor by hearing, nor by smell, nor by taste, for it is neither colour, nor sound, nor odour, nor juice. Neither can it be touched, for it is not a body, but it becomes corporeal on being blended with sensible qualities. And, in a later essay, he describes it as receiving all things and letting them depart again without retaining the slightest trace of their presence.483 Why then, it may be asked, if Plotinus meant extension, could he not say so at once, and save us all this trouble in hunting out his meaning? There were very good reasons why he should not. In the first place, he wished to express himself, so far as possible, in Aristotelian phraseology, and this was incompatible with the reduction of Matter to extension. In the next place, the idea of an infinite void had been already appropriated by the Epicureans, to whose system he was bitterly opposed. And, finally, the extension of ordinary327 experience had not the absolute generality which was needed in order to bring Matter into relation with that ultimate abstraction whence, like everything else, it has now to be derived. That the millionaire was genuine, ¡°in person and not a caricature,¡± as Dick put it, was evident. Both the nurse, his relative, and his wife, were chatting with him as Jeff delivered the heavy packed ball made up of the gum. 233 "I guess not," said Landor, tolerantly, as he turned[Pg 106] his horse over to his orderly; "but, anyway," he added to Ellton, "we had a picnic¡ªof a sort." Si, unable to think of anything better, went with him. The train had stopped on a switch, and seemed likely to rust fast to the rails, from the way other trains were going by in both directions. The bridge gang, under charge of a burly, red-faced young Englishman, was in the rear car, with their tools, equipments, bedding and cooking utensils. THE DEACON HAS SOME EXPERIENCES WITH THE QUADRUPED. "You are not within a mile of the truth. I know it. Look here: I believe that is Gen. Rosecrans's own cow. She's gone, and I got an order to look around for her. I've never seen her, but from the description given me I believe that's she. Who brought her here?" "Deacon, these brothers and sisters who have come here with me to-night are, like myself, deeply interested in the moral condition of the army, where we all have sons or kinsmen. Now, can't you sit right there and tell us of your observations and experiences, as a Christian man and father, from day to day, of every day that you were down there? Tell us everything, just as it happened each day, that we may be able to judge for ourselves." HAS AN ENCOUNTER WITH THE PROVOST-MARSHAL. "Wonder which one o' them is the 200th Injianny's?" said Si to Shorty. "And your mother, and Harry?" The daughter must be the girl who was talking to him now. She sat on a little stool by the fire, and had brought out some sewing. "Over at Grandturzel¡ªcan't see wot's burning from here. Git buckets and come!" These things, however, gave little concern to the worthy who commanded the Kentish division. Tyler, though an excellent blacksmith, possessed few of the qualities requisite for forming a good general. Provided there was no very sensible diminution in the number of his followers, he cared not a straw for the score or two who, after quarrelling, or perhaps fighting, withdrew in such disgust that they vowed rather to pay the full tax for ever than submit to the insolence of the rebels. One man could fight as well as another, reasoned he; and, provided he was obeyed, what mattered it by whom. Dick went and Tom came¡ªit was sure to be all one in the end. But this burst of indignation soon passed away, and upon the suggestion of the prudent Sir Robert Hailes, he sent an evasive answer, with a command that the Commons should attend him at Windsor on the Sunday following. That it was a stratagem to gain entrance to the Tower, was the opinion of several, but, after much discussion, it was decided that the man should be admitted, and that the monk should be exhibited merely to intimidate the rebels, until the result of this promised communication should be known. HoMEŮͬÐÔÁµcbcb
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